Dynamometer Results & Comparisons - 2002 Z-28 swap to truck coils.

legitimate gains. Made a pull, swapped coils, made another pull.

wow nice gain! which truck coils did you use?

also how many miles were on the old coils

im having a tough time reading that. 381/343 to 398/355.....correct?

if so, very impressive, and i think this would be thread #2 ive seen on this. might have to give her a shot.

Wow. That is more than a decent gain. You are correct WSsick.

What coils did ya use?

wow nice gain! which truck coils did you use?

x2!

Other questions:
What is the current combo? Stock w/bolt-ons?
Were the ls1 coils old?
Do they bolt right up/ plug in?
Did you have to change the tune?
Did you see any spark knock after the swap?

Thats wild that a coil swap (unless the old ones were bad) would make that much difference. Whats the difference in volts between the 2?

Did you change the dwell on spark or leave it stock? Very interesting! Thanks for posting.

Answers please lol

Coils don't "wear out" or get weaker with time and/or use. They may go bad and stop working altogether but they either work or they don’t, there’s no in between. It’s an electrical component with no moving parts, nothing to wear out resulting in reduced performance.

A functioning old coil will perform exactly as it did when it was new.

The gains shown here are similar to what I had in a rough dyno run as well as what others's who've done the swap have said about driveability and performance "feel"

put some ls1 coils on a truck and lets see some before and after please

I'm sold... eerrrrr, I was sold, and currently have the truck coils.
Just watch this video:
http://video.google.com/videoplay?docid=-6218245369765754251&ei=GiDLStyoEMn5lAfasrS8Ag&q=d585+coil&hl=en#

He specifically spells out the difference in power that the truck coils deliver compaired to the ls1 coils. Fact is, when you start to bump up the compression and load on a motor, you will benefit from a stronger spark. Why do you think GM replaced the coils when the ls2 was introduced, and once again when the ls7 and ls9 were introduced. GM doesn't spend money switching things for no reason. Fact is, trucks experience very high loads on their engines when towing, and trying to push around 6,000+ lbs, so they needed a higher energy coil. GM saw the benefit, and integrated similar performing coils on the ls2, ls7, ls9.

This is the second dyno that proves they work.

1-what years and engines can be used? 5.3 and 6.0? 2000-2006?
2-is it a direct fit and plug and play?
3-retune needed? or it will just give a stronger spark and that`s it?

thanks for sharing and waiting for the info thanks for that too if these questions are answered maybe more people will post results of this swap

{----watching

Did you change the dwell on spark or leave it stock? Very interesting! Thanks for posting.
I would like to know this too cause if this is stock LS1 dwell, I wonder how much more gains could be made with the same dwell setting as the trucks use? THANKS Jeff! :D

Did you change the dwell on spark or leave it stock? Very interesting! Thanks for posting.


nothing was changed. just swapped the coils.


to answer a few other questions.....

Its basically a plug and play swap. There was some minor drilling needed on the truck coil bracket to make it fit....but very minor.

No retune was needed.

I do not know what year truck coils they were. The customer brought them in with him. We did not provide them.

The car is a stock cube, bolt on car with a cam, long tubes, FAST 90 intake, 90mm TB, 243 heads with mild port work, A4, stall, 9 inch.

still uses ls1 plug wires right?

still uses ls1 plug wires right?


yep. same wires.

I installed the D585 truck coils on my Procharged '02 Z28 nearly 3 months ago after seeing Megasquirt's comparison and analysis and joining Paul Bell's thread on the subject. That was enough for me to pull the trigger, but this just reinforces it.

http://www.fquick.com/images/vehicles/full/20354270151.jpg?1247784107

I might ha to give this a shot, I currently have the square truck coils but might be able to find a set of the round ones with the heat sink...then I'll have to finally get fuel rail covers though cause those round coils are ugly as sin in comparison

thanks for answering MR. Jeff

can anyone help with what years coils that will bolt right up just like the one in the first post? 2000 - 2006 all the same?

Junk Yard Wait For Me :D

What would need to be done to do this on a 01 vette?

Need to know what years also.....somebody has to know what year they started showing up on the trucks.

I just looked up the prices on the D585 coils and man they arent cheap brand new. Almost $70. Would be great to find out what years they came out of so you could scour the JY for them.

I just looked up the prices on the D585 coils and man they arent cheap brand new. Almost $70. Would be great to find out what years they came out of so you could scour the JY for them.

Ouch. For that kind of money, I might as well buy some spray.

Is the spacing of the bolt holes on the thin metal pieces on the side of the coil the same from car to truck coils?

I have aftermarket valvecovers that have the coild bolt directly to them...

Ouch. For that kind of money, I might as well buy some spray.

True but I found some on ebay for around $100 for the WHOLE set up.

Looks like 2003 full size trucks had them. Doesnt matter what motor apparently as they are all the same coils.

There is already a very long thread about the swap to D585 coils. It will answer all of the basic questions.

http://www.ls1tech.com/forums/generation-iii-external-engine/1116161-coil-swap-yields-9-25-hp-18-6-tq.html

Nice back to back comparo guys. :thumb:

I was on the fence about whether or not the truck coils were worth the swap. I might try and get a hold of a set to use on something.

There is already a very long thread about the swap to D585 coils. It will answer all of the basic questions.

http://www.ls1tech.com/forums/generation-iii-external-engine/1116161-coil-swap-yields-9-25-hp-18-6-tq.html

Thanks for that and that is a HUGE read.

Is the spacing of the bolt holes on the thin metal pieces on the side of the coil the same from car to truck coils?

I have aftermarket valvecovers that have the coild bolt directly to them...

They are different Alex. I can try and take some pics tonight.

my 01 1500hd has these coils on them factory.

Almost sounds to good to be true, thats a huge gain.

Maybe its time for some scientific testing to find out why the huge gain.

Nice back to back comparo guys. :thumb:

I was on the fence about whether or not the truck coils were worth the swap. I might try and get a hold of a set to use on something.

I had my doubts that we would see any gains at all....but the customer wanted to do the swap and he paid for the dyno time.

He was happy with the results and I was surprised to say the least.

Almost sounds to good to be true, thats a huge gain.

Maybe its time for some scientific testing to find out why the huge gain.

I agree. I think some of the gains may be attributed to dyno (even back to back I would thing its possible that a dyno may read a little differently between pulls), weather (it was a very cool day and good for dyno work) , or even maybe the engine just felt froggier on the last pull?? who knows.....but I do believe you can say he got a legit 10 rwhp and 10rwtq from the swap.


also I want to point out, we dont have anything to gain from this post. We arent trying to sell anyone anything. No, I dont have a warehouse full of used truck coils im trying to get rid of......haha.

Do truck coils have a higher output voltage than ls1 coils?

Somehow it got more efficent.

Anyone on here have any technical specs on truck and ls coils?

i have used and have the truck coils on my vehicles, ive always beleievd they made a noticable improvement over the car coils, although they are not the heat sink version, they still amke a diff.
im gonna have to take the heat sink coils off my truck and use on my car next time i go to dyno to see if anyhting improves.
the car currently has truck non heat sink coils.

Couple questions:

1. Are these better coils with heat sink used on the LS2, LS3?
2. If these are in fact better, why wouldn't GM have used them on the Vette LS1 (at least on the later ones once they had experience w/ the truck coil)?

Thanks.

Maybe its time for some scientific testing to find out why the huge gain.

Again, please look at the Megasquirt testing. Video is in this thread where we have been discussing these coils for a couple months already.

http://www.ls1tech.com/forums/generation-iii-external-engine/1116161-coil-swap-yields-9-25-hp-18-6-tq.html

And are we positive the horsepower gains aren't from the engine cooling down during install? :confused:

Just seems unlikely given the same AFR's that horsepower would increase. Once that flame front is lit, it should be good to go... which is why you might see an increase in power with super high compression or boost in which the spark may not light off and then you'd be getting misfires and that should correspond with a different AFR, should it not?

And are we positive the horsepower gains aren't from the engine cooling down during install? :confused:

Just seems unlikely given the same AFR's that horsepower would increase. Once that flame front is lit, it should be good to go... which is why you might see an increase in power with super high compression or boost in which the spark may not light off and then you'd be getting misfires and that should correspond with a different AFR, should it not?

we always start dyno runs at the same engine temp. we dont just start the car and make the pull. we warm it up on the dyno.

Did you change the dwell on spark or leave it stock? Very interesting! Thanks for posting.

I'd like to know this too. I enquired about doing this on my car to eek out a few more rw hp/tq and was told its more trouble then its worth and sometimes even after tuning for the new duell times the gains just don't materialize.

Thanks for the back to back comparison man. GOod job !

I got mine today for $125. so if I get 10rwhp, thats $12.50 / hp. not bad. junk yard is the way to go :thumb:

More LSX coil info here http://www.megamanual.com/seq/coils.htm

this is interesting. how come there aren't more threads on this???

I'd like to know this too. I enquired about doing this on my car to eek out a few more rw hp/tq and was told its more trouble then its worth and sometimes even after tuning for the new duell times the gains just don't materialize.

Thanks for the back to back comparison man. GOod job !

I'm not sure I agree with the "it's more trouble than it's worth" attitude, considering it took me about 10 minutes and $130 to do the swap. I guess it was more trouble than an intake lid swap, but certainly not troublesome. Sounds to me like someone just wanted to get you out the door Doug.

Let's face it guys, to make combustion, you need three things, oxygen, fuel and spark. We increase the oxygen supply by changing cams, heads, headers, intake manifolds, and even spraying nitrous oxide. We then bump up the amount of fuel through tuning, even going to bigger injectors, or in extreme cases, upgrading the entire fuel supply. But what about spark?

You don't think there is a gain to be made by increasing the spark?

Let me ask you this, what lights a grill quicker, a little bic lighter, or a blow torch? I'm no expert, but if you increase the intake charge of fuel and air, you've now packed the cylinder with a lot more fuel and air, so you need a stronger, better spark to light it off. You have to remember that at WOT, the timing of combustion is incredibly quick, so the difference in milliseconds of a weaker vs stronger ignition source most certainly could acheive more power. If not, why do we change plugs? Why don't we just leave the factory platinums in till 100,000 miles?

I've checked on the Delphi website and tried searching AC Delco's site with some part numbers for the coils but can't seem to find anything on their sites. Just wanted to see what they were listed for on there, since I have a connection at Delphi I was going to see if he could get a discount on them.

Exactly. Why cant more/better/powerful spark give you more power? If you think about it the truck engines are constantly being worked harder than the LS1 just because it has to pull around 2X the weight. Add in a trailer and payload and you are really working that engine.

Makes total sense to me that this makes power.

how much for a set of these new? I may try it

if a JY doesent have any available do you think the same gains would be acheived with the MSD coils

NO. The MSD coils have shown no improvement over stock coils and go bad often and are expensive. It's been chatted to death here...

why not? their mA is even higher than the d585s.

Why do they not show any improvement? Nobody has been able to determine this. Regardless, they go bad often so it's not really a wise investment.

no one has improvements?

I remember reading that the problem with the MSD's is that they can handle the stock dwell time in the ls cars, so by being overcharged constantly, the msd's actually burn out and fail. The benefit here with the D585 coils is that they can handle more dwell time, and release more current than the stock ls1s.

I would be willing to bet my left, err, hand that GM engineering spent considerably more time and money on their coils than MSD did.

I'll take you're word on it, I almost pulled the trigger on some msds. I have to say i only know of 1 person using them. And his cammed 6.0 runs like ass lol not that much faster than my car with the stock 5.7.

check this out on corvetteforum.com

http://forums.corvetteforum.com/1571749649-post27.html

Well, again, back to back dyno, with solid gains, and both posters have nothing to gain from doing the test. What more do you want?

I dont get why people keep saying its impossible to have this happen. A far better spark will help make more power. Same reason we change the spark plugs when they get miles, they loose the ability to make that spark.

It's official i'm sold on this mod. Let the phone calls begin . . . . . Paul Thanks for sharing this in the other thread i'm the 1st to admit I had my doubts but it's obvious the results are SOLID.

Anyone know how these compare to LS3 coils? I am doing an LS3 swap soon and would like to get the truck coils if they are different. Thanks!

BTW, to doubters: This is a NO BRAINER. If changing plugs, helps, this is obvious. If you improve what the spark passes through, you'll get even more benefit from an improvement in the part that actually generates the spark!

Again, it's the combustion triangle. With more fuel and air, you need more spark...

LOL. Great. Because of this thread, there's going to be a shortage of truck coils nationwide. ;)

LOL. Great. Because of this thread, there's going to be a shortage of truck coils nationwide. ;)

Considering there's probably more trucks with these coils in junkyards than there were ls1 f-bodies sold, I don't think it's going to be a problem. :D

Well, again, back to back dyno, with solid gains, and both posters have nothing to gain from doing the test. What more do you want?

I want you to explain several 9sec cars in gmhightechperformance running stock coils and ls6 intakes;) I noticed that trend a while back.

More spark is more spark. MSDs are supposed to give a better spark too. At least for the time that they work properly, they should show some kinds of gains. They do not. Do more research than just 2 or 3 threads off ls1tech.

Now if you're pushing about 1000hp it may be a different story on the coils.

Yea they were back to back dynos, but there could have been other variables.I dont get why people keep saying its impossible to have this happen. A far better spark will help make more power. Same reason we change the spark plugs when they get miles, they loose the ability to make that spark.

Think of it this way... it does not take an atomic bomb to burn down a forest, it can be done by a cigarette too.

Still it needs to be explained why people are running 9sec 1/4 runs with stock coils

Still it needs to be explained why people are running 9sec 1/4 runs with stock coils

People run 9s with the LS1 intake as well. Doesnt mean its better right?

Taking your atomic bomb analogy, which burns it faster? A stronger spark or a weaker one? Which will ignite the fuel faster and have a more complete burn?

People havent swapped over because lets face it, we are followers. Once someone does it and produces results, tons of people will do it as witnessed by the amount of people who bought the D585 coils already.

I was a doubter not afraid to admit it. This is black and white it's not if I do the swap it's when. Things dont get much more apparent than this folks this is as stated above a no brainer.

I want you to explain several 9sec cars in gmhightechperformance running stock coils and ls6 intakes;) I noticed that trend a while back.

More spark is more spark. MSDs are supposed to give a better spark too. At least for the time that they work properly, they should show some kinds of gains. They do not. Do more research than just 2 or 3 threads off ls1tech.

Now if you're pushing about 1000hp it may be a different story on the coils.

Yea they were back to back dynos, but there could have been other variables.

Think of it this way... it does not take an atomic bomb to burn down a forest, it can be done by a cigarette too.

Still it needs to be explained why people are running 9sec 1/4 runs with stock coils

Your analogies are wrong. This isn't about how quick can you go with the least amount. According to your analogy, since some people managed to run 9 second 1/4 miles with ls6 intakes and stock coils, there isn't anything better.

If you don't think that better coils are a good thing to have, then don't upgrade. No-one is twisting your arm. I'm just glad you're not in charge or r&d anywhere.

With your thinking, why would gm ever upgrade anything since they sold X amount of cars, why bother making it better. And who's to say those 9 second cars couldn't run a tenth or two quicker if the switched to a better intake or better coils.

why do msd coils show no gains? why do shops not offer coil swaps as upgrades?

why do msd coils show no gains? why do shops not offer coil swaps as upgrades?

MSDs outpreform themselves. They just arent engineered right and the fact you have to replace them often makes them a shitty upgrade.

Who cares why shops dont offer them?!?!? :lol:

Some shops dont offer a lot of stuff, does that mean that its not worth it?


Better spark means more power. D585 coils are about 4 times as strong as LS1 coils.

From what I've read, the MSD's don't show any gain because they have even less capacity than the stockers. I read somewhere that the msd's get cooked because the factory dwell time is actually too much for them.

As to why shops don't charge for the swap as upgrades, I don't know. Maybe there's no money in it considering guys are pulling them off junkyard motors for not much money.

How many 12-bolts or Moser rears would be sold if the truck rears were direct swaps and you could buy one out of the junkyard for $500? I'm guessing not too many.

just went to the jy and they quoted me $200 for the set. I'm not seeing them for the prices members are getting them for.(125)

I intended to try them out and let you know what I think.

Also to be noted is the car that this thread is all about is a cammed car. A stock one like mine may show no difference.

So we can use truck coils from ANY truck with an LS1??? Or is the some sort of specifics involved???

JY prices are pretty negotiable. I once got a pair of headlights for my old car and they wanted $100 and I walked out of there paying $15.

I offered $125 and they wouldn't deal so I walked.

I offered $125 and they wouldn't deal so I walked.

Why didn't you drive?

I did, I drove back and bought them.:D I'll let you know what I think.

I did, I drove back and bought them.:D I'll let you know what I think.

What are your mods and are you planning on doing a before and after on the dyno?

I saw one funny post on the corvette forum saying that somebody must have a warehouse full of these they are trying to get rid of.

But I also saw an interesting post, that if somebody had unlimited access to a dyno, they could do 3 pulls with the stock coils and then 3 pulls with the truck coils to see what the average gain is. That would show the doubters that the gains are real, and not just from too many variables from one dyno pull to the next.

After going back and looking at the graph again, I like that it seems to be a consistant gain over the entire curve. It's not like the peak numbers were the only part that was better, its a nice gain the whole way.

I think the dyno graph on the first page says a lot.

I'd like to see an A-B-A test done (with brand new LS1 coil and brand new truck coil) and also understand dyno run to run variation (what kind of variation is normally seen)? Are the values from the original poster corrected to account for any ambient change between runs?

If these coils aren't used on the '02-04 LS6 for example (maybe they are, I'm not sure), then I'm questioning why GM would spend $$$ on lightweight valves, new cam, etc to bring hp from 385 to 405, when they could have used a high volume truck coil to get half way there on their hp targets.

Do the LS6, LS2, and LS3 have the truck coil with heat sink?

Thanks for the thread!

Makes sense. More spark energy should make more power. I don't think much would be seen on a stock car. But a stout heads/cam should show gains. We do heads/cam/intake/raise comp but do nothing better for spark. It is clear by the video and readings that the truck coils are more powerful.

FYI on car parts.com I found sets around $100.00

First start after installing them it seemed to idle smoother and react to the pedal a little better. 2+s

I went out for a very spirited drive(haven't done that in a while) I think it revs faster now. I hit the rev limiter once in 1st. Butt dyno? I think I may have gained something:)

My coils are ugly as sin now lol... They have a little rust on them, but I did get the heat sink ones. Driver's side went on perfectly and the drivers side, not so much. Driver's side has 1 bolt in the rack to hold it down and the rest is black zip tied lol.

btw I found the ONLY D585 in a salvage yard in ALL OF NASHVILLE I called every salvage yard that showed up on google. I did pay $200 as well.

Guess what my coils came off of? A clunkered 2003 GMC 1500. I thought the vehicles would be immediatly crushed, but they said not yet. They can keep them for a little while. Then they get crushed.
What are your mods and are you planning on doing a before and after on the dyno?

I saw one funny post on the corvette forum saying that somebody must have a warehouse full of these they are trying to get rid of.

But I also saw an interesting post, that if somebody had unlimited access to a dyno, they could do 3 pulls with the stock coils and then 3 pulls with the truck coils to see what the average gain is. That would show the doubters that the gains are real, and not just from too many variables from one dyno pull to the next.

After going back and looking at the graph again, I like that it seems to be a consistant gain over the entire curve. It's not like the peak numbers were the only part that was better, its a nice gain the whole way.

I had it dynoed last year with the same stuff I've got now, minus my truck coils.

I like that part too about the gains. I don't really feel like going to get a dyno though. I'm not rich you know lol

I will say my car does feel different. I've got full boltons

btw Nowhere... have I seen prices near $100 for the set of 8... They're always $25/piece and up. Unless you find someone who is kinda clueless I don't think you're getting them that cheap.

Everybody keeps saying $125 or $100, but they never provide links.

I might have to swap the coils off of my trucks 5.3 onto the LS1 now, never knew coils would make that much of a difference on a bolt on car

yea mine started having a little starting trouble as of late and after I seafoamed the gas tank and put these coils in I noticed a big difference in starting the car. The coils made the biggest difference in that.

Do it and let me know what you think of how your's feels.

I need to take the driver's side rack back off later on to trim it so it'll fit better and use bolts instead of zip ties.

I bought a set of the D585 coils w/brackets and harness on Ebay. Beginning of next week I will be putting on the LSX 102 intake + 102TB on my LS3 427 the car will be run at a local 1/8 mile track next Thurs to compare the results to current setup w/Jeremy F ported intake+ 92 fast TB. Next Fri I will swap to the truck coils and compare the difference, weather conditions should be about 1800' to 2000' DA each day. The car runs 6.85-6.87 @ 101.5mph on every run as it sits very consistant bracket car.

jason2687 had asked earlier in this thread "So we can use truck coils from ANY truck with an LS1??? Or is the some sort of specifics involved???"

No. The coils are very specific, they are the truck coils with the external heat sinks. They need a different coil wiring harness and coil mounting bracket. Also, at least on a F or Y body car, you'll need to fool with some other engine componants that will be in the way.

It's starting to be a long thread and I'm trying to get a sticky faq posted but until then, every bit of information about the swap is here:

http://www.ls1tech.com/forums/generation-iii-external-engine/1116161-coil-swap-yields-9-25-hp-18-6-tq.html

I bought a set of the D585 coils w/brackets and harness on Ebay. Beginning of next week I will be putting on the LSX 102 intake + 102TB on my LS3 427 the car will be run at a local 1/8 mile track next Thurs to compare the results to current setup w/Jeremy F ported intake+ 92 fast TB. Next Fri I will swap to the truck coils and compare the difference, weather conditions should be about 1800' to 2000' DA each day. The car runs 6.85-6.87 @ 101.5mph on every run as it sits very consistant bracket car.

Very nice!

I think I'll get mine dynoed tomorrow. A place within 1hr of where I live dynos 3 pulls for $40. I'm interested in if I got any gains too.

by the way I dynoed there before and I put down 363rwhp/380tq std, and 344rwhp/360rwtq sae.

I should be able to compare my sae numbers and get a very accurate number with respect to my first pull there.

jason2687 had asked earlier in this thread "So we can use truck coils from ANY truck with an LS1??? Or is the some sort of specifics involved???"

No. The coils are very specific, they are the truck coils with the external heat sinks. They need a different coil wiring harness and coil mounting bracket. Also, at least on a F or Y body car, you'll need to fool with some other engine componants that will be in the way.

It's starting to be a long thread and I'm trying to get a sticky faq posted but until then, every bit of information about the swap is here:

http://www.ls1tech.com/forums/generation-iii-external-engine/1116161-coil-swap-yields-9-25-hp-18-6-tq.html

how do you make the driver's side fit right? I just squished it up in there with 1 bolt and a few zip ties. looks retarded

If you dyno it bring your stock coils to do a back to back comparison.

how do you make the driver's side fit right? I just squished it up in there with 1 bolt and a few zip ties. looks retarded

:read:

It's all in there.

has anyone tried the stock lenght wires?

got dynoed... Last time I did not have the fan on the intake, but this time I did and I had these coils on. I gained 6rwhp and 2rwtq... I don't really recommend everybody go out and buy these coils unless you're bored.

I guess I'll keep them. It does start easier and feels slightly more responsive. I thought I felt something lol

now I've got 350rwhp/362rwtq sae

has anyone tried the stock lenght wires?

Mine are using stock length wires right now just fine. (Though, they are 99blanco's wires.)

I have a set on the way. I might be able to get some back to back dyno tests. I know they produce more power. Plus they look much better than the square ls1 coils I now have now.

We tried them yesterday on the Tick Performance race car (cam only ls1 pulling to 7300-7500) and it didn't make a difference at all. I've always thought that .055 gap is way to wide for anything but a bone stock LS1. Anytime someone swaps a cam or just expects to rev higher than say 6300 the gap needs to be tightend up to .035. And I've seen on more than one occasion 7-10rwhp going from .055 gap to .035 I wonder if this test car was gapped on the high side and thats why the coils helped.

would you mind asking the customer where he purchased them and how much they were? this seems like a great find!

nothing was changed. just swapped the coils.


to answer a few other questions.....

Its basically a plug and play swap. There was some minor drilling needed on the truck coil bracket to make it fit....but very minor.

No retune was needed.

I do not know what year truck coils they were. The customer brought them in with him. We did not provide them.

The car is a stock cube, bolt on car with a cam, long tubes, FAST 90 intake, 90mm TB, 243 heads with mild port work, A4, stall, 9 inch.

We tried them yesterday on the Tick Performance race car (cam only ls1 pulling to 7300-7500) and it didn't make a difference at all. I've always thought that .055 gap is way to wide for anything but a bone stock LS1. Anytime someone swaps a cam or just expects to rev higher than say 6300 the gap needs to be tightend up to .035. And I've seen on more than one occasion 7-10rwhp going from .055 gap to .035 I wonder if this test car was gapped on the high side and thats why the coils helped.

alvin-so what was jonathans car gapped at .035? im glad you guys tried it out i was almost convinced in trying it for a little extra power. id like to see dyno results from stock coils to the msds too.

What a bummer! These figures are coming in all over the place from no gains to 17 rwhp.

I may sell mine...I'd rather use my $200 elsewhere.

Swapping these coils onto a LS1 equipped engine has shown improvements in horsepower and torque. Some car owners who’ve done this swap have also reported better throttle response, engine smoothness and fuel economy. A few have done back to back dyno pulls to document the results. Power improvement results can vary from an increase high of 9 rwhp/18 rwtq to a low of 6 rwhp/2 rwtq. One shop showed no improvements at all. Obviously, results will vary and may be affected by other modifications done to the vehicle or the engine’s overall condition.

I paid $200 for my set, anybody want them for $200 shipped?

I paid $200 for my set, anybody want them for $200 shipped?

Do they come with the brackets and harnesses? If so, $100 shipped? hah:judge:

$200 shipped coils, brackets, and harnesses;)

I may sell mine...I'd rather use my $200 elsewhere.

ABANDON SHIP!!!!!!!!!!!!
http://www.jamescairdsociety.com/pix/BoatIceburgREX_500x291.jpg

$200 shipped coils, brackets, and harnesses;)

I'll give you $50 shipped for all the bithcing you've done.:D

I'll give you $50 shipped for all the bithcing you've done.:D

I'll give you $50 for spelling lessons:mullet:

One test shows no improvement and people are jumping ship.lol I would be happy if I saw a difference in throttle respone. a hotter spark should make a difference.

We will see. I have a heads/cam motor with a good sized cam 11.8/1 comp. Should have them middle of next week. Also have a wideband to monitor any a/f change.

All I know is I love the way the car is driving. Throttle response is great, gas mileage is up a solid 2-3mpg. Right now I've got 178 miles with a 1/3 tank of gas left. That should put me at 250 for a tank, and 15 gallons to fill, right at 17mpg, and that's with doing a lot of spirited driving tyring to get my VE table spot on.

Hey, no-one is twisting anyone's arm. Are the d585 coils better than the stock ls1's? No doubt. Are they worth swapping for $150-200, it's your call.

I bet you experts think a $1000 FAST intake is worth it too, feel free to buy me one. I'll be more careful of who I take my advise from. Besides, I think my gains were from the fans.

Alchemist, do you happen to work for APC?

I have a GMC. I switched from the standard (square) truck coils to the D585s and there was NO difference whatsoever. BTW, I paid $115 for the D585s. So if I was going to switch coils I would just go with the square truck coils. They can be had much cheaper. If you haven't noticed, some truck L92s come with the square coils and some come with the round ones. So there really is no difference between them IMO.

I have a GMC. I switched from the standard (square) truck coils to the D585s and there was NO difference whatsoever. BTW, I paid $115 for the D585s. So if I was going to switch coils I would just go with the square truck coils. They can be had much cheaper. If you haven't noticed, some truck L92s come with the square coils and some come with the round ones. So there really is no difference between them IMO.

what mods are on your car?

I bet you experts think a $1000 FAST intake is worth it too, feel free to buy me one. I'll be more careful of who I take my advise from. Besides, I think my gains were from the fans.

Alchemist, do you happen to work for APC?

You gains werent real though. Youve got to do back to back pulls. Even though you were using SAE its still not accurate. Besides $200 for 6 HP is good and even if you dont feel it when you do more mods (if you do) later on down the road itll even improve them more. Hell people pay $325-350 for a LS6 intake that gets them 10 HP.

I asked in the other thread, but I'll ask here as well. Would there be an negatives to putting LS1 coils on a 6.0 Denali? I was thinking of stealing the ones off my wife's Denali and just putting my LS1 coils back in hers, but I don't want to cause any problems to it. Any thoughts?

I asked in the other thread, but I'll ask here as well. Would there be an negatives to putting LS1 coils on a 6.0 Denali? I was thinking of stealing the ones off my wife's Denali and just putting my LS1 coils back in hers, but I don't want to cause any problems to it. Any thoughts?


A lot of people in here have been mentioning the dwell time being different... So, you might possibly fry the LS1 coils in the Denali because it wants to "overcharge" them. Unless you change the tune.


This is just an educated guess using context clues..haha :lock::mullet:

You gains werent real though. Youve got to do back to back pulls. Even though you were using SAE its still not accurate. Besides $200 for 6 HP is good and even if you dont feel it when you do more mods (if you do) later on down the road itll even improve them more. Hell people pay $325-350 for a LS6 intake that gets them 10 HP.

how is it not accurate being sae? it was on the same dyno and the only difference this time was the fan and coils.

how is it not accurate being sae? it was on the same dyno and the only difference this time was the fan and coils.

SAE isnt accurate though. Its a computerized formula.

If you would of done the swap there like the OP did then sure. Two different days will produce two different numbers regardless of SAE.

SAE isnt accurate though. Its a computerized formula.

If you would of done the swap there like the OP did then sure. Two different days will produce two different numbers regardless of SAE.

Sounds like there is one output for each input, know what I mean? aka accurate.

A lot of people in here have been mentioning the dwell time being different... So, you might possibly fry the LS1 coils in the Denali because it wants to "overcharge" them. Unless you change the tune.


This is just an educated guess using context clues..haha :lock::mullet:


Interesting theory...anyone else want to chime in.

7camaro7, you said it's been a year since your last dyno, ever consider the potential of some loss of power over that time period? Seafoamed your car since then? Consider you may have lost 5rwhp over the year, and the coils made it back up +6rwhp. That would be an 11rwhp if that were true. Interesting concept. It's reasons like those that different dyno days aren't apples to apples comparo.

Although you're disappointed with 6rwhp, I'm sure those with larger fuel systems like myself (Racetronix kit and 36lb injectors), and a higher compression ratio (11.2:1 in my case) will see a better gain.

Mark me down as another "future truck coil user".

I've been needing to dyno my new motor so once I get some time and truck coils, I'll set a dyno appt @ TSP, I'll check with them to see if it'll be OK to do a back to back pull with the different coils.

FWIW, my setup is a H/C/I/E LS6.

got dynoed... Last time I did not have the fan on the intake, but this time I did and I had these coils on. I gained 6rwhp and 2rwtq... I don't really recommend everybody go out and buy these coils unless you're bored.

I guess I'll keep them. It does start easier and feels slightly more responsive. I thought I felt something lol

now I've got 350rwhp/362rwtq sae

Nice to have met ya, Nice SS too.

Nice to have met ya, Nice SS too.
back at ya man and thanks. You still have an ls1 car? And what do you think man? You think the gains were from me adding the fan to my intake during the dyno, the coils, or both? You seem to know your stuff.

7camaro7, you said it's been a year since your last dyno, ever consider the potential of some loss of power over that time period? Seafoamed your car since then? Consider you may have lost 5rwhp over the year, and the coils made it back up +6rwhp. That would be an 11rwhp if that were true. Interesting concept. It's reasons like those that different dyno days aren't apples to apples comparo.

Although you're disappointed with 6rwhp, I'm sure those with larger fuel systems like myself (Racetronix kit and 36lb injectors), and a higher compression ratio (11.2:1 in my case) will see a better gain.

Mark me down as another "future truck coil user".

I've been needing to dyno my new motor so once I get some time and truck coils, I'll set a dyno appt @ TSP, I'll check with them to see if it'll be OK to do a back to back pull with the different coils.

FWIW, my setup is a H/C/I/E LS6.

All of what you said makes sense except how if I lost 5hp how it would not show up on the sae. From what I understand is that sae levels the playing field of dynoing. I specifically requested sae numbers when the operator was wanting to do std only. The std I dropped almost 30hp, but that is due to the difference in temp on the days I dynoed. The 1st time it was cold as hell out and the 2nd time it was hot. I got sae to compensate and make it more apples to apples. I figure if on the same dyno and using sae corrections, that would eliminate all the variables except for the fan added.

I'm no expert, but when I think of sae I think whether your car is being dynoed down in death vally or on mount everest, (regardless the elevation)the numbers should be exactly the same if dynoed on the same dyno, with the same car, with the same mods. I see no reason that it would be different.

And to answer your question, yes I have seafoamed in between the dynos.

Also I am not saying the truck coils will not do anything for you if you're passed boltons. If you've even got a cam in I think it'd help and even more the more you add.

I feel so so about them with a stock engine like I've got.

99hawk262, I'd say if you swapped a truck motor to LS1 coils you'd be going backwards in coil output power. The heat-sinked truck coils have proven themselves to be a better coil then anything else that GM has offered on their engines-regardless of whom may say they've seen improvements or not.

maybe we should start filling our tires with nitrogen:)

I bet you experts think a $1000 FAST intake is worth it too, feel free to buy me one. I'll be more careful of who I take my advise from. Besides, I think my gains were from the fans.

Alchemist, do you happen to work for APC?

Kiss my ass. No one forced you to do this. No one twisted your arm or sold these to you and promised gains. Some of us like upgrading things and making them better. I don't know what's done to your car, but if you're pissed that you dropped 2 bills on a set of better coils and only made 6hp, then that's your problem.

People asked about the gains, people kept screaming for dyno tests, and someone posted a back to back result and you're pissed because you didn't get the same results.

Seriously, don't mod your car if you're going to act like this.

Also a FAST does work. :lol: Dont know who said it doesnt.

Alchemist has been around and has a point. $200 for a better set of coils that did give ya more power and helped with starting as you mentioned isnt bad at all. It is better to do back to back pulls on the dyno to show real world results although I agree with you on using SAE corrections so that it would be as real as possible if back to back pulls were not possible. Ive personally took a car I owned to the dyno and pull 329 and go back to the dyno 2 months later and pull almost the same curve with 329 being the peak(torque being almost an overlay too with the same peak) without any changes. I have also seen people have two different #s doing that too. You may have even gained more than 6rwhp....then again less. I say 6rwhp is a great gain with just swapping ignition parts. I too believe in FAST intakes but is it worth the money outlay is up to the customer. GM felt it necessary to put a 90mm on the LS2 in stock form.....

My intention with this thread wasnt to convince anyone of anything. It was simply to show the results from ONE test. Thats all.

IMO, dynos arent even completely accurate with regards to a back to back test.....much less a test where the first pull took place last year sometime.

My opinion is that the gains showed in our test are probably legit for 8 to 10 rwhp. The other power gained could EASILY be differences in the dyno, weather, car, etc. even though the pulls were back to back. They were still what, an hour apart or so?

I think its a legit mod. I will be doing it on our 98 vette once we get the LS2 in it in a few weeks. We will post that test when the time comes as well.

Im sure many people think my opinion means absolutely nothing, and I have no problem with that. All I know is I was the guy standing in front of the computer screen watching the results for myself.

If anyone is coming to the LSX shootout this week and you want to do this comparison, I will get you on the dyno.

Our tools, advice, facility, and drinks from the fridge are free for LSX shootout atendees.

50.00 sound fair to strap the car on the dyno and make the two pulls?

just throwing it out there if anyone is interested.

Alchemist has been around and has a point. $200 for a better set of coils that did give ya more power and helped with starting as you mentioned isnt bad at all. It is better to do back to back pulls on the dyno to show real world results although I agree with you on using SAE corrections so that it would be as real as possible if back to back pulls were not possible. Ive personally took a car I owned to the dyno and pull 329 and go back to the dyno 2 months later and pull almost the same curve with 329 being the peak(torque being almost an overlay too with the same peak) without any changes. I have also seen people have two different #s doing that too. You may have even gained more than 6rwhp....then again less. I say 6rwhp is a great gain with just swapping ignition parts. I too believe in FAST intakes but is it worth the money outlay is up to the customer. GM felt it necessary to put a 90mm on the LS2 in stock form.....

I was just messing with alchemist... his pussy is all sore now.

Yea I guess my gains weren't so bad. I was expecting more like most of us do when we mods. My underdrive pulley probably gave the same results. I haven't had them long enough to fully judge how I like them anyway. My biggest problem is how they fit on the driver's side. I really don't feel like fabbing right now. I did rearrange them last night to where the coils and rack do not contact other stuff so much. The way I have it now it fits much closer to stock and will not be tapping the engine or anything else.

As far as FASTs go, I was talking about in stock form on my car. I think it'd be one of the worst ways I could possibly spend $1000 and get the least gains at this point. Now if I had H/C and/or a SC, it will be a different story.

My intention with this thread wasnt to convince anyone of anything. It was simply to show the results from ONE test. Thats all.

IMO, dynos arent even completely accurate with regards to a back to back test.....much less a test where the first pull took place last year sometime.

My opinion is that the gains showed in our test are probably legit for 8 to 10 rwhp. The other power gained could EASILY be differences in the dyno, weather, car, etc. even though the pulls were back to back. They were still what, an hour apart or so?

I think its a legit mod. I will be doing it on our 98 vette once we get the LS2 in it in a few weeks. We will post that test when the time comes as well.

Im sure many people think my opinion means absolutely nothing, and I have no problem with that. All I know is I was the guy standing in front of the computer screen watching the results for myself.

If anyone is coming to the LSX shootout this week and you want to do this comparison, I will get you on the dyno.

Our tools, advice, facility, and drinks from the fridge are free for LSX shootout atendees.

50.00 sound fair to strap the car on the dyno and make the two pulls?

just throwing it out there if anyone is interested.

I wish I could be there. I'll be at 6 Flags next weekend:D

I was just messing with alchemist... his pussy is all sore now.

Yea I guess my gains weren't so bad. I was expecting more like most of us do when we mods. My underdrive pulley probably gave the same results. I haven't had them long enough to fully judge how I like them anyway. My biggest problem is how they fit on the driver's side. I really don't feel like fabbing right now. I did rearrange them last night to where the coils and rack do not contact other stuff so much. The way I have it now it fits much closer to stock and will not be tapping the engine or anything else.

As far as FASTs go, I was talking about in stock form on my car. I think it'd be one of the worst ways I could possibly spend $1000 and get the least gains at this point. Now if I had H/C and/or a SC, it will be a different story.

I couldn't care less... I'm not the one who came on and was pissed and wanted to sell them because your gains weren't as high as you thought they should be.

$200 for 6hp really isn't that bad, especially if you are running out of mods..hah

That's about how much of a price and gain it is for an underdrive pulley.

I couldn't care less... I'm not the one who came on and was pissed and wanted to sell them because your gains weren't as high as you thought they should be.

this pewter on pewter crime aint right man

Can't we all get along:usa:

$200 for 6hp really isn't that bad, especially if you are running out of mods..hah

That's about how much of a price and gain it is for an underdrive pulley.

But it was on a bolt on car that isnt even fully bolt on right 7camaro?

Regardless, i knew what you mean about the FAST. IMHO they are insanely expensive because its just NOT the manifold you have to buy but the fuel rails as well.

FAST's work with stock fuel rails.

FAST's work with stock fuel rails.

I was under the impression the new ones need new rails and injectors. Maybe I read wrong but still insanely expensive especially when a cam is about a 1/3 of the price.

My intention with this thread wasnt to convince anyone of anything. It was simply to show the results from ONE test. Thats all.

IMO, dynos arent even completely accurate with regards to a back to back test.....much less a test where the first pull took place last year sometime.

My opinion is that the gains showed in our test are probably legit for 8 to 10 rwhp. The other power gained could EASILY be differences in the dyno, weather, car, etc. even though the pulls were back to back. They were still what, an hour apart or so?

I think its a legit mod. I will be doing it on our 98 vette once we get the LS2 in it in a few weeks. We will post that test when the time comes as well.

Im sure many people think my opinion means absolutely nothing, and I have no problem with that. All I know is I was the guy standing in front of the computer screen watching the results for myself.

If anyone is coming to the LSX shootout this week and you want to do this comparison, I will get you on the dyno.

Our tools, advice, facility, and drinks from the fridge are free for LSX shootout atendees.

50.00 sound fair to strap the car on the dyno and make the two pulls?

just throwing it out there if anyone is interested.

Well look at it from a different perspective. Upon your post, there had been one case of someone gaining hp with this swap, and his was stock. Now you came in with your modded car and got similar results. So now 2 have gained power. Now 7camaro7 came in, did the same thing, and although he didn't see the gains yourself and the gentleman did, he still improved some. So far this mod is 3 for 3 in improving hp regardless of the extent of the mods done. So don't sell yourself short and assume it's the dynos or some other reason.

I wish I could make it to the LSX shootout, I'd be more than willing to be another guinea pig. Hopefully we'll get more solid results like were seeing. Please post up once the weekend's over. :)

But it was on a bolt on car that isnt even fully bolt on right 7camaro?

Regardless, i knew what you mean about the FAST. IMHO they are insanely expensive because its just NOT the manifold you have to buy but the fuel rails as well.

I call my car full bolton, but I know there are a few other things I could do without going internal. I do not have an ewp or aftermarket intake manifold. Otherwise, yes. I've got the lid, ftra, pptb, free mods, full exhaust, pulley, and a tune. An ewp as well as a fast are not cost efficient to me.

I never knew about he fuel rails. They do NOT come with the intake do they?

No, fuel rails aren't provided with the FAST intake, seeing as they are compatible with the stock rails. Running my ported FAST 92/NW92 with stock rails right now, no problems.

No, fuel rails aren't provided with the FAST intake, seeing as they are compatible with the stock rails. Running my ported FAST 92/NW92 with stock rails right now, no problems.

Ok, good to know. Ive heard the majority of people going to different rails and just figured that they were doing so for a reason.

Seems like you would benefit from going to the truck coils!

That's what I'm hoping! I'm for sure gonna be doing this, hopefully wherever I dyno it, they'll be cool with letting me swap 'em right there on the dyno and do another side by side comparo. If it's for sure helping people's start ups and throttle response I'm all for it, the hp increase will be an added benefit.

Alchemist, before your coil pack swap did your exhaust emit a real gaseous smell? Mine smells like it's dumping fuel, but A/F is dead on. Reason I'm asking, I wonder if the added capacity of the truck coils will assist in burning ALL of the fuel, thus decreasing the gaseous omission from the exhaust. Just a thought.

Hell you are paying for the dyno time! With two people swapping them out it should take around 15 mins.

you dont need to retune for these right

With two guys working on the swap, wearing high temp gloves, the swap could be done in ten minutes. Get it started with just one bolt to the valve cover on each side, choose an easy one. Dyno pull, swap, dyno pull.

------------------------------------------------------------

No, you shouldn't need a re-tune for this swap but there may be some power in fooling with timing and/or dwell if you're lucky enough to have a tuner working on your car while you're at the dyno.

So now that we have tested these and had them on the dyno. is anyone going to make a all in one kit for the guys who just want to buy them and install them without having to mod the mounting brackets themselves? Otherwise SpeedInc sells the Accel truck coils and the TR coil relocation kits so im just going to go that route i guess.

Interesting..

So now that we have tested these and had them on the dyno. is anyone going to make a all in one kit for the guys who just want to buy them and install them without having to mod the mounting brackets themselves?

I'm not intending to be really rude here, but if someone on this board cannot install these coils by themselves, without a "kit", they should sell their car. Perhaps you are making it out to be more than it is?

none taken. as someone who is deployed pretty often and currently, i like to be able to spend as least amount of time working on my car as possible, i just want to drive it as much as possible when i am home. When i saw that we have to modify the bracket a little for the coils that just opens the door to my impatience to do little tasks. If im making a bigger deal out of it than what it really is, well oh well, i am not one of the fortunate ones who get to tinker and mod at will.

I think by "kit" he means one part number or item purchase to get all the items needed for the swap. 8 coils, 2 brackets and 2 harnesses for one price.

At least one sponsor on THE REAL COIL SWAP THREAD has posted a "special"

http://www.ls1tech.com/forums/generation-iii-external-engine/1116161-coil-swap-yields-9-25-hp-18-6-tq.html

none taken. as someone who is deployed pretty often and currently, i like to be able to spend as least amount of time working on my car as possible, i just want to drive it as much as possible when i am home. When i saw that we have to modify the bracket a little for the coils that just opens the door to my impatience to do little tasks. If im making a bigger deal out of it than what it really is, well oh well, i am not one of the fortunate ones who get to tinker and mod at will.

Read you lickin' chicken. Former Army here and I enjoy being a dumb fat civilian now and coming home every night to a nice bed and a garage full of cars and tools that I can play with at will. I appreciate your service. :usa:

The install would have taken me almost no time at all except for the bolt that holds the vacuum diaphram bracket that is attached to the coil bracket on the driver's side. This bolt is on the backside of the cylinder head and I had to take it off by touch. The bracket that holds the vacuum diaphram is slotted to slip over the threads of this bolt and then you tighten the bolt back up against the head to hold the bracket. There is an electrical wire that runs back there and it's a little tricky to hold it out of the way, hold the bracket in place, and simultaneously tighten the bolt back up... all without really being able to see it while spinning the wrench (gear wrench for the win in this case). Plus I fabbed up two metal tabs to move the bracket back down on the valve cover (see my pics earlier in this thread) because I didn't want to bend my fuel inlet line and relocate the evap solenoid.

Due to those two considerations, it became a little bit of a project rather than a 10 minute jobbie.

Interesting..

i agree

i just sold my ls1 coils, brackets and wiring and baught the truck coils brackets and wiring and it only cost me 55 bucks all said and done alot of people still need ls1 coils i sold mine for 75 so for 55 bucks if i gain 1 hp it was worth it

anyone else have results?

I wonder what spark plug gap and quality has to do with these gains. In other words, are these big bad coils making up for big gaps and/or old crappy plugs?

We did a back to back dyno test on this and actually lost a few hp up top. This was on an h/c/i ls1 6 speed that makes ~425. I can post dyno sheets this week when I'm back at the shop but I did 2 back to back pulls, changed coil packs and did 2 more back to back pulls. This was just one test with a set of coils we pulled off a plow truck to try while we were getting this car ready for the track. A/F was within .2 from the stock coils to truck coils and no timing was pulled on any pulls. There maybe more to this such as plug gap and heat range but we were getting this car ready for the track and didn't have time to get into all of that. This was also just 1 set of coils but that's what we found in this test.

i just baught a set so ill be comming down for a test

We will be testing this tomorrow on H/C car. we will post results.

We will be testing this tomorrow on H/C car. we will post results.

Will be doing a back to back test saturday on my cam only full bolt on car Saturday. Very interested to see how your so as well.

watching intently...

Interesting thread!
Plug gap vs RPM and cylinder pressure maybe a factor.
Bob

i know these coils sell like hotcakes... i posted 2 sets up for sale not even an hour later my inbox was full....fastest 200 ive ever made......

fail check out my new post

I didn't read this entire thread so maybe this has been answered allready but the only problem I have with these posts is multiple/repeatable runs need to be made before/after swapping a component, not just one run before and after.

As an example, look at the second dyno graph in this post-

http://www.ls1tech.com/forums/generation-iv-external-engine/1145651-speed-inc-fast-lsx-r-nw-102mm-tb-dyno-test.html

Those are the kind of results I would prefer to see when validating a part.

fail check out my new post


interesting.

Like I said before, we have nothing at all to gain by doing this test. We arent selling coils or tuning "tricks"

we did the test and the results are what they are.

I plan on doing the swap on an LS3 we are putting in our FOX mustang, and on an LS2 we are putting in our 98 vette.

should have results on the vette in a couple of weeks, the stang will be a little further down the road.