Jason 98 TA

iTrader: (4)

After 5 days of engine dyno testing different combinations & packages I'm proud to announce I finally have some extra time to provide you guys with some of the information we've learned!


The very first dyno testing we did compared header primaries & power output from 3000 to 6000rpm. The base engine was completely stock 01 engine with only a Fast intake installed. We dyno tested both the Pacesetter 1 3/4" coated long tubes & the TSP 1 7/8" long tube headers. The goal was to see how the larger primaries would effect power on a basically stock engine. To my suprise the 1 7/8" headers made a considerable amount more power than the 1 3/4" headers! Power output was virtually identical untiL 4800 rpm when the 1 7/8" headers began to outpower the smaller 1 3/4" primaries. The 1 7/8" headers made a peak hp of 414.x hp & 421lb ft while the 1 3/4" headers made 408hp & 419 lb ft of torque. While this isn't a huge difference, it definately shows that even on a basically stock car the larger headers are still a good investment! Power under the 4800rpm point was virtually identical! Infact the 3000 rpm numbers were 209hp 366 tq from the 1 3/4" headers & 209hp 359.9 tq!

Both dyno runs were backed up several times & the combos used very similar air fuels & locked in timing at 28 degrees. I thought this was a pretty cool comparision, because the common thought is the 1 7/8" headers is just overkill on anything smaller than stroker setups. This is apparently not the case....

Here's a few pics of the 1 7/8" headers installed on the engine dyno



The dyno video can be seen at:

http://www.precisionracecomponents.com/178dyno.mpg

I'll have some of the guys help me bust out some detailed dyno graphs for you guys to checkout in the morning.

Enjoy!!

I would like to offer anyone who doesn't agree with these finding to come down to our shop & I will be more than happy to redo any testing we've done over the last 5 days. All our engine dyno testing was done at a independent dyno facility & as long as your willing to pay the dyno testing fees, I'll glady reproduce any testing we've done. This is a very reasonable offer, if you don't want to put your money where your mouth is then please don't jump in this thread & talk crap. I'll gladly defend any testing we've done, I'm always looking for a opportunity to get back to the engine dyno for more testing.

180ls1

iTrader: (4)

wow, what a misconception that has been spread around here. Glad to see the dyno. Thanks guys.

firehawk#682

iTrader: (19)

very good info interested in more!

Trav's_TransAm

iTrader: (5)

Well I think you just received a future header customer!

ChocoTaco369

That's good to know, but that's not an apples-to-oranges comparison. The TSP 1 7/8" headers are a brand new design and of pretty high quality for coated headers. The Pacesetters are a design half a decade old, and they're one of the cheapest longtubes on the market and also the smallest. Just look at the difference between Pacesetters vs. Edelbrocks:





They are both 1 3/4" headers, and I can guaran-damn-tee you that the Edelbrock 1 3/4" headers will outperform the Pacesetter 1 3/4" headers just the same.

IMO, this comparison is meaningless because you're comparing a quality header to old, bottom-of-the-barrel junk. You need to compare the same design. If it were Kooks 1 3/4" headers vs. Kooks 1 7/8" headers, then I'd be content. if it were ARH 1 3/4" headers vs. ARH 1 7/8" headers, then I'd be content. That way, it's an apples to apples comparison.

Also, the fact that you can't show power below 3000 rpms is discouraging. That is the powerband for daily driving, and that's where the 1 3/4" headers shine. You're not going to see the benefits of the 1 3/4" headers because the dyno won't allow it.

I'm not trying to insult you or discourage you. I'm just pointing out facts. It's a bad comparison by not choosing the same brand and design, and even if it were, the dyno leaves out the very powerband that shines with the smaller primaries. I'm not going to sacrifice a 15rwtq loss @ 2200 rpms for a 3rwhp gain at 5800 rpm's. Sorry to be a buzzkill.

primer84z

iTrader: (7)

seems pretty common sense to me, I dont see why someone would dispute that the larger primaries made more power from 4800-6000. I think the argument for them being over kill would come in on the mid-range, "under the curve", which you've shown that the smaller primaries made the same HP at 3k, but 6 more ft/lb's. Especially on a stock cam that peaks around 5500-5800 anyway.

primer84z

iTrader: (7)

choco taco,

you covered what I wanted to, just took me too long to type it. I agree.

conan

iTrader: (5)

great comparision test. Wish i would have known this a few years though. You guys do great work down there, most of whats in my sig came from TSP and i couldn't be happier. keep up the good work.

ChocoTaco369

Glad I could save you some time.

Honestly, I'm not trying to be disrespectful at all to Jason. I'm 100% confident that if his headers were 1 3/4", they'd still outperform Pacesetters just as well if not more all over the curve. His headers are just a better design. Pacesetters are garbage by comparison of almost every other newer header on the market. I've seen QTP's make 18rwhp and 30rwtq over Pacesetters on a H/C car in the midrange. That's 1 3/4" vs. 1 3/4" headers. Brands make a HUGE difference. We need the same brand, same design, different primary diameter on a stock motor, all tuned to the ideal AFR. Only then will this argument be laid to rest.

On the upside, I'm happy to see a bone stock motor with just an intake and headers make well over 400 hp. Glad to know I'm past that

silverLSWON

iTrader: (16)

good info and nice work

primer84z

iTrader: (7)

I cant really talk about overkill though, I'm running a FAST 90 on a stock cammed car.....

dug

iTrader: (10)

how about a dyno test of open headers vs. ypipe

BREWS02WS6

iTrader: (6)

What difference does power make when you're daily driving below 3k rpms? I know what you're saying, but still...

bigsticksupra

iTrader: (3)

the picture above with the pacesetters and edelbrocks is mine. i bought both to compare. the edelbrocks are actually 1 3/4 stepped to 1 7/8 with a 3.5 inch collector. I like the TSP 1 7/8 headers but would like to see a merge collector with velocity spike.. i think that would make them real nice..

Omec

iTrader: (2)

Even tho every time i see Choco post anything about headers or exhaust i wanna punch my self in the face, im gonna agree w/ him 100%. my personal opinion is it was a usless test other than comparing two brands.

chpmnsws6

iTrader: (70)

Two brands most people use though.

ChocoTaco369

Throttle response and low end grunt for quick passes are essential to me. That's why I don't have a stall and a big cam. I like my snappy throttle response.

-Joseph-

iTrader: (12)

These are the two most popular headers we go through and keep in stock. It was a last minute decision test, I wanted to compare them before we tore into the engine, mostly for our own background knowledge. Ideally I wanted to test them with a stock engine, and then with the "all-out" H/C setup and compare numbers. But this will do for our customers that ask "what's best for me?" type questions.

Someday if we ever get a dyno on-site at TSP I'll spend a day testing headers. I can't test y-pipes or any exhaust though, the dyno is RIGHT where the exhaust would end up, it was a crapshoot whether F-body headers alone would even fit until we tried...

Edit, I'm not quite sure if we can run a loaded engine dyno below 3000rpm. I'll find out for next time though.

SladeX

Seems pretty reasonable, though I think the discrepancy in power may not be from the size but rather the design. Kooks, ARH and QTP have small design and quality aspects that help the flow of the exhaust that could very well narrow that gap further even above 4800rpm. As for down below, it's doubtful you'll see too much of a drop with 1 3/4 headers, while not a perfect example, I've driven stock cammed LS1 auto with 1 7/8 headers and still had one hell of a low rpm snap response that was well beyond a stock LS1 auto. If you think about it, the LS1 responds incredibly well to any exhaust mod, from headers to mufflers, it wants to get rid of that exhaust quickly.

Jason 98 TA

iTrader: (4)

Ok ChocoTaco time to put your money where your mouth is. I have the headers & engine still sitting here. The engine dyno is open a few days next week. If you can guaran-damn-tee your 1 3/4" headers will make the same power as the 1 7/8" headers then come on down. I'm not discouraged by your opinion, I'm discouraged because you have no true data to backup the claims that you guran-damn-tee other than your eye dyno....

The eye dyno lies to people all the time. This was a very good comparision because it showed that even at stock motor levels the larger 1 7/8" primaries can produce a little bit more power. For headers that cost very comparable that is a great option for our customers. Honestly I don't care if the customer buys 1 7/8 or 1 3/4" headers as long as they buy from us! Our goal is to give our customers the most accurate data for making purchasing decisions.Once again your eye dyno is completely off. If you think the primary swap from 1 3/4" to 1 7/8" will kill 15 torque at 2200rpm your completely crazy. I'll take that bet & I have the chassis dyno for us to test with. Come on down & I'll take that bet all day long.