Dynamometer Results & Comparisons - Disappointing 408 Results

Here's the details

TSP 408 shortblock
Stage 3 tsp LS6 plus hand worked locally milled 59.5
YT rockers 11.64scr 8.54 dcr
Fast 92/92
24x/24x 62x/6xx 112+2
EWP
6speed thru TEX clutch
4.11 9"
Numbers 467hp 445tq
cutout open 476hp
Dynoed on dynojet by Geoff at EPS Great Guy lot of good info!
Thinking about going to TFS235's what are your thought on swicthing heads and dyno results?? Sorry dont have the graph Geoff didnt have printer on dyno computer!
GRAPH ON POST #22 THANKS MACH1

You will definitely pick up a lot with the TFS 235's, the question is how much? Won't know until you do it ;)

I will say I think its worth it and their are a few recent 408's with similar mods as yours making 540-550rwhp but those are Vettes with 4.10's. I think 530 is within reason with your setup depending on how well the cam matches up to the heads. Also make sure the valvetrain is set up properly.

Can you post the graph? Its definitely very low for a 408 with those parts. What is the exhaust setup?

What headers, y-pipe, size, where is the cutout at?

Kooks 1 7/8 flowmaster merge, cutoff under pass rear seat, magnaflow 3" exhaust

Unless the head porter has a lot of experience in LS style heads and have proven results time and time again, I'd say the heads are to blame for your low numbers. All your other mods look good.

With a good ported 243 head, you should hit 500 RWHP with no problem.

Flow numbers on the heads were 315int 215exh at .600

afr during pulls? what do your timing tables look like? what did the local porter do to the heads?

should be alot higer maybe if those were stock 3243's but stage III from tsp how many miles are on the motor?

cleaned the combustion chambers! Dont think stock heads would be better than stage 3 heads 2.08 1.60 valves opening to 4.00 bore etc...

Waiting on Geoff to email me the dyno sheet!!

peak flow numbers arent everything.... what does the whole flow curve look like

cleaned the combustion chambers! Dont think stock heads would be better than stage 3 heads 2.08 1.60 valves opening to 4.00 bore etc...


thats not what i was saying i meant your numbers look like your car had stock heads not CNC'd heads with a 2.08 valve

lft int exh
200 140 112
300 204 177
400 258 199
500 296 209
550 310 213

thats not what i was saying i meant your numbers look like your car had stock heads not CNC'd heads with a 2.08 valve

Sorry mistook what you meant

do you have any dead animals stuck in the intake?
looking fwd to seeing the dyno graph

/\ /\ /\ :D for real. i would think that thing would easily put down 520 ish.

Geoff sent the sheets but I cant open them, anyone want try, send me your email thanks!

sales at supraspeed.com

I went from the TSP stage 1 heads to the TFS 225's and would never look back. This is on a 6.0L. I think it would be a great change for your car. I love the animal stuck in the intake theory, lol

If it were my motor and I was sure the tune- afr, timing ect. was right I would look really hard at mechanical, leak down test, cam timing (with a degree wheel not just dot to dot)

I know Geoff's dyno is conservative but those numbers sound really low for your combo. I'm sure Geoff would have picked out anything obvious in the dyno graph for you such as valve float, clutch slippage, etc... The TFS/TEA 235's might be a little overkill for your app. I'd look at the 225's to boost torque with a cam of that size and 4.10 gears...

Shane

Here is the graph

I'm not a tuner by any means but have studied alot of A/F graphs on other peoples dyno sheets and you look a little rich. Could run leaner safely and get more power that way I guess. Where's your timing at?

Mis-matched combo IMO.

Really low numbers...

We've made 515rwhp with TSP PRC LS6 Stg 2.5 heads, PatG Cam, fast 92/92 intake and tb, TSP 1.7/8 Headers true duals, M6 Car 3.42 10bolt and only 11:1 compression with hot wheather too.

I know your 9' is taking some power but not that much.

my vote is the heads,for some reason the ported factory castings dont always make good power,my 402 is a perfect example. I have seen as many poor #s as good#s. Thats why my "Mamofied" 225s are on a ups truck someplace now.

look at timing and massage the air to fuel ratio a little, cheaper option first before dropping more money on different heads, unless $$$ isn't an issue

i dont think the tfs would be over kill but he should be making more power than it is now those would be nice numbers for a 4l60 or th400 unlocked

peak flow numbers arent everything.... what does the whole flow curve look like

Exactly! :nod:

Mis-matched combo IMO.

The cam was spec'd by Patrick G. All of the bolt on parts were researched and tought about for a long time. Going into it I knew the LS6 heads would be my weak link just didn't think they would be that big of a bottleneck!

^^^that is exactly what i thought, i made 470 rwhp-m6 and a 12 bolt. I was on a budget when i was doing the motor, as i was also completely redoing the body. I wish i would have just waited and got the good heads from the get go. What gets me is there are some people that make great (peak) #s with the budget heads. I was hoping to be one of those people. I just ran mine the way it is for part of last summer and this summer (probably less than 2k miles) and saved up for a good upper end.

Here's the details

TSP 408 shortblock
Stage 3 tsp LS6 plus hand worked locally milled 59.5
YT rockers 11.64scr 8.54 dcr
Fast 92/92
24x/24x 62x/6xx 112+2
EWP
6speed thru TEX clutch
4.11 9"
Numbers 467hp 445tq
cutout open 476hp
Dynoed on dynojet by Geoff at EPS Great Guy lot of good info!
Thinking about going to TFS235's what are your thought on swicthing heads and dyno results?? Sorry dont have the graph Geoff didnt have printer on dyno computer!
GRAPH ON POST #22 THANKS MACH1

go with TFS heads from advanced induction (AI), they have great heads. tell them all info about your 408.

look at timing and massage the air to fuel ratio a little, cheaper option first before dropping more money on different heads, unless $$$ isn't an issue


I love these posts... you are making the assumption that his tuner is not thorough or doesn't know what he is doing. You would be wrong. You would also be wrong if you thought that there was more than another 2-3 to get out of it from the point that Geoff left it at. People on here think there is some voodoo to tuning.... there may be for driveability, but not for WOT. They make what they make. Of course that never stops anyone from posting stuff like "check your toon" rather than having folks look to the real problem areas.

I am satisfied with the tune Geoff gave me car actually made 476 with the cutout closed but Geoff said that was on the edge of detonation, knock and he was not comfortable leaving it there because of the possiblity of engine damage. AGAIN I AM NOT BLAMING GEOFF FOR THE POOR NUMBERS!!

I went from the TSP stage 1 heads to the TFS 225's and would never look back. This is on a 6.0L. I think it would be a great change for your car. I love the animal stuck in the intake theory, lol

I saw where you picked up 64 RWHP and 50 RWTQ over your TSP heads and cam, what cam where you running with those heads?

FWIW, I had a guy with a 402 pull TFS 225's off and install TFS 235's and picked up over 10 RWHP and over 10 RWTQ, so I think the 235's are a consideration.

FWIW, I had a guy with a 402 pull TFS 225's off and install TFS 235's and picked up over 10 RWHP and over 10 RWTQ, so I think the 235's are a consideration.
Across the board? Did he lose any down low?

I love these posts... you are making the assumption that his tuner is not thorough or doesn't know what he is doing. You would be wrong. You would also be wrong if you thought that there was more than another 2-3 to get out of it from the point that Geoff left it at. People on here think there is some voodoo to tuning.... there may be for driveability, but not for WOT. They make what they make. Of course that never stops anyone from posting stuff like "check your toon" rather than having folks look to the real problem areas.

SAY WHAT???!!!??? You mean your HPtuners or EFIlive didn't come with the +50HP button???????? You better call em up and get the new version. :D

Geoff only uses the +50 button on VERY special occasions!!! Its called "hold the bottle in front of the airlid..." :jest:

you can ask Jason99TA about the BMW nitrous fire...:secret2:

Shane

It looks to be about 12.5:1 so maybe getting it to 13:1 will get it another 30hp.:poke:

Seriously, I talked with Geoff today about this car in particular. The car was on the edge of detonation and is tuned as far as possible as the car sits. I would say this car should dyno in the 480 range on most dynojets, Geoff's is the 224LC which in my experience reads 20-25 lower than the old 248 we had.

Shane

My friend has a LS2 402 with almost the same mods with the TSP stage 3 LS6's and made 47x. He lost power going from a MS3 to a bigger cam too. We also think that the heads need to be swapped. Trickflow advised the 235 i think, don't quote me on that. Those numbers are on at least 11.5 compression too.

FWIW, same cubes, TEA LS6 heads, 24x/25x cam,Fast90(home ported),TPIS 90tb, Kooks 1 7/8 ory w/4"cutout, 4l60 3600 through a 12 bolt made 505/450ish. Stock fuel pump was going out as I only had like 50psi of fuel. Maybe the heads were "overworked"?

If it is on the edge of detonation, what gas are you using? I would say it could take a little less fuel and lean it out, but I don't know the conditions or what the car was doing. The only argument I have with the graph is smoothing at 0, makes it hard to compare apples to apples, but it looks like a good graph so no beef there.

Gas used was 93. Just ordered TFS235 from Ron at Vengence think that should take care of everything:nod:. Hopefully some of that Vengence magic gets put in the box when they ship the heads!!

Gas used was 93. Just ordered TFS235 from Ron at Vengence think that should take care of everything:nod:. Hopefully some of that Vengence magic gets put in the box when they ship the heads!!

you will have a beast now. some people have really low numbers with ported stock heads and some get lucky. my junk puts out 53x rwhp with a scrub
244*@ .050 cam through 1 3/4 tubes with a ported 243 head but alot of folks aren't as lucky. the tfs 235 head is an awesome head. you will be more than happy with them.

The cam was spec'd by Patrick G. All of the bolt on parts were researched and tought about for a long time. Going into it I knew the LS6 heads would be my weak link just didn't think they would be that big of a bottleneck!

Your heads and cam is what I was referring to. I'm sure Pat did a great job but it seems that the TSP heads are all over the place... and I'm sure whoever did the "hand work" did make things much better...

LS6 heads in the right hands, such as Tooley's (Since he is a sponsor posting in this thread ;)) can produce results that would hang right with any other aftermarket head (within reason of course).

Best of luck with the TFS 235's. I'll bet you pick up quite a few ponies :thumb: