Hey fellas,

I just got my 408 retuned last week and am a little disappointed in my peak rwhp numbers. I was almost certain I was gonna be over 500 rwhp.

I made 465 rwhp and 445 rwtq w/ an LS6 intake, stock TB, gutted cats, 1 3/4 Kooks. I just upgraded to a FAST, LS2 TB, 3'' x-pipe, no cats, 1 7/8'' headers and put down 492/ 486. I'm very happy w/ the torque since it increased 30 to 40 lbs ft across the board. It made 400+ lbs ft of tq from 3,000 rpm up to 6500. The tq peaks at 4200 rpm. Sorry for not having a graph to post.

My setup:

Y2K Triple Black Vert M6. Borla Stingers ,Kooks 1 7/8 ,B&M Ripper, Z06 sway bars. 408ci Iron block 11.1:1 static compression ratio;Fresh LQ4 block bored .030 over,Eagle 4" crank,Eagle 6.125" rod w/ L19 bolt upgrade,Diamond flat top pistons,Comp OE style lifters,A.R.P. head bolts and main studs,Cometic MLS head gaskets,TEA Stage III cylinder heads,FAST intake w/ LS2 TB, Comp XER grind 242/248 .608/.612 112 lsa

I have done some research on some other boards and have a good idea what is holding me back, but wanted to hear from you guys.

I do not have an UD pulley and keep in mind this is IRS and stock 3.42's.... There are guys running smaller cams than me that have put down 520 rwph/500tq. Any comments or ideas....I'm all ears.

Thanks in advance.

 

Your #'s are on par with most. Your IRS might be hurting you alittle but the 3.42 help alittle. How many miles do you have on the motor? Remember almost 500rwhp is

 

Try porting the fast at all? If not do that, try some cutouts, and get the UD pulley, you will probably be around 520 hp after that.

 

Those heads are 72cc, right? Mill them .030" to 67cc (11.8:1 CR) and add the underdrive pulley. Don't be afraid of compression. The cam, if it's installed on a 112+0, will work better with more compression.

Port match the FAST 90LSX to the TEA heads and get the off-road Kooks 3" X-Pipe if you don't have it, too. You'll be in the 520-530 range then.

 

My fast intake was ported plus some of guy are running a little more compression. I am 11.6-1. That Irs may be hurting some. I would definitely port the intake though.

 

The motor probably has somewhere around 1,000 miles on it.

I initially thought my cam was a weak link until I saw guys w/ smaller cams make more peak hp than me, but they also had AFR heads?????

UD pulley and port the intake. I agree w/ that; just not sure if it is gonna be worth the time and effort for me.

Does anyone think I would have made more power w/ AFR 225's? I "heard" the T.E.A. heads don't flow as high as they are advertised???? I also have "read" that the TEA heads have better numbers under the curve vs. AFR. NOT LOOKING to start a war, but if anyone has personal experiences....please post it.

 

Hey bro, RPM called me a couple of days ago and asked if I wanted my FAST port matched. I asked if it would be worth it and was told it looked like it was a pretty big restriction. I also have TEA stage 3's. I imagine that and an UD pulley will easily get you over 500. Don't think your heads are the weak point at all if you are certain they are true TEA's. Seen people here get over 550rwhp n/a with them. Do the small stuff and you should get 515-520rwhp or so, which should be pretty good with that cam in a 408. What rockers are you running?

 

mods and hp in sig, my cam is a FMS 246/250 630/630 114+4 but i had the cam degreed in at 113 ICas per Tony's suggestion. I think I still have a few ponies in there as im running a little lean at 13.5 at wot running a 11.0 CR. I just had the heads off and milled them down a bit to bring the CR up to 11.8 going to the dyno later this week to bring the AF down and see If I picked up a couple of ponies from the CR.

 

I honestly dont think your heads are the problem.... are you positive they are TEA's though? also just out of curiousity, what kinda of "block work" was done to your block, also, was your cam installed right (I don't even mean "degreed") I've heard of a few "shops" that THOUGHT they went "dot to dot" and was off by a tooth or two.

either way.....

good luck and keep us posted

 

Good question!

 

Not sure what rockers are in it, but I can find out.

I KNOW that there isn't anything wrong w/ the install or the tune (A/F is at 13's across the board). Just trying to figure out if there is anything that i can do to get over the 500 rwhp mark on paper....before it gets sprayed.

I've heard my cam is holding me back, some have told me the TEA heads (yes they are true TEA heads) don't flow as advertisied, and now I have heard to port the intake. Hmmm?

I know an UD pulley will give me some horses & porting the intake, but not sure if I want to put another $500 to $1,000 in it for the 20 or so rwhp. I'd rather put that into my nitrous setup.

Thanks again for all the input guys.

 

Try getting a graph to post, might help some people answer some questions.

With your setup I'd be lookin for 520ish or so, even without porting the FAST.

How much timing are you running?

Did you have the heads flowed before they were installed, or did they come with a sheet?

 

an UD pulley is one of the cheapest easiest mods to do. not sure why you wouldn't have spent the extra $200 for 10hp when you spent thousands for the motor?

I wouldn't worry about the intake as much, but might as well do the UD pulley.

 

to be honest, i see the heads as being your problem with having low peak numbers but im not sure. There are good results with those heads but i just feel that that is your problem.

i agree where i dont think in spending money on an ud pulley... but a good port should yield some nice numbers over the 500rwhp but nothing really big...but enough to make a nice difference....

try this, run it at the track..get the best time syou cna get..im sure you wont be that dissappointed and take it from there. You can swap the heads out of port the tea's. I dont think its your cam but a regrind could be help out. MAybe something on a longer lsa like a 114.

good luck!!

 

what was your HP peak at?? 1 3/4 headers were probably a better choice for that cam size.

 

Was this on a dynojet 248C or a Mustang Dyno? The Mustang dynos read much lower.

 

Heads came w/ a sheet & it was tuned on a dynojet dyno.

So far, I have heard the intake needs ported, could be my heads, and I know I could benefit using an UD pulley. Thanks for all the info, what I have found out is that no one has a concrete idea what it would be. The kind of luck I have I would have to do all of the above and spend some more $$$$ just for the majic number. I'm adding spray like I mentioned, so I am gonna put that money into my kit.