Car is a 2004 CTS-V. I built a 402 for it early this summer. I went with TEA Stage 2 LS3 heads, ported LS3 intake and a custom LS3 cam for the top end.
It served me well, ran good, decent mileage etc.. layed down numbers in the 485 rwhp/455rwtq SAE range.
I couldn't leave well enough alone, and switched over to a cathedral setup with TEA Trick Flow 235's, FAST 102 and a custom RPM Motorsports "Gargamel" cam
New numbers yesterday were 518 rwhp SAE, 532 rwhp STD. I feel this is a better optimized setup for the 402. If I had a 427ci. or larger, the LS3's would have worked better in my opinion then they did.

Build list....
LS2 based 402
Compstar crank and h beam rods
Manley pistons
Virginia Speed CNC block prep
ARP mains and head hardware
ATI 10% underdrive balancer
ZR1 LS9 twin disc clutch
DSS axle bar upgrades
Aeromotive 340 Stealth fuel pump with Racetronics hotwire
Stock 3.73 gears
TEA prepped Trick Flow 235 heads
Out of the box stock FAST 102 LSXR intake manifold
Ported LS7 throttle body
43 lb. LS3 injectors
RPM Motorsports custom "Gargamel" cam
Stock rockers with Comp trunion upgrade
LS7 lifters
Ported LS6 oil pump
Custom 4" cold air intake with LS7 MAF
Kooks 1 7/8 long tubes with off road pipes
Stainless Works dual 3" exhaust with turbo mufflers

Videos are form my phone and not the greatest quality. Click pics for vids...

Walk around at the car wash...



Dyno pulls..





Here is the STD graph. I will get better graph pics and overlays on Monday.

 

Congratulations for becoming a member of the 500rwhp club !

Nice build but I think that something was wrong in your previous build before swapping the heads.

What were the specs of your previous cam? current cam?

I think what made the big difference is the intake manifold not the heads.

Your old torque number (455rwtq) is a bit low for a 402 engine.

 

I could not disagree more. It's totally the heads. I have seen TFS 235 heads consistently pick up anywhere from 30-40 over stock or ported LS3 heads on 402-408 engines...every time. You L92 lovers have to understand that these heads are not ideal for a 4" bore. The big 2.165" intake valve is slammed right next to the chamber wall and cylinder bore. Might flow well at 28" of H2O but it does not make great power on a real running engine...not compared to a well designed cathedral port head. Ask Mike C. He's done the same exercise and had the same results. I had similar gains taking off L92 heads on my L76 engine and replacing them with AFR 230 heads.

 

How do cam only ls3 cars make 500+ but a 400+ cube motor can't?

 

The previous cam was a custom cam that was specced for the LS3's and in a 402. It is a proven cam that worked well with WCCH LS3 heads, but possibly wasn't optimal for the TEA LS3 heads. It is a huge intake runner.
Keep in mind this is not in a F-body with a 10 bolt. My drivetrain is a bit heavier every where. My ZR1 LS9 twin disc with steel flywheel is very heavy, two piece steel drive shaft, upgraded larger diameter axle bars ( which is a new addition since the last dyno) etc.....
My numbers are right where I was expecting (now). It is hard to argue with the idle this cam delivers. Very tough sounding, and gets some strange looks coming out of a Cadillac!
The upgraded fuel pump was put in with plans for N2O. I'm curious to see what a Nitro Daves plate kit jetted for 200 will net!

 

We do tons of cams in LS3's....470 to 480 is about max on a LS3. 500 on a 6.2L is a stretch for cam only.
LS3 has a bigger bore too. See Pat's post on valve shrouding.
I have been messing with L92/LS3 heads since they came out. They have their place, but are a different animal.

 

what kind of power do you think id see in gains going from a ls3 ported head to those trick flows on a 418?

 

With the supporting mods, FAST 102 intake and a cam for the trick flow heads. 20-40hp

 

yeah 40 his isnt worth 3k to me lol. pretty sure il keep my setup and go on the bottle like i planned rather get 150hp for 1000 maybe in a few years when i need to replace/upgrade parts

 

I dont agree. and I'll explain why.

LS3 intake sucks. no way around it. and A LOT of guys spec cams for these heads and totally miss it.

MY setup is as fallows.

GMPP 6.0L block, stock bore
2007 LY6 rotating assembly, installed in said block.
flycut stock pistons .100" for intake and exhaust was already done cause of DOD piston.
L92's milled .070" to get compression up. Also a street port on heads, nothing crazy here.
Custom Spec Bullet Racing by Tony Bischoff from BES Racing Engines.
242/246 655 625 108 lsa Has some good lobe profiles from what I was told.
GMPP L92 single plane intake
Edelbrock Ultra low profile elbow
Holley 90MM TB.

M6 car
9", spool, 4.86 gears(no dyno queen here) with 28" slicks on dyno.

It made a touch over 500whp, making power all the way to the peak of 7500, and never really fell off till it hit rev limiter of 8200(yeah stock rods with ARP 2000's)

Yes its a rev happy little 6.0L. I street drove it, I drag raced the **** out of it with over 200 passes on it. Ran a best of 10.91 at 127 3820lb raceweight, so it backs up the dyno numbers it laid down.... and if not better after more tuning was done at the track.

I have out ran just about every 408 402 setup around here. I know one setup has Tick flow 235's, fast 102 intake, but cant run the ET mine does, and dyno's about the same.

I didnt really like the comparing LS3's with stock ls3 intake to a aftermarket cathedral port Trick flow 235 and 102mm. like apple's to oranges to me. I honestly think a L92 head really wants a single plane intake, I cant wait till my 6.0L finally dies so I can try out a Victor Jr L92 intake and a 4150 TB.


BUT Nice number none the less!

 

Did you mill the heads to 0.070" to get what compression? and did you use the stock head gasket thickness (0.051")?

 

Nice numbers! Congrats!!

 

Same dyno both builds? Sorry if I missed that.

 

33 rwhp gain is great ... grats veee8 !

BES ... sick lil 6.0 you got


but I can also agree with 82cetuner ... the rectangle ports are great budget wise
if I hadn't already sunk $ into the cathedral intake setup I'd prob'ly have gone rectangle ... but the other hand (Pat G) makes strong debate about rectangle use on 4" bore

lots to learn ... thank LS1Tech!

 

G6x3 have prooved to make 500+ in ls3 even in 2010 camaros with heavy drive trains just like yours. Curious to see what a cam change would have done. LG.has 570ish rwhp 6.2 motors with ls3 heads.

 

this is impressive for 570rwhp with cam in 6.2 Liter

I wish I saw a thread about it...

 

yes milled for compression. and used cometic's .052" compressed gasket.

I even stuck a 150 shot on it to run a 10.20 pass a few times, no issues.

 

This is odd...I pulled 517/497 with CNC LS3s, PAT spec Cam and FAST 102/102. It's hard for me to consider that the TFS 235s would pull more power. I do agree what PAT said that the LS3 int valve to close to the cylinder bore could null the flow effects of the big int valve...still though I'm happy with the results.

 

Nice combination you have there, Tony knows his stuff and is an awesome guy to boot.

The LS3 intake doesn't suck any worse than the Fast LS3 or the Fast cathedral intake.

However, that big 2.16" intake valve makes any LS3 headed combination very sensitive to overlap events, which can seriously over scavenge a long runner intake and kill peak power. The big intake valve and port also makes the LS3 heads very sensitive to intake valve close point. With a carb intake there is no issue with over scavenging during overlap, so you only have to get the IVC close to make power.

I was so concerned with over scavenging on my 454 that made 705 hp even with my smallish 2.10" intake valve that I did two things. I used a 115 LSA and I put the exhaust seat on a 50 degree angle which reduces low lift flow, which has the same effect as reducing overlap.

I would like to see the valve events for both combinations. You can easily get away with up to 25-30 degrees of overlap with the TFS heads/Fast 102, but I think you have to be 15 degrees or less with the LS3 heads/LS3 intake to make good peak power. A 50 degree exhaust valve job should help the LS3 heads as well.

 

I would question your 497 unless your motor is much bigger than the OP's, what displacement is your's?