hankisonc

Today i got 3 free pulls at the dyno and got decent hp results but my torque numbers are much lower than i hoped for. my car pulled 359 hp all 3 pulls and torque ranged from 334-338 ftlbs. Does this sound correct for my set up?

355 hot cam
195cc trick flow port and polished heads
ported intake and Tb
Full intake, exhaust and ignition system
PCm for less tune
6 speed
10 bolt
17x11 zr1

Shangrila

Sounds about right for those heads and cam. You have upgraded injectors?

hankisonc

Yes i have 36# injectors

KW Baraka

Agreed.

KW

Shangrila

What kind of numbers were you expecting?

hankisonc

i hoped that my combo would make about 360hp and 360 torque as a baseline. But i guess the giant runners on my heads and the decrease in compression really hurt my torque numbers. 62cc chambers and 200cc runners after head work was done.

Injuneer

You need a bigger cam to take advantage of the head capabilities. And the TF's have a thick deck, so they can be milled to reduce the combustion chambers, and regain compression.

hankisonc

Injuneer I love the driveability of the hot cam. I got it back in 2001 when it was very popular. To keep the driveability and still get more performance what would you suggest?

Injuneer

The intake runners and the large intake valves are probably hurting low end torque. I'm not sure how they fit 2.02" intake valves in those heads without excessive shrouding. I've seen claims of over 400 lb-ft from 3,000 - 5,000 RPM with the LT4 HOT cam. They were referencing an article in Chevy High Performance from the year 2000.

I'll let someone else address the next steps up in camshaft vs. driveability.

KW Baraka

Try to get the combustion chambers down to about 52cc......install a thinner head gasket (about .030" compressed thickness) and you'd be ready for a cam along the general lines of the CC-503 cam.

You could have Comp Cams grind you a cam with the same intake/exhaust duration as the 503 cam but with more lift (.600"+).....lobes 3192 intake and 3194 exhaust.....but then you might want to go with NSA rockers, guideplates and hardened pushrods.

Oh.....and a PCM re-tune is a must with more cam and more compression.

The cam will be tamed enough enough for daily driving.......and along with the bump in compression, should get you into the 375HP/365TQ range at the wheels. The CC-503 cam should also be able to pull clear up to about 6300 RPMs.

Good luck with whatever you choose.

KW

KW Baraka

I think that was at the crank.....not at the wheels.

At the crank, those numbers would equate to a shade over 320HP at the wheels with stock LT1 heads......which is what the Impala guys were mostly pushing with that general set-up way back in the 'old days' (late 1990's).....

KW

hankisonc

thanks for all the advice everyone.