Final CT Corvette 1997 C5 H/C #'s inside
Final CT Corvette 1997 C5 H/C #'s inside 
Final #'s 412rwhp/394 tq corrected. 441/422 uncorrected.
1997 M6/120,000 miles
Texas Speed CNC'd LS6 Stg1 heads
ARP head studs
GM MLS head gaskets
Comp Cam 228/232 custom grind cam
TSP/PRC dual springs, titanium retainers, new seals, seats
TSP/Trend hardened pushrods
LS7 lifters
LS2 timing chain
LS6 Oil Pump
Powerbond UD pulley
97/99 valvecover/coilpack conversion
Textralia OZ700 clutch/New LS6 slave/master
Some decent gains under the curve
Drivability is near stock, lots of fun on the street with 350ft lbs available on tap down low just a bit off idle. Car didn't peak like it should have. Many things are possible. 120k on the motor is one of the top theories, another is a restriction in the 1.75 headers/2.5" catback, lastly the intake (Ls6 vs FAST). I'm not going to chase my goals with mods or tuning. I was hoping for ~430-450 rwhp and ended up with and honest 412. 485hp at the crank is good enough for me. Chasing that last 20-40hp could cost me hundreds or even thousands. Not worth it.
Originally Posted by c5_ls1_6spd
you should definately have more power than that. do a compression test and see what it turns up.
As for the power vs mods it's respectable.My dyno is no queen.We've had numerous so called big hp cars on it that dyno'd alot lower than the previous shop's dyno spit out.The heads on average are good for 30hp,so that leaves 50hp for the Cam.Pretty good,but a free flow exhaust would probly help in the # department but it would be too loud for this case.
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84rwhp is great gain from a car with a medium sized cam and a stage 1 heads and finally a restriction in the exhaust plus the 120mi motor disadvantage.
all i can say is congrats!
try to dyno it back with a cutout if u had the chance in the future.
all i can say is congrats!
try to dyno it back with a cutout if u had the chance in the future.
Bill,,,
Congrats,, the numbers look good to me. I doing final assembly on a similar motor and I’m hoping for similar numbers.
Can I ask about your cam specs and SCR/DCR??
Thanks!!
Congrats,, the numbers look good to me. I doing final assembly on a similar motor and I’m hoping for similar numbers.
Can I ask about your cam specs and SCR/DCR??
Thanks!!
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From: Was New Orleans, but swam to Baton Rouge
I have to agree with some others do a compression test first. If it reveals anything look further with a leak down. If the car still has a Ls1 manifold it would be time for an upgrade. I also suggest porting the throttle body as well. As for exhaust you do not state what type you have. The stock C5 catback is restrictive. I would look for some Z06 Ti exhaust or a nice aftermarket system. As for headers a 1 3/4 header would be all you need. Only when you step up to strokers do you need the 1 7/8 headers.
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Originally Posted by Sigforty
I have to agree with some others do a compression test first. If it reveals anything look further with a leak down. If the car still has a Ls1 manifold it would be time for an upgrade. I also suggest porting the throttle body as well. As for exhaust you do not state what type you have. The stock C5 catback is restrictive. I would look for some Z06 Ti exhaust or a nice aftermarket system. As for headers a 1 3/4 header would be all you need. Only when you step up to strokers do you need the 1 7/8 headers.
Everyone I see is putting down ~430-450 with my combo...but there is one factor that Slowhawk and I didn't rule out last night. The new part is going on today and we'll see if that improves things.
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From: Was New Orleans, but swam to Baton Rouge
Originally Posted by Billdog350
Haven't done compression yet, its on the list. Car has new LS6 manifold, ported TB, and z06 Ti's already. I didn't think the 1.75's were a big restriction but every car is different. With 120k mi I'm sure there is SOME hp loss but I didn't think I was down 20-30hp.
Everyone I see is putting down ~430-450 with my combo...but there is one factor that Slowhawk and I didn't rule out last night. The new part is going on today and we'll see if that improves things.
Everyone I see is putting down ~430-450 with my combo...but there is one factor that Slowhawk and I didn't rule out last night. The new part is going on today and we'll see if that improves things.
Okay, I serious doubt it is the exhaust then. The intake also is not holding you back to bad. I know the Z06 Ti and the B&B bullets had no difference on my car's dyno performance. It layed down the same number with both. My car is making 452 rwhp H/C setup with the Ls6 intake. Let us know how the new part does.
New 02 is on. We noticed after the car readjusted to the new tune that Don threw on, one sensor was reading low and causing about a 3% LTFT variance. Obviously at WOT that could throw one bank real rich and one lean. Car is running mint now, LTFT's are perfect everywhere. At some point I will take one last trip to the dyno and have a few spare parts available to swap on and off and see if they were the cause.
Agreed the peak hp is low, now its just finding out WHY. With the torque so high, it makes me think that my bottom end is pretty tight. I would expect a torque loss with compression problems.
I wonder...I have z06 screens in front of my vararam...I wonder if that's causing enough restriction/turbulence that it loses peak hp....hmmm. Those are some pretty thick wires. I'll have to gtech it and see.
Agreed the peak hp is low, now its just finding out WHY. With the torque so high, it makes me think that my bottom end is pretty tight. I would expect a torque loss with compression problems.
I wonder...I have z06 screens in front of my vararam...I wonder if that's causing enough restriction/turbulence that it loses peak hp....hmmm. Those are some pretty thick wires. I'll have to gtech it and see.
Originally Posted by Billdog350
New 02 is on. We noticed after the car readjusted to the new tune that Don threw on, one sensor was reading low and causing about a 3% LTFT variance. Obviously at WOT that could throw one bank real rich and one lean. Car is running mint now, LTFT's are perfect everywhere.
my 01 z06 put up the same numbers. 414 hp and 373 tq
I had the same cam on a 114 (G5x1) and stage 2.5 ls6 heads.
i had the tpis headers and catted xpipe which hurt the tq some.
i might have got more but the 3.90 gears and the ls7 clutch and flywheel might have took 10hp away.
im sure it drives great.
I had the same cam on a 114 (G5x1) and stage 2.5 ls6 heads.
i had the tpis headers and catted xpipe which hurt the tq some.
i might have got more but the 3.90 gears and the ls7 clutch and flywheel might have took 10hp away.
im sure it drives great.
Originally Posted by vettenuts
Curious about this since mine is similar, my driver's side is a little richer than the passenger side but a new O2 on the driver's side made no difference. Can you provide more info on this?
We were dynoing at 12.9:1 and the car was still blowing black smoke...showing that it was rich. If the tailpipe AFR was 12.9...one bank could have been 13.5 and the other was 12.6! Now you see how that might make a difference at high rpm!
When you say "a little richer" do you mean >.01 volts or more than .3% LTFT? Mine were .880 and .930 at WOT, that's too much of a difference.
Originally Posted by bad6as
i got some questons
1. what lobes are you using?
2. what is your lsa and icl?
3. and why the ls6 heads over say 5.3's?
1. what lobes are you using?
2. what is your lsa and icl?
3. and why the ls6 heads over say 5.3's?
I went with the LS6's over the 5.3's because of cost and because I would have needed to have the 5.3's milled to get the right compression and the chamber supposedly isn't a good as the Ls6 chamber. I haven't seen people putting down MORE hp/tq with the same setup and ported 5.3's.....
Originally Posted by Billdog350
Basically fuel trims drive your PE/WOT tables. If your LTFT's are off (positive for instance) it will throw off your AFR when it dips into PE. Having the car at 0 or slightly negative will force your LTFT's to 0 when you dip into PE and make your actual AFR match your PE AFR perfectly.
We were dynoing at 12.9:1 and the car was still blowing black smoke...showing that it was rich. If the tailpipe AFR was 12.9...one bank could have been 13.5 and the other was 12.6! Now you see how that might make a difference at high rpm!
When you say "a little richer" do you mean >.01 volts or more than .3% LTFT? Mine were .880 and .930 at WOT, that's too much of a difference.
We were dynoing at 12.9:1 and the car was still blowing black smoke...showing that it was rich. If the tailpipe AFR was 12.9...one bank could have been 13.5 and the other was 12.6! Now you see how that might make a difference at high rpm!
When you say "a little richer" do you mean >.01 volts or more than .3% LTFT? Mine were .880 and .930 at WOT, that's too much of a difference.
So what you are saying is that once you got the car dialed in the LTFT on one side went positive?
