91 z/28
GMPP ZZ383 short block
10.82:1 Compression
AFR Eliminator 195cc Heads, 65cc comb. chamber angle milled to 55cc
Comp roller .510/.520 230/236 110lsa
Holley 670 Street Avenger Jetted 64/70
Total timing at 34 degrees
Dual Plane High Rise Weiand Stealth
1 3/4 shorties
Solid 3" with Spintech (Catless)
Built 700r4/4L60
3.70 Aussie 9 Bolt Rear

Best run of 327.34 Hp/360.02 Tq on a Dynojet
Correction Factor of SAE 1.21
Up here in Denver, Colorado About 5500ft elevation

Bone stock manual ls1 fbody cars were putting down between 260-275 on this dyno, just for reference.

 

That dyno seems pretty brutal...

 

^Agreed. With a little bigger cam, that engine should put down 500 at the flywheel.

 

is your intake portmatched to the heads you've got? Just curious. Might be able to pick up a few that way also, albeit a very minor detail. I'm curious if you'd see any more power with an annular 750 DP carb as well. That and what kind of shorties are you running?

 

Are those numbers before, or after applying the correction factor?

Whose dyno? My son has been getting his '01 S10 Blazer w/LS1 clone dyno tuned, puts down about 300 uncorrected RWHP.

 

This was at Colorado Speed and Chassis. Numbers are after the correction factor.

 

It's not portmatched, but the gaskets were so close it didn't seem necessary. I used to run a 750 cfm holley, vac secondary as well. I had it tuned every which way, but the 670 was so much better on the street. It was literally night and day, I played with jets, power valves, and different springs. The 670 is much better for this elevation though! My shorties I believe were either an older hooker or edelbrock setup, they have air tubes and are not a ball and socket type..

 

No doubt, I built this after a catalog 480hp/500tq combo. I followed every step, heads, cam, intake, carb etc. I even bumped the compression from their 9.6:1 to 10.82:1. At 20% loss through drive train I only come up around 409/410 hp. The reason I posted this is to see other rear wheel numbers of afr heads on all motor combos, I never really had found any!

 

What's your A/F ratio?

 

Old AFR 190's (ported), 10.8:1, 236/242 hydraulic roller, 1 3/4" long tubes. With the miniram setup, the previous owner claimed 400RWHP on the dyno (and I believe him). I switched to a carb and ported Air Gap and it went a little faster in 1/4 (on comparable days). With carb, 11.89@115MPH in a 3000'DA was my best. With miniram, 11.66@117MPH at sea level was the best time. Car is right around 3400lbs with me in it.

I think you need more cam (especially lift), full length headers, and maybe some port work on the manifold.

 

Your dyno doesnt sound right if stock LS1's are putting down 260's whp!! Most are 290-310whp if manual and good condition. That right there is 30-40whp missing.

So your motor is likely closer to 360-370's whp which is about what i'd expect even tho the cam lift is small.

 

At 5k rpm it was 13:1 and at 6k it was around 13.5:1

 

Mine is an auto, but still I wonder about that as well. On other dynos up here (5000+ft elevation) a c5 z06 still makes 355 wheel bone stock, which seems correct. I'm just not sure what or who to believe, the motor only has 4800 miles on it!

 

the downfall of living in the mountains

 

There is the big reason for lower numbers.

 

True, i've seen C5 Z06's make closer to 370whp stock but 355-360's wouldnt be too far out the norm. So that seems alittle odd that other cars would dyno so low. I'd take your car to the track and get an idea what it runs mph wise, and correct that to sealevel using the NHRA altitude/DA corrections and see how it compares to other builds.

A 3400lb 330whp thirdgen should go 110-112 mph depending on weather/air conditions at near sealevel altitudes.

 

What kind of torque are you making a lower engine rpms? Between 3000 and 5000 for example.
Do you have a dyno graph printout?

 

One more thing...what torque converter is in it and was it locked up during the run?

 

It is the lockup converter, however it is not locked during the 3rd gear 1:1 pull.
When I get a few minutes I will scan the dyno graphs and everyone can check them out.

 

With 3.70's any guess of what a quarter mile time would be? Mine weighs around 3350lbs.

 

I know if it was a true 330's whp at or nearer to sealevel tracks it would go low 12's if properly stalled/geared. If you have a stock stall or real low stall speed, it wont 60 foot as fast as it should and thus not run as low into the 12's as it could.

I have no idea what it would do at 5500+ feet elevation. probably cut a second off the times? What do stock LS1 to bolt on LS1 cars do up there? They are low mid 12 second cars with some typical bolt ons and in autos with 3.73's and 3000-3600 stalls on average at sealevel tracks. Most bolt on LS1's are 330-350whp depending on trans and are 3500-3650 lbs race weight depending. Being almost 300lbs lighter with same power is gonna be MUCH quicker. 200lbs off my LS1 car was worth 2 mph and 2 tenths 1/4 mile.

Oh and unlocked converters are not gonna show the true hp...its gonna be less due to the slippage. Once locked, it can be 10-30whp more. I know my bolt on L98 was around 12-15whp gained by locking converter. Thing is tho, I didnt gain performance at the track with the converter locked...it ran abit slower and I tried various speeds. Never found a spot where I could lock the converter during the run and lower my ET and raise my MPH. I always went quicker with open converters.

 

Cool, best times on ls cars here are 14.2 auto and 13.9 manual in stock form. That I have heard anyway, I kinda wanna hit a different dyno now. However, with the a/f on I suppose it is what it is. No complaints about how it runs, I pulled hard on an ls3 G8 six speed car. They are heavy, but still felt nice.

 

You got decent parts so the setup should go pretty good in that light weight. IF air fuel is good, then it should run well. Timing looks spot on for a AFR headed car. Dont compare to others times at sealevel since thats a huge difference. Look at what the factory cars are doing at your altitude and compare that to what they do at sealevel and see about how much of a difference in ET you'll find.

If a stock auto LS1 car is 14.0-14.2's, they are 13.3-13.5's where I'm at, around 1200 ft altitude with DA in the 1500-2000 ft range typically. So thats a good 1/2-3/4 sec difference.

 

Last September in Brainerd, my LS1/4L60E car was running 12.0's.

Three weekends ago at Bandimere (my "home" track), it was running 13.0's (typical to decent for the conditions). Best it's ever run up here is 12.82.

That's typical losses at our altitude.

I haven't had it on a dyno, so I have no data for "real" HP. It weighs 3450 lbs going down the track, which with one internet HP calculator puts it at 325 RWHP for the best it's run here, 300-ish for "typical". For what that's worth.

 

Sea level in nj at englishtown raceway park stock Ls1 6 speeds have reached 12.8-13 flat. 13.1-13.3 for the autos. If that helps. I think the elevation is around 5 or lower without looking at it. 249rwhp gets you a 13.6@103, which is what my 2005 stock Pontiac grand prix LS4 did.