Track results - couple of questions

[Joe 1320]

I am surprised Joe has not jumped in on the "no suspension mods" comment. If I remember right Joe accomplished about the same times on a nearly stock LT1. The power is there I just need to learn to get it to the pavement.

ok... since you mentioned it. Pick up some lower contol arms, relocation brackets as a minimum. The stock parts aren't rigid enough to control the rear. Put those on, remove the end links front the front sway bar for the track, air the rear tires down to about 20 psi, pump the front up to 40. If that doesn't give you a 2.0 60' then there is a problem somewhere. I've cut a 1.9 on that basic setup. If you've got the extra dough, an adjustable torque arm is great. Combine that with airlift bags and you'll have a much stronger rear suspension.

Consider getting a T/A specialties or similar rear girdle. It comes with studs, preload studs for the bearing caps and adds more rigidty to the differential. It will add a little insurance against breaking the stock rear. Still not too strong, but it can take a little more abuse than what you think. Mine has lived with more quarter mile passes than Linda Vaughn. Then again, I'm also running a basic bolt on LT-1 with no power adders and an automatic which shocks the driveline a little less than a stick. If you put on drag radials or slicks combined with the suspension mods above, you'll hook outstanding. Just don't try dumping the clutch at high rpm (4000+) on a launch or you can kiss the rear goodbye.

With your times, I can see that the power is there. Now the job is to whittle down the ET with all the various tricks until there is no more left. If you think the MPH is still low, you'll have to look at a few things....clutch is one, reading the scanner to detect any knock, etc...... persistance will pay off.

[N20LT4Bird]

380 rwhp DynoJet cars trap much higher than 110. My 345 rwhp dynojet car trapped 109.98....... and even that is a bit low.

I guess we'll have to wait for Casey to work out all the issues - new clutch and new tach - before you guys will believe it. I'm not sure why though... there are plenty of examples of cars with his mods and the times he SHOULD be running out there.

The trap speed is the best indicator of power, not the dyno. Dynos vary from one to another......even amongst dyno-jets. His 380 rwhp may be 345 rwhp on another dyno......put it on a mustang dyno and he probably makes 320 rwhp. Which one is right? WHo knows?.....the track will tell.

His 60' time has little impact on the trap speed....it is what it is......unless he was letting off before the traps or not revving it like he was on the dyno. Or maybe something changed in the way the engine was running from dyno day to track day? If you do the math (hp = weight * (speed / 234)3), on a 3600 lb car, a 110 mph trap is about 380 HP...so IMOP hes not far off.

[Jay 02 TA ws6]

The trap speed is the best indicator of power, not the dyno. Dynos vary from one to another......even amongst dyno-jets. His 380 rwhp may be 345 rwhp on another dyno......put it on a mustang dyno and he probably makes 320 rwhp. Which one is right? WHo knows?.....the track will tell.

His 60' time has little impact on the trap speed....it is what it is......unless he was letting off before the traps or not revving it like he was on the dyno. Or maybe something changed in the way the engine was running from dyno day to track day? If you do the math (hp = weight * (speed / 234)3), on a 3600 lb car, a 110 mph trap is about 380 HP...so IMOP hes not far off.

345 rwhp on a bone stock LS1 with bolt-ons vs. a cammed LS1 with bolt-ons at 380 rwhp. There is absolutely no chance his engine is making the same power as mine. I'm stock internally, and he isn't... that just doesn't make sense.

He was short shifting because he knew the tach was slow, and he had clutch slippage on top of that... that's exactly what he's saying... something isn't quite right.

All you need to do is go look up some setups for members cars on ls1tech and find ones with similar mods and power numbers to Casey... you will see that most are trapping 114-115. These are real experiences of drivers with real mods - they are not numbers pulled from a generalized equation (which LS1s have atendancy to deviate from the median at top end anyways).

Casey is exactly right that he should be expecting more out of his car... I can't believe that the LS1 motor is this badly under-estimated by some members on this board sometimes. Casey's asking for help, and you guys seem to be too reluctant to admit that he is right to think something is wrong. A 110 mph trap is barely an improvement over bone stock.

[raroZ28]

Casey, I invisioned mid 12's for you after that cam. Something is definitely F'd. Bad tune? Those 60' times are terrible. You need to cut those down half a second. Theres your 12.5 right there.

[fastTa]

345 rwhp on a bone stock LS1 with bolt-ons vs. a cammed LS1 with bolt-ons at 380 rwhp. There is absolutely no chance his engine is making the same power as mine. I'm stock internally, and he isn't... that just doesn't make sense.

He was short shifting because he knew the tach was slow, and he had clutch slippage on top of that... that's exactly what he's saying... something isn't quite right.

All you need to do is go look up some setups for members cars on ls1tech and find ones with similar mods and power numbers to Casey... you will see that most are trapping 114-115. These are real experiences of drivers with real mods - they are not numbers pulled from a generalized equation (which LS1s have atendancy to deviate from the median at top end anyways).

Casey is exactly right that he should be expecting more out of his car... I can't believe that the LS1 motor is this badly under-estimated by some members on this board sometimes. Casey's asking for help, and you guys seem to be too reluctant to admit that he is right to think something is wrong. A 110 mph trap is barely an improvement over bone stock.

Jay is completely right. LS1's do not adhere to the "conventional" math in roughly estimating someones power or ET potential. Most 18° or less heads don't follow that basic math. LS1's have a 15° head and that makes them even more defiant. For people to talk of a 22% drivetrain loss and 312 RWHP on a lightly cammed LS1 with a T56 and 10 bolt makes me really wonder.

Like Jay said, I think alot of people don't neccesarily have a grasp on the potential of an LS1. Many people on ls1tech.com are putting down very similar dyno numbers as each other with the same exact mods as each other on Dynojet's. This tells you that Dynojet's are "normally" very accurate and consistant. It has been proven time and time again by comparing power numbers amongst cars with similar mods. Sure the track is where it is at, but a dyno is a very good measurement to look at the power you are actually getting to the ground. In a drag race that is all that matters...the power that makes it to your tire.

With Casey's power and mods, he should be trapping easily 115-116+. There are lots of guys trapping over 117 over on ls1tech with very similar power to Casey's.

As soon as Casey gets a feel for his new setup and gets it to hook, I guarantee he will be posting some much better times.

[casey02ws6]

Thanks for all of the replies guys. It seems that most of what I am thinking is in line with you guys. As far as dyno numbers - I agree that the track is more important and dyno numbers can be inflated. But for the "non-believers" it should be noted that I dyno'd this car on the SAME dyno 10 mnths ago. It dyno'd at 330.9 RWhP with lid and cat-back. I trapped at 108-109 with that set up. I am using the dyno as a tuning tool not for bragging rights. The car dyno'd 53 RWHP stronger on the same dyno - I should expect higher trap speeds and lower ETs. I want to get better because clearly I am the weak link in this equation. That is why I posted - there are many more experienced drivers on here and I value their advice. How about this - another member dyno'd on this dyno at 377 RWHP. He ran a 12.3 at 115. He is an auto and has a 3500 stall - my numbers should be similar - and they will be when I get a little more experience. I have now run the car down the 1/4 a grand total of 18 times - this is the only car I have ever taken to the track. I know it takes practice - - thankfully practice is fun in this case.

[casey02ws6]

2 more things - I had it computer tuned 4 days prior to the run - everything was in line. I had the computer tuner run 2 times with me at the track with his laptop - the motor is performing flawlessly - 0 knock sensed and 28 degrees of timing. A/F is spot on. So now I know that the problems lie elsewhere. I think the biggest problem is me short shifting it - note I trapped at 109 and Bill trapped my car at 112 - just holding out a little longer before shifting helped. I also am fairly certain the clutch is slipping at the motor's peak. It is a ZO6 clutch (all 2002s had them) which is made for a 405 crank HP car - it is not made for the power mine is now putting out. I am excited about improving - stay tuned!

[Dave Vince]

N20LT4

N20Lt4BIRD is right on with statement on 60' times. This car should run mid to low 12s even with 110 mph trap speeds, but to do this you have to have a good launch, which means no street tires. My own LT1 had lousy 60' times of 2.2. The only way I could launch was by a slow roll of the throttle. When the drag radials arrive I may lunch the rear, but this is an automatic car with a new converter, that is very tight. I also added one of those rear cover braces which might help. Why did they put such a junk rear in these cars?? I am not denying that he sould be a little faster in the 1/4, but he should be alot quicker even with the power he is making. I stick by my calculated HP as it has always been reliable indicator for me. I only used the RW dyno once for my drag car, when I had the small motor in it. It showed 526rwhp on motor, and 624 with a pair of 78 jets in our plenum nitrous system. For some reason I did not try the fogger that day, which had a 400 shot in it. The car ran 122mph 1/8th mile on motor & 132 with the small juice setup. On the fogger it ran 142. The car at the time weighed 2345lbs with driver. These speeds indicated about 660 hp at the flywheel, and what should have been 462hp at the rear wheels. 30 % parasitic loss with a high stall converter, 5500, and a glide is not unrealistic, as I have seen tests that back this up.