i went to the track friday with my new cam setup, went from JBP stage 2 cams to the secret cams with a 55 shot. i had high hopes for the new setup, and it felt faster in the lower rpm.
i went from 15.990@84.70mph, with a 2.283 60' on the old cams to a 16.336@82.59mph 2.326 60' with the secret cams off the bottle. when i sprayed (first time) at about the 60' mark i got a 15.915@86.99mph 2.382 60'. does anyone have any ideas of what the problem is. my reg is up to date. any help or suggestions very welcome
14.728 @ 92.14 (65 shot)
Im no expert ... but dont you have to get your computer reflashed when you get anything major done to your engine? Or, for that fact, it just may need some tuning. It could be an air to fuel ratio that is hurting you.
dan
i'm going to guess that your 18" rims that weight a decent amount aren't helping you. i don't know what the 18's weigh, but according to the sticky in the wheel section, the 17's weigh in at 24lbs, and i think stock 16's weigh about 20 or so. i would say that is a huge problem. i saw a big decrease in times when i went from my 16's to 17's and the 17's weighed in around 20lbs also.
Goal is to make my N/A Auto faster then a manual without doing engine internals
Yeah, big heavy wheels are murder on the drag strip. I blame mine for keeping me in the 15's with probably over 200 hp.
i know the wheels are a big deal, but all the time i have posted are with the 18"s. what my concern was the JBP cams slowed me down from stockish, then when i switch to the secret cams it slower me down a good half a second. from 15.9 to 16.4
14.728 @ 92.14 (65 shot)
You've got an auto with a stock torque converter don't you? Switch to a TC with about a 2800 rpm stall. This will give you a much better launch and acceleration.
Also, you could have one of the higher ratio (numerically lower) effective drive ratios, this could hurt your times also. Even with the 4sp and the lower geared 1st gear, you could still be just a tad off in your gearing for those cams.
Also, read through
This Thread, at the bottom of page one I gave this guy some tips. If you aren't doing them already, try them.
i do have a high stall torque converter, not sure of the its stall speed. thanks for the informative post.
14.728 @ 92.14 (65 shot)
I just looked up the HT3s and the 17" X 8" weight 24lbs, I can just imagine what the 18"s must weigh. Not that would make a difference, since all the runs were on the same wheels.
To check stall speed-
Have engine running and up to operating temperature.
Put vehicle into drive.
Step on brake as far as you can and hold.
Full throttle, record rpms at which it doesnt climb anymore.
If you dont have a tachometer, must use a scan tool.
And make sure, before you do this, not to have your vehicle pointed at anything. You dont want to crash if your brakes fail to hold you.
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04 Cavalier LS Sport- Red with factory silver stripes.
16.186 @ 86.98mph
how much time between the run with the jbp cams, and the secret cams. I'm just curious because if it was a lot of time, then i'm just curious what else you have done to the car since then like adding things which would make it heavier. also what was the differences in temperature between the 2 runs. what was your tire pressure for the 2 runs. was it the same track that both runs were done on. did you have the same tires, or did you switch to a different set of tires. did you drive it the same, meaning did you launch at the same rpm's for the runs. you are going to need to think of everything that was different between the 2 runs, and i mean everything, and then post them. everything makes a difference. for instance, if you ran one of those times on one track, and then moved to a different area and ran the second time at a completely different track, you will run into track differences, plus elevation differences, etc. so think of the differences, and post them please.
Goal is to make my N/A Auto faster then a manual without doing engine internals
I'm gonna say you need a tune up or some computer mods considering you went through such a big change in your set up, prob. the air/fuel mixture is off
Tinytim12333 wrote:To check stall speed-
Have engine running and up to operating temperature.
Put vehicle into drive.
Step on brake as far as you can and hold.
Full throttle, record rpms at which it doesnt climb anymore.
If you dont have a tachometer, must use a scan tool.
And make sure, before you do this, not to have your vehicle pointed at anything. You dont want to crash if your brakes fail to hold you.
For a more accurate way read
Yank Converters' FAQ, the third question. Flash stall is a more accurate method.
i think its a 3000rpm tc.
the runs were done 2 weeks a apart, tire pressure was at 26-27psi both times. at the same track. the weather with the jbp cams was 75-80F and the track was run most of the day. the secret cam weather about 70F on a cold track, but there was no one with traction problems.
the only change was to ngk tr6 spark plugs for the nitrous.
14.728 @ 92.14 (65 shot)
try tuning it and dynoing it. you might be able to figure it out with that. you might not be hitting the right amount of air/fuel, which would obviously cuase you to lose power, so put it on a dyno, tune it, and go from there.
Goal is to make my N/A Auto faster then a manual without doing engine internals
