Poor Trap Speed
12-10-2008 | 09:33 PM
#21
12-11-2008 | 09:45 AM
#22
I have an Idea OP please copy and paste you time slip exactly as it shows
Originally Posted by STANG KILLA SS 2
im running 12.1 @ 115 w/ 1.95 60' nearly identical with lower trap. my fast trap was 117 on a 12.44 run.
dynoed 432
dynoed 432
12-11-2008 | 10:21 AM
#24
Thread Starter
Teching In
Joined: Sep 2005
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I was going to include the timeslip in the OP, but the girlfriend appears to have thrown it away. IIRC the ET in the 1/8 was 8.0 sec and the trap was ~90mph. I'll go look around again tonight and see if I can dig it up.
12-11-2008 | 12:00 PM
#29
12-11-2008 | 01:45 PM
#31
Hmm.
1) I wasnt shifting like I hated my car, just like I disliked it.
2) Clutch doesnt appear to be slipping. It's an OZ700. Grabs plenty hard.
3) I'm running a 27" tall tire on the street, but that day at the track I had a 25.35" tall tire on the car. I was shifting into 5th as I ran through the traps.
4)I was logging the runs in HP Tuners and I didnt see any knock. The car was tuned on the street by me. I'm running stock timing. The dyno numbers I spoke of before are based on this tune.
I'm clueless at this point. I guess I will just have to take it back to the track and compare again. It's only been once with the current motor.
1) I wasnt shifting like I hated my car, just like I disliked it.
2) Clutch doesnt appear to be slipping. It's an OZ700. Grabs plenty hard.
3) I'm running a 27" tall tire on the street, but that day at the track I had a 25.35" tall tire on the car. I was shifting into 5th as I ran through the traps.
4)I was logging the runs in HP Tuners and I didnt see any knock. The car was tuned on the street by me. I'm running stock timing. The dyno numbers I spoke of before are based on this tune.
I'm clueless at this point. I guess I will just have to take it back to the track and compare again. It's only been once with the current motor.
1. come on man, why go to the track if your not going to beat your car like a red headed step child?
2. I don't think its the clutch either, you would have seen it on you data log, RPM climbing, MPH not.
3. a smaller tire is like having more gear, it would only help build MPH, untill you run uot of gear that is. Shifting 5th will hurt, but not that much. Example: about 4 years ago I had a old *** H/C setup and a 75 wet shot, I would get close to running out of gear doing a 10.70 @128 qwith 4.11s and staing in it untill the 7000rpm limiter. On time I tries shifting 5th instead of holding it in 4th, I ran 10.72 @ 126. So I only lost 2 mph. You are loosing, in my oppinion close to 10+mph. So I don't think shifting 5th is your problem, though I would not shift 5th if I could avoid it.
4. Once again, dyno numbers are great, but they sometimes show a HUGE disconect from track times. I would start with that stock timing table, that cant posibly be benefitial with a not stock combo in the car. Im no tuner, but if you changed your motor, wouldn't you need to change ur timing? Heads are more efficient, different cam, so on so forth. Just cause it made great numbers on the dyno, does not mean it will run well at the track.
My money is still on the tune being off. Unless you were racing on top of a mountain in the middle of the summer.
12-11-2008 | 03:48 PM
#32
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Teching In
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I adjusted the timing on the dyno. Added timing in 2 deg increments. Subtracted in 2 deg increments. I was able to find a few more lb/ft of tq with the extra timing, but not enough to justify the higher timing. It makes perfect sense that I wouldnt need to adjust my timing that much. I have ported stock heads on the car. The chamber hasnt changed that much. Compression hasnt changed that much. GM spent a fair amount of time building those timing tables. I think its running 28 deg total at WOT. Thats seems like a lot of timing for a modern head. If I was running trick flows or AFRs I could see it needing some work though.
btw...I spent a week dialing my VE table in with a wideband. My AFR across the board is dead on.
btw...I spent a week dialing my VE table in with a wideband. My AFR across the board is dead on.
Last edited by Mechryn; 12-11-2008 at 03:53 PM.
12-12-2008 | 04:41 PM
#33
I adjusted the timing on the dyno. Added timing in 2 deg increments. Subtracted in 2 deg increments. I was able to find a few more lb/ft of tq with the extra timing, but not enough to justify the higher timing. It makes perfect sense that I wouldnt need to adjust my timing that much. I have ported stock heads on the car. The chamber hasnt changed that much. Compression hasnt changed that much. GM spent a fair amount of time building those timing tables. I think its running 28 deg total at WOT. Thats seems like a lot of timing for a modern head. If I was running trick flows or AFRs I could see it needing some work though.
btw...I spent a week dialing my VE table in with a wideband. My AFR across the board is dead on.
btw...I spent a week dialing my VE table in with a wideband. My AFR across the board is dead on.
12-12-2008 | 05:21 PM
#34
Ok I'm a noob trying to learn so dont flame, but is it possible to add/subtract timing to where your hp/tq numbers are higher, but in reality the car does not perform as good? Or gets worse times? I know hp/tq is ussually a pretty good indicator of the cars capabilities but isnt that why some cars have 500hp and are in low 11's and theres cars with 400hp that are low 11's as well? Its about getting everything dead on, not just throwing bigger power adders or more time or more fuel.
for example, you can lean out a car and run more timing on the dyno, it will show more power, but at the track with more load on the motor, it will run worse times.
Tuning for the track, and tuning for a dyno number are two vastly different things.
But that may not be the case with this car. Though, who knows. The OP says its not. But either way, somewhere, he is missing something.
