Going to the drag strip later today. Shift question...
Thread Starter
Joined: Feb 2003
Posts: 2,145
Likes: 133
From: East Chatham, New York
Going to the drag strip later today. Shift question... Is there any advantage to short shifting 1st gear on a Turbo car?
My setup is all done by 6,200 rpm so I was wondering if there's any concensus on doing the 1st - 2nd shift at say 5,600rpm instead of winding her all the way to 6,200? In theory, this seems like it would keep the turbo under load for a greater length of the 1/4 mile. Am I off base here?
My setup is all done by 6,200 rpm so I was wondering if there's any concensus on doing the 1st - 2nd shift at say 5,600rpm instead of winding her all the way to 6,200? In theory, this seems like it would keep the turbo under load for a greater length of the 1/4 mile. Am I off base here?
Experiment and let the masses know, the theory is good but a few things come into consideration.
First will it make you have to shift and extra time by the end of the quarter?
Second what gear ratio and weight/load are you running and will shifting this soon make you come into the next gear below optimal RPM range.
Third what does your turbo spool at and what RPM range is most beneficial torque to horse power ratio.
There are more, but this should be some food for thought.
First will it make you have to shift and extra time by the end of the quarter?
Second what gear ratio and weight/load are you running and will shifting this soon make you come into the next gear below optimal RPM range.
Third what does your turbo spool at and what RPM range is most beneficial torque to horse power ratio.
There are more, but this should be some food for thought.
Is there any advantage to short shifting 1st gear on a Turbo car?
My setup is all done by 6,200 rpm so I was wondering if there's any concensus on doing the 1st - 2nd shift at say 5,600rpm instead of winding her all the way to 6,200? In theory, this seems like it would keep the turbo under load for a greater length of the 1/4 mile. Am I off base here?
My setup is all done by 6,200 rpm so I was wondering if there's any concensus on doing the 1st - 2nd shift at say 5,600rpm instead of winding her all the way to 6,200? In theory, this seems like it would keep the turbo under load for a greater length of the 1/4 mile. Am I off base here?
I have been told by experts to keep the car in the peak tq range as long as possible....which is lower than redline on our turbo cars. Here is what I do:
1-2 shift light comes on at 6400 (trans probably shifts at ~6700 by the time I pull the lever). I try to shift as soon as I see it light up.
2-3 shift I always grab right on time as the RPMS are not climbing as fast as 1st gear. SOmetimes I shift a tad early just to take advantage of the full 1:1 gear ratio of 3rd.
1-2 shift light comes on at 6400 (trans probably shifts at ~6700 by the time I pull the lever). I try to shift as soon as I see it light up.
2-3 shift I always grab right on time as the RPMS are not climbing as fast as 1st gear. SOmetimes I shift a tad early just to take advantage of the full 1:1 gear ratio of 3rd.
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Thread Starter
Joined: Feb 2003
Posts: 2,145
Likes: 133
From: East Chatham, New York
Well... Only got to make the one pass tonight. The Clutch got kind of stuck after the burnout when I was going to do the second pass. It was weird. THe pedal felt fine but the clutch wouldn't disengage so I could put it in gear. The burnout went fine and the car hopped right up to the staging lights. I clutched it so I could tickle the car into the staging beams but it was acting as if I'd never pressed the clutch pedal. I had to be pushed back off the track. Once there, with the motor off, I put it in reverse and cranked it. It bumped a couple of times, then caught and I backed it into the pits. After that, the clutch made a few 'inappropriate' sounds like squeals but returned to functional status. WTH? Anyway, on the one pass...
I'd ran out of time and didn't get to unbolt the front sway bar. I also didn't get to swap out the stock LCA for my BMR. This caused the 245x50x16 Nitto DR's to do some wheel hopping. I *did* the short 1st to 2nd shift and 2nd gear felt flat wonderful, then I shifted to 3rd and 4th normally but the acceleration felt a bit flat so I let off before the end of the track.
Result:
Reaction: 0.135
60 foot: 2.017
330 ft mark: 5.417
660: 7.941
MPH1: 108.52
1000 ft. Mark: 10.041
1320 ft mark: 11.876
MPH2: 119.86
The time slip is so grainy it's hard to see and I'll post it in a minute. The Cobra beside me thought he was going to hand me my head. I think once I got into 2nd gear, he had a rethink moment. Looks like he let off and coasted...
Here's the pass. Please forgive my wife's shaky camera work (Think Blair Witch), lol..
I'd ran out of time and didn't get to unbolt the front sway bar. I also didn't get to swap out the stock LCA for my BMR. This caused the 245x50x16 Nitto DR's to do some wheel hopping. I *did* the short 1st to 2nd shift and 2nd gear felt flat wonderful, then I shifted to 3rd and 4th normally but the acceleration felt a bit flat so I let off before the end of the track.
Result:
Reaction: 0.135
60 foot: 2.017
330 ft mark: 5.417
660: 7.941
MPH1: 108.52
1000 ft. Mark: 10.041
1320 ft mark: 11.876
MPH2: 119.86
The time slip is so grainy it's hard to see and I'll post it in a minute. The Cobra beside me thought he was going to hand me my head. I think once I got into 2nd gear, he had a rethink moment. Looks like he let off and coasted...
Here's the pass. Please forgive my wife's shaky camera work (Think Blair Witch), lol..
Last edited by mightyquickz28; Sep 21, 2009 at 10:00 PM.
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Verdad Gallardo Thread Starter
Joined: Feb 2003
Posts: 2,145
Likes: 133
From: East Chatham, New York
Peak torque on the dyno occurred at 4,650 RPM, Peak HP was at 6,000RPM.
I have been told by experts to keep the car in the peak tq range as long as possible....which is lower than redline on our turbo cars. Here is what I do:
1-2 shift light comes on at 6400 (trans probably shifts at ~6700 by the time I pull the lever). I try to shift as soon as I see it light up.
2-3 shift I always grab right on time as the RPMS are not climbing as fast as 1st gear. SOmetimes I shift a tad early just to take advantage of the full 1:1 gear ratio of 3rd.
1-2 shift light comes on at 6400 (trans probably shifts at ~6700 by the time I pull the lever). I try to shift as soon as I see it light up.
2-3 shift I always grab right on time as the RPMS are not climbing as fast as 1st gear. SOmetimes I shift a tad early just to take advantage of the full 1:1 gear ratio of 3rd.
Thread Starter
Joined: Feb 2003
Posts: 2,145
Likes: 133
From: East Chatham, New York
Well... Only got to make the one pass tonight. The Clutch got kind of stuck after the burnout when I was going to do the second pass. It was weird. THe pedal felt fine but the clutch wouldn't disengage so I could put it in gear. The burnout went fine and the car hopped right up to the staging lights. I clutched it so I could tickle the car into the staging beams but it was acting as if I'd never pressed the clutch pedal. I had to be pushed back off the track. Once there, with the motor off, I put it in reverse and cranked it. It bumped a couple of times, then caught and I backed it into the pits. After that, the clutch made a few 'inappropriate' sounds like squeals but returned to functional status. WTH? Anyway, on the one pass...
I'd ran out of time and didn't get to unbolt the front sway bar. I also didn't get to swap out the stock LCA for my BMR. This caused the 245x50x16 Nitto DR's to do some wheel hopping. I *did* the short 1st to 2nd shift and 2nd gear felt flat wonderful, then I shifted to 3rd and 4th normally but the acceleration felt a bit flat so I let off before the end of the track.
Result:
Reaction: 0.135
60 foot: 2.017
330 ft mark: 5.417
660: 7.941
MPH1: 108.52
1000 ft. Mark: 10.041
1320 ft mark: 11.876
MPH2: 119.86
The time slip is so grainy it's hard to see and I'll post it in a minute. The Cobra beside me thought he was going to hand me my head. I think once I got into 2nd gear, he had a rethink moment. Looks like he let off and coasted...
Here's the pass. Please forgive my wife's shaky camera work (Think Blair Witch), lol..
I'd ran out of time and didn't get to unbolt the front sway bar. I also didn't get to swap out the stock LCA for my BMR. This caused the 245x50x16 Nitto DR's to do some wheel hopping. I *did* the short 1st to 2nd shift and 2nd gear felt flat wonderful, then I shifted to 3rd and 4th normally but the acceleration felt a bit flat so I let off before the end of the track.
Result:
Reaction: 0.135
60 foot: 2.017
330 ft mark: 5.417
660: 7.941
MPH1: 108.52
1000 ft. Mark: 10.041
1320 ft mark: 11.876
MPH2: 119.86
The time slip is so grainy it's hard to see and I'll post it in a minute. The Cobra beside me thought he was going to hand me my head. I think once I got into 2nd gear, he had a rethink moment. Looks like he let off and coasted...
Here's the pass. Please forgive my wife's shaky camera work (Think Blair Witch), lol..
What clutch are you running?
Thread Starter
Joined: Feb 2003
Posts: 2,145
Likes: 133
From: East Chatham, New York
Like i said in the other thread, most manual cars gain 28-30mph in the 2nd half, so your 108mph 1/8th shows some high 130's potential as is. that smoke that came out once you hit 3rd gear isn't a good sign though.