Shifting question. . .
09-20-2007, 01:12 AM
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Shifting question. . . Normally I would be in 4th gear and about 5200-5500 rpm as I cross the line (1/4 mile), but tonight I was actually in 3rd and JUST hitting the shiftpoint (rode it to the limiter a couple times) vice going to 4th.
The only thing I've changed is a little stouter launch RPM (2500-3000 vice 2K) and the torque arm. My 60' has dropped about 2/10s but the speed has dropped too (about low 109's verses a few low 110's).
Running stock rear end (3.4something) and for the last 3 visits to the track, 26" ET Drags (damn I want the ET Streets now)
Once the shift is complete, I'm on the floor w/the gas.
Ideas or thoughts why the gear seems longer? Clutch going out or something?
Thank you!
Duff-12 Second member
The only thing I've changed is a little stouter launch RPM (2500-3000 vice 2K) and the torque arm. My 60' has dropped about 2/10s but the speed has dropped too (about low 109's verses a few low 110's).
Running stock rear end (3.4something) and for the last 3 visits to the track, 26" ET Drags (damn I want the ET Streets now)
Once the shift is complete, I'm on the floor w/the gas.
Ideas or thoughts why the gear seems longer? Clutch going out or something?
Thank you!
Duff-12 Second member
09-20-2007, 01:22 AM
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I weighed in at 5 pounds lighter than my last visit and 30 pounds lighter than my visit before... (both visits was high into the 4th gear) Torque arm and weight make that difference? But I like that idea
09-20-2007, 01:33 AM
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Originally Posted by JMBLOWNWS6
And what was your 60FT comapred to last time?
My visit to the track in June netted me an average 2.4348 60' (4 crappy passes)
My visit in July got me an average 2.2432 60' with 12 passes
My visit in August got me an average 2.1820 60' with 2 passes
Tonight with 8 passes, I averaged 2.0486 60' with a best of 1.9428.
June-August were on stock T/A. Tonight was on my Random Tech T/A (roughly set to -2 degrees)
D
09-20-2007, 01:34 AM
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Originally Posted by Duffster
Good question!
My visit to the track in June netted me an average 2.4348 60' (4 crappy passes)
My visit in July got me an average 2.2432 60' with 12 passes
My visit in August got me an average 2.1820 60' with 2 passes
Tonight with 8 passes, I averaged 2.0486 60' with a best of 1.9428.
June-August were on stock T/A. Tonight was on my Random Tech T/A (roughly set to -2 degrees)
D
My visit to the track in June netted me an average 2.4348 60' (4 crappy passes)
My visit in July got me an average 2.2432 60' with 12 passes
My visit in August got me an average 2.1820 60' with 2 passes
Tonight with 8 passes, I averaged 2.0486 60' with a best of 1.9428.
June-August were on stock T/A. Tonight was on my Random Tech T/A (roughly set to -2 degrees)
D
Now put a cam and tune it! 
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09-20-2007, 01:49 AM
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Why wouldn't the same speed need the same engine RPM and gear though?
Not being argumentative. . .just don't understand.
If you need 6K RPM in 4th gear to do 120 last year, with the same engine/tranny/rear, why would you get away with 5K RPM in 3rd gear at 120?
Not being argumentative. . .just don't understand.
If you need 6K RPM in 4th gear to do 120 last year, with the same engine/tranny/rear, why would you get away with 5K RPM in 3rd gear at 120?
09-20-2007, 01:56 AM
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I understand. But the 60ft is the most important thing. Here is an article I read just the other day when I was bored. Im sure it will help you understand. The same thing happened to me when I put a built rear in my car. I have the same gear set in the 10 bolt (4:10's) that I did in my 9' (4:10's). But I noticed that when my car 60'ed better I was only using 3 gears instead of 4 passing thru the traps right at 6650 rpm's.
60 ft
60 ft
09-20-2007, 02:04 AM
#10
Everywhere I go Duff I hear about your 12second passes. And personally I'm getting tired of it. haha jk good job you got your money's worth on that torque arm. Well maybe next time my pig of a car can make 12's then we should have some interesting runs. I'll call you out when the time comes Duff I'm just broke right now 
. I need to start selling crack or something unless I can find some cheap tires.
. I need to start selling crack or something unless I can find some cheap tires.
09-20-2007, 10:24 PM
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JM, that article doesn't discuss gear ratios or shifting at all. Just that the better your 60', the better your time. I still don't get the shifting issue and not needing to any more.
09-20-2007, 10:33 PM
#12
dddd INteresting post. My car passes traps @ top of 3rd bouncing off limiter. I know my car has a lot more in it. It really doesn't make a difference if I'm launching at 2200 or 3500, the car still traps @ top of 3rd. (only difference being my quarter mile time improves).