Running out of gear with 4.11’s. 3.90’s or 3.73’s?
10-29-2009, 12:55 PM
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Running out of gear with 4.11’s. 3.90’s or 3.73’s? Here is the setup.
02 Z28, 4L60E conversion, 3400 stall, bolt-on’s, MS4, 150 shot, 9in w/ 4.11’s, full suspension, 28in tire, tuned myself with HPTuners.
Ran the car last night for the first time with the Auto, MS4 150shot. Car went 11.1x at 121 w/ 1.59 60’ completely running out of gear. I have the tranny shifting at 6800 and limiter set to 7000, and the car would bounce off limiter 5-6 times before going through the traps (in attempts to break 10’s). All the calculators I would use say that this gearing is good for over 130mph.
My question is what is everyone else RPM vs Speed in 3rd ( or 4th for the 6 speed guys)? and with what gears? I am trying to decide to go 3.90’s or be safe and go with 3.73’s.
Thanks in advance,
Kev D
02 Z28, 4L60E conversion, 3400 stall, bolt-on’s, MS4, 150 shot, 9in w/ 4.11’s, full suspension, 28in tire, tuned myself with HPTuners.
Ran the car last night for the first time with the Auto, MS4 150shot. Car went 11.1x at 121 w/ 1.59 60’ completely running out of gear. I have the tranny shifting at 6800 and limiter set to 7000, and the car would bounce off limiter 5-6 times before going through the traps (in attempts to break 10’s). All the calculators I would use say that this gearing is good for over 130mph.
My question is what is everyone else RPM vs Speed in 3rd ( or 4th for the 6 speed guys)? and with what gears? I am trying to decide to go 3.90’s or be safe and go with 3.73’s.
Thanks in advance,
Kev D
10-30-2009, 06:42 AM
#2
Well with 28's on the back I would say you should be able to hit 130 no problem at 6800. Issue could be with tuning, you have your tune adjusted correctly for the rear end ratio and for running the extra diameter tires? Maybe you are blowing through the converter up top?
Give us a breakdown of your entire slip.
Also dumb question, but are you sure you're running 4.11's? Maybe theres some 4.30's in there. Either way you shouldn't be tapping the limiter at 121.
I run 3.90's now, but havent gotten a good pass on them. It's a decent ratio a little aggresive for a street strip car, but not bad. Before you start swapping gears though, I'd find out whats up with your car.
Give us a breakdown of your entire slip.
Also dumb question, but are you sure you're running 4.11's? Maybe theres some 4.30's in there. Either way you shouldn't be tapping the limiter at 121.
I run 3.90's now, but havent gotten a good pass on them. It's a decent ratio a little aggresive for a street strip car, but not bad. Before you start swapping gears though, I'd find out whats up with your car.
11-02-2009, 01:01 PM
#4
i have the same problem but i have tried several things. my car actually went real lean causing me to run out of gear what i was told, put a dedicated fuel system in there and bam no more problems i think i am blowing thru the converter in 3rd gear in my th400 but i shift early now instead of 6800 i shift at 6000 and no more problems
11-02-2009, 03:52 PM
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i have the same problem but i have tried several things. my car actually went real lean causing me to run out of gear what i was told, put a dedicated fuel system in there and bam no more problems i think i am blowing thru the converter in 3rd gear in my th400 but i shift early now instead of 6800 i shift at 6000 and no more problems
that makes as much sense as dog **** no offense.
a car going lean has absolutely nothing to do with it running out of gear.
the only thing I could see is it blowing thru the converter.
I have the same 325/50/15's on my car 4th gear (6 speed) tops out at 135 bouncing the limiter @ 6800rpm (GPS verified)
Chad
