5 vs. 6 gears for racing 1/4 mile

[bigbird]

I have a friend with a truck that we are getting setup to take to the track. Question is do you guys with 6 speed autos let it shift into 6 th or let it rev in 5th? Truck is an LBZ with fully built motor, GT4202, dual fuelers, stage 2 heads etc, dual lift pumps, etc.

Kelly

 

[Turbotug]

With the setup in my truck I'm crossing the line right at 3k in fifth. IMO, sixth would be a waste..

 

[sweetdiesel]

Could also depend on tire size

 

[Turbo Buick 6]

I would try both and compare time slips It prob wont help much using sixth unless you are starting to run out of the power band in 5th and you are going fast enough to stay in 6th for a little bit befor you cross the traps. Doesn't make much sence to shift into sixth if your only going to spend 1 sec in it. But maybe the MPH is high enough to warent using sixth....iduno

 

[Mike L.]

Try it both ways. No two trucks are alike.

 

[LBZrcks]

I usually keep it in 5th. once it hits 6th it's already almost over

 

[RPM Motorsports]

Not sure of the ratio diff between 5 & 6 speed allisons, but when I use 1st on my truck the ET was 12.296 @ 109.14 and 1st delete (with T/H) was 12.236 @ 108.68. Not much of a diff. if you ask me.

 

[Turbotug]

Not sure of the ratio diff between 5 & 6 speed allisons, but when I use 1st on my truck the ET was 12.296 @ 109.14 and 1st delete (with T/H) was 12.236 @ 108.68. Not much of a diff. if you ask me.

If I gained that much I'd have a 12 second time slip instead of a hand full O' 13.0xx.

 

[Turbo Buick 6]

Not sure of the ratio diff between 5 & 6 speed allisons, but when I use 1st on my truck the ET was 12.296 @ 109.14 and 1st delete (with T/H) was 12.236 @ 108.68. Not much of a diff. if you ask me.

there really is no diff, just an extra OD with the six speed

 

[whitetrash21]

i thought 5th was a little "deeper" on the 6 spd trans than 5th on the 5 spds

ie, 5th gear ratio on my lb7 falls between 5 and 6 on the 6 spd allisons.... am i a little off here??

 

[JoshH]

i thought 5th was a little "deeper" on the 6 spd trans than 5th on the 5 spds

ie, 5th gear ratio on my lb7 falls between 5 and 6 on the 6 spd allisons.... am i a little off here??

1st through 5th are the same ratios in the 5 and 6 speeds. The 6 speeds just have an extra overdrive gear of 0.61 I believe.

 

[whitetrash21]

1st through 5th are the same ratios in the 5 and 6 speeds. The 6 speeds just have an extra overdrive gear of 0.61 I believe.

ok. thanks. too much bongwater inhaled here, i guess :rofl: seeing and hearin things

 

[Turbo Buick 6]

six speed
1st 3.10
2nd 1.81
3rd 1.41
4th 1.00
5th 0.71
6th 0.62

five speed
1st 3.10
2nd 1.81
3rd 1.41
4th 1.00
5th 0.71

 

[Turbo Buick 6]

6 Speed Version Allison 10005 Speed Allison 2000 123456R3.101.811.411.000.710.614.4912345R3.511.901.441.000.745.09

WTF? Henry:rofl:

 

[ripmf666]

not posting right lol

 

[LBZ]

not posting right lol

Speaking of bong water :rofl:

 

[whitetrash21]

:rofl: lol