[Culpepper]

Current car is 2827lb (with me) turbo 2.3 mustang and been 1.47 60' [email protected] On a more clean pass at less boost I trapped 103 in 3rd which was about 7200ish rpm.

Trans was a doug nash with:
1st: 3.25
2nd: 2.06
3rd: 1.53
4th: 1.24
5th: 1.00

3.73 rear gear and tire was a 28x11.50 Et Street

Trans is apart now and when its back together it will have
1st: 3.25
2nd: 2.06
3rd: 1.53
4th: 1.16
5th: 1.00

I'm wondering about putting enough gear in that I run the 1/8th in 4th instead of 3rd. Ive got 4.56s sitting here and if I go to those with the different 4th I'd be able to trap about 112 in 4th at the same rpm. It def wont trap that fast so I'd prob be going through the lights closer to 6700. I think I can trap 135ish in the 1/4. That would put 5th gear rpm near 8k.

So... after all that, would it be better to run 1/8 in 3rd, 1/4 in 4th or 1/8 in 4th 1/4 in 5th?

Although a little squeamish i think I'm ok to turn that rpm but what all goes into picking a target 1/4mi trap rpm?

 

[3pedals]

I set mine up to run as close to peak rpm at the 1/4 finish line as possible in 1:1 gear. Then just let the rest fall wherever it falls. I realize we can change the individual ratios in the Nash trans, but I would not put a 1.16 4th in your trans, the gear split is too large between 3-4 with 1.16. Leave it at 1.24.
If you need more gear on the starting line, just change the input gear set and the whole ratio set changes equally, along with getting a deeper first.

 

[Culpepper]

I almost dont have a choice on the 4th gear. Thats about the only part I cant help much right now. I ended up with a completely new 4th gear set for $60. I know the split is a bit much but for now its all I have to put it back together. By calculating gear speeds Id see a drop back to about 5600 on the 3-4 shift which still keeps me in the power.

Ive really been thinking about doing a faceplated DN after talking to larry.

 

[3pedals]

I have the parts in hand to faceplate 5th right now, I am going to do 1-4 this winter