Ight I have 3.42's and a 2800 stall along with a cam and other supporting mods. Went to the track yesterday and got new bests but for some reason I think it might be shifting early. Peak power is at 6400 rpms. Right now the kickdown up/down shift points are set at 1-2 38mph 2-3 66mph 3-4 126.

Seeing this and then lookin at the mph vs rpm calculator 38mph is 5200rpms, 66mph is 4800rpms and 3-4 is 5650ish.

That looks to me likes its shifting way early. Is this right or am I missing something? Any help or info you can give me would be greatly welcomed.

Joe

 

What is your upshift rpm set at?

 

Is that in the same table as the other three numbers I stated? I guess I really need to know is, am I shifting at 6400 1-2. And I think I should shift around 6200 2-3.

Joe

 

this is the formula for scaling the shift tables. its (old gear ratio / new gear ratio= number to scale by.

ex. 3.23 / 3.42 = .94444444

if you have tuner cat all you do is hightlight the whole table and right click then click on scale and put .944444 and hit ok. and it will change the shift points.

what was you origanal gears 2.73 or 3.23.

 

It was a 3.23 car. What table do I do that in? And will that be sufficent for a none stock car? And does it matter then I went from 3.73's back down to 3.42's?

Joe

 

So if the old gears were 3.73's and the new ones are 3.42's I go

3.73/3.42 = 1.090643

Is this right?

Joe

 

Ttt

 

I was just about to post the same thing. Mine read 1>2 39mph (5000rpms); 2>3 81mph (5550rpms); 3>4 139mph (5900rpms).
3-4 shift seems right, but right now my car shifts @ 5800 in every gear. This is off my stock tune. My friend's Z28 also reads the same.

To change shift points should I just add x mph to get the desired shift point w/o using this rpm/mph calculator: http://www.f-body.org/gears/

 

I have 34, 70, and 120 in mine. I'm running basic bolt-ons with the stock stall and 3.42s

 

I have a cam, a 2800 stall, 3.42 gears and nitrous. Anyone suggest a good number to get me to where I wanna shift 1-2 6400 2-3 6200? Car will trap over 120 in third on the gas

Joe

 

Try: 45, 85, and 138 and see what you get.