Solo2GS

I still have the factory 3.45 rear end.

I'd like to look into getting a different rear end, but don't want to drastically affect the top speed of 2nd gear as I am an Auto-xer. No 4:11 drag race stuff...

What experiences can others share with what they have. I am interested in the acceleration different and the top MPH in each gear compared to the factory rear.

MarkBychowski

I have a 3.73 in my LT4. I changed to it mostly because of the aluminum flywheel to help drivability at lower speeds. Also helps to make 6th more usable since my car is dual-purpose.

For sharper corners I'm still in 2nd, just wind the motor out a bit more (which works well with an LT4). I don't autocross, but since the turns are generally pretty tight, it may actually help you since you'll be a little more into the powerband.

I put together a spreadsheet that has shift points for each gear and speed for all three rear ratios. I'll e-mail it to you. You can play with the shift points and see what affect the different ratios will have on top speed in gear.


-Mark

MarkBychowski

Just realized the e-mail and PM options here don't allow attachments. PM me your e-mail address and I'll send you the file if you're interested.

69autoXr

To stay in BSP (which I think you mentioned in your post about 335's) you have to stick with the factory option gear selection. Otherwise you're into SM2, which maybe isn't an issue for you.

In any case,

mph=(engine rpm * tire dia")/(trans * axle * 336)