Sirenty

My transmission is getting torn down because something wore out at my last track day, so it’s time to play on the “since we’re in there” slippery slope. Something I’ve wanted to do since getting the car is shorter gears. The stock gears are poor for my local track, poor for autocross, and a little annoying on the street. There is just too much drop between the first four gears. I’ve read most of the shorter gear threads that have spanned the past 20 years, but don’t really have answers to my questions. Lots of talks of ratios, and lots of images and posts from Bill, but I couldn’t really find something that related to what I was looking for.

The main thing is I’m not going to track the car anymore, or rarely, so it’s going to be mostly curvy roads and autocross, with some touring. I want to shorten 2-4 since I still take the highway sometimes, and don’t want to be doing 4K at 80mph in fifth. A slight shortening of fifth is okay.

After perusing all the threads, I think ratios like the below would work as they were marked good for dual use in another thread; however, I didn’t shorten fifth as much. I don’t know if .92 is actually a valid gear ratio. I just chose something between stock and the other thread.

1st gear 3.154 (stock)
2nd gear 2 or 2.25
3rd gear 1.45
4th gear 1.13
5th gear 0.92 or stock

Anyone have thoughts on these or have experience with good dual use ratios? If I shorten fourth and don’t touch fifth, what would that be like to drive? I see a lot of comments that gears rare the best mod some people have done, but is doing relatively minor ratio changes like this even worth it?

spartansix

I can't give you as expert advice as many on this forum about particular ratios, but having driven cars with shorter 2-3-4 and stock 1st and 5th, I think this is a great setup for the street.
I've found this a helpful guide for figuring out ratio options:
https://www.blocklayer.com/rpm-gear.aspx

Foxman

I can understand wanting shorter gears for the track, but the stock second gear is perfect for Autocross IMHO. It takes you just up to the rev limiter. Are you planning on shifting into 3rd gear at AX? Do you have an open diff? A Guards LSD is worth a look.

Peteinjp

I thought stock 1st is 3.50. Personally I think fifth gear is just right for highways. also it’s nice and quiet. I did a six speed regear and kept the top gear the same as 5th on the 5 speed box. After all was said and done I found the 5 speed ratios to be pretty good and if I were to choose a stock geared transmission I’d take the 5 speed over the 6.

That said if I were to change the 5 speed I’d change 1-4 and keep 5th a stock (quiet) gearset. I’d consider bringing 1st up to 3.15 and tightening up 2/3/4 unless I lived in a city with lots of starting off on hills. I have not driven
a 3.154 1st but it was stock on G50/04.

http://www.gboxweb.com/g50specs.html

Of course driving preference also plays in. I’m not concerned with off the line starts so I higher first would not be a problem for me.

Sirenty

Our courses are pretty tight, so it’s more about the really tight corners where the revs drop, like far enough to almost need to downshift to first. I also don’t think any have had enough space to come close to winding out second. We need bigger lots...

Thanks. There is a local 993 box set up exactly how I want, but the owner isn’t sure if he wants to use it or sell it, and I couldn’t wait any longer. Really wish I could’ve gotten that.

You may be right on the first ratio. I just copied that from another post. I’m fine with first being stock.