What do you think about this transmission ratio?

Shift518 Automotive
1

http://i278.photobucket.com/albums/kk94/kkkustom2/gears.jpg
gears.jpg870×583

My car spools at 4K atm.

The top one is what I was running in my Jetta until I stripped out 4th gear last week. The middle one is a dead stock 02J box. The bottom one is the new box I am going to build. It will increase my 1st, 2nd and 3rd to help with wheel spin and keep me in the power band for my turbo much longer. With that box and 22" slicks it will put me over the finish line right at the top of 3rd gear around 118 mph, which is where I think my car will trap as it sits now.

On street tires, a 225-40R18 is around a 25" dia. For roll racing 40mph puts me right at 4krpm in 2nd gear, which is perfect. Also 65mph in 4th is 2850RPM. Which if you look at the stock 02J box, 5th at 65mph is actuall a little high rpm. so mileage will be around the same, even without a 5th gear.

I am running a ATP 5th gear cuff, which eliminates 5th gear and replaces it with 2 bearing supports for the shafts and adds 2+ inches of solid billet to the transmission case to get rid of the case flex that propably killed my transmission last friday.

I really think this is a good all around selection of ratios. What do you think?

2

ask mk430r he would put ya right where ya need to be

3

you have to take into consideration also, when you shift to the next gear, where in the rpm range will you recover? is it going to fall far out of boost? land in boost?

also 225-45-17 is a 25" tire. 225-40-18 is slightly larger than 25"

for reference my EHA code O2J (3.648:1 FD) did about 80 in 2nd at 7500rpm. shifting to 3rd would slightly fall off boost. but being a DBB turbo, transiant response is great and it recovered quickly. with my FML code O2M, i never fell out of boost between gears. shift at 7500ish and the wastegate would reopen as soon as the clutch engaged again. the gear spacing is great on the O2M with a BT and higher than stock limiter.

if O2Junk is where you plan to stay, find out where each gear is going to put you when you shift. sure would suck to build a mystery box and each time you change gears the turbo falls off.

4

22" tire
shift pt 4400 5000 5850 6100

25" tire
shift pt 4100 4700 5500 5700

5

well above full spool. I think I am good to go. Even with a clutch shift, a WOT shift will keep me in boost much better too.