Hey, I'm currently in the process of building a B series transmission since I have been though 3 in the last two years. I have several questions regarding swapping in a built higher ratio gear set and and a lower final drive. Anyone with some actual experience going to this level to come up with my top speed in each gear and comparing it to a stock LS transmission. I just would like to chat over PM for a few minutes to see if this is the direction I want to take. Right now I have a LS trans and I'm looking at buying a M factory 4.01 FD, M factory LSD, an ITR B16 Pro series gearset, upgraded detent springs, and a syncro tech syncro kit. Car is not for drag it's for the track(No autoX). After so much seat time, I cannot stand being between gears anymore. Going from a long geared 5 speed (06 WRX 3.7 FD) at the same event to the short (ik its the longest but its still sucks) LS trans. Ideally I would like to be able to do 0-60 in one shift with a 7,200RPM rev limit. I also am running 215-45-16 tires. Wheels are +35 16x7 2 degrees of camber falkon azenis' tires, lowered almost 3 inches. I am not opposed to getting a taller tire to make this happen but the functionally as far as rub and turning cannot be affected. Currently the fenders are rolled and pulled between 1/4 and 1/2 inch. I have considered a 225-50-16 however with an extra 1.8 inches over the 215-45-16 I do not see it being possible unless I bang in the frame on the rear of the fender arch and even then its questionable. Nvm if it will negatively impact the handling. I have also had a b16 transmission in the car at one point and driven a full b16b CTR N/A swap with a ITR transmission, and I have zero interest in feeling like I'm driving a 6 speed with a missing 6th gear.

As far as the build is concerned is has a 60 trim Ram RFD fab manifold, Edelbrock fmic, flex fuel, non vtec built b20 with stage II cams, springs, retainers P8R head 33mm intake valves, ~14psi with a wastegate & map switch. As everyone knows the B20 sleeves are weak, I am not comfortable with revving it past 7,200. Swapping over to a 1.8 block is out of the question at this point. I'm not after any crazy power, 350 is plenty enough for what the function of the car is. If you have nothing nice to say because it isn't your typical b20vtec sleeved setup click away, lots invested over the last 5 years to get to this point and I don't wanna hear it unless you been in my shoes. Unless you have hot lapped on the track with a similar setup I'm not interested in hearing how you were able to rev to 8k on the street once in a blue moon.

Thanks an advance to whoever made it all the way though and is will to chime in!

 

I've built lots of close ratio/long FD setups for the track. You're handicapping yourself with the 7,200 limit if its still making power. RPM doesn't hurt the sleeves. If you bump up to 225/50 you're going to eat gears up with 350whp.

 

I hear you with the rev cap. I am just not comfortable with anything higher, almost every time I have in the past, the valve lash rocker lock nut loosens up. has the same issue on the stock LS. Torqued to spec every time, 18 ftlbs. Leak down checked for bent valves, nothing every time. I think this will will cover what I need considering at this point no plans for vtec:
-1 3.07
-2 1.90
-3 1.36
-4 1.03
-ls 5th
3.47 FD
Stick to 215-45-16
Thoughts?

 

If you have a dyno graph that would help with the gearing selection. I wouldn't do the LS 5th. The car will fall on its face on the 4-5 shift and you'll have to really wind out 4th just to make 5th usable. Lower cruising RPM does not mean better fuel economy.