Thread: IT WORKS! Put QG18 gears in your P11 TRANS! 56k take a nap.

Just make a new thread clean thread, then I'll approve it.

Thanks!

So what your saying is to convert the b15 trans to the p11 gearing you would need to swap in a b13/14 ring gear from the differential. But if you wanted to keep the gearing the same as the b15, swap the gearstack from the Q into it and keep the same b15 final drive/ring gear.

I was making sure its not necessary to swap the ring gear with the different gearstacks because of the tooth count difference on the pinion gear.

Interesting indeed. Thanks for the great info Coheed as always.

Just to clarify things a little bit here since I have experienced with this before Coheed..
B15 QR18 gear stacks (input and output shaft including all gears) are exactly the same as P11 SR20 gear stacks..
To convert from B15 SR20 to P11 SR20 what you need is either B15 QR18 gear stacks or P11 output shaft alone and swap gears form one output shaft to another and a B13,B14 or P11 differential ring since 5th gears ratios are different from P11 and B15 SR20

And you can do it vice versa you can swap the final drive on the P11 to B15 just need to get B15 SR20 output shaft and differential ring from B15 SR20

BTW the only advantage from B15 and P11 transmissions IMO. Its that gears come individualy and can be replaced buy as a set and they are not indestructible a couple of guys here in PR have broken several sets of 3rd and 4th gears that why when I broke 4th in my car there were on backorder jejejeje and i had to buy a B15 QR18 tranny to fix my car....

Exactly payu. I will add this info to the new thread. The B15 conversion to P11 gears will require you to use the different main-shaft, and 5th gear is different as well. Best thing to do in this case is:
Get QG18 stacks
get 5th from your B15 SR trans
Swap 5th gear onto the QG18 stack
Get the 4.176 FD from older tranny
Throw everything in and you are good to go with a taller 5th gear, and 5% longer gearing overall!

You could also do the same as above and keep your B15 shafts, and swap over all the gears if you really love your B15 shorter gearing. This will help the NA guys.

I should add that I just put in some Pennzoil Synchromesh trans fluid. OMG this stuff is immediately better than the valvoline 75w90. Immediately. I put the stuff in and it just glides into reverse like butta. In fact, there is no fluid I have used that has worked this good. Going about 25-27mph and it GLIDES into 1st gear with minimal effort. No rev matching, just goes right in.

This is some really cool fluid! Love the way the car reacts with it. It is running better than ever before! Put some 100 octane in there and holy moly, the car feels great! Spins a bit in 3rd gear now. I am going to raise the boost for tomorrow's dyno day. Hoping for 25psi or so on this 100 octane, which is like 20psi or so at sea level. I think she'll handle it, not sure about those couplers though! I wanna hit a solid 375-400whp with a nice broad powerband! The boost is going to have to be raised a lot to hit my goal. We will see.

I always ran synchromesh in my stock b13 trans. I guess that might have something to do with why it never went out even with lots of pulls from 3rd.

This is some good info here in case I ever need to make repairs to my B15 trans.

man thats cool you got your ride goin again without forkin out an arm and a leg!!!! cant wait to see some dyno #'s


p.s told ya that valvoline stuff sucked! heheh

yes you did. that gear lube sucked balls! This synchromesh should do very well. It may not cushion the gears, but honestly, I don't think the heavy shockproof helped that much.

ya, who knows i might try that stuff next.. but for now this mt90 does the job since my car doesnt see too much abuse..

The synchromesh is like a very thin MT90. It shifts soooo nice with it. But it is like 10w30 motor oil lol. Thin stuff.

Overall I don't think this is going to have any ill-effects on the transmission life at all. You can feel a sotp difference in power and response though. It is very nice!