Thread: B15 trans with P11 FD and Nismo Diff....

Sh*t....that probably means I am utterly clueless.

I think he's mentioning the P11 final drive just for informational purposes, but it doesn't have any effect on the outcome of this carnage.

The final drive gear is always engaged. On RWD cars it is in the rear differential. In our cars it is built into the transmission casing. Basically you have the regular gear (1st, 2nd, 3rd, etc.) and then after that the torque goes through the final drive gear set. Always. It's basically a constant gear multiplier. It does it's job on all gears.

hehehe

Maybe you are thinking of "over drive" final drive is more like a rear end, it affects the overall ratio in each gear.


Dudeman

Well, at least I am only sort of half-wrong.

Which means I'm half right. Hooray.

Time, once again, for "How Stuff Works" dot com......

So, what would be stronger, a "treated" (MotoIQ article) B15 tranny, or a Spec V six-speed swap? Or do we not know which would be stronger and/or more cost-effective?

Cost is the area the 6 speed falls into. Look at about 3 times the cost of a B15 tranny, plus a bit of extra work.

I would love a 6 speed swap, even for 320hp.

Well whatever Nate decides, he needs to decide on something that his Nismo LSD Diff will be compatible with.

You are right, i never used any upgraded lsd for one which im sure is a big contributing factor. Two my tires were regular street tires not the widest i could go and im sure some BFG 225 drag radials would have made a big difference but the car was a daily and didnt feel like going through tires every 3 months. lol.

Three, my alignment and suspension is good. Never had issues. I dont have camber issues that would cause only parts of the tread to be fully seating against the ground and i have a nice stiff suspension and bushings all around to help keep the tire planted and the back from squating.

So i know its more of a power issue but there was little things i could do to improve and possibly maybe have traction in 3rd and above whereas not. haha

Keep up the good work though and get that thing back out there. I cant wait to see how well the 6 speed is gonna hold. Ill be running the same 85w-140 gear oil in it as well. It should be nice and cusioned against any shock during shifts with the twin disk clutch and should be able to hold the power. Im definetly getting some wider stickier tires though. haha

Based on (3X) cost then, "treating" the B15 tranny would be far less expensive per that MotoIQ article.

Of course, someone could get the 6-speed and then "treat" that prior to installation....

That was the intent ... Yes I know I have odd sense of humor

Correct. I was just listing what was done to the trans so everybody knew gear ratios and what LSD was in it.

For sure the LSD helped apply more load, but you could do the same damage IMO with open diff and slicks.