S15 6 Speed transmission Weak????

[sil80hks]

Ok, so I've read other posts noting that the 6 speed transmission found in the late model S15's is "weaker" than the 5 speed found on all earlier SR's. The reason I want to know is because I'm about to buy a 2001 SR20DET with the 6 speed to drop in a S13. So if anyone has some useful information on what the real deal is on this transmission I'd greatly appreciate it. Oh, and I also hear that the notch top SR with the 6 speed is not a direct swap into the S13 body. Some modifications have to be made. Any one have details as to what is required?

Thanks!

[quiksilvia]

go to http://www.srownersclub.com for swap info, or search here. but yea the 6 spd is weaker, i wanna say the synchros go out soon for some reason, i know something goes early.

[ItzGenX]

IIRC, the S15 Turbo 6 speed transmission is the same one in the 350Z, G35, and RX8 (different bell housing of course). The most popular car out of the 3 is the 350Z, so there is more of a user bank on that for error. The main problem seems to be early synchro wear for many. Same goes for the G35 (same thing anyway). The RX8 has had a few here and there popping up on boards all over the net about the 3rd gear syncro. The 4th gear syncro is showing signs of giving up in my friend's 30k mile 350Z.

On a side note, everyone thinks the S15 6 speed is weak due to fitting a 6th gear in the same space that would normally fit 5 gears. This to me is false (unless a form of proof pops up) because the 6 speed's internal gearbox is designed totally different. There is nothing in "size" that makes it the same as the 5 speed as I have seen both SR 5 and 6 speeds sitting next to each other. In fact, I think the 6 speed is stronger, just has crappy syncros.

[D1SR240]

I've heard about this, but never seen any actual proof of it.

[sil80hks]

So maybe I'll be going with the 5 speed. I don't know, for the trouble that people seem to be having with the 6 speed it doesn't really seem worth it. Is there something that can be done to improve the durability of the 6 speed, or are you pretty much stuck with what comes from Nissan? Any way, thanks for the input.

Bump!

[kane2g]

As far as installing it in S13, the speed sensor is in the diff, so you need that too to make it work.

[skylndrftr]

ITz are you sure about the transmissions being the same? I can see the 350Z and the G35 being the same, and along that lines the S15 but the RX8 is a toally different company (basically ford) not to mention I have heard very poor things about the reliability of the RX8 gearbox when the power goes up at all. Basically the limiting factor in that case is not the motor its the box. I have never heard that about the 350 or the 35

[ItzGenX]

I am positive they are the same gear box with different bell housings. Just because it is a Mazda doesn't mean it can not share parts with that of another car. I'd bet anything you can find the same garrett turbo found on SR's mounted stock on other motors too. The fact of the matter is, car manufacturers have other companies make things for them. One prime example is the GETRAG 6 speed transmission found in the Toyota Supra and the Nissan Skyline GT-R.

[skylndrftr]

relax man i'm just saying that:RX8 = 197 HP350Z = 287 HP

i have heard of problems with the RX8 gearbox and not with the 350Z, specifically that pushing power on the rx8 tends to grenade the gearbox before the motor. That just doesn't makes much sense to me if they are the same box...not really important though your probably right

[ItzGenX]

It might be due to the difference in gearing between the two because the RX8 redlines at 9k stock.

[ruthlesstyper]

The 6 speed will be just fine if you are not putting down some serious power. D1 and driver and other racers swap out the 6 speed for 5 speed sometimes becuase they like the gear ratios in them and it can hold more power. The s15 motor will basically drop in but have fun wiring it.