s15 transmission (tryna learn something)

[Scuffed_ChukiCoupe]

Is there anything tht goes commonly wrong with these transmission. Would you perfer it over a s14/s13 sr transmission ? Any info would be appreciated.

[david200095367]

I heard its a little weaker because every gear has been slimmed down to fit into a 5spd gear box. Also i believe the s14 sr transmission is the strongest.

[Tulsa_S-13]

Is there anything tht goes commonly wrong with these transmission. Would you perfer it over a s14/s13 sr transmission ? Any info would be appreciated.

I haven't seen any substantial data to back up the theory that the S15 SR transmission is weaker than the other SRs.

If I had the money and had a power goal of 250-300rwhp I would probably go with the 6 speed.

[inkslingers13]

I heard its a little weaker because every gear has been slimmed down to fit into a 5spd gear box. Also i believe the s14 sr transmission is the strongest.

ive heard the same thing, think about it, same gearbox and another gear. you do the math. go for a s13/s14 transmission.

[Scuffed_ChukiCoupe]

i did hear about the s15 transmission being weak... just wanted to clarify or get any other info i can

[RPS13.5]

I have my 6spd gearbox for a year now and still no problem, so far im not sure what my HP now.upgrades:a better transmission oil 1.8L3" full exhaustone step colder plugs apexi filter10 psione piece drive shaftsolid mountsexpensive tires100 octanebest time 13.2 sec.

I beated this transmission so many times and still good. No matter what; I think SR transmission wont last beyond 350HP and high torque. So you might be able to get an HKS, Nismo, PPG, Dog Box for serious power, smooth shifting, and fun gear ratio's. Instead of buying multiple stock transmission's

[Scuffed_ChukiCoupe]

k thanks, good info

[tripleJs15]

the drifters in jp found it weak in their track cars.........but thats a track car and very abused......i like mine, daily driving and weekend fun, the gear ratios are nice IMO
Modified by tripleJs15 at 3:43 PM 3/3/2008

[codyace]

how does one get around the speed sensor issue?

[Emperor_Tha]

Is it possible to swap the 6 spd internal to a s13 transmission?

[tripleJs15]

how does one get around the speed sensor issue?

There's some kits you can buy to get the signal, you looking for a 6 speed cody........hey what was the lifespan on your block before you went with CP's, I am almost done with the head build and wondering if I should start on the bottom end or run is and see what up, also my engine had about 50k miles on it before starting the build, never was modded or anything before that

[rocketman240]

The 6 speed is the way to go for the street. I have mine a couple years with no problems. Saves on gas too.

[j_rocc2003]

how does one get around the speed sensor issue?

you can swap out the whole rear end with an s15. i think if you have an s14 se w/ abs and vlsd, you have to swap out the dif w/ something like a kaaz. i might be wrong, i know heavythrottle.com has the swap w/ the difs. and im pretty sure that you have to get a 1 piece drive shaft. someone correct me if im wrong.

[tripleJs15]

^ thats the right way to do it....get the whole rear end, then you get the s15 diff which is a big plus

[TDIX121286]

I broke my 6 speed.... Third gear is rolling around in the bottom of the transmission somewhere. I had the trans in the car for a year or more and never mis shifted.... I was dead set on keeping the 6 speed too... I looked into re-enforcement options for the 6 speed but none are really economic. 5 Speed hooks better on the street

[tripleJs15]

^ I guess it all depends on what you get...mine works great, had a whining problem when I first got it but fixed it with some syn. GL4 gear oil. runs great, if it ever goes down I'm still going back 6speed, maybe the nismo trans.

[CoupedUp]

I haven't seen any substantial data to back up the theory that the S15 SR transmission is weaker than the other SRs.

If I had the money and had a power goal of 250-300rwhp I would probably go with the 6 speed.

Agreed. I think it is honestly forum rumor.

Although, I might believe that above 400WHP the transmission may see some problems with abuse. But, I refuse to believe that anything less than 400WHP is going to be breaking the transmission.

How many people on here are above even 300WHP? Not more than 33%. More than 50% of that 33% are below 400WHP. So this whole "Don't use the S15 transmission because the gears are shorter because its the same bellhousing! ZOMG!"

For all we know the component spacing inside the 5-Spd transmission is large and the 6 speed transmission brings the gears closer together and doesnt reduce the width of the gears at all.

S15 transmission will be fine for about 80% of SR20DET owners.

[Hijacker]

I've had s13 and S14 transes apart. Nissan uses all the space available in the gearbox, I will say.

However, I agree that the S15 trans will hold up just fine. You abuse anything with 6k clutch dumps and rev limiter bouncing, you're bound to break something.

As far as the speed sensor is concerned, I've seen conversion kits offered that alter the speed sensor signal to match an s13 signal. I'll ask around about what exactly needs to be done for that. But in the end, you'll need the rear diff carrier to have the speed sensor.

[CoupedUp]

To convert the S15 Rear Differential VSS signal to a compatible S13 or S14 Tach signal, you will need the Dakota Digital SGI-5. It will convert the S15 VSS Pulses per Mile to the correct one for inputting into your existing tach.

http://www.dakotadigital.com/i...6.htm

[Hijacker]

Ahah! Thanks, Sean, I couldn't remember the name of that little guy

[tripleJs15]

To convert the S15 Rear Differential VSS signal to a compatible S13 or S14 Tach signal, you will need the Dakota Digital SGI-5. It will convert the S15 VSS Pulses per Mile to the correct one for inputting into your existing tach.

http://www.dakotadigital.com/i...6.htm

Thats the thing I was talking about, there's a few others out there as well.

[CoupedUp]

Ahah! Thanks, Sean, I couldn't remember the name of that little guy

No problem, calling me out by name. Dayum. LOL.

[RPS13.5]

For all S15 Six speed gear box users...what type of oil you used?

[Broadfield]

6-speed user here on 400whp, about to be more on new turbo setup, and not a hint of a problem. Daily driven at that level for 2 years and 15,000 miles. I rape it pretty good, but not as bad as some I'm sure. Blitz twin plate clutch/flywheel, S15 rear end and Redline fluids.

[Scuffed_ChukiCoupe]

nice so basically like any other automotvie part it breaks if u torture it, and if u take care of it it'll be alright.

[Kitswa]

Not a rumor. Drag or drift an S15 trans will break a lot sooner than S13 or S14 in the same situation. On the street it will not be a problem.

- Bill

[supreamS14]

The s15 transmission has a 26 lb. flywheel and the s13/14 has a 20 lb. flywheel. That should add some stress!

[RPS13.5]

Thats why my TCHO needle goes up & down slowly....I still have the stock clutch & flywheel since I first got it, Dint change them just because its somewhere 10000 miles on the engine. I cant wait to get a nismo flywheel for the six speed transmission.

[tripleJs15]

^ whats the price on the nismo flywheel ?