Hey guys, I have a '96 Spec ITR with the '98 Spec 4.785 final drive and Mfactory 3.07 first gear. I put in the 4.785 two years ago and it was awesome. I put in the 3.07 earlier this year and it was Super awesome, when I shifted at 8600 rpm, it would fall above 7000rpm which was great. So I figure if I could get all my shifts/gears to drop above 7000 rpm it would be pretty fast.

I have some parts laying around and was thinking about building a separate close ratio transmission.

I have a Spoon LSD (clutch type), a complete S4C housing, a 4.266 Final drive and SiR-G gearset (aka GSR gearset)

I was going to get another Mfactory 3.07, a B16A 2.105 2nd and Mfactory 3rd-5th (1.636, 1.313 and 1.028)close gears and put them on the 4.266 final drive with the Spoon LSD.
Eventually, this transmission may end up on a circuit car, but for the first few months it will be on a street car.

Any comments, suggestions, experience?

 

You can use the 4.266 (I used it in a customers GSR trans with the MFactory 1.625/1.296/1.000 close gear set), but I would use the MFactory 4.05 FD instead. Used it in another customers ITR trans with the same gear set and 3.07 1st. With the 4.266 you'll top out in 5th on some tracks unless you can rev it over 8,500. This is tire size dependent though.

 

I think I'll go for the 4.05, it should be stronger then the OEM 4.266 anyway.
I should be able to get 240kph with the 1:1 5th and 4.05FD with 215 45 16 Tires if i push it a little (the Spoon B18C ecu revs to 8900).

What setup would you recommend for a boosted street car about 300-325whp?

 

What size tires? Boost by gear?

 

Not built yet, just theory!

 

Depending on the above (and what tires you run) I'd either go with a 4.785 in a GSR trans or a 4.05 in a B16 trans.

 

I got the gears, but not exactly the ratio I wanted. It's the 1.695 3rd, 1.384 4th and 1.000 5th.
I should have the 3.070 1st gear this week.
I've decided to use the 4.266 final drive.

In 2-3 weeks I'll try to put up a video.

 

We actually have a stronger 4.266 available now as well, but if you're not pushing that much power, the oem should suffice

 

very interesting
i never really thought about using the 4.26 before

 

I'll take some pics of the assembly and record a small video of it running.

 

Okay, it's done!

I'm trying to find a suitable fluid for the spoon lsd before I put it in the car though.

As soon as I get that, I'll throw it in the car and give it a run.

 

Torco MTF (or RTF if track only) + Torco Type-F Friction Modifier

 

I'm in Trinidad so that fluid will have to be shipped overseas, and I know there's a lot of restrictions on oils in airplanes. It just called my freigh forwarders and they said there will be a 40% duty on that commodity and it will take extra time.

Sucky!

 

Enjoy!
http://www.youtube.com/watch?v=Pp7S9Zeua5k

Previously...
http://www.youtube.com/watch?v=wgefNBFmwjk