Guys,

in order to have a better 4ths gear ratio in the ITR 98 engine.

Since the ITR 98 JDM has a 4th > 1.034, while ITR 95-97/SIRG/Si has 1.107

What would be needed to improve the 4th gear as faster in a 98 ITR S80 tranny.

The5th also is 0.787 , while others are 0.848

Just want to know what to change and what to buy and where.

Please help out.

Rishi

 

get 4.9 final drive
"improves" acceleration for all gears. but you will lose some top speed

 

why would you even say this? the 98+ already has the 4.875 ring





anyway, if you were just after acceleration you would buy the usdm itr or 96-97 spec tranny and run the 98+ final drive. honda used the gsr 4-5th in the 98+ to try and keep freeway driving somewhat livable. that means you need the b16 4-5th to get the same thing. or you could just switch 4th and keep 5th for highway driving

 

I was going to do this on my car when I was rebuilding the trans, but nixed the idea to save on costs. You'll need the gear for both the main and counter shaft I believe.

 

To clear up any confusion, JDM 98+ spec ITR has a longer 4th and 5th gears combined with a shorter Final Drive when compared to the JDM 96-97 spec or all USDM ITR gearboxes.

As the other guy said, 96-97 spec (or USDM) gears w/ JDM 98+ spec final would be the quickest combo of OEM parts.

 

I dont understand why they did the GSR 4th gear too? Who cruises in 4th gear? I can put it in 5th at like 30MPH if I really wanted to lol. It bothered me most at the track since on the street I had never gone all out into 4th gear due to the car already going well above posted speed limits. 1st, 2nd, and 3rd felt great! and then I hit 4th and hear my RPM's drop . I started getting pissed lol. Since the car is on the road and not a strictly track car I rather not shorten everything because of highway cruising. If anything and I decided to take apart the trans I think I would do a B16/96-97ITR 4th gear and possibly an LS 5th gear. Sure the gap from 4th to 5th will be huge lol but when have I seen a quick 5th gear shift? I have done that once in my life. To decide though I need to figure out mostly for drag racing what gear I will finish in after building the motor a little. 4th gear is where you want to be. If I build it for an even shorter gear and don't rev to more RPM's I could be in a dilema. Of course road racing is where my heart is but drag racing events are more common and still fun to go out and drive the R.

 

Just replied to the email you sent to MFactory.

 

If youre gonna swap out the final drive in a 96 spec tranny you might as well put in a 4.9. I am using the 4.928 final drive from MFactory with no complaints at all. Gotta love that acceleration!

 

I have the 4.785 in a '96 ITR tranny with 3.070 1st.

I have a GSR 4th and 5th that I'm gonna put in since my car does more daily duty these days. I was gonna put in the 5th alone but I don't want the awkward shift, so the 4th as well would make the transition better.

Here's a vid of my current setup:
http://www.youtube.com/watch?v=wgefNBFmwjk

 

Actually, the USIM stock gears are nicely spaced, and there is NOT a greater gap between third and fourth than between the other gears. In fact, it's a smaller gap than for the lower upshifts. Here are the RPM's after upshifting from the 8400 RPM redline in each of the gears with the stock USIM gears (regardless of what final drive you're using):

1 ==> 2: 5474
2 ==> 3: 5818
3 ==> 4: 6378
4 ==> 5: 6435