I have a 94 integra ls and would like either usdm or jdm ITR final drive upgrade. Not to sure which one would be better? Will this lower my top speed by alot? I have a DRAG 3 turbo setup.

 

A higher FD will definitely help that turbo spool up faster, but it will lower top speed a bit (does that really matter?) as well as increase RPM when cruising, which of course lowers fuel economy, and makes it more annoying in general to drive long distances.

 

Before you do this, just make sure the 4.785 (JDM final drive) will work with the USDM ITR LSD. The 4.400 differential/FD might not mate with the 4.785 version and vice versa.

There was a thread on it a while back, but I forgot what it said. However, your 4.400 countershaft and 4.785 countershaft are the same and can be used interchangeably. Just forgot about the FD gears.

I did something sort of the same with my setup. I couldn't get my hands on a GSR tranny (like I originally wanted) for my Drag 3 setup in my LS. So I got a USDM ITR LSD and put it in my LS tranny. It ended up with a 4.400 final drive because that's the only way it would work, and I kept the LS 1-5 gears. Worked well and accelerated a tiny bit faster than normal (based on a butt-dyno).

 

Sounds like the stock usdm 4.4 FD and usdm itr lsd would be the best combo. I'm planing to increase my redline a little bit also so the top speed would probably be the same as stock.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AlienKrOZ &raquo;</TD></TR><TR><TD CLASS="quote">Sounds like the stock usdm 4.4 FD and usdm itr lsd would be the best combo. I'm planing to increase my redline a little bit also so the top speed would probably be the same as stock.</TD></TR></TABLE>

Sounds good. My LS tranny with 4.400 FD seemed to not have an effect on the top speed. Perhaps I didn't notice it before, but the stock 4.266 had lots of trouble hitting 130+mph (WITHOUT turbo). With turbo and the 4.400, I got to over the 150mph tick mark in mere seconds.

Just a little FYI, the ITR LSD cannot hold that much power. The general consensus is that it seems to hold up until about 300whp. Even before that power level, it's very bad to load and unload the differential (turning on a bumpy surface, as the tires catch, slip, catch, etc). Mine grenaded running an untuned 13psi. Yes, it literally grenaded. The transmission was literally in pieces inside.

 

mos def the 4.7'll lower your times. can't really answer that for turbos, but if i had a turbo car i'd probably want a wider trans.

 

i've been told that the stock itr lsd can't handle to much power also. my daily will be 300whp stock and i mite go with pistons and rods for 400whp. should i stick with stock or pay more for a quaife. i've heard nothing but good stuff about teh quaife.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AlienKrOZ &raquo;</TD></TR><TR><TD CLASS="quote">i've been told that the stock itr lsd can't handle to much power also. my daily will be 300whp stock and i mite go with pistons and rods for 400whp. should i stick with stock or pay more for a quaife. i've heard nothing but good stuff about teh quaife.</TD></TR></TABLE>

Quaiffe is definitely good. But have you considered the OBX one? I've heard that it's exactly the same as the Quaiffe (looks the same, feels the same) and also has the lifetime warranty. Only thing is, it's more than half the price.

There have been a few threads on that here, search for them. I've seen good things and bad things. Usually, in that case, I'd go for the Quaiffe. But $350 versus $850 is a big difference.