I had an inlinePRO turbo kit with a GT3071R turbo, various supporting mods, and a 4.57-R FD. I have seen many posts talking about boost and an upgraded FD, and it seems like the jury is still out in terms of whether a higher FD negatively impacts a boosted car's potential. Well, I purchased some Full-Race turbo parts, along with a GT3567R turbo (the install started yesterday) and would like to continue the debate as to whether the higher FD will indeed hinder my S2000's performance.

When boosted, what is the real issue with having a higher FD? I often hear something along the lines of not being able to stay in boost long enough in each gear. To me, this sounds like an issue with the rev limiter. Well, my rev limiter is currently set at 8500 rpms. With that in mind, is the upgraded FD still negatively impacting my S2000's performance?

 

i have one with a SC and it helps tremendously because there isnt shit down low with the SC.

Now Im selling the SC and going turbo, so I will let you know how that goes.

Only thing I have noticed is low end torque, but 1st gear seams a lot shorter.

 

With my old setup (inlinePRO, GT3071R), first gear was up in smoke and second gear wasn't much better. With my new Full-Race setup, and GT3567R, I know that the mid-range and top end will be even crazier, and that traction will be even worse! I am sure my 4.57-R FD will further complicate matters, but would like to hear some more real-world experience.

 

I've "heard" this aswell.. and your guess is as good as mine.

 

Heard what?

 

Justin, I've driven an almost identical setup to mine, at 10psi making 370 at 9:1. Honestly, the 4.1 felt like it was too short. It almost seemed like the car needed a 3.9. That's just my opinion. As you know, I used to have 4.77s, and I made sure that I sold them before my install because everyone talks about how bad their traction is with stock gears on high boost - and I knew that the shorter gearing would have been insane.

The car revs SO FAST in boost - it seems like you'd have a hard time shifting before redline once it kicks in if you had shorter gearing.

I'm not saying sell the diff, but it'd definitely be something to think about. You could easily get 1K for it + a stock diff swap. I had the CT diff, which I wish I still had - but new diffs pop up all the time for 400 bucks so if I ever do ruin mine, I can get another quickly for cheap.

 

Thanks for your input bro!

My intention is to do the R200 conversion, which will result in a 4.09 FD. At that time I will attempt to sell my rear diff, which will include not only the 4.57-R FD, but the Comptech reinforced diff!

 

Awesome - I might try cryotreating my diff (I can get it out quickly as I've done it a few times ) or get my tuning shop to fab stuff for the R200 diff.

The R200 is the N/A 300zx diff right? Isn't the turbo diff 3.7 or so?

If you're just selling your diff outright, you'll easily get 1500+ for it

 

[quote name='2QYK4U' date='Mar 27 2007, 06:58 PM'] At that time I will attempt to sell my rear diff, which will include not only the 4.57-R FD, but the Comptech reinforced diff!

 

It is my understanding that the 300zx non-turbo diff has a FD of 4.09--at least that is what inlinePRO is stating on their R2000 thread. Anyways, I would want at least $1500 for my rear diff. I would also be trying to sell the axles, hubs, etc.