Hey Lads.

2nd stock LSD is now acting up and won't last long…

Whats the best best LSD for a daily driven 20B FD T04 500 hp?

Cheers

 

I just bought ATS hybrid LSD and i am installing on my car. I have a 20B but i am making more Power than 500 WHP. I will let you know very soon how it feels and how it holds up.

BUT for those power levels the diff from an FC TII (turbo model) comes with an LSD clutch type (basically disc plates not mechanical gears). Plenty of guys on the forum run this LSD because it handles comfortably 500whp, there is plenty of them, they are very serviceable and best of all they are very affordable. This is probably what I would look into for those power levels.

Andrew

 

TII diff is questionable at 500whp if you run sticky tires. My vote goes for a cobra 8.8 conversion, that is what I am doing. Lots more parts available and any ratio you want, plus much stronger. If you arent a DIY type you can buy a kit.

 

I have been running the ATS Carbon LSD for years on my 20B, holding up fantastic and is completely silent.

ATS LSD (93+ RX-7)

 

are you running the 1.5 or the 2 way?

 

1.5 Way

 

Ive found a slightly used ATS carbon 2 way in UK, which means half price on diff and shipping.

Whats the difference on 1.5 and 2 way?

 

Okay did some research.

The Diff I'm looking at is 2 way. Is that going to be a problem on a street car and is it going to be noisy?

 

i went with OS Giken for LSD as well as close ratio gear set but i dont have things installed yet.

 

A friend of mine is running the stock Torsen at 660 bhp on his 20B so I went ahead and put another one of those on. Im hoping I was just unlucky with the old one and the first replacement.

Im going to LeMans next week to see the 24h race so thats a small drive of 2000 miles,
im gonna try not to break the third before I get back home!

 

Are you launching this thing?

I had zero issues at all whatsoever on my stock rear making 525rwhp on the 13b for nearly a year. I did not launch the car, nor did I pop off the clutch. Always rolling into throttle as to not shock the rear.

I'm guessing with sticky tires over 500hp you could break the stock rear in 2nd/3rd gear, but it seems more likely that abrput loading is what breaks stuff.

 

I guess you've got a good point there!

Just drove 2000 miles in three days and no issues what so ever. I only made hard pulls
when already moving.

 

There's alot of play in the old stock diff. If your gonna be launching the car, you need to load up on the diff 1st. See what happens is that when most people stage up at the tree, they shoot past the start line and have to reverse. Then once they get settled, they put the gear selector in 1st, depress the clutch and rev waiting for the tree to turn green. Then they drop the hammer and wonder why their diff just took a ****. Well the problem with what just happeed is that the diff was loaded on the back side of the gear face because you were in reverse. When you launch forward, the pinion gear free spins until it hits the other side of the gear. Though this is a very short distance, the excessive play in the diff makes this very very stressful and causes a shock/impact style load on the gears. Preloading on the forward face of the gear will eliminated a ton of shock load while launching any vehicle.

 

The Ford 8.8" IRS seems to be the favorite for the V8 swap folks in both the FC and FD. It should handle the torque loading, give you a wide range of gear ratios options as well as LSD types. Take a look here;

FD Ford 8.8 IRS mounting kit

 

I roadraced my 20b racecar at 700 hp for 5 years and never had a diff issue with the torsen fd. Money no object get the 8.8 cobra diff w. sanberg kit and your choice of ratios..

 

How are you keeping the diff fluid from over heating? Fritz Flynn tracks, his stock rear end fd with only 350rwhp and claims he has problems with heat back there.

 

This is gold. Has never even crossed my mind. This needs to be a sticky.