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S4 T2 LSD into FD pumpkin notes.....

Old 12-10-04, 12:29 PM
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S4 T2 LSD into FD pumpkin notes.....

I'm writing this for those of you thinking about upgrading the LSD in your FD on a budget and not wanting to pay the $800+ price tag on an aftermarket unit (Kazz/Quaife).

I plan on putting somewhere around 450rwhp/400rwtq down when my car is done (Jan. '05 goal) and know that the stock FD Torsen is a weak link when pushing the envelope. I've heard about countless cars breaking them at the strip... even ones with only bolt ons (exhaust/intake and stock turbo).

I didn't want to spend the money for a KAZZ so I had researched and found that the S4 Turbo 2 LSD was a good option since it was the clutch pack style and known to be a strong unit.

I was lucky enuf to be able to do a straight up trade with a board member for my Torsen. After emailing a few others about installing this unit into the FD carrier all the replies I got back were just remove the old one... and install the new one. Of the 3 people I asked none of them went to a shop to have the lash checked or even thought about doing it.

Well I certainly wanted it checked so I went to a well known diff shop and brought them the empty FD carrier and the T2 LSD and told them what I wanted. I said I simply wanted the lash checked and it should be easy pacheesy. I didn't pull the pinion gear or do anything other than pull the stock Torsen out of the housing.

Well I return the next day and he said it wasn't a walk in the park. Upon installing the LSD with the existing 3:90 FD gear he said the lash was so far off he couldn't even get a reading. He said he had to shim the pinion gear in order to get it right and gave it a clean bill of health after that. He only charged me $125 for all this which I thought was fair at $85/hr. The guy also works on bus/Caterpillar rear ends and I saw ring gears in there as big as a small hoola hoop!

So to those of you that plan to do this upgrade I would recommend having the lash checked by a professional. My guy said it would've lasted a matter of miles before chewing itself up into worthless bits.

I'm building a road race car that I hope can run 10's n/a at close to 130mph on drag tires. With a 150hp NOS shot I hope to be in the 9's. We'll see how the T2 LSD holds up. I hope to weigh 2900lbs with driver or less.

Anyone want to donate some used FD stock halfshafts for testing? Or have a good deal on some 300M axles .

-GNX7
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Old 12-10-04, 01:03 PM
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I put mine together and set the backlash wrong. When you are doing the swapbuy a new pinion collar. They are one use only, and i put about 300 miles on the diff with crappy backlash. You can hear it wine and clunk. I need to take it back apart again and install a new pinion collar...
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Old 12-10-04, 01:05 PM
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Good info Mark. Mark, being from the domestic end of things, any thoughts on shops that might make some custom axles for my FC at less than the ~700.00 wanted for 300M, if I can even find them?
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Old 12-10-04, 02:09 PM
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Carl- I wouldn't have any good leads. Unless you plan on making them in volume.... $700 is pretty much what you are looking at I'd bet. Call RX-7store or talk to Cris "Speed" Anderson in FL (Orlando area I believe).

You don't plan on drag racing anyway. Why not just have a bunch of stock T2 halfshafts? You haven't broken one yet have you?

-GNX7
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Old 12-10-04, 02:34 PM
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No, and I do not plan on DR, so we shall see.
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Old 12-10-04, 03:24 PM
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I can't believe anybody would swap the diff out of a pumpkin and not have the lash checked. Heck, you're supposed to do it even if replacing with the same type of diff!
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Old 12-10-04, 05:28 PM
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Mark,
Glad to hear that everything went well. I'm lovin the Torsen. I can get the rear to do exactly what I want now. I can place it almost perfect.
I paid about $250 for my guy to set the lash. But I guess thats the difference lbetween living in CA and CT. Here good shops are hard to find.
peace,
-a
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Old 12-10-04, 10:34 PM
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Sunshine- thanks again for swapping diffs with me. Worked out great for both of us. I hope mine lasts and works well like yours.

Just picked up an LS1 motor today . 23K miles complete with wiring harness/computer for $2K! Soooooo stoked.

-Mark
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Old 12-10-04, 10:53 PM
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Mark, going to JGTC? Gimme a call
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Old 12-13-04, 08:59 AM
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Originally Posted by gnx7
Just picked up an LS1 motor today . 23K miles complete with wiring harness/computer for $2K! Soooooo stoked.
awesome, keep us updated on the progress, that sounds like a great deal on a LS1.
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Old 12-13-04, 11:51 AM
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.... actually got it for $1500 since he couldn't find the computer for it

Very very happy.

-Mark
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