was wondering if any of you road racers have considered putting the axle resovoir on that comes on the KR'S
shelby part
http://www.shelbystore.com/ProductDe...e=8R3V-4022-KR

 

The side gears need a small amount of friction so they stick in their bores without binding up too tight. I used synthetic in a trutrac and it bound up so tight I nearly broke it taking a turn at the end of the track. I changed to good ol' el-cheapo gear oil and it hasn't bound up since.

 

Wow that thing's huge. Given almost none (if any) of the KRs ever see track duty, who knows how well it works. I put on Ford's TSB 10-3-7 a.k.a the turkey baster this weekend. I left the factory spring valve on top of the diff for now. I'll see how it goes down at MPH on Thursday. If it still vents from the factory location, I might just move the plug I took out of the axle up there. The turkey baster has a plastic vent on top of it as well if pressure got too high.

P.S. doesn't look like you can buy the KR one anyway: FOR GT500KR WARRANTY PURCHASES ONLY

 

The KR one works, I can attest to that. I have it on my '06. I might even pull it off and slap it on the BOSS when she arrives. But as you mentioned, I don't think you can get them any more.

 

Well pull it off then! You'll need something the way you drive Hopefully the turkey baster works, but that KR one looks like it would hold 1/2 the rear end fluid so I can't imagine it wouldn't contain all the overflow. I actually ran a piece of hose connected to a small breather filter on the GT500 and it did the trick.

 

On our race car, we just zip-tied a Dasani bottle in a little nook behind the fuel tank and ran a hose to it

 

KR Overflow Tank has been removed, as have brake ducts. Quick clean-up and they will be ready to go onto DA BAUCE

 

Found out today for sure the Torsen does NOT need friction modifier. Mark from Ford Racing said no because it didn't have clutches in the diff. The supplement manual must be saying that to cover the standard Boss diff.

 

Good to know. Hopefully doesn't "hurt" though since my dealer put it in since the supplement called for it?

 

Shouldn't be a problem. I've got 4oz in mine and don't plan on swapping it out soon.

 

I think this FAQ directly from the Torsen website ought to put this issue to rest for good:

http://www.torsen.com/general/genera...difier%20added

Looks like Ford may have added the friction modifier as a precaution against possible differential noise.

 

Update on the turkey baster. I had no fluid venting from either the turkey baster or the factory vent so it must have worked. However, it also must hit the exhaust when the suspension fully compresses. It melted part of the white plastic cap on top but seems to still be functional.

 

Roasty toasty!

 

The bottom line is if you have the Torsen in your Boss you don't need friction modifier. If you have the standard Boss differential you need it. Mark is Engineering Manager for Ford Racing Production Based Vehicles. In other words he's the final authority on what is needed and what is not on the Boss.

He did say if he had a track only boss he'd run an external diff cooler. With a street Boss that gets tracked he wouldn't go through the trouble. BTW- Mark has more awesome high performance Mustangs than one man should and we should be very happy and grateful to have such a passionate guy in that role at Ford.

 

I'm with you - it's not "required" for proper operation.

However, as a mechanical engineer myself, I like to know "why" things work, so the fact that GM recommends it for noise reduction is interesting to me.

Here's a Ford mechanic that says that you are supposed to use the friction modifier in a Torsen http://www.fordtruckfanatics.com/for...31&postcount=3 Of course that was 2 years ago - things change over itme.

Another thread I read states that friction modifier will reduce torque bias by 0.2 with no effect on durability. Also, using 140W versus 90W will reduce torque bias by 0.2. People who autocross a lot seem to think these things are important.

Many sites selling Torsen 2's state that you're supposed to add friction modifier on initial fill. I wonder if that's just for break-in?

 

 

But I didn't buy a camaro

 

Very nice Scott! That OEM cover rocks.

 

Very nice

 

Scott, very nice. So, whatcha gonna put there? Cooler?

Gary, need moar spring rate. Save the turkey basters!

Jimmy