fastfred92

Anybody have any experience with a locked rear axle on the track? I am running a 944NA in SCCA IT and with the exception of a few slow turns I can think of, a fully locked rear may be the way to go.... any ideas? <img src="confused.gif" border="0">

Sloth

I used to rent a 944na ITS car that had a locked rear end. I was always concerned when navigating through the paddock, but never had any problems on the track.

Geo

[quote]Originally posted by fastfred92:
<strong>Anybody have any experience with a locked rear axle on the track? I am running a 944NA in SCCA IT and with the exception of a few slow turns I can think of, a fully locked rear may be the way to go.... any ideas? </strong><hr></blockquote>

I've been sort of pondering this for my car as well Fred. In fact, I wonder what advantages there might be (if any) to a LSD rather than a locked rear end. We don't have this option with our Sentra, so this is new territory for me.

Oh, BTW, I haven't had a chance to write to Sven yet. I'll try to do that this week.

Bill L Seifert

I have talked to Jim Pasha in Calif, and Nort in Orlando, and they say if you lock the rear end, the car will push badly. I am putting a Porsche limited slip in my NA 944 race car. I found one for $300. It needs rebuilding, so I am going to put also put a 4-11 gear from a 1990 Audi 5000 in also. Some people say that gear is too weak, but I guess I will find out. If you put a Porsche limited slip in you have to fool with thicker clutch plates to raise the lockup about the stock 40%. They both say the Porsche unit is better than a Quaife. They say the Quaife unloads too early out of a corner. Me and a friend both have ITS 944's and if you would like to stay in touch and trade info, email me at BillLSeifert@aol.com.

Bill

belz

Anybody have any experience with the GT limited slip in a 944 / 951?

Sloth

[quote]Originally posted by belz:
<strong>Anybody have any experience with the GT limited slip in a 944 / 951?</strong><hr></blockquote>

I have a GT unit in my 951 track car. However, I have no basis for comparison as the unit was put in before I bought it. I know I can still get some spinage on the inside tire on sharp turns like #7 at Rd Atlanta. I would have hated to see it before. Probably a stiffer roll bar/suspension to reduce roll would help considrably in my case.

Sloth

[quote]Originally posted by Bill L Seifert:
<strong>I have talked to Jim Pasha in Calif, and Nort in Orlando, and they say if you lock the rear end, the car will push badly.
Bill</strong><hr></blockquote>

I never felt like there was much of a pushing problem in the rental car I drove. YMMV

Bill L Seifert

To Sloth,

You said you rented a car and had no problem. Was it a na 944 or a turbo? If welding the spider gears works, I sure would like to know, as it would be the cheapest way to get rid of the inside tire spinning. Please let me know who owned the car, as I would like to talk to them. You can email me at BillLSeifert@aol.com.

The people I talked to said it was not a good solution, but I like to get as many opinions as possible.

Bill

Geo

[quote]Originally posted by Bill L Seifert:
<strong>The people I talked to said it was not a good solution, but I like to get as many opinions as possible.</strong><hr></blockquote>

I asked a friend who is an engineer for an OEM and has also engineered championship winning cars in almost every category he's competed in. Here is his answer.

It requires a really aggressive and somewhat unusual driving style. It can also be slower in slow corners.

BTW, glad to see you here Bill. I've seen your name in the results in Sports Car many times.

Paul

[quote]Originally posted by Sloth:
<strong>

I have a GT unit in my 951 track car. However, I have no basis for comparison as the unit was put in before I bought it. I know I can still get some spinage on the inside tire on sharp turns like #7 at Rd Atlanta. </strong><hr></blockquote>

What you have is a GT torque-biasing differential, not to be confused with a GT limited-slip differential. Torque-biasing differentials cannot eliminate tire spin in a high speed track car when the inside tire is unweighted. These are best for autocross and street use, while limited-slip is best for track.

Paul

Bill L Seifert

I hope FastFred92 got his question answered, I know the info I have read on the subject has helped me a bunch. Good luck to everyone tracking or racing a 944, both NA or Turbo. Thanks guys, and if anyone knows anything about Porsche emission warantees check out my posting on the Boxster list, I need an answer on that.

Bill

Sloth

[quote]Originally posted by Bill L Seifert:
<strong>To Sloth,

You said you rented a car and had no problem. Was it a na 944 or a turbo? If welding the spider gears works, I sure would like to know, as it would be the cheapest way to get rid of the inside tire spinning. Please let me know who owned the car, as I would like to talk to them. You can email me at BillLSeifert@aol.com.

The people I talked to said it was not a good solution, but I like to get as many opinions as possible.

Bill</strong><hr></blockquote>


Bill,

The rental car was an early 944na that was run in ITS. The car was built and rented by Albert Broadfoot and I am pretty sure that he told me that the spider gears were welded. Take a look at his <a href="http://www.broadfoot-racing.com" target="_blank">web page</a>for contact information.

Bill L Seifert

Sloth,

I think I met the Broadfoot guy when we raced at Daytona earlier this month. He didn't have anything in ITS, but he said he as run lots of 944's. I will give him a call or email. By the way, we really got our clock cleaned down there. Our 5th gear ratio sucks, and I was hitting 4700 at the flag stand, while the other 944's (Most were friends of Nort or Nort himself) were hitting 6000. We were going 122, and they were going about 145. (At least that's what they said.) I was 6 seconds off the fastest 944 time, and I won't tell you how far I was off the fastest car in the class, it is embarrising. As is my spelling.

Thanks for your help,

Bill

Bill L Seifert

To fastfred, sloth, etc.

I talked to Albert Broadfoot this morn. He said his car with the locked rear was just experimental. He quit using it because it tore up the rearend, and wore the heck out of the CV's. He recommends a 951 trans out of a 944 Turbo S. But, I think those would be rare. He thinks limited slip is next in a normal 944 gearbox with .83 fifth, and adding a Quaife is next. Sorry, no cheap rides.

Bill

Geo

[quote]Originally posted by Bill L Seifert:
<strong>I talked to Albert Broadfoot this morn. He said his car with the locked rear was just experimental. He quit using it because it tore up the rearend, and wore the heck out of the CV's. He recommends a 951 trans out of a 944 Turbo S. </strong><hr></blockquote>

That would be completely and totally illegal in ITS.