2025 GT PP 6sp transmission rattle.

[NegativeMultiplier]

I had no idea Euro spec PP didn’t have the Toresen diff.

It's at least part of the reason why the Euro spec feels like it has less get-up-and-go. I think it might be an emissions-related modification.

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[AZ_Ryan]

It's at least part of the reason why the Euro spec feels like it has less get-up-and-go. I think it might be an emissions-related modification.

Aren't they tuned down too?

 

[Cz_Ziemniak]

Personally.... I'd much rather have a clutch style LSD. Especially on a race track.

I've heard that the guys who were seriously racing the Trac-loc diffs had to replace the clutch packs pretty much every weekend before switching to the Torsen.

Torsens seem to make the most sense for hard driving

 

[NegativeMultiplier]

Aren't they tuned down too?

They are, unfortunately...

 

[Gregs24]

It's at least part of the reason why the Euro spec feels like it has less get-up-and-go. I think it might be an emissions-related modification.

Aren't they tuned down too?

They are slightly lower power output here, but on the dyno it seems it is all in the last 1000rpm (they are the same up to that point). Not sure the LSD would make any difference.

 

[Garcia172]

I've heard that the guys who were seriously racing the Trac-loc diffs had to replace the clutch packs pretty much every weekend before switching to the Torsen.

Torsens seem to make the most sense for hard driving

Never used a trac-loc LSD in a racing environment so I can't comment on that specific clutch type lsd. I've used the factory Porsche and more specifically the Guard assemetrical clutch type lsd (my favorite and definitely faster around a track than a torsion LSD). I think I used the guard LSD for about 5 years on the racetrack with zero maintenance. In fact, that same differential was used in probably four or five different transmissions that I managed to destroy on the track (unrelated to driving style).

I could be wrong but I can't imagine it Ford would build a limited differential that would only last a weekend on a racetrack. If that's the case I would probably look to the setup being incorrect because there must be a whole lot of wheel spin and if that's the case then you definitely have a setup problem. A lot of wheel spin with slicks in about one lap and you'll have everybody passing you (you'll be a sitting duck) and you'll be lucky not to finish the race in last place... With much slower class cars passing you. Been there done that.

And the only reason a clutch pack would wear is because of a difference in wheel speed and if the tires aren't slipping/spinning without traction... There really isn't much difference than street use.... And it pretty much would mean that the clutch pack LSDs in the mustangs that don't have the torsion LSD are going to wear out really really fast from street use.

Anyway in short I think it really becomes a theoretical issue rather than an actual issue since these are street cars, not race cars (far from it) that might see a few days a year for spirited driving on a racetrack.

Just my .02

 

[Cz_Ziemniak]

Never used a trac-loc LSD so I can't comment on that specific clutch type lsd. I've used the factory Porsche and more specifically the Guard assemetrical clutch type lsd (my favorite and definitely faster around a track than a torsion LSD). I think I used the guard LSD for about 5 years on the racetrack with zero maintenance. In fact, that same differential was used in probably four or five different transmissions that I managed to destroy on the track (unrelated to driving style).

I could be wrong but I can't imagine it Ford would build a limited differential that would only last a weekend on a racetrack. If that's the case I would probably look to the setup being incorrect because there must be a whole lot of wheel spin and if that's the case then you definitely have a setup problem. A lot of wheel spin with slicks in about one lap and you'll have everybody passing you (you'll be a sitting duck) and you'll be lucky not to finish the race in last place... With much slower class cars passing you. Been there done that.

And the only reason a clutch pack would wear is because of a difference in wheel speed and if the tires aren't slipping/spinning without traction... There really isn't much difference than street use.... And it pretty much would mean that the clutch pack LSDs in the mustangs that don't have the torsion LSD are going to wear out really really fast from street use.

Anyway in short I think it really becomes a theoretical issue rather than an actual issue since these are street cars, not race cars (far from it) that might see a few days a year for spirited driving on a racetrack.

Just my .02

If you have an S650 without the performance pack, then you've got a trac-loc.

I should probably elaborate that these were modified S197's that were on very very wide wheels doing a lot of hard cornering. There is far more strain on a diff when its dealing with such wide and sticky tires, constantly slipping those clutches mid corner, generating so much heat.

I'm sure a less aggressive setup wouldn't wear as aggressively, of course I know plenty of people who run road courses on their trac-locs who don't have the same issues, but they're also not running 315's in the rear on hoosiers. The biggest hurdle was heat, if I remember correctly.

Again, apparently these issues went away with the Torsen. Less things to wear, better setup for transferring power under hard cornering.

 

[Cz_Ziemniak]

Just googled, it was Vorshlag.

https://vorshlag-store.com/

 

[AZ_Ryan]

They are slightly lower power output here, but on the dyno it seems it is all in the last 1000rpm (they are the same up to that point). Not sure the LSD would make any difference.

Torsen is just another kind of limited slip diff. Torsens use gears while standard limited slips use clutch packs. It's not anything that would effect engine output or dyno numbers. Torsens are more durable on the track is all.

For what its worth, Google says Euro spec GTs have 40 less HP (448). Probably not that noticeable unless you are racing.

 

[AZ_Ryan]

Double post

 

[Garcia172]

If you have an S650 without the performance pack, then you've got a trac-loc.

I should probably elaborate that these were modified S197's that were on very very wide wheels doing a lot of hard cornering. There is far more strain on a diff when its dealing with such wide and sticky tires, constantly slipping those clutches mid corner, generating so much heat.

I'm sure a less aggressive setup wouldn't wear as aggressively, of course I know plenty of people who run road courses on their trac-locs who don't have the same issues, but they're also not running 315's in the rear on hoosiers. The biggest hurdle was heat, if I remember correctly.

Again, apparently these issues went away with the Torsen. Less things to wear, better setup for transferring power under hard cornering.

I raced a Porsche 944 with a V8 in it making 480 horsepower to the wheels.... Actual racing in the POC Red run group against cup cars.... At the time I was running nitto NTO1 315 on all four. And I got to tell you I ran that car for 5 years hard and never once had to touch the guard GT clutch style LSD.. infact I even put it in four or five different transmissions that I blew up along the way.

And I can't imagine that the Ford clutch pack LSD wouldn't survive more than one weekend. It must be a piece of junk or something wrong with it for that to be that fragile.

After that I moved into a professionally built race car that ran the same guard differential for years... Still never serviced it one time and won a lot of races as a matter of fact and the GT1 class in the POC (and those are some of the best pro level drivers you'll ever race against).

After that we moved to albins pneumatic computer controlled sequential which also has a clutch pack style LSD. 6 years of racing that never once touched the LSD differential.... And this is running 300 Michelin slicks on the front and 330 Michelin slicks on the rear.

That said I'm not sure what's up with the Ford clutch pack style LSD but I find it really hard to believe that it has to be rebuilt every weekend on a race weekend.

And that brings me to internet forums and the gossip and all the crap that spewed on the internet forums... 80% of it is worthless and wrong

I will tell you, when you get into high end serious racing, the asymmetric ramp style LSD blows a torsion lsd out of the water in terms of lap times. We're talking seconds. Well documented and well proven

But like I said before I have no experience with that LSD on a racetrack only in my street car. And on a street car I can't imagine why it even be an issue... Even a dark horse which is a streetcar... Will never be a race car.... Is it really that big of an issue?

I do think the dark horse is a cool car Don't get me wrong.... It's just a million miles away from a real race car. It's a street car. So does it really matter? Lol

 

[LouG]

It's at least part of the reason why the Euro spec feels like it has less get-up-and-go. I think it might be an emissions-related modification.

50 ponies less than ours.

 

[LouG]

There's some mechanical design magic in a Torsen that I've never been able to figure out.
But the name refers to Torque Sensing.

 

[Tomi.86]

The sound might be from the torque converter.

 

[Gr8ful]

6 speed

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