Rebuild Trac-lok vs Torsen upgrade

[ShifterX]

So would you say that is not a good way to measure wear then? A couple of us are trying establish some sort of wear rate using that. It seems like a few people have had them start to get pretty loose and spin the inside tire without a full season on them yet. I saw the @TeeLew steels mentioned elsewhere but I haven’t had much like finding out about them.

There might not be a direct relationship between clutch plate wear and break away torque. From my experience the axle end play pretty much dictated how much the plate stack wore down. Adding a fresh Ford plate stack brought the axle play right into factory spec with no shimming needed.

My question would be, what complaints do you have with your current trac-loc action?

 

[MikeBard]

There might not be a direct relationship between clutch plate wear and break away torque. From my experience the axle end play pretty much dictated how much the plate stack wore down. Adding a fresh Ford plate stack brought the axle play right into factory spec with no shimming needed.

My question would be, what complaints do you have with your current trac-loc action?

Sorry for the slow reply we were running a scca solo tour this weekend. Most of us seem to be having trouble with it spinning the inside tire on tighter turns at autox speeds. I haven’t tried it yet on track since it started being really noticeable but looking back I think it may have been digging out of some of the slower corners. We checked breakaway torque on everyone’s cars and they were very similar to a fresh one. We are thinking maybe the plates are getting a glaze to them or something? Trying to gather enough data to suggest that the T2 might be a more viable option for longevity.

 

[TeeLew]

There might not be a direct relationship between clutch plate wear and break away torque. From my experience the axle end play pretty much dictated how much the plate stack wore down. Adding a fresh Ford plate stack brought the axle play right into factory spec with no shimming needed.

My question would be, what complaints do you have with your current trac-loc action?

All of it? It doesn't have enough preload, it doesn't have enough torque bias and it wears quickly. The stocker is built to give about a 1.75 torque bias ratio and not much preload. It's benign to drive and quiet in parking lots, but it doesn't take much running to burn enough of the friction material to lose what little preload you started with, which is a big deal on track. There is absolutely is a direct relationship between the two. Yes, putting in fresh Ford plates will make it as good as you can get, but, then again, that's nothing special. The ones with carbon wear plates are better than stock, but all of the above is still an issue.

Keep in mind, this is the same basic differential that Ford has used since at least the 1960's. A lot has changed since then.

 

[TeeLew]

Sorry for the slow reply we were running a scca solo tour this weekend. Most of us seem to be having trouble with it spinning the inside tire on tighter turns at autox speeds. I haven’t tried it yet on track since it started being really noticeable but looking back I think it may have been digging out of some of the slower corners. We checked breakaway torque on everyone’s cars and they were very similar to a fresh one. We are thinking maybe the plates are getting a glaze to them or something? Trying to gather enough data to suggest that the T2 might be a more viable option for longevity.

I changed the rear end ratio in my car to a 3.15 from a 3.55(w/ Torsen), which is a smaller ring gear than the 3.31 on up (S550), so it uses a different size differential. The T2 is a good diff, but it's heavy and creates a lot of heat. There is a smaller Torsen available for the 3.15, but I wanted to give this a shot before going that route. Just looking at it, I knew there was low-hanging fruit.

If I were going to stick another diff in the car, it would probably be the OS Giken, but, again, only with a 3.31 or higher (numerically) rear gear.

 

[ShifterX]

Sorry for the slow reply we were running a scca solo tour this weekend. Most of us seem to be having trouble with it spinning the inside tire on tighter turns at autox speeds. I haven’t tried it yet on track since it started being really noticeable but looking back I think it may have been digging out of some of the slower corners. We checked breakaway torque on everyone’s cars and they were very similar to a fresh one. We are thinking maybe the plates are getting a glaze to them or something? Trying to gather enough data to suggest that the T2 might be a more viable option for longevity.

So the difference between a completely wasted trac-loc and fully rebuilt one with Ford carbon plates was noticeable but not revelatory. I still get inside wheel spin on slow corners, however it does drive out better. The increase in lockup was not substantial. Thank god I went with the green spring. For my use case, not chasing lap times, it will be fine for now.

However I would submit you can pretty much tell the condition of your trac-loc by checking the axle endplay. Barely audible noise and play you almost cannot feel should be around the .010" zone. Any solid audible clunk you can hear and feel and the plates are probably worn. As far how that translates to breakaway torque, no idea. But as @TeeLew said, you are not starting with much to begin with.

 

[MikeBard]

So the difference between a completely wasted trac-loc and fully rebuilt one with Ford carbon plates was noticeable but not revelatory. I still get inside wheel spin on slow corners, however it does drive out better. The increase in lockup was not substantial. Thank god I went with the green spring. For my use case, not chasing lap times, it will be fine for now.

However I would submit you can pretty much tell the condition of your trac-loc by checking the axle endplay. Barely audible noise and play you almost cannot feel should be around the .010" zone. Any solid audible clunk you can hear and feel and the plates are probably worn. As far how that translates to breakaway torque, no idea. But as @TeeLew said, you are not starting with much to begin with.

I was going to check it today while I was swapping brakes but I couldn’t find my indicator and I discovered my radiator was seeping so that became the more important crisis before I head to midO this weekend. It was suggested to do a drain and fill with no friction modifier so I may do that real quick as well.

 

[TeeLew]

Has anyone ever heard anything about this one?

Wavetrac® Differential - A torque biasing differential with a difference

www.wavetrac.net

 

[blacksheep-1]

Has anyone every heard anything about this one?

Wavetrac® Differential - A torque biasing differential with a difference

www.wavetrac.net

It has some advantages, but longevity in a competition car doesn't seem to be one of them

 

[TeeLew]

It has some advantages, but longevity in a competition car doesn't seem to be one of them

Bummer.

 

[TeeLew]

I do think the OS Giken would be a good S550 diff. I don't think they ever made one for the live rear. I do know that the last version of stick axle Camaro ran one in the Conti GS class.

It's got real ramps, a proper preload spring and a max of 7 plate pairs per side. It also has a ramp delay capacity, which is probably overkill for our purposes, but it's something else to play with if you're having trouble confusing yourself.

The Japanese site has better pictures, but don't ask me to read the words.

OS技研｜LSD

OS SuperLockLSD,DualCoreLSD,TCD,スーパーロックLSD,デュアルコアLSD,スーパーロック4,スーパーロックST,岡﨑式差動制限装置,DualCoreNEO,SuperLockST,DualCoreST

www.osgiken.co.jp

The US site is just business.

OS SuperLock LSD for Ford S550 Mustang

Description The OS Giken Super Lock LSD uses our patented pressure ring design that allows for smooth, progressive locking. This design is a spline-through-side-gear design that allows for fitment of more friction plates (up to 2x as many as competitors versions). All components are chemically...

osgikenusa.com

 

[Mad Hatter]

I must admit, I love my OEM torsen that came with the Boss. Racing for 10 years now and its a set one of the only things that just keeps on working well and never had a failure.

 

[JDee]

I must admit, I love my OEM torsen that came with the Boss. Racing for 10 years now and its a set one of the only things that just keeps on working well and never had a failure.

Heat will kill them, that's what happened to mine. Any warm day and I'd get axle overheat warnings after 6 or so laps at Mosport. Any hard driven track car needs a diff cooler. The Mach 1 came with oil coolers on the engine, trans and diff and so far no issues.

 

[TeeLew]

I must admit, I love my OEM torsen that came with the Boss. Racing for 10 years now and its a set one of the only things that just keeps on working well and never had a failure.

I like how the Torsen acts on power. It does a really good job of both rotating the car and not allowing inside wheelspin. Having said that, it's too free for me on entries. I prefer to have the rear wheels tied pretty tightly together in the brake zone and on turn-in. It really sucks to get the inside rear wanting to lock or micro-lock on a non-ABS car and with ABS, it just allows you to stop better because of the reduced modulation.

 

[TeeLew]

Heat will kill them, that's what happened to mine. Any warm day and I'd get axle overheat warnings after 6 or so laps at Mosport. Any hard driven track car needs a diff cooler. The Mach 1 came with oil coolers on the engine, trans and diff and so far no issues.

I've found this in different cars. It's particularly apparent on tracks with sweeping corners, which is basically all of Mosport. In my experience, the Torsen never really locks. It's always trying to differentiate. Because of this, it creates more heat that a plate diff. Plate diffs tend to actually lock when they lock, so they stop trying to differentiate between the rear tires and less heat is made. I think this helps reduce the amount of heat they create.

I love my finned rear cover. It's heavier than stock, but a passive way to cool the diff that's way lighter, cheaper and simple than a pump/cooler arrangement. It works great.

 

[Mad Hatter]

Heat will kill them, that's what happened to mine. Any warm day and I'd get axle overheat warnings after 6 or so laps at Mosport. Any hard driven track car needs a diff cooler. The Mach 1 came with oil coolers on the engine, trans and diff and so far no issues.

Ahh,, maybe its a issue with the S550. My old chariot wheel set up is more primitive.

 

[EF1]

Everyone says S550’s need diff cooling for the track. I have never had heat problem with my S197. I just run good fluid and a finned aluminum cover and I’m running 4:10 gears.

 

[blacksheep-1]

Everyone says S550’s need diff cooling for the track. I have never had heat problem with my S197. I just run good fluid and a finned aluminum cover and I’m running 4:10 gears.

I keep saying the S197 platform is perfect for most of us. It's stupid simple, works, hard to break and easy to fix. It's the automotive equivalent of the anvil.

 

[Mad Hatter]

If I had to start all over again, and lots of cash. I think I would do the S197 again with out hesitation.

 

[JDee]

My first 'stang was a 2011 S197 GT, it was a luxo barge loaded up with leather and all the options for luxury, it probably was one of the heaviest Mustangs ever built. It was definitely not a track car. It had diddly for miles, the owner was fastidious about the car, had complete maintenance records, dust cover and so forth.
The clutch was horrific and the trans was not much better, a horrible thing to shift, especially first shift of the day to 2nd gear, big crunch. It lasted a year and I traded it on the '16 PP1 car, which was a stripper spec'd with just go fast stuff and no luxo junk, a much better experience than the S197.
To me, whether it's S197 or S550, it's about the weight, less of that is always way better for the track. The Mach 1 is no lightweight, but it certainly feels way better than that '11 heavyweight did.

 

[bnight]

Everyone says S550’s need diff cooling for the track. I have never had heat problem with my S197. I just run good fluid and a finned aluminum cover and I’m running 4:10 gears.

Because the S197's have solid axel that is big and help with absorbing a lot of the heat from the differential. Obviously IRS cars don't have that advantage.