S550: Torsen vs LSD observations at the track

[JAL racing]

I live 300 miles North of Watkins Glen. During the racing season, ambient temperatures range from the 50s to the low 90s in general at the local tracks.
I have never felt the need for any additional cooling of anything (2019 base GT) except brakes.
Of all the regulars at my local track, I have the only base GT. Most others drive PP1, there are 3 GT350 and 1 GT500.
I am the only regular who tracks an LSD S550. All cars are manual except the GT500 obviously.
During the season, several of the other S550 guys mentioned to me that their car went into limp mode after their differential overheated. Mine never did. Is the Torsen differential more likely to overheat than the LSD?
The track is a 3rd gear track for me. I use the 4th gear in the esses to better modulate the throttle but I could stay in 3rd as the top speed before the braking zone is around 100mph.
The Gt350 cars run the course in 2nd and 3rd, probably because of gearing. I don't know about the PP1 cars. Any ideas what could explain the PP1 cars going limp but not me?

 

[JDee]

Welp, at Mosport we are seeing close to 150 mph, usually 147-148 without a tailwind, up the long back straight and on hot days I used to get axle overheats regularly with my PP1 car with the BG fluid. The light would only come on up the back straight and would go out after getting to about Turn 3 or 4 on the next lap. This only happened on very hot days, which are not uncommon in the dog days of summer.

However, this year using Redline 75/140 I have had no overheats. No other track has given me any overheats, but Mosport is a power track where you are full throttle most of the lap and rarely below 90 mph or so. I am running in Open class so it's pretty hard on the car.

Do the non-Torsen cars even have a heat sensor in the diff? I've never looked at one so I have no idea. Based on what I saw in racing way back in the day, I would expect the clutch pack cars would produce more heat than a torsen unless the clutches were set to be almost locked solid. That's what the old Player's GM Camaros needed to keep them alive, any slip in the clutches and the diff would die a quick death from heat, had that happen to me personally while driving another guy's car which didn't have the clutch packs locked tight enough.

What track are you running, not Tremblant I expect given the lower speeds.

 

[JAL racing]

What track are you running, not Tremblant I expect given the lower speeds.

Hi JDee,
I mostly drive ICAR, a 2.1 mile track at the airport in Montreal (therefore it is perfectly flat - see attached pic). Calabogie, Mont-Tremblant and ICAR are all the same 1-3/4h driving time for me, but ICAR has HPDE nights every Tuesday and several all day events throughout the summer for very cheap. I focus on this track to gain experience because it is 25$ (CDN) per 20 minute session, so I can get a lot of track miles this way.
I would like to go to the bigger tracks next year but it seems very difficult to be able to go with any regularity. And Tremblant and Calabogie are very expensive at around 500$ per day, with 4x 30 minute sessions, and very infrequently during the season. I don't know if I can improve much on a track if I can only go 3 times a year. What is Mosport like? Is it possible to HPDE there with any regularity without being a millionnaire? I want to try it for sure. I've been to Tremblant and really enjoyed it.
Watkins Glen seems to be open frequently to HPDE and is about the same distance for me as Mosport. I look forward to going to the big tracks but I'd like to find one I can go regularly and will give me good $ per track hour so I can improve skills.

 

[JDee]

Speed Therapy at Mosport is $439.57 tax in for 6 X 20 minute sessions, that's the least expensive group that I know of. You would have to start in Beginner until they get to know you and your skill level. For Mosport I would highly recommend starting in Beginner and if possible get a coach, they may require that anyway. That track demands respect, it is extremely fast, tied with Road Atlanta for fastest track in North America. An off at Mosport can be very expensive even if you don't hit anything. It is a must run track IMHO, a real adrenalin rush.

Shannonville is right beside the 401 about 15 minutes east of Belleville, their lapping days are only 200 bucks (plus tax). It is a very good learning track, mostly flat, lots of linked corners that teach you the importance of hitting your marks. Blow one corner there and you've likely blown the next 1 or 2. If ICAR is flat then it looks like it would be a very similar type of track to Shannonville.

Calabogie is $375 if you go on a track day organized by the track, not by a club. It's a long track if you run the full course and it's similar in nature to Shannonville though not flat so a little more interesting.

Then there's Atlantic Motorsport Park. @RES_22 can fill you in on that one. Might be a bit far east though.

 

[RES_22]

Yeah JDee...you nailed this. Shannonville is absolutely the first and best place to make the transition from a prefab facility like Mirabel to a traditional track...ancient training facility (like TMP). Lots of consequential corner combos and camber changes that force you to get ahead of the car. And cheap track time...dirt cheap lol.

Tremblant is awesome...but more racing oriented vs hpde. And expensive per lap...then again, it's owned by Larry Stroll...and he didn't get rich by giving stuff away.

Mosport (CTMP...euuuch) is *that* track...not for anyone who can imagine what an off at 150mph might cause...lol. It's a bucket list spot once you've done Shannonville and Tremblant a few times. And the JRP crew are top notch. Fantastic value per lap at what they charge.

And ssshhh about AMP...it's supposed to be Canada's Area 51. Don't talk about it until after you drag yourself out here and try (survive) it .

PS: I've tracked a lot of big power Subarus with Torsens and with clutch pack lsds. All things being equal, a loose clutch pack lsd runs hotter than a decently set up Torsen. And a Torsen is kinder to the fliud, the pump, filters and coolers since it doesn't shed abrasives.

 

[JAL racing]

Yeah JDee...you nailed this. Shannonville is absolutely the first and best place to make the transition from a prefab facility like Mirabel to a traditional track...ancient training facility (like TMP). Lots of consequential corner combos and camber changes that force you to get ahead of the car. And cheap track time...dirt cheap lol.

I might try Shannonville... The last HPDE day is this coming Friday!

 

[mikeD4V]

There is no diff temp sensor on the non-PP cars so no limp mode for diff heat.

 

[RES_22]

You'll have fun at Shannonville. Surface is smoother than ICAR...car will have a more relaxing time putting down power and in braking zones. Also, surface is darker, so it'll warm up faster, have grip earlier and hang onto it longer than ICAR...very shallow sun angle this time of year in the Snowy North...