A80 Toyota Supra

PerformanceSound

Well-Known Member
Joined
Aug 18, 2017
Threads
19
Messages
1,873
Reaction score
3,357
Location
USA
Car(s)
2020 Tundra TRD Pro, 1994 MKIV Supra TT
Vehicle Showcase
2
He used to own a MKIV back in the day so I'm sure he's got a bit of fondness for the Supra.
Yeah, I remember. He also owned two NSX's and a few several Porsche's...one of which I believe is a Shark Werks. Joe is a big gearhead, and he said one time (I think on someone's podcast) that he regretted selling his MKIV Supra...it was the only fast sports car he owned that never gave him problems.
 

XtremeMaC

Well-Known Member
Joined
Aug 8, 2018
Threads
41
Messages
2,957
Reaction score
3,205
Location
_________ SE Michigan, USA
Car(s)
2020 Supra
This it?


Same
 

XtremeMaC

Well-Known Member
Joined
Aug 8, 2018
Threads
41
Messages
2,957
Reaction score
3,205
Location
_________ SE Michigan, USA
Car(s)
2020 Supra

vb22

Well-Known Member
Joined
Jun 7, 2017
Threads
6
Messages
1,814
Reaction score
2,510
Location
USA
Car(s)
SC300
Alright that means whole world needs to cancel him right now. :flame:
Right lol.

Also one of Supraforum's mod removed the profile and seems to be making excuses for the driver/shop owner.

https://www.supraforums.com/threads/mechanic-wrecked-mkiv.1129014/page-2#post-14008301

Emphatically confirmed it was a technician doing a check drive after work performed on a paying customers car. Likely if not probably the owner of the shop, whose name and social media screenshot I deleted from another SF member's post upthread.

Based on the video and various accounts of the incident, as well as pictures of the wreck, my semi-educated wild-ass-guess is this:
An older ~900hp capable build on older engine management with zero traction control features,an incredibly poor choice of performance tires in general for a high HP RWD car (wreck pics appear to show Nitto Invos), cold weather that made those tires even worse to drive on, and likely a stock torsen diff doing what we all know the stock torsen diff tends to do when you combine lots of HP and especially in low traction situations - unlock unpredictably and seriously upset the car.

In the video you can see the car accelerate and step out a little bit to the left. The driver countersteers but it swings out a bit further to the right with a slight overcorrection. Then you see the car nose-down as the throttle is lifted. At that exact moment it almost looks like the inside (right side) rear wheel starts braking because the car rotates harder to the right, which is very consistent with how the stock Torsen LSD acts. The low traction from the cold and the poor tire choice only exacerbated and lowered the threshold for that shit.
Based on the video again, and how the car accelerated, I'd bet it was on wastegate boost or pump gas boost levels it wasn't on the 'let it eat' setting at all.

Sucks for the owner, sucks for the driver, sucks if that guy is the owner of the performance shop, it all just sucks.
It's only made worse by the peanut gallery and bloodthirsty court of internet justice who think themselves invulnerable to such mistakes trying to make that dude's life even worse. Doxxing that guy or dragging his name or the shop's name through the mud isn't going to enhance the end outcome for the owner of the now-wrecked car nor is it going to make that dude feel worse than he already does.
 

C-Pike

Well-Known Member
First Name
Chris
Joined
Jan 15, 2022
Threads
4
Messages
285
Reaction score
520
Location
N.A.
Car(s)
Supra

vb22

Well-Known Member
Joined
Jun 7, 2017
Threads
6
Messages
1,814
Reaction score
2,510
Location
USA
Car(s)
SC300
They're probably friends lol. Also mistake my @ss... he was flooring it and went well over the 55 mph speed limit. The camera car was already going around 80 mph.
Yup, here is the proof.

_nc_ohc=meG7i8Z27H0AX9wjYsL&_nc_ht=scontent-hou1-1.jpg
 

gymratter

Well-Known Member
Joined
Dec 29, 2014
Threads
15
Messages
1,046
Reaction score
1,162
Location
TX
Car(s)
Silver Spur & F-150
the full vid for all those that dont wanna click on a bunch of random links

 

KahnBB6

Well-Known Member
Joined
Aug 23, 2018
Threads
24
Messages
1,224
Reaction score
1,726
Location
Florida
Car(s)
'93 Lexus SC300 2JZGTE R154 LSD & 2023 GR86 6MT
Right lol.

Also one of Supraforum's mod removed the profile and seems to be making excuses for the driver/shop owner.

https://www.supraforums.com/threads/mechanic-wrecked-mkiv.1129014/page-2#post-14008301
I'm not going to defend the mechanic who did the work and who drove the car. I don't know anything about him or his shop. The Supra was in his care while he was servicing and tuning it.

But that SupraForums member Wreckless is a well known senior member there and is a No-BS fellow. He knows his stuff regarding MKIV's and tuning them forwards and backwards.

...

Now as to that car and what happened... the very first thing that I thought when I saw the video of the wreck was that it looks EXACTLY like how a stock Torsen T-1 LSD does when it steps out to the left and then SNAPS back.... which usually causes a severe loss of control and usually a wreck or potential spinout.

I should know. I still have one of those T-1's installed in my SC300 5-speed (which has never had factory traction control like all 5-speed M/T SC's and MKIV NA M/T Models). A 200mm version from a factory MKIV TT Automatic model.

Even when my SC had its stock NA engine and that LSD had 4.272:1 gears bolted to it after I swapped it in I had a couple of far lower powered snap-oversteer loss of control situations like that when I was first getting used to it and when I had tires on the car with very poor wet road traction.

After that I learned how to avoid it and better understood where its limitations as an LSD are.

I also researched and installed much better tires with superior wet road traction almost immediately after it first happened to me.

Today I still have that same Torsen T-1 LSD in my car now with a mild 350hp after my 2JZGTE swap.

I am OK with mine because it's basically just doing duty against a near stock tune engine that is only driven around normally in the city.

If I were going for even 500whp in my car I would swap it out immediately without a second thought. It's just very old LSD technology by today's standards and not truly safe and predictable beyond even a 450whp power level.

....

The Torsen T-2 LSD that later model Supra MKIV's, Soarers and Aristos got does not exhibit this issue. It is a characteristic of the Torsen T-1 in either a very low traction road situation with too much power applied...

...Or it is a characteristic of a dry road condition with over 500whp applied through it. The T-1 design does not handle power reliably or predictably past 450-500whp in the SC/MKIV/Aristo.

And yet they are very rare, in demand and go for $800-$1,000 used if in good working condition as a full TT Auto stock LSD pumpkin.

People have commonly made the mistake of putting HUGE power through them and have had loss of control situations like this happen.

Again, not so much an issue with the Torsen T-2 LSD design. Just the old T-1.

.....

I would like to know more fine details about the decisions that lead up to this test drive but based on the way that Supra MKIV initially lost control in the video it REALLY looks to me like the engine was tuned a lot but no one thought to take out the factory Torsen T-1 LSD and replace it with a more appropriate and safer 2-way clutch type LSD, Kaaz 1.5-way clutch type LSD or OS Giken 1.5-Way clutch type LSD.

And since this wreck involved the mechanic who tuned that MKIV and was responsible for it while it was under his shop's care... IF it is truly the case that the car was still running a T-1 LSD that was a HUGE liability waiting to happen with anything over even 450whp.

That and possibly not having any aftermarket traction control against a very high powered 2JZ turbo engine. That could also be a strong possibility here (as Wreckelss mentioned in his SF post).

...

I don't know anything more than the video I saw with *looks* to me like the behavior of an overloaded and at that point unpredictably behaving Torsen T-1 causing that sudden violent snap oversteer under acceleration.

Aftermarket traction control and better LSDs have existed for the MKIV's for years now.

It's very sad all around. I'm glad to learn that the mechanic is physically OK after that horrible wreck. For the owner of the car... that is a heartbreaking complete loss of his classic car model that is becoming ever rarer each year.

I find it impossible not to imagine that something leading up to this crash could have been prevented beforehand.

It just really looks to me like Torsen T-1 LSD behavior above 500whp at play.

....

Honestly having experienced in the past how badly a Torsen T-1 LSD can "bite" you if you're not careful with it I am considering once again upgrading to a much more predictable and thus overall safer OS Giken LSD in the near future.

Note that the 2002-2005 IS300, Toyota Altezza, FRS/GT86/BRZ/GR86, GR Corolla and even some Lexus F and F-Sport models all use the far better Torsen T-2 LSD design. And as I mentioned above the later Supra MKIV's, later Soarer Z30's, later Toyota Aristo "V" models, all the 1JZ-GTE four-door 5-speed manual JDM Toyota performance sedans and the limited run JDM Mark X GRMN 6-speed M/T sport sedan also use their own versions of the Torsen T-2 LSD design.

All with some form of traction control as all modern cars come with.

Toyota and JKEKT Corporation retired the Torsen T-1 LSD design many, many years ago for a good reason. It was revolutionary through the 1980's especially with Audi Quattro rally cars, Celica GT-Four rally cars and several other performance cars of that era but the improved Torsen design that lives on in today's production cars is far more predictable and thus safer to offer.

It's good as a stock to mild power capable LSD that needs no maintenance except for a normal 75W-90 GL5 synthetic gear oil change every 20k-30k miles. Un-abused under mild stock power they can last for a VERY long time (300k miles or more). This is why I still use one in my SC300.

But a high powered car like the one in the video has zero business running an old Torsen T-1 LSD. Usually the result that happened here is the common horror story that many MKIV Supra owners have reported over the years.

It's the single biggest reason why aftermarket LSDs and today's aftermarket traction control offered by standalone ECUs are popular today in the Supra MKIV (and turbo SC) tuning community.
 
Last edited:

Supra93

Moderator
Staff member
Moderator
Joined
Jul 7, 2014
Threads
82
Messages
2,486
Reaction score
4,339
Location
TX
Car(s)
Supra & RX7
The profile screenshot was removed because we don't know for sure who was behind the wheel. However, I replaced it with a link to the shop which is fair game IMO. Customers should have info regarding good and bad shops, and in the end, it was the shop's responsibility to get the car back safely to the owner.
Sponsored

 
 




Top