Clutch Slipping on stock A91 MT...

[Eastwood]

Thanks for the shoutout @Eastwood ! We have been removing these CDV from BMW vehicles for well over 10+ years now with good results. They don't usually affect clutch wear/tear but usually allows you to do a much harder (read regular MT) 1-2 shift if doing a power shift or hard shift without much trouble. Without the CDV removed it will cause issues on a hard 1-2 shift - a delay and sometimes difficult to slam it into the 2nd gear. There is plenty of info on this issues with regard to BMWs. If you anybody wants to do reading from a good source without conjecture:

https://www.zeckhausen.com/catalog/index.php?cPath=6562



There are threads on this forum if you want to reference it. But the below attached picture someone posted is where its located - and it has to be removed from inside the Slave Cylinder. After removal you will need to properly bleed the Clutch Slave cylinder so there is no air in the line.

No problem! I specifically went to Speed Logic because of the extensive BMW knowledge and experience and now with A90 Supra experience.

I definitely felt a difference and would recommend the CDV delete being done at Speed Logic.

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[FLtrackdays]

I was just thinking about this, track use really exposes weak links in the hardware (car) and software (driver). Toyota must have been "pretty confident" the MT's can take some abuse if they're encouraging us to run at least one track day.

And right, if the cars do have issues there should be a trend and hopefully Toyota will take note. Otherwise I suppose we're stuck with aftermarket solutions... Let's hope they're listening (esp. manufacturers familiar with the B58 engine), this is a potential opportunity for them to cash in if the OE clutch ends up being an issue.

I just got my info packet in the mail yesterday from NASA, I plan to run the car later this year and see how it goes. I'm really excited to melt my clutch

Glad you’re going to track that bad boyEE!

 

[Pizza]

Alright reporting back after my first track day:

I reached 1000 miles quite literally as I pulled into the paddock. I've been half following break in done some pulls here and there after 250 ish miles. Been pretty nice on the clutch though, nothing jerky or slamming gears. Temperature for the whole day was about 45° F, so definitely could've helped with any potential heat issues.

The transmission performed great overall. Rev-match, quick shifts at WOT, slight intentional slippage on launching, me being dumb and not smooth with the car etc. all went off without a hitch. I did notice a few anomalies though.

- I thought I experienced the described slippage once on the back straight going from 3rd to 4th. As I went to 4th, the revs were climing, but it just didn't seem like the car was putting power down. I was paying attention after that and it seemed normal for the rest of the day, so maybe it was just my imagination. Also I did a lot of hard 2-3 shifts and it pulled hard every time without issue.

- The one thing I did notice is on a couple fast gear changes, the clutch pedal didn't return/follow my foot up quite as fast as I would've liked. I would assume I can attribute this to the CDV or the stock fluid getting too hot/getting some air in it.

Pretty happy with the result, and I'm definitely going to hold off on buying a clutch until I experience anything concrete. Probably going to do better fluid soon and a CDV delete at some point.

 

[mdpalmer]

Alright reporting back after my first track day:

I reached 1000 miles quite literally as I pulled into the paddock.

Congrats on the magic 1k mile mark! Hell yeah SEND IT! I love hearing people actually enjoying the car.

Speaking of MTs at the track, check this guy out he's absolutely flying in his MT. Anybody know him or his clutch/car setup?

 

[Stvee]

Someone on one of the facebook groups posted that they tested it out and the E90 slave cylinder works fine on the Supra. That slave cylinder doesn't have the CDV from the factory. This is just another option if you don't want to modify the stock slave cylinder by removing the valve.

BMW part# 21526785964 -- costs around $80

 

[AJRMKV]

I did a 500 mile clutch break in with city driving. Did plenty of WOT in 2nd 3rd and 4th with no issues whatsoever for the next 100 miles, although this clutch does not like fast shifting.

 

[Stvee]

I did a 500 mile clutch break in with city driving. Did plenty of WOT in 2nd 3rd and 4th with no issues whatsoever for the next 100 miles, although this clutch does not like fast shifting.

Removing the CDV helps with that. I've done it on every BMW I've owned.

 

[UYCR]

Someone on one of the facebook groups posted that they tested it out and the E90 slave cylinder works fine on the Supra. That slave cylinder doesn't have the CDV from the factory. This is just another option if you don't want to modify the stock slave cylinder by removing the valve.

BMW part# 21526785964 -- costs around $80

I will probably still mod mine but thanks for sharing this PN in case I mess something up .

 

[Cptnslo]

This may have been shared on here already but I just saw it and figured it’s worthwhile.

 

[bushido]

Toyota USA:
"Let's go own the weekend."

 

[RyanA90]

Someone buy that and give us a DIY install pls and thx!

 

[robotvoice]

This may have been shared on here already but I just saw it and figured it’s worthwhile.

There's literally no proof that this is causing people to "burn up their clutch". I'm sure it helps fine with better pedal feel and power shifting, but it's ridiculous to claim this is a solution to a problem that isn't even fully understood yet.

 

[lucky phil]

There's literally no proof that this is causing people to "burn up their clutch". I'm sure it helps fine with better pedal feel and power shifting, but it's ridiculous to claim this is a solution to a problem that isn't even fully understood yet.

If indeed it actually is a "problem". It's like Mastermind sometimes. Your specialist subject?.....answers to problems that aren't yet proven to exist, lol.

Phil

 

[UYCR]

Someone buy that and give us a DIY install pls and thx!

Remove clutch line, loosen two bolts and reinstall in reverse with part that doesn't have CDV. Then bleed the system.
Or remove clutch line to be able to remove CDV with a wood screw. Then put back the line and bleed.

Just look up videos on how they do it on BMW's pretty much the same thing.

 

[FuzzyRev]

Well look what I got this morning...

..and here's the little bastard we all want to be rid of

One key thing to note, is that the BMW #21526785964 people are talking about is not the BMW number stamped on the MKV slave cylinder. The actual BMW part number on this is #21526795713, so that's what I'd recommend ordering instead.

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