Supra Bump Steer fix...

Rocksandblues

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what was/is different in the rear components 2020 vs 2021?

Have not experienced any rear wiggle up to 135 on home track in my 2021 but there are not a whole lot of hilly turns. It feels plenty planted at 130 backstretch into a 65 mph turn one. And feels stable through "s" section that ave 80-90 mph
 

Escapist

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Oh shit well TIL this is a thing. The Supra is my first RWD car and sports car in general for that matter so I thought what I was feeling was normal for a vehicle with a sportier/stiff suspension.
 

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I've not noticed bump steer of any concern while driving my Supra on the streets. If there was any bump steer I felt, then it was no more than light tramlining.
 

Rocksandblues

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I've not noticed bump steer of any concern while driving my Supra on the streets. If there was any bump steer I felt, then it was no more than light tramlining.
You won’t It’s not a street driving issue
 

BA9092

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The performance shop that did my alignment have been racing and tracking various JDM and Euro platforms.

They recently purchased a 2020 LE for tracking. When I asked them about the bump steer, they said they never had a problem. But did mention that the last M2C was WORSE than the 2020 Supra as far as handling, without any mods. :dunno:
 

JackieD86

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Just some clarifications on our thoughts:
Does the Verkline kit help with reducing bump steer? Yes, it is engineered to.
Does the Supra come from factory with bump steer? Yes, it is designed to have bump steer, this car handles with a real sense of agility and requires a driver's full attention.
The car 'loses rear toe in' on corner entries, which really helps the car rotate into these corners. It doesn't understeer, at all. On a tighter, twistier track, this can be thrilling and really easy to control, a little loose on the entry, grips up (more toe in) as you exit the corner. But at autobahn speeds or the fearsome Nurburgring, I can also see how it can be unnerving. Especially if Apex is using the car as a rental for customers of all skill levels.

For the majority of us, I think a reasonable ride height and a little more rear toe in will go a long way. If you absolutely hate the Supra moving around under you, well, the Verkline kit is there as an option for you. This is my honest opinion.
 

Supra Werty

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The video is interesting because they don't actually explain what they did to the geometry to fix the "problem"

The only thing that I can see is the slot for toe arm. But I don't see how that makes much sense because the arm is also length adjustable

Replacing the rubber bushings is the real fix in my opinion (not an engineer) . Taking out all the deflection makes the geometry work as intended.

I'll be going with SPL.
 

nibble

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Just some clarifications on our thoughts:
Does the Verkline kit help with reducing bump steer? Yes, it is engineered to.
Does the Supra come from factory with bump steer? Yes, it is designed to have bump steer, this car handles with a real sense of agility and requires a driver's full attention.
The car 'loses rear toe in' on corner entries, which really helps the car rotate into these corners. It doesn't understeer, at all. On a tighter, twistier track, this can be thrilling and really easy to control, a little loose on the entry, grips up (more toe in) as you exit the corner. But at autobahn speeds or the fearsome Nurburgring, I can also see how it can be unnerving. Especially if Apex is using the car as a rental for customers of all skill levels.

For the majority of us, I think a reasonable ride height and a little more rear toe in will go a long way. If you absolutely hate the Supra moving around under you, well, the Verkline kit is there as an option for you. This is my honest opinion.
Correct me if i'm wrong..

sounds like it is not as big deal as the OP's youtube link says.. personally, I like it way this is as when I do this right on the corner, car rotates very fast unlike some cars has to turn on same corner forever...
 

geert.bieseman

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Just some clarifications on our thoughts:
Does the Verkline kit help with reducing bump steer? Yes, it is engineered to.
Does the Supra come from factory with bump steer? Yes, it is designed to have bump steer, this car handles with a real sense of agility and requires a driver's full attention.
The car 'loses rear toe in' on corner entries, which really helps the car rotate into these corners. It doesn't understeer, at all. On a tighter, twistier track, this can be thrilling and really easy to control, a little loose on the entry, grips up (more toe in) as you exit the corner. But at autobahn speeds or the fearsome Nurburgring, I can also see how it can be unnerving. Especially if Apex is using the car as a rental for customers of all skill levels.

For the majority of us, I think a reasonable ride height and a little more rear toe in will go a long way. If you absolutely hate the Supra moving around under you, well, the Verkline kit is there as an option for you. This is my honest opinion.
Guess you nailed it :)

It all comes down to how you like the characteristics of handling.
And as each circuit/track is unique, the same setup is not working (or not be perfect) for all of them.

I mean... that is the entire reason why racecars are setup differently each track and based on weather/track & driver conditions.
 
OP
OP
Reppunkamui

Reppunkamui

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Oh shit well TIL this is a thing. The Supra is my first RWD car and sports car in general for that matter so I thought what I was feeling was normal for a vehicle with a sportier/stiff suspension.
It isn't a RWD exclusive thing, FWD car suspension can be designed with bump steer too. Personally, I haven't noticed it on the A90, so there is a reasonable chance you haven't too... but for my 135i it has been noticeable a few times when on bumpy roads. Fortunately, that was a relatively easy fix, (replace rear subframe bushings).

No Bump steer I felt so far, not on public road nor track. I strongly believe OP's Youtube posts were clickbait. BTW, that video was posted multiple places here.
Look, they aren't my videos... I linked the previous discussion on these forums when others were concerned. I just thought it may be interesting for some people on the forum. Personally I haven't experienced it on my car either, but mine is slightly lowered with KWs so it is probably not the best comparison.

The car 'loses rear toe in' on corner entries, which really helps the car rotate into these corners. It doesn't understeer, at all. On a tighter, twistier track, this can be thrilling and really easy to control, a little loose on the entry, grips up (more toe in) as you exit the corner. But at autobahn speeds or the fearsome Nurburgring, I can also see how it can be unnerving. Especially if Apex is using the car as a rental for customers of all skill levels.
Thanks for the feedback, it sounds like the bump steer could likely be an intentional part of the suspension deisgn. Just clarifying, if we were changing alignment, a good general rule is to keep some toe-in for the rear wheels. Neutral toe may result in unexpected oversteer on entry?
 

JackieD86

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Just clarifying, if we were changing alignment, a good general rule is to keep some toe-in for the rear wheels. Neutral toe may result in unexpected oversteer on entry?
On a (relatively) high-horsepower, RWD car, it is almost always a good idea to have some static toe in at the rear. Neutral toe will 100% cause more oversteer on entry AND exit, whereas a little more toe in will help with traction as well.
 
 




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