Kujiwara
Well-Known Member
- Joined
- Aug 17, 2022
- Threads
- 3
- Messages
- 95
- Reaction score
- 126
- Location
- Vancouver, BC, Canada
- Car(s)
- 23 Supra AT Stratosphere, GLI32, SVT Cobra
- Thread starter
- #1
EDIT:
Thanks to everyone's suggestions and 2 alignments later the problem has been largely solved, the little bit of twitchiness remaining is most likely due to soft rear subframe bushings and short wheelbase and wide track + tires.
1. Essentially the car alignment was off from the factory, right rear being the worst (and still appears to be the common theme since 2020)
2. Dealer aligned it but wasn't accurate, however they did find the right rear toe adjuster loose.
3. (Thread #22 pg.2) Realigning at performance shop with the following specs and has worked well for me.
Front:
Camber: not adjustable
Caster: Not adjustable
Toe-in: 0.05 deg per side, (I think 0 to 0.10 is all fine, more in= more stablity but less turn-in, see what fits your needs and driving style, just make sure it's even)
Rear:
Camber: -2.0 (make sure it's even)
Toe-in: 0.18 deg per side, (again make sure it's even, 0.1x - 0.20 all seems fine depending on who is driving, all within factory specs still)
More alignment explanations in Page 2
Original Post:
Hi everyone,
I purchased a new 2023 Supra 3.0 AT just shy of two weeks ago, current experiencing some pretty new-to-me experience when it comes to bump steer. Before someone asks me to search "bump steer" I have already went thru all 6 pages of results and haven't found the exact same kind of descriptions as what I'm about to ask.
When I first bought it I noticed the wheel was off center and car was nervous over bumps when the right rear wheel hits certain bumps or holes on the ground. Took it in to the dealer at 500km for alignment they found the right rear toe adjuster was loose, retorqued, aligned pretty well, and drives straight. The next couple days I didnt drive into Vancouver which has a bunch of slightly below surface manhole covers (especially within the right side of most lanes), call it small annoying bumps.
A few days ago when car has around 650km I drove it in the Vancouver, these bumps and manhole covers seem to really upset the rear end (wobbling) when the right rear rides over them. I dropped the rear tire pressure from 39psi to 35psi and seemed to help a bit over a 100km drive in the city today, before doing this I checked all the bolts in the rear are still darn tight. I also ended up finding seems when left rear hits these specific kind of bumps it upsets the rear a bit too, but just most of these bumps end up being hit by the right side so I didn't notice it till later (need to let a friend drive tonight to see if it's just me)...
It may still just be in my head but I still think the right wobbles more. I have another appointment scheduled in 2 weeks at the dealer, other nearby ones can't seem to service Supras any earlier... Is this just the norm for driving a Supra in a large city with slightly crappy roads? I notice it more in Normal than Sport perhaps the suspension compresses more due to less compression damping (PHd's bump steer video shows not much toe change till ends of travel) and this is reaching that in Normal mode? 2023 does seem to ride softer than the 2022 I rented, perhaps this is amplifying the problem since it's reaching closer to the end of the suspension travel? Handling all seems fine when the roads are smooth even when it gets real twisty, this doesn't happen when I hit bigger bumps or small road cracks with one wheel, or any magnitude of bumps with both rear wheels... And no it's not tramlining I am asking about.
0.10 toe-in in each rear corner seems to be a bit low perhaps? Have owners with similar issues been able to reduce the effect of these bumps by having more toe-in let's say 0.17 or so?
I've asked a 2020 owner and he didn't notice, a 2023 MT owner that haven't noticed either, technician at the dealer (close friend knows him and he PDIs all the Supras) says Supra's have very bad bump steer cuz of wide 255/275 tires... I didn't expect it to be so affected by bumps either since I lurked here for nearly 2 years before buying my own and didn't see that many issues like this. Perhaps I'm too used to longer wheelbase sedans but my wife who doesn't know much about cars noticed the car relatively unstable over bumps too
Thanks to everyone's suggestions and 2 alignments later the problem has been largely solved, the little bit of twitchiness remaining is most likely due to soft rear subframe bushings and short wheelbase and wide track + tires.
1. Essentially the car alignment was off from the factory, right rear being the worst (and still appears to be the common theme since 2020)
2. Dealer aligned it but wasn't accurate, however they did find the right rear toe adjuster loose.
3. (Thread #22 pg.2) Realigning at performance shop with the following specs and has worked well for me.
Front:
Camber: not adjustable
Caster: Not adjustable
Toe-in: 0.05 deg per side, (I think 0 to 0.10 is all fine, more in= more stablity but less turn-in, see what fits your needs and driving style, just make sure it's even)
Rear:
Camber: -2.0 (make sure it's even)
Toe-in: 0.18 deg per side, (again make sure it's even, 0.1x - 0.20 all seems fine depending on who is driving, all within factory specs still)
More alignment explanations in Page 2
Original Post:
Hi everyone,
I purchased a new 2023 Supra 3.0 AT just shy of two weeks ago, current experiencing some pretty new-to-me experience when it comes to bump steer. Before someone asks me to search "bump steer" I have already went thru all 6 pages of results and haven't found the exact same kind of descriptions as what I'm about to ask.
When I first bought it I noticed the wheel was off center and car was nervous over bumps when the right rear wheel hits certain bumps or holes on the ground. Took it in to the dealer at 500km for alignment they found the right rear toe adjuster was loose, retorqued, aligned pretty well, and drives straight. The next couple days I didnt drive into Vancouver which has a bunch of slightly below surface manhole covers (especially within the right side of most lanes), call it small annoying bumps.
A few days ago when car has around 650km I drove it in the Vancouver, these bumps and manhole covers seem to really upset the rear end (wobbling) when the right rear rides over them. I dropped the rear tire pressure from 39psi to 35psi and seemed to help a bit over a 100km drive in the city today, before doing this I checked all the bolts in the rear are still darn tight. I also ended up finding seems when left rear hits these specific kind of bumps it upsets the rear a bit too, but just most of these bumps end up being hit by the right side so I didn't notice it till later (need to let a friend drive tonight to see if it's just me)...
It may still just be in my head but I still think the right wobbles more. I have another appointment scheduled in 2 weeks at the dealer, other nearby ones can't seem to service Supras any earlier... Is this just the norm for driving a Supra in a large city with slightly crappy roads? I notice it more in Normal than Sport perhaps the suspension compresses more due to less compression damping (PHd's bump steer video shows not much toe change till ends of travel) and this is reaching that in Normal mode? 2023 does seem to ride softer than the 2022 I rented, perhaps this is amplifying the problem since it's reaching closer to the end of the suspension travel? Handling all seems fine when the roads are smooth even when it gets real twisty, this doesn't happen when I hit bigger bumps or small road cracks with one wheel, or any magnitude of bumps with both rear wheels... And no it's not tramlining I am asking about.
0.10 toe-in in each rear corner seems to be a bit low perhaps? Have owners with similar issues been able to reduce the effect of these bumps by having more toe-in let's say 0.17 or so?
I've asked a 2020 owner and he didn't notice, a 2023 MT owner that haven't noticed either, technician at the dealer (close friend knows him and he PDIs all the Supras) says Supra's have very bad bump steer cuz of wide 255/275 tires... I didn't expect it to be so affected by bumps either since I lurked here for nearly 2 years before buying my own and didn't see that many issues like this. Perhaps I'm too used to longer wheelbase sedans but my wife who doesn't know much about cars noticed the car relatively unstable over bumps too
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