Hi everyone, another one where I'm not sure if this has been discussed before, but genuinely at a loss.
So after fitting new wheels, my car decided to start playing up on right hand turns, causing TCS and VDC lights to flash on the dash and brake the car. Originally I thought this was down to my tyre setup, so since then I swapped to a staggered tyre setup on 9j all round wheels,
running 245 40 18 front and 265 40 18 rear. Originally believing that was within tolerance and would sort the issue. The drive quality definitely became better but the issue hasn't gone away.
I have tried adjusting toe various ways, thinking it was an alignment issue but still having the issue.

The only thing I can think of is maybe the wheels simply do not want to work with the car, for reference I have to run 20mm spacers on the front to clear the brakes and run nothing on the rear, would this cause a fault?

Genuinely at a bit of a loss for what's happening so as much as I like these wheels and on left hand turns they perform brilliant, is it something best solved by selling them and finding some different wheels or something I can sort?

Appreciate absolute any advice (or slander for me not thinking about wheels clearing the brakes!)

Happy to provide more information about my setup if needs be.

Cheers!

 

Any suspension work, lowering springs , headers or anything installed ?

 

Yeah its got, coilovers and some adjustable upper control arms. Was happening before the upper control arms though.

 

Another possibility is the stagger (at ~2.5% for a 246/265 combo} isn't enough and speed sensors are telling ECM to trigger VDC.

Typical stagger is roughly a 30mm tread width separation F-R or equating to about 2.9% as ECU is looking for a 3.0% +/- 0.25% speed differential.

 

Ah ok! That would make sense, I tried to get as close to spec as I could, but chickened out on putting a 275 40 on a 9J! Is that something achievable on my previous post I believe it was said performance fall off was at 120% so would that be ok, having a 265 40 on at the moment I don't think fitment or rubbing would be too much of an issue. So mainly just practicality, Alternatively are their any other size I could pair with the 245 40 front to reach spec?
I phoned a specialist and they were convinced it was still wheel size, but I didn't understand how that made much sense as realistically the contact patch would still be a stagger? (Correct me if I'm wrong, I am absolutely stumped with it all!)

 

What sort of size would you recommend? I phoned a local specialist and they were convinced it was the wheel setup not the tires, but I thought the contact patch being staggered wouldn't make a difference for the wheel size. Would a 275 40 18 work with a 9j wheel, I believe this was recommended last time but chickened out thinking it would be too much for the wheel, now with a 265 on the rear I don't think that would be an issue. Alternatively are their any other sizes that would work with a 245 40 18 front? Appreciate any help I've been absolutely stumped for the last couple weeks, Cheers!