245/30/19 on Stock 326rims

[timber511]

Hi guys

In order to reduce the understeer, I am considering to put 245/30/19 tires on my z435is. Do you guys think i will have rubbering issue ???

[jparnes1]

Originally Posted by timber511

Hi guys

In order to reduce the understeer, I am considering to put 245/30/19 tires on my z435is. Do you guys think i will have rubbering issue ???

Only if your girlfriend makes you. Otherwise, no rubbering issue.

[jannisa]

On an 8 inches rim like your front one 225 is the maximum optimal size you can use.
245 and even 235 won't function properly.

[09cbb]

Originally Posted by timber511

Hi guys

In order to reduce the understeer, I am considering to put 245/30/19 tires on my z435is. Do you guys think i will have rubbering issue ???

No. I run 235/35R19 on my 296 (8" width) without any problems. 245 might look a bit bulgy and donuty on the wheel. What are you running on the rear wheels? I went with 265s for better overall balance.

I hope you are not buying non-RFTs!

[09cbb]

Originally Posted by jannisa

On an 8 inches rim like your front one 225 is the maximum optimal size you can use.
245 and even 235 won't function properly.

I am sorry, but that's not correct. 245 might be borderline, but 235 work just fine.

[timber511]

i plan to keep back as 255 35 19 , just change the front to 245/30/19

[jannisa]

Originally Posted by 09cbb

I am sorry, but that's not correct. 245 might be borderline, but 235 work just fine.

I am not saying it won't fit, all I 'm saying is that both tires (235-245) will be limited by the width of the wheel and they will marginally deform when under load while cornering.
This guy in germany has a racing background and is performing alignment on the Zs with stunning feedback by his customers.

Here is his take on tire dimensions on post #8, if anyone can read german it is very informative as his team has already dealt with practically every case of motor, suspension (normal, adaptive, kw3), rim size, antirollbars, lowering springs, tire type (rft, non rft) and plenty tire brands, all on our e89.

http://www.zroadster.com/forum/index...fassung.83627/

The whole story behind his project:

http://www.zroadster.com/forum/index...ahrwerk.82318/

[ManiacGT]

You would be better off looking at rear camber alteration. Reducing camber at the rear will reduce understeer at the front.

[jannisa]

Originally Posted by 09cbb

I hope you are not buying non-RFTs!

Sad but true.
I recently mounted back my old rft for winter storage and (compared to contis sc3) I have to admit that I preferred the feel while cornering and on high speeds with the rft, it felt like there were poly bushes especially on the front axle.

[ChuckB]

Originally Posted by ManiacGT

You would be better off looking at rear camber alteration. Reducing camber at the rear will reduce understeer at the front.

I can personally state that reducing rear camber does help significantly, I took 1 degree out of the rear settings and it is a huge difference, not to mention the improvement in rear tire wear.

[ChuckB]

Originally Posted by jannisa

I am not saying it won't fit, all I 'm saying is that both tires (235-245) will be limited by the width of the wheel and they will marginally deform when under load while cornering.
This guy in germany has a racing background and is performing alignment on the Zs with stunning feedback by his customers.

Here is his take on tire dimensions on post #8, if anyone can read german it is very informative as his team has already dealt with practically every case of motor, suspension (normal, adaptive, kw3), rim size, antirollbars, lowering springs, tire type (rft, non rft) and plenty tire brands, all on our e89.

http://www.zroadster.com/forum/index...fassung.83627/

The whole story behind his project:

http://www.zroadster.com/forum/index...ahrwerk.82318/

The guy above is Dieter Weidenbrück, who drives for the "Z Racing Team", which is pretty successful. Dieter has been running in the VLN/RCN series for quite a while, http://www.zracingteam.de/cm/

[az34]

Originally Posted by timber511

Hi guys

In order to reduce the understeer, I am considering to put 245/30/19 tires on my z435is. Do you guys think i will have rubbering issue ???

you are gonna need aftermarket wheels to go as wide as 245's