I'm seriously considering this size and need to know how the VDC/ECU will handle it. It's the closest sizing I could find to match up with oem diameter and circumferences.

Thanks for any info. or help.

 

That is quite a width stagger from front to rear, and while I understand the need for traction with an FI setup, I think such a width stagger will lead to detrimental effects on handling, with the car likely understeering significantly more than stock. I would look for at least a 265/275 up front. 265/25/20 or 275/25/20 would be best, assuming you have a 9.5" front

 

245/35/20 Front 285/30/20 Rears.

 

255x35 and 295x35 with no slip issues

 

245 streets/ 295 drag radials, no prob

 

I understand what you're saying but to give you an example of even a much larger stagger than I'm looking at, consider the Ruf 911 Rt 12. It's tire set up is 255/35 ZR19s & 345/25 ZR20s. This Porsche tuner is world renowned for it's performance modifications. So I'm guessing the stagger I'm looking at shouldn't be a problem, but I could be wrong. Does anyone else have an opinion?

I'm running an 8.5" up front so the largest I could go would be 255/30/20 but the problem with this is, the front tires will be larger in circumference than the rears, that's no-no with our VDC/ECU.

 

You are talking about a completely different car setup in that case which was track tested to obtain those results. The weight distribution in a 911 is significantly different compared to a 350z/g35. Being rear engined, more weight is concentrated in the rear, so in a turn, the car is more likely to rotate and swing the rear end out, hence the need for wider rear tires. In the case of the g35/350z, the engine is in the front, so if the front is undertired compared to the rear, it will slip first, hence the undesteer. I don't know of anyone runnin that much discrepency in widths. I run a staggered width of 245/285, and I already feel the car understeers quite a bit, and I'll be going to 255 in the front with the next tire change. But in the end, its your choice.

 

This is a close call because the difference in circumference is only 0.839%. I would prefer to see 1% for VDC. As you know, VDC looks for a difference in tire RPM. I do not have those numbers available

 

Makes sense on what you're saying. I'll obviously look into it a little further before I decide. Thanks for the input.

 

Ok, so if If I go 255/30/20s & 305/25/20s will the VDC/ECU have a fit?

According to kcobean's sticky thread, the rears should have a larger circumference than the fronts. 255/30s are 81.74" and the 305/25s are 81.68", is this close enough to not cause a problem?

 

I was gonna use the Porsche example also, they do crazy staggered fitments and the cars handle great. Id say go for it.

 

Ok, so if If I go 255/30/20s & 305/25/20s will the VDC/ECU have a fit?

According to kcobean's tire/VDC sticky thread, the rears should have a larger circumference than the fronts. 255/30s are 81.74" and the 305/25s are 81.68", is this close enough to not cause a problem?

 

Your original numbers (245/30 & 305/25) are about 0.2" different in OD. That's on the lower limit of the recommended stagger of 0.25 to 0.75". You probably won't have any problems with VDC/TCS unless the tires are actually different than the calculator estimates. Remember that the size calculators are mathematical estimates, the physical tire may be slightly different in size.

The 255/30 & 305/25 combo will likely cause problems because of the taller front relative to the 245/30 choice.

 

Thanks, I appreciate the info. Another member runs 255/30 & 305/25s and I'm waiting to hear from him how it's done for him.

 

I'm running basically the same thing on 19's (see my sig) with no issues

 

Im running 265/30/19 fronts and 275/30/19 rears with no VDC problems if that helps any...

 

I never said there would be "problems", simply that handling could be affected, most likely resulting in excess understeer. Alot of people have already reported more neutral handling with minimal to no width stagger, and my explanations above explain why an extreme width stagger can result in understeer characteristics.

 

I am running 255/30 R20 on 9.5" +22 offset and 295/30 R20 on 10.5" +22 offset. The overall diameter of this tire is almost exactly same as stock. The front is exact same diameter, rear is .3" bigger in diameter. Absolutely no VDC issues, I did have to roll the rear fender. I am lowered on GF210's.

 

This is also the size I'm considering. I noticed you're driving on the exact tires I'm looking at in this size, Proxes 4s.

I was actually going to post a new thread asking for reviews. So how do they perform? I've heard they're very comparable to summer tires in performance, if not better than most.

 

They are excellent! Very impressed with the tire for the money. Not sure if you know about this site. http://www.treadepot.com They have awesome prices and extremely fast shipping. This is were I got mine. They are a little bit noisy, but that sort of thing doesn't bother me. They are pretty decent in rain as well. By far probably the best tire for the money. If you get these I have the PSI recommendations for them too.