Wider tires on sport rims?
 

As I wear my way through the stock rubber on my sport rims, I'm looking for my replacement tires. I've pretty much decided on the Ventus v12s. However I'd like to go wider on the tires, particularly the rear.

So, a couple questions:
1) How much wider can I go on the sport rims? Stock rear size is 275/35R19 and front 245/40R19. I don't want to push the limits or stretch/squeeze the tires.

2). How do I keep the rolling circumference the same? For example, if I can put 285s on the rear rims, do I still keep the 35 proportion?

Thanks in advance.

I think 285/35-19 on the rear is fine,same size as the NISMO 370Z..

Someones already put 305s on the stockers

I have 295's on a 10" rim and wouldn't go any wider personally.

Just checked Hankook's size chart and in 19" you could go 255/35 Front and 295/30 Rear which have the same overall diameter front and rear (26.0) but are a bit shorter than stock. Differences with the shorter tires would of course be ride height (car would sit about .3" lower) and a little quicker off the line, with a corresponding loss (marginal) at the top end. You would also gain a little understeer with a 40mm stagger (difference between front and rear), likely not a big deal anywhere outside of the track (especially considering the Nismo has a 40mm stagger stock). Sways would make a big difference here.

Closer to stock diameter you could go 255/40 Front and 285/35 Rear (don't see a 295/35 listed), which are close enough to each other in overall diameter (within .2") but just slightly taller than stock.

Personally I'd go with the 255/35, 295/30 option, especially if you plan to add sways.

I'm running the Hankook V12's 305/30/19 Rear 255/35/19 fronts. The rear tire has a slight squeeze, but not too bad IMO. A 295 would be more Ideal for a 10 rim. I'm planning on changing to 10.5 rim very soon, so thats was why I went with the 305.
Overall the car feels very good, great tire for the money. :tup:
I'm running the Eibach springs with 15mm frt & 20mm rear wheel spacers. No rubbing issues on the fenders what so ever. However since these tires are slightly smaller in height I have notice that my front wheel air diffusers and chin spoiler scrape more often on driveways and large bumps. I was hoping to go with coil overs and lessen the wheel gap by about 1/2 inch more, but now I'm re-thinking that. I would definitely have to remove the chin and wheel deflectors if I did that, I'm actually considering taking them off now.

Thanks for the advice guys. I've written down my specs for the V12s...going with 255/35 and 295/30s. Can't wait to burn through my stock rubber now so I can make the upgrade :)

Why would those tires benefit from sways? Would they compensate for understeer in a 40mm stagger setup? I'm rather new to some of these mod interactions.

Any pics?
(OT) I am about to pull the trigger on some wheel spacers 15mm fr & 25mm rr and remember your comment on another thread suggesting to consider the 20mm rr in the event I may want to oversize the rear tire upon replacement and rubbing issues.

(back on topic) My question (even though I know you went with 305's on the rear), do the oversize rear tires look out of place on the sport rim? I have seen in many cases with oversizing the tire on stock rims and they look like the Michelin man.

Here are some pics with the 305/30/19 rear and 20mm spacers and 1"inch drop. IMO: I don't think the tire bulge is all that bad, but Ideally I would prefer a 10.5 rim :-)
As far as 25mm spacers go, I personally wouldn't do it, unless you have some neg camber, as it stands with mine I dialed out the camber with some SPC adjustable arms, the 25mm spacers would probably make the tire stick out past the fender.

Looks good to me. I don't see too much bulge. Do you have a pic from the back so I can appreciate the super wide rubber?

You lads should read and understand this before messing with widths :tup:

Dunlop Tires | Care & Maintenance | Rim width and aspect ratio

Some of the pros here are better equiped to answer this, but from my research, aftermarket sways will typically reduce understeer and move the car back towards neutral. For example, I am about to add Stillens to my car, daily driver. The fronts are 29% stiffer than stock, and the rears, in their stiffest setting (which everyone here recommends, as well as Stillen) are 70%stiffer than stock. So you can see, this sway setup will dial oversteer back in, taking the car from factory understeer more to neutral. A 40 or 50mm stagger will add understeer, so if your sway setup has taken the car to neutral or slight oversteer, that much stagger will dial some oversteer out.

John

My other car was parked behind it, so I couldn't get one. We just installed the new Berk catback exhaust last night, so I will be taking pics of the back, as well as video of the new awesome sound! :tup: This car sounds like a baby Ferrari now!!

Definitely in for Berk CBE pics and vids :)

Wait...you have the final production Berk exhaust with the X pipe?