I tried to do a search but didn't have much luck. I want to get a square setup for my is350 for some track specific tires. I would like to run 245/40/18's all around and was wondering if anyone had any ideas of it this is possible and if so what wheels and offsets I would need. I found a set of Evo X GSR Enkei Rims for cheap which are 18X8.5 with a +38 offset which I think may work. I am lowered about 1.5 inches and really can't stand any rubbing as this will be a track only setup. Any help would be great.

 

That would definitely work or you however you'll notice that the offset is going to be really conservative. Check out my Signature and you'll see my setup and tire specs.

 

Like the OP, I've been weighing my options for quite awhile now, but still leaning towards a square setup if I can find something that works well. I've asked about the Evo wheels on here before, and was told that you would need the lug nuts to go with them as well.

@e46m3lol - if the he wants to run 245/40/18 all around, I would think his setup would have to be somewhat conservative to fit up front if not stretching a narrower tire. Personally I'm thinking for my own car that I'd like to fit 235s vs. 225s if possible.

In any case, I'm still doing research, but interested to see how this turns out!

 

For a dedicated track setup you should also consider 17" rims/tires. You'll probably spend a bit more up front on wheels vs a set of (I'm guessing used) OEM Evo wheels, but you'll save money in the long run on cheaper tires that wear out quickly. There is a pretty big selection of competition tires in 245/40-17, which will also reduce your diameter a bit and might keep you from rubbing.

You've been to the track enough to know that anyone arguing that an 18" wheel handles significantly better than a 17" wheel (both on competition tires) is smoking something illegal in most states.

Just an idea

 

Thanks for all the info. I was thinking of running 17's as well but not sure if they will clear the 350 brakes. I also just remembered that I am currently running 245/40/18's in the rear so I may just put one up front and drive around and see how it works.

 

I'm running '06-08 17" OEM wheels on my 350 with winter tires now, due to budget this spring I'll be running summer tires on the same set of wheels. Some 350s came from the factory with 17" wheels as well. Eventually I plan on a set of 17 x 8.5" RPF-1s for the summer tires; I've been told by an Enkei vendor they will fit over the calipers as well.

 

^With that said, please note that not ALL 17" wheel will fit over the larger IS350 fron calipers.

That size front tire you might end up having rubbing issues up front, especially if you're lowered much.

GL!

 

^ Good point on 17" fitment.

Which size of tire are you saying might rub, 245/40-18, or 245/40-17? Shouldn't a fender roll take care of rubbing with either of those at a reasonable (2" drop or less) ride height?

 

I'd imagine since the OE front stock 18" wheel is 18x8 +45? (is that right?) with a 225/40 tire with plenty of room on the inside and outside...you should be okay in the front which means you'll have plenty of room on the rear.
You're adding about 13-14mm overall width to the outside of the wheel.
A 245/40 tire should be pretty sqaure on an 8.5" wide wheel but you're gaining 16mm of overall height to the wheel.

I ran an 18x9.75 +20 with 255/35 tire all around with no rubbing. I'm on air but i never rubbed when I turned full lock.
A wheel with 255/35 would be about 18mm shorter than a wheel with a 245/40 if that helps you.

 

Thanks for all the great advice guys. After looking around I am kind of leaning towards running a 17" rim as tires are so much cheaper and a 245/40/17 will give me a bit more clearance up front with a 2" drop. Dose anyone have any recommendations on 17" rims that will fit the IS350? Kind of want an 17X8.5 or 17X9 and unfortunately the stock 17s are just 8" wide. The wider wheels will give me a bit more flexibility to run something wider in the rear if I don't like the square setup. Don't really want to spend a lot of money here and used is cool as I don't really care about looks.

 

The answer to 17", light, track use, on a Japanese car is always RPF1! I think a 17 x 8.5 40 offset would work well, (30 offset would likely work as well, but that is putting the tire closer to the fender, which is probably the first place you are going to rub on the front) For a 17 x 9 I think the 45 offset is your best bet. There are several wheels in the PF01 family that would work as well with a ~1lb weight penalty compared to the RPF1.

As far as finding a set used, eBay is more miss than hit, I'd start trolling other message boards. 17" RPF-1s are very popular for the RX-7 & RX-8 crowd, and can often be found on those message boards with competition tires. If you have any local racer classifieds I'd look there as well.

 

Sorry to interrupt, i wonder that for some $4000-8000 forged lightweight wheels, are they made for track or more for look and brand name?? Why would someone pay so much more premium for it if something like Enkei RPF1 can perform damn good already?

 

It depends on what you are after and also the brand

For instance good track wheels such as Enkei wheels are great and budget minded as well.

However if someone wants a super light monoblock forged racing wheel specific for only track use then it can be pricey.

Why is this because in one day of track use you are putting your wheels through tension and strains that are not occurring during the DD.

This being said you can also get a great wheel for both on and off the track.

We have used are own wheels both on and off the track so we have figured what works and what doesn't.

Now the initial post the 18" wheel will work fine but be sunk in and not really pushed out towards the fender for wider stance.

17" wheels will need to be flat and a large X factor ( for brake clearance)

 

I have actually been looking a lot at the RPF1 and PF01 and they are my number 1 candidates for now. I really like the RPF1 but a lot of people say that big calipers are an issue with them and I have not been able to find anything to confirm they will fit the IS350 calipers without the use of spacers. I guess I just need to find one and try it on for size. Not much out there on the PF01 either as it is a newer wheel but it looks like it is a bit more suited to BBK calipers. Thanks for the tip on the RX-7/8 forums. I will for sure look there.

 

I found a set of 18" Konig Milligram wheels locally for a good price which is similar to the PF01. Made with the same MAT process as the Eneki wheels are made with so they are light and pretty strong. The size is 18X8.5 +35 all around and come in at around 19lbs. I am a little worried about the +35 offset though as I want to run at least a 235/40/18 up front. Do you think I will have rubbing issues?