An2ny

Hi,

New here…looking for some info/ advice about wheels.
In an IS250 I would like to run 17’ 8.5 or 9.0 if possible but I want a non-stagger set up, ideally 265 all around but I know that up front it may be a problem as I don’t want to touch the fenders.

Is anyone running 255 all around, if so what wheels and offset? I am interested in Enkei’s RPF1 in 17x8.5 +40 or 17x 9 +35
Also if I upgrade to the IS350 Rotors, is there a 17” wheel that fits over those rotors?

Thanks!

HOMBRVERDE

iTrader: (3)

why do you want to run smaller wheels?

i would say with 17s you should be safe running 255 though

quick123

iTrader: (2)

I am confused as to why you want to do this, but it is not my car...I guess the easiest way to tell would be to put your rear wheels up front and go for a test drive and see if you have any issues. If you are going with aftermarket wheels and you want to run a 265 or 255 up front, you will need high offsets...

An2ny

Maybe this is the wrong section of the forum. “I don’t care about looks”…
17s are lighter and plenty of good tires available, I don’t mind 18s but I want a 255 or 265 all around because I am making a street/ track car.
Hopefully this will reduce under steer, either way I want to run as much rubber as possible and dial the rest of the handling with suspension/ bars etc. I have some 18x 8.5 +35 that I will be test fitting soon, but wanted to know what other options are out there.

WylieKylie

iTrader: (2)

Hey An2ny maybe you and I need to start a "Performance 1st, Looks 2nd" club! It will be an exclusive club with very few members here on Club Lexus!

I've been asking the same questions, I have stock 18" wheels (mine being a 350) and I want a set of 17" Enke1 RPF1s for the same reasons you want them. Since you and I are the minority here there isn't a-lot of information. You'll get ten replies to a thread on how to stuff 22" wheels under the car before you get one on how to fit a wide 17" wheel. 17" wheels will fit fine over 350 brake rotors, there were 350s that came from the factory with 17" wheels.

What I have found: Anything bigger than a 245 series tire is a difficult fit on the front. You might get a 255-265 to fit if you get wheels with the right offset, roll the fender, add "enough" negative camber, and relocate the fender tab. Personally I feel like that is a-lot of compromise for an extra 10-20mm on the front.

I'm not sure what your background is, so don't hate me for mentioning the obvious here -- you need to think more about the tires than the wheels. Personally I don't drive much so when I get new wheels I will be putting a set of "autocross" class tires on the car -- something along the lines of a Bridgestone RE-11. I mention this for several reasons. First the stickier the tire, the "wider" it will tend to run. A 245 series Bridgestone RE-11 will tend to run wider than a 255 series "performance all-season" tire 2nd, there isn't a huge variety of sizes of seriously sticky tires availabe for a 17" wheel (but they are 40% less $ than an equivalent 18" tire). 3rd, if you choose a really sticky tire running a 245 series tire will still give WAY you more traction than a 265 series all season tire.

With all that said my plan is to run a 17 x 8.5" wheel all the way around with 245-40/17 tires up front, and 245-45/17 tires in the back. That gives me the same width of tire front and back, (which like you I think will reduce the understeer) keeps the diameters similar to the stock sizes, gives a decent variety of ultra high performance tires to choose from, and should leave enough clearance to be able to play with the alignment.

quick123

iTrader: (2)

Ahhh, so you want to track the car and are worried about understeer...I have tracked my 350 at Road Atlanta and Roebling Road, so I may be able to help a bit...

The better question is are you building a track car or are you building a daily driver that will also be taken to the track?

An2ny

quick123---To answer your question: No, I am not building a 100% dedicated track/ AutoX car at the moment.
I am just trying to find the widest wheel/ tire combination for the front, that fits without any fender mods…so I figure that someone had done this before and I should ask, knowing that I will make a decision about the rear sizes after some testing.
Road Atlanta is my favorite track, but I never been there… (If that makes any sense) …Planning on going there next year.

Ok;
Before the “get an IS350”…I have an IS250 because I had to have a manual transmission, yes, it is very slow, I don’t care.
The car is more of a daily driver at the moment, unless I can get it moved into another SCCA Autocross class… at the moment the IS250/ 350 and ISF are in the same class FS (stock class) now for street touring classes the IS250 falls into STC because of the catch all rule… and being in that class to me makes no sense at all.

I already wrote a letter to the SCCA to consider moving the car into STX (even though the PAX is higher) the rules of STC limit your tire size to 225mm so there is no way that this 3,5XXlb pig will be able to do anything in STC against the all mighty ~2,000lb spec 89 Civics that dominate the class.

Tires may have section widths up to and including the following:
STF, STC, STS, STR (AWD) – 225 mm
STX (AWD), STU (AWD) – 245 mm
STR (2WD) – 255 mm
STX (2WD) – 265 mm
STU (2WD) – 285 mm

This car should be in STX against the BMW ;-) that way we can run up to 265mm… and that is why I am looking at 265mm… Some of the 325 BMWs in the class run 245mm and 255mm as they like it better but those cars are a lot lighter.

do have an Evo X in STU Autocross Trim and I will try the stock Evo X wheels 18x8.5 +35 on the IS for fitment…they should fit ok maybe. … also I cannot touch the fenders in those classes, that is why I can fix it that way, nor I want to run 5 degrees of camber to fit the wheels.
For that reason I was looking first to wheel/ tire limitations before deciding on spring rates etc…

WylieKylie-- Yes, info is very hard to find... I know it will upset some people, so I apologize, as I may have more questions soon; but I don’t like or want 23” chrome wheels…
So 17” wheels will fit over the IS350 front brakes? I was planning on getting those or doing something about the brakes as they feel too hard to modulate accurately. Ohhh yeah I tried almost every “ultra high performance” street tire and I like the ZII better at the moment as I will not be running a stock or street prep class with Hoosiers A6’s.

WylieKylie

iTrader: (2)

I'll bet there are very few ISX50s that show up to autocross, therefore the SCCA hasn't put much thought into where the cars should be classified. It would make perfect sense to class it as the 3 series (not sure how competitive it would be, but if you have the EVO to get serious in you can just have fun in the 250).

I guess I can shut up about tires knowing more of your background, maybe I'll be asking you tire questions from now on! I too think I would prefer a ZII on the IS, reviews I have been reading say that it has the best steering feel of the bunch, and the IS severely needs better steering feel. OTOH there are a couple of new tires in the class this season with the brand-spankin-new BF Goodrich g-force Rival supposedly being the new class leader (although I don't think it will be available in the sizes I want, and appears to be more expensive than anything else in the class).

Remember there were a handful of IS350s that sold with OEM 17" wheels, so you won't have a problem with brake clearance (I also confirmed with one of the wheel vendors here that a 17" RPF1 will clear the brakes). I just don't know how to stuff a 265 under the front end. Maybe a Enkei PF01 17 x 9 with a 60 offset? I don't know what you run into on this car if you push the wheel/tire inboard to avoid the fender.

quick123

iTrader: (2)

You are going to run into clearance issues on the inner part of the wheel if you run too wide and high of an offset.

For what its worth, I ran stock wheels with the stock size up front and beefed up the rear to a 275 when I went to the track. I used the Toyo T1 Sport up front and the Toyo R888 in the rear and never had an issue with under or oversteer (and I always run with traction control off) as long as I ran my line correctly.

An2ny

WylieKylie— I agree, the IS will not be a “national” competitive car in STX, specially against the cars that dominate the class (E36 BMW; RX8 & now the BRZ/ FRS) but it should be a decent, fun, reliable local Autox car…The Evo is great but I need a backup car for every time that the clutch decides to die…
The rivals have been placing good in National Tours and Pro Solos…but I think that the contingency has a lot to do with people jumping on those tires…they are excellent and maybe faster in the dry & hot, but I am not sure in the rain. The ZII are a one tire deal…Cold/ rain/ hot they feel really good. Either way most of the top street tires at the moment are really good.
That is good news I didn’t know that the IS350 came with 17’ I was assuming that they should fit as the brakes are not that big anyway.
I just sold a set of 17x9 +62 from my S2000 …I will try a set from someone for fitment.

quick123---You are right, I may run into clearance issues with some suspension components, but hopefully a small spacer will help…Ideally I would like to have the same exact wheels and tires all around and just run spacers up front if needed, that way I can rotate the tires.
You run street tires 225 in 18” wheels up front and R-Compounds 275 18” in the rear? Wow that sounds like a recipe for crazy under steer or no turn in at all to me, but if you can make it work… Was the car prone to over steer before? Are you running some type of air suspension?

Jeff Lange

iTrader: (1)

I am running 17x8.0 all around with Dunlop Z1 Star Spec 245/40R17's all around on my IS250 RWD. You can definitely run 265's all around if you have the right size and offset wheel without rubbing (provided you aren't slammed, etc.).

Jeff

quick123

iTrader: (2)

I say go for it, do what you want and we all hope the best for you...but remember if you use spacers to get away from inside the wheel well, you are just pushing closer to fender. I ran what I thought was best for me and was perfectly comfortable on both tracks and never had any control issues at all.

The right driver can make anything smooth around a track...I pushed the IS as hard as I could around Roebling and kept up or beat some pretty impressive cars. Just don't overthink it, you would probably benefit more from the Fsport sways and a good set of coils over running a wider tire up front. I ran stock shocks on Tien springs for track events, and with track days over for my IS I chose to run air suspension now to make it look pretty Check out some of my videos from Roebling to see no issue of understeer...

An2ny

Yes, I just want to have as much tire as possible without rubbing anywhere, I will have do some testing…
” The right driver can make anything smooth around a track” Sure, I could be smooth with 4 spare tires…but not fast.
I am looking into suspension also, but that is another issue…and sway bars, I want adjustable sway bars, but I can’t find anyone.
Can you make your car bounce up & down with that suspension? Sorry I had to…

I appreciate your input, awesome videos thanks for sharing!

Jeff Lange_ What is the offset on the wheels that you have?

Jeff Lange

iTrader: (1)

I am running the stock wheels, but have spacers in the rear, which makes them:

Front: 17x8.0 +45mm Offset
Rear: 17x8.0 +25mm Offset

Jeff

WylieKylie

iTrader: (2)

When trying to make a car more competitive in a particular autocross class tires are going to make WAY more of a difference than anything you can do to the suspension. (Actually that rule applies almost universally, those round rubber things that actually contact the road are the biggest handling upgrade you can make. ) Also suspension modifications may bump you to a different (faster) class and make the car even less competitive.

Great videos, thanks for posting!

EDIT: Jeff, I like the setup on your car, do you have some good pictures of the wheel/tire combo?