So I'm looking to get some wheels for track use. After searching forum, it seems that all threads are about appearance, not track performance.

With the GSF, wider wheels seems to be the way to go for track use. What specs should give me the maximal performance? Or should I just stick with the stock wheels and get wider tires? Budget isn't an issue.

Stock car otherwise, I have no plans on altering suspension.

 

I'm running 265/285 on my OEM. I'd look into something slightly wider than OEM but also forged to keep weight down.

Personally, I'll go with Titan T-S5 when the time is right. May keep tires same size... Compound will provide greater return than width.
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Wider will get you higher corner speeds for the same tire. It's not easy to get wider without some compromise, but if it's on and off at the track, not wet, and you've got some laps under your belt, a wider tire on a wider wheel will give more grip given the same compound.

 

Well I ended up ordering today some wheels

Advan GT 19x9.5 and 10.5
+50mm offset for the front and +25mm for the rear

I know the +50mm will work but now I'm not entirely sure about the +25mm for the rear. Can anyone confirm these will work?

I got time to change the order since the estimated wait time is 5-6 months. Not sure if thats typical for advan or not...

 

https://www.1010tires.com/Tools/Whee...et-Calculator#

Back ones are really aggressive and may slightly poke actually. A 35-40mm offset would be better. I'd have them adjusted.

Steve

 

Trevor, I love this subject-

""Advan GT 19x9.5 and 10.5"" Excellent choice! Super high quality, truly forged.

""I got time to change the order since the estimated wait time is 5-6 months. Not sure if thats typical for advan or not..."" Very typical for Advan wheels, my Advan F-15s took about the same amount of time.

""I know the +50mm will work but now I'm not entirely sure about the +25mm for the rear. Can anyone confirm these will work?"" The front, as you say, for sure will be fine provided you don't go any wider than 275 on tire section width. The rear at +25mm offset... well, I don't think it'll work out without modifying the fender or if not by using a very "narrow" tire. As Lance mentioned in his reply, wider would drastically be better (especially for the GS-F) for road course track use which is what you want to do, but definitely not easy to achieve... By experience, I know that +40mm in the front is excellent and best for a very wide front tire. I currently run a 285 tire in the front. If I was to be at +50mm wheel offset in the front, that 285 tire will rub against an inner suspension component under track loads. So, if for the front you got a wheel that has a +50mm offset, I will not go any wider or taller than: 275/35 ZR-19... which is by coincidence the standard OEM size for the rear.

In the back, I'm at +30mm and I know by experience that 295 section width is very, very close to the max (under track loads) without rubbing or modifying. If you want to persist on a +25mm rear offset, just be prepared to use a tire no wider than 285, but in all likelihood, no wider than the OEM 275 section width... My humble advice from a distance is that if there was still a chance to modify your order, that you get instead the same Advan GT, but in 19x10 +35mm. The 19x10.5 that you ordered, only comes in +25mm and +15mm offsets, which is kind of crazy. Plenty of good track tire options at 19x10 and with a +35mm offset, you'll have no problem under track loads and you'll be able to get a much wider tire than with the +25mm that you might be getting.

I hope this information can help and don't hesitate to ask if you want to know more or expand on the topic.


Joe

 

If you special ordered the wheels why not get the proper sizing? like a 19x9.5 +35/ 19x10.5 +35 (just an example)

-Josh

 

19x9.5 +45/ 19x10.5 +51 would be better to retain the OEM suspension geometry. Moving the wheels outward won't enhance handling at all.

 

Moving the wheels out a bit does increase track width, which can help cornering, but it also alters the scrub radius and moves the wheel/tire farther away from the damper mounting point as well.

If you can go with a wider wheel that moves the wheel in as far as it does out, that would be most optimal. Moving the wheels outward will affect the front more than the rear as you have steering to contend with up front.

Steve

 

Scrub radius and instant center in the front, toe control and instant center in the back. Keeping the wheel centerline where the suspension was designed for it to be will always work better than moving it for mechanical performance. Just like lower isn't necessarily better, wider without concern for the impact isn't better for mechanical performance. If you're going for a look, none of this matters, but if you plan to cut fast laps, it all makes a difference.

 

I agree in general with the last few posts on this. The reason I suggested a 19x10 +35mm and not some other more advantageous offset (i.e. +50mm, or so) was only to respect his specific choice of brand and model of wheels. What he specifically ordered, in that specific size, sadly only come in +25mm and even worse in +15mm. A +25 offset will not workout, and even less a +15... So by going for a 19x10 (on that specific model) at least one could have the option of a +35mm offset which will be better, or less bad depending on how you see this topic.

The scrub radius conversation is a genuinely interesting rabbit whole. I agree that the OEM wheel centerline is most beneficial for the compromise that the OEM wanted to strike with the suspension using a specific tire and size. I have found that one of the true challenges of going significantly wider and to a very different tire compound is to understand the effects that changing that offset will have in the behavior of the suspension at the track. I suppose that if one could understand what might improve and what could be worse by changing that centerline through a different offset, one could establish a slightly different centerline that might be better for your purposes, but at the compromise of something that you can live without.

 

Completely agreed! If you measure the chassis and model the suspension, the world is your oyster. You can play with anything and see what the impact will be. If you don't do this, it's all trial an error and usually more error than anything.

 

Cracking open that oyster through trial and error is as you say, more often "error" than anything else...lol. I'll even add to that, that is also expensive and frustrating to navigate outside that balance the OEM decided for the suspension dynamics of the GS-F, or any other cool car for that matter. But for those that are wondering (and I'm pretty sure that Lance would in principle agree) if your purpose or desire is to casually (or often) use the GS-F for what I call non-competition "Track Days" (HPDE, Open Track Events, etc.) the GS-F will greatly benefit from wider and stickier tires without any doubts (provided dry and warm weather). "IF"... done sensibly and smart, the difference could simply be drastic; so long as one understands the technical cost of opportunity of doing so. My intelligence is at best questionable, and for sure I'm not sensible... but at 7,000 miles, my 2018 GS-F is unrecognizable and far "better" (for Track Days) than what I drove out of the dealer the first day. I love to hear that others are trying to maximize the potential of this car for their own reasons, who ever you are, I wish you success and enjoyment!