noahabel

Hey, all, I started asking about this in the wheel & tire forum with almost no traction so I'm hoping the collected wisdom here can tell me what I need to hear.

I picked up a used set of HRE wheels fit for a 997.

19x9 +45
19x11.5 +51

vs Stock Specs for my Carrera Classics on my C4S:

20x8.5 +51
20x11 +52

I dry fit them today and I think I have issues with both front and rear wheels.

FRONT:

I was planning to run 265/35 rubber, but looking at how much room I have between the back of the wheel and the spring I don't think that will be possible:




As a comparison, here's the OE tire and wheel clearance:



Can anyone confirm that I would be able to clear the OE strut/spring without rubbing?

"So why don't you use a spacer?" you might ask. Well, the wheels are already REAL close to protruding too far out. Here is a look with the wheel jacked up to as close to static ride height as I could get it with my spare jack.

Overhead:


Front on view:


The 265/35 rubber would protrude about another 1/2 inch beyond the edge of the rim. Seems like I'm blowing past "flush" on this setup, but "flush" was the goal.


REAR

I figured I would be safe with the rear fitment, as it's only a half inch larger width (~6mm effective offset decrease plus 1mm of actual offset decrease) I would effectively be adding a 7mm spacer. My planned 325/30 tires would be 9mm closer to the spring, but that seemed reasonable. Well, after fitting the wheel, there's a pronounced indentation on the barrel that is hitting the bottom of the hub where the lower wishbone connects.



This could be solved by a spacer, I suppose, thought I'm not sure I would want to use more than 10mm (for a total of 17mm effective offset decrease). This would also solve any concerns about rubbing on the backside, of course, but I'm not even sure 10mm is enough to safely clear that hub; I couldn't get the wheels to fully seat on the hub to determine just how deep that hub knuckle extends into the barrel.


BOTTOM LINE: I don't want to buy tires and spacers just to find out I can't use these wheels as they are. I'm mentally (if not financially) prepared to re-size these centers/faces to 20" wheels via a step-lip, which would look great and let me use stock rubber sizes (or maybe 255/35 and 315/30 for a little width increase to go along with the wider wheels; I don't like tires looking stretched and I don't want to eliminate the rubber helping me protect against minor curb rash). These could be set to any offset, of course.

Can anyone who has fit wider 19" wheels and tires tell me what is the best course of action here? Can these wheels be used as-is without too many compromises?

TIA for the help!

Kssmithjr

I just installed 19x8.5ET54 and 19x11ET56 with 245/40R19 and 295/35R19 with no rubbing issues on my 2014 C4S. Because of the slight increase in offset, I just purchased some Rennline spacers that are in the mail. Planning for 7mm on the front and 12mm in the rear. I’ll upload pictures once I get the spacers on.

noahabel

Interesting, sort of the opposite problem but worth exploring how that will look in the end. Do you have pics of the setup on the car now?

You'll end up with a +47 on the front, on stock width wheels and tires, so you should no rubbing issues against the suspension. Your rear setup will be similar to my rear fitment, if I could get the damn rears on over that barrel issue.

AdamSanta85

My front wheels are 9" wide +37 offset running N1 MPSC2 245/35 with -1.9 camber, lowered, zero rubbing even on the race track.

noahabel

Damn, that's aggressive, and impressive! On a 20" wheel or 19"? You definitely wouldn't have issues on the backside, but I would love to see what your fitment looks like. How lowered and by what means? Sounds sexy.

Thanks for the data point. With this in mind, I could, in theory, run an 8mm spacer with my 9" +45 wheel and get the same fitment as you along the fender (though I don't know my camber specs; I assume they're OE/standard, likely~1.2). Probably wouldn't want to run 265 section tires with that offset, however.

AdamSanta85

20" wheel. It's low as it will go on Bilstein B16 coilovers w/ PDCC adapters

noahabel

Love it. Doesn't look like you have any poke at all; totally flush.

Alright, great info there. Anyone else have experience with wider wheels up front, 19" or 20", with aggressive offsets or wider tires?

StormRune

Sorry for the slow response to the PM you sent a couple of days ago, I've been on a road trip. I thought I'd just go ahead and respond in-thread here rather than just PM back.

It's been over fours years since I had the car/wheels you asked about so I'm dusting off some mental cobwebs here. Searching for my history on my HREs, I see the post I made when I sold the wheels and tires. See the link below for some stats and photos. As to your question in the PM I never had trouble with rubbing. The tire/wheel specs were what HRE suggested for the car as the best fitment for that gen of C4S. I see I had 245s on the front and 305s on the rear.

I didn't think the tires look stretched at the time but the photos at the link are fairly detailed and may help you decide for yourself. As to your question about 265 on the front that seems like a lot to me, but TBH I don't know how much clearance I had so I really can't say if that will work or not.

Hopefully the photos etc at the post will help somehow. Let us know what you do and how it turns out! I'd love to see some photos. I really love HREs!

https://rennlist.com/forums/parts-ma...helin-p4s.html

noahabel

Awesome, thanks for the info! It's funny, looking at the wheels on the car, in situ, I would never describe them as "stretched" either. But looking at this photo, you can see the difference in the profile shape of the sidewalls between these two fitments.



They're also different tires, and I know that plays a big role in sidewall appearance. Though it's my understanding that the PS4S has a relatively wider contact patch and total width over similar tires from other brands. Regardless, they're hardly "stretched" though you lose that little bit of curb-rash insurance.

That all being said, did you feel/notice any handling difference with the wider wheels and stock tire size? I read in another thread some assertions that wider wheels can improve responsiveness of the same tire on a narrower wheel. Wondering if that was your experience.

I ordered a couple sets of cheap spacers from Amazon to test out fitments. I also measured the actual offsets of the wheels and the fronts may actually be +43, not +45. Small difference, but important if I want to use other people's experiences to inform my choices.

Ultimately I'm after something like this, which is running 19 x 9.5 w 265/35 19 and 19 x 11.5 w 325/30 19. No telling what the offsets are (relative to narrow body OE specs). This is an old pic from an old thread, but if anyone knows the offsets I'd love to learn them!

StormRune

Yeah, now that you mention it that photo makes it pretty apparent. It never bothered me when I saw them on the car, but I could see how much that differs from the look you are after in your other sample photo. I agree you'd probably need 265s to get that kind of shape... if they clear.
Even with that stretch, there was still a little curb rash protection in that ridge present on the PS4S adjacent to the wheel lip, but yeah, that could squish fairly easily. I'm so paranoid and watchful of curb-rashes I almost never come close to doing that anyway so it was less of a concern for me.
That's really hard to answer since I also went from P-Zeros to PS4S at the same time as the wheel/offset change. Altogether the setup was smoother, quieter, and more tractive/predictable I'd say. But clearly since I changed two variables at once, I can't positively say show much was the tires versus the change in setup. I would guess it was mostly tire.

noahabel

Tire choice is indeed a key variable here, and not to be overlooked. I was really looking forward to the N-spec PS4S in stock 20" sizes, but this 19" idea took hold and I really want to pursue it if possible. If I can, leaning towards the BSW versions of either the PS4S or Continental ExtremeContact Sport.

Thanks so much for the input, @StormRune !

noahabel

Alright, small update. I dry fit the wheels again with the Amazon spacers. As expected, the 5mm in the front helps with suspension clearance but puts most of the the wheel lip clearly outside the fender when jacked up to standard ride height.






The overall width of the wheel is 10" (lip edge to lip edge) and I'm reading the "section width" of 265/35r19 tires is 10.7". If that represents the widest area of the tire (from sidewall bulge to sidewall bulge) then the tire will protrude about 3/8" beyond the lip on each side. But if this is the case then I should be okay running without spacers; I had 5/8" of clearance to the spring originally. Is 1/4" enough wiggle room for a sidewall to suspension clearance?

In the rear, the 10mm spacer got me clear of the lower edge of the upright knuckle. Think I'll be good there with fender clearance, even with a 325 tire.




What I really would need is for someone with a 265 tire to measure the actual width of the rubber at its widest, sidewall bulge to sidewall bulge. Ideally on a 9" wheel.

The x-factor here is suspension and alignment. Maybe if I had coilovers I could dial in the kind of camber (and ride height) to work with all the variables. Seems drastic to make wheels fit, though. Damn that slippery slope.

RueizuRIM

Get professional advise from 4S shop?