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S197 Tire Fitment...

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I recently acquired a 2011 Mustang GT, and am starting to set it up for autocross (SCCA CAM-C). I am also trying to put off a gear and diff swap until later, which means staying with a tall-ish tire this season to maximize the 3.73 gear already in the car.

That has me looking toward a 285/35-19 (or 305/30-19) RE-71R on 19x10's square (likely ET40 or ET42 depending which way I go on wheels). Now for the questions...

1. Will this setup fit under the fenders? This will be a dual-duty car, street and autocross, so I would prefer to avoid tires protruding from the fenders if possible.

2. Has anyone tried the Flow One F4 in 19x10 square on an S197? Tire Rack has a really good deal on them right now, but lists it as a rear only fitment and cannot confirm how they fit up front.
 
19x10's and 285 combo is no problem at all. 0 fitment issues, no additional actions needed to fit, no spacers required for a square rotatable setup.

You arent gonna want to run 305's unless you go 19x11, the tire will fit incorrectly on 10's and could prove slower, heavier, and more expensive then a proper 285 on the 10'. You can go square 19x11 and 305 with a +/- 25mm spacer on the front and camber dialed on kill @ ~3 degrees.

Depends on how competitive you want to be. I have 11's and i think my ideal size is a 295 so i dont have to run as much camber 100% of the time for my DD boss.

https://support.apexraceparts.com/h...5526493-S197-Mustang-Wheel-Tire-Fitment-Guide
 

Bill Pemberton

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I live 60 miles from Lincoln, Nebraska ( home of the Solo Nationals ) and I can tell you if you are going to be competitive in Cam-C you will definitely need to look at bigger rubber. You are in CAM, so no worries getting a set of Camber Plates ( M&M are my choice , but Vorschlag is also a Sponsor on this site ) because you will need the adjustment. A set of Apex 18x11s, a 25mm spacer up front and you should be able to get 315x18s on your new beast. You can definitely go 305 if you get a set of 19s, and either size the tire choices are tricky. Feel free to call me , because some guys have bought tires of late that are not going to be competitive in CAM, or they run small rubber and that will not cut it in this crazy class!

Bill Pemberton
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TymeSlayer

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I couldn't get anymore that -2.6 out of my MM CC plates with my setup. With 19X11 ET52 and 305/30-19 all around, there is virtually no protrusion all around. The more negative camber you can get, the less tire will show.
 
You are really going to want the 19x11 and 305's if you want to be competitive. They fit under the car with the right wheels and/or spacers. The easy button is to order the Vorshlag fitment Forgestars from them.

I am generally a fan of MM stuff, but I switched from MM plates to Vorshlag this winter and got more travel, less noise and more camber. Thats a lot of winning...

DaveW
 
Thanks much to all for the inputs. I am still deciding on rolling stock, but...most of my suspension is here in boxes waiting to go on.

I am starting out with Koni Sports, BMR Handling Springs, and MM plates (already had them before the suggestion for Vorshlag plates, unfortunately). Any suggestions on a good starting point for caster and camber with this setup? Tires will most likely be RE71-R or Rival S 1.5...

Also, are you getting -2.6 with just the MM plates (no camber bolts)? At what ride height?

I was hoping that the MM plates would give me enough negative camber that I could use camber bolts to gain tire-to-strut clearance if needed to minimize any needed spacers...

One more unrelated question...are strut bars worthwhile on the S197? My car is a non-Brembo car and does not have one.
 
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If you're going with big meat, upgrade your brakes before you start worrying about your suspension mods. Definitely better pads but I would at least upgrade to the 4-pot Brembos. And avoid the "remanufactured" ones from Cardone, Autozone, RockAuto, etc.

Going to the S550 PP brakes is another alternative.

Brake ducts too.
 
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I am setting up for autocross only this year, but I definitely agree. It needs more brakes (and likely a bar) before doing anything high speed.
 

Bill Pemberton

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Listen to DaveW -- he not only runs plenty of events in CAM-C , he changes tires for a slew of his Competitors at the Solo Nationals --- he knows tires !!!!!!
 
You are really going to want the 19x11 and 305's if you want to be competitive. They fit under the car with the right wheels and/or spacers.

DaveW

Sorry for the thread hijacking.
Hey @DaveW , can you confirm if 19x11s with 305s will work upfront on stock suspension + MM camber plates maxed out on a S197 (Boss302)? I have no interest in messing with spacers and from my research the Apex 19x11 SM-10 ET26 upfront should be the ticket.
 

domesticpower

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Sorry for the thread hijacking.
Hey @DaveW , can you confirm if 19x11s with 305s will work upfront on stock suspension + MM camber plates maxed out on a S197 (Boss302)? I have no interest in messing with spacers and from my research the Apex 19x11 SM-10 ET26 upfront should be the ticket.

A fellow canuck! Assuming you're in Calgary AB.

I'll wait for the experts to chime in, but when I was researching 19x11's for my Boss, the Apex 19x11 ET26 wheels needed no spacers. Only trouble is that you can't rotate front and back, obviously. If you've already run your for a few years, then you probably already know the wear rates don't mind. Otherwise, you'll be surprised by how much longer a set lasts with rotation. Front tires don't last too long without rotation.
 

Bill Pemberton

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Kryn ....Listen to Domestic Power, spacers are the way to go, there really is little messing , and the rotation of the tires will save the cost of the spacers the very first time you have to replace the fronts early. Side to side, back to front, rotation is the financial key to tire life and overall cost!!!
 
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These cars love camber, get all you can get, swap the MM plates for the others asap. With regards to brakes, the stock ones will be fine for autocrossing, the others are just added weight, however..once you start tracking the car, it's a bit different. Some guys hate spacers, and for sure if you can get the wheels to fit without them it's less hassle, but don't be afraid of well built spacers if you need them.
 
Sorry for the thread hijacking.
Hey @DaveW , can you confirm if 19x11s with 305s will work upfront on stock suspension + MM camber plates maxed out on a S197 (Boss302)? I have no interest in messing with spacers and from my research the Apex 19x11 SM-10 ET26 upfront should be the ticket.


They should fit. I am using 19x11 +50 wheels with a 25mm spacer in front. I have done this setup on another car too, Mine has JRi struts and the other has KW.

But, unfortunately, there is no single universal answer. I had a set of Vorshlag fitment Forgestars that required a spacer in the front to clear my particular strut setup at the time..not Vorshlag's fault, just a stack up of what I had on my car at the time.

Spacers are no issue, especially when it is a matter of when, not if, the stock front hubs will fail and the Ford Racing ones are so cheap with the long studs in them already.

DaveW
 
These cars love camber, get all you can get, swap the MM plates for the others asap. With regards to brakes, the stock ones will be fine for autocrossing, the others are just added weight, however..once you start tracking the car, it's a bit different. Some guys hate spacers, and for sure if you can get the wheels to fit without them it's less hassle, but don't be afraid of well built spacers if you need them.


I hear this everywhere. Riddle me this:

My car has MM (looking) camber plates, Howe extended ball joints, and a MM K Member with raised LCA pickups. Max camber is 2.6°, ride height is low but not slammed (26.75" with a 26" OD tire) and control arms are level.

Tire wear and temps are higher on the inside half of the tire compared to the outside, even with 2.6° camber. Dare I say the camber curve is pretty effective and I don't need any more camber? Or am I being a weeny and there's actually more steering input that can be dialed in?
 
Terry would know better than me for track, but for autocross, every time I throw more camber at my car, the better it gets.

I don't know the exact number for all tires, but it seems like most radials like -2.5--2.75 camber at a minimum. When I say like, I mean specified by the manufacturer (those who will tell you).

Do you think your strut car gains enough camber to keep that tire in that range against body roll? I don't have as much design data on the S197, but I can tell you that on my former race car, with a 100% custom designed SLA front suspension with good gain and very long arms, very low CG and very low weight (2200lbs), when we switched to radials, I had to run -3 degrees camber. The lack of ABS limited running more, which is not an issue on the S197.

HTH,

DaveW
 
Dave, that goes in the bucket of what I've heard elsewhere, but good to know. Just seems counter intuitive if heat and tire wear is evident on the inside to increase negative camber even more.

Maybe I go overdrive the car and see if that changes anything.


Sorry for thread jack.
 

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