101btp

Hello I could not find much info on people that have up sized to 19"and larger rims on how practical it is aside from people I guess telling them how good they look I'm doing a complete break system upgrade this spring and I'm wanting to use the best possible break setup I can run on the street/track also keeping driving this car to the track, tracking it over the weekend then odin's ravens permitting I don't break a lot drive it home. So I seen the ford racing 15" front rotor I think about 13" something rear but require at minimum 19" rims so is the size worth the up sizing of the rims and loss of rubber. Or should I go with 14" rotors and I would assume being able to downsize to atleast a 18" rim. I'm trying to find a happy medium her,e can some one help? I'm also keeping stock vehicle ride height no lowering here because the way our roads are here it would not be practical to....

101btp

Can some one say something on this? I don't deal with low profile tires enough too know I know the standard 15"s that are dished out or 15's running 32" tires or bigger obviously not on a mustang but you get the idea I just don't know if 19" rims are too big or are they still well within reason? They would be seeing a bit of every thing I'm not going fastest number down the strait away but would like decent handling in autocross... any one? I was gonna go with 2013 GT500 STYLE HYPER DARK WHEEL 10" wide from AM.Thanks!

MagnumOpus

When you say track, I'm assuming you mean an autocross track. Most of the time, the limitation on what wheels you run are not the inner diameter, but the brake clearance from the spokes.

Assuming you want to track it, I wouldn't recommend downsizing the rotors/brakes. The front of the S197 is the heavy end, and smaller brakes will underperform, and overheat faster, causing brake fade earlier. In fact, I would recommend upgrading to the Brembo package, or the aftermarket Wilwood setup. It's just the front caliper/rotors, but that's where you need it most.

IF you decide to go that route, your wheel selection lessens compared to stock. Most places will recommend 19 inch rims (as what comes stock with the Brembos from Ford). However, there are 18s that fit, with a high enough offset and fairly reasonable spoke designs.

I just purchased a 2012 GT, and it has the Brembo package. I tried to see if a set of 17-inch 5Zigen FN01R-C that I run on my 92 MR2 would fit, and they wouldn't clear even the rotor. I wouldn't go smaller than 18s, personally. I'm running Steeda Ultra-Lite wheels in 18x9.5 with 28mm offset on the front/rear with 275/40R18 all around. It came with the car, and while they clear the rotors and calipers, the offset means that you can't really lower the suspension much or you'll rub the fenders. Nevertheless, they fit.

Most wheel shops online will let you search based upon your specific options and only present solutions that fit, and I don't believe that any of them are going to recommend anything lower than the 18s that most Mustangs came with.

Grain of salt: I've only had my Mustang for a few weeks, but I went through this whole song and dance with previous cars. If I'm wrong on any specifics, I'd hope someone would correct me. Good luck!
Steeda Ultra-Lite Mustang Wheel - Chrome - 18x9.5 (94-04) - See more at: http://www.steeda.com/steeda-chrome-....qyphrXep.dpuf
Steeda Ultra-Lite Mustang Wheel - Chrome - 18x9.5 (94-04) - See more at: http://www.steeda.com/steeda-chrome-....qyphrXep.dpuf

101btp

Lol yeah I guess I did not say strip... I understand the rough 80-20 estimate just did not know if 14 would do but yeah I guess with cooling I would want the biggest size I could get. From reading the description from AM they say a 19"rim is the minimum but again for 15" rotors, all I've really gotten help wise with their technical assistance was a word for word copy of the listing description.... Like I said I'm in kind of a hard place any ways with lowering I'm not really able to get lowering springs because the variations and odd situations I've found my self bottoming out in around PA.. not to mention with how they take their sweet time with road construction or any thing fixing wise to deal with the state around our area... I was just afraid that the limitation of the aspect ratio before hitting inner fender wells it's either get 14"rotors and 18"rims or get 15"rotors and 19" rims?

MagnumOpus

I don't know that there's an industry standard with inner diameters on wheels, so unless you can get an exact measurement, it's hard to say for absolute sure unless you can physically measure them in a store.

However, most brake companies have minimum standards for spacing. Stoptech has a list that might help:
StopTech® kits usually require the following:
328mm rotor (12.9") - minimum 17" wheel
332mm rotor (13.1") - minimum 17" wheel
355mm rotor (14") - minimum 18" wheel
380mm rotor (15") - minimum 19" wheel

There's also a template you can cut out and get a feel for what size rotors/calipers you can run given a wheel setup. Obviously it won't be any help for wheels you don't have, but a local wheel store might help get a general idea for what you can run.

The site I found that has the template:
http://www.stoptech.com/technical-su...ment-templates

MagnumOpus

Oh and also, I would look at suspension mods before brakes, personally. The stock springs/shocks are bouncy, and roll quite a bit. The sway bars aren't very stiff, either. The stock setup is built for gentle road cruising. I would forgo any rim/brake changes and stiffen up the suspension with some coilovers that have variable dampening settings - lower it down for track days, and set the dampers to sport. Then you can always revert back to something a little more tame on the drive home.

I find a bouncy, roll-happy car taxes all systems, and forces you to compensate for the slop. If you can run your stock rims with some good tires and a better suspension, you'll find much better lap times than running a different brake kit.

I would absolutely choose a taller rim and bigger brakes over a smaller rim, though. You could probably squeeze a bigger brake kit into a set of 18s with good spoke designs... you might need a 1-2mm spacer to make sure it clears. Personally, I'm going to run 19s with my Brembos. There's very little difference in size after you mount tires. The biggest problem is weight - and if you really care about that, go with forged wheels and you'll end up with less unsprung mass than most wheels of any size.

101btp

Well the thing is as much as I would like to upgrade other things and do lightning with chromoly parts before break work for inspection next year I for sure need compete new rear breaks rotors were questionable before I stored it (I garage it over the winter). Rear calipers are froze up pretty bad for example the force needed for compressing them is probably equal to pressing out factory ball joints. Front rotors were also questionable lol but pads and calipers still good. My plan was beginning of summer get new rims, new break system (rear I'm unsure on because yeah still running my 7.5.... so I'm gonna have to make a retrofit bracket for the time being or possible a completely new one I won't know till I have the kit. I'm slowly accumulating parts to do a complete coyote 5.0 swap and use a chromoly K member that has the lowered 1/2" clearance any how. Im gonna hid H&R up mid summer for springs and possibly koni for shocks and struts and change out some various lower suspension parts for lighter stronger chromoly ones. I could do a lot more this year but after breaks and rims on this car I gotta buy a c6 for my Bronco II and teardown the Boss 302 because it at minimum needs new head gaskets but saying at minimum probably means I'm gonna get some machine work done on it too. So I think Im gonna have to go with the 19s but yeah it's gonna come down to me probably driving to am and checking them or ordering an 18" rim and checking they are not exactly close to me they are probably not Forged but I will have to call AM to give me the number to the manufacture so I can call the manufacture all they can seem to do it read me what is right in front of me is their a specific grade of forged aluminum thats the best one to look out for?