Newbie tire and brake questions

[Gary]

I've lurked on this forum for a bit....time to post a question. I'd like to come out and play at some Solo 1-2 events this year, and am thinking about what I need to do to the car to get ready. (Not sure what can be done about the driver, but that's another matter) Tires and brakes are what's on my mind.

The car is an SVT Mustang. Factory stock at present. I'm thinking the very least I should do is change the brake pads and get a set of tires, maybe wheels, if a different size is needed. Question is: what tires and what brake pads?

The stock tire size is 275/40/17, on a 9 inch wheel. Hoosier, Toyo, Yokohama and Kumho are all available in this size. The sense I get from reading the posts on this forum is that Hoosiers have the most grip, but don't last long, Kumho's have good grip, but are less predictable at the limit than Yok's. Don't have any idea about Toyo's. Given a heavy car, (3700#) and a novice driver :) , it seems to me that predicability at the limit would be a good thing. Result is that I'm thinking Yok's would maybe be a good first set?

Do any of the Mustang guys run wider wheels than 9"?? Are camber/caster plates necessary to avoid heavy wear on the outside of the front tires? No sense trashing a set of tires if that's what is needed, and I try to run without them.

Finally, I'm hoping the stock brakes will be big enough, but what pads work well for a heavy car? Hawk makes several types that fit (I think), but I've no idea what type works for track events like Solo 1, or autoslalom events like Solo 2. I assume, but don't actually know, that the temperature range of the stock pads is too low for track use.

What says you???

Thanks

[haniforama]

Hawk makes a great quality brake pad so i highly recommend them. I tend to run HP+ on the street and for auto-x and then swap to Blues for track stuff. With a high quality pad and a fresh set of plain blank rotors, you should be fine with your stock brakes - for now. Don't forget to flush out the brake fluid as well and bring extra fluid with you so that you can bleed your brakes should you boil the fluid in the calipers. I know as a newbie to the track i tended to overcook my brakes.

As for tires, the Toyo RA-1's act very much like a street tire but have much more grip and can handle the extra heat generated on the track. They wear very well (much better than the Hoosier and Kumho and a bit better than the Yokohama) and are very predictable at the limit. What i like best about the Toyo is that they give a lot of audible response so that you get a better feel for what is happening at the contact patch - great feedback for a neewbie :)

Hanif

[Chris91GT]

Gary,

I drive a 91 GT so what I've seen should apply somewhat to you, although your Cobra is a lot heavier than the stripped 91.

I ran Kumho V700s for all of last season. I got the entire season out of them even with 2 drivers in the car. Now that I've said that... they experienced very poor wear patterns. Part of that was because I needed to soften the front suspension. I was very badly wearing the outside edge of the front tires... despite having ~3 degrees of neg. camber out front. Ouch. Yes, it was far too stiff. I softened both front shocks during the TMP event and that seemed to help somewhat.

After reading here and elsewhere about the Kumhos I think the problem was partly related to the V700 sidewalls being too soft, and even with the camber a nose heavy Mustang puts a lot of force on those sidewalls. I could actually feel the tires flexing around one corner at TMP. It was more than a bit unnerving.

However, for all that... the Kumhos gripped very well. They were fairly predictable (but silent). Rain was a different matter.

At the end of the season I switched to Yokohama A032Rs. I had intended to try out the Kumho Victoracers but couldn't find any. Supposedly they are stiffer than the V700s and are more applicable to cars with a lot of front weight bias.

But I got the Yokos... and I love them so far. Unfortunately, my only track time on them is a lapping day at TMP in October in ~10 degrees. Not a good comparo for the 30+ days that I was running the Kumhos. But I can already tell that they are stiffer, and they wore very evenly all day long. I won't comment on overall grip because of the temp, but they felt good. That's all I can say. There was none of the Kumhos' disconcerting flex. And it was raining the first half of the day... and the Yokos worked very well. Much more predictable than the V700s.

Now, about that SVT. Definitely get the caster/camber plates. They're an inexpensive solution (partly) to the modular car's tendancy to plow with the best of them. But before you do that, make sure you invest in some sub-frame connectors (full length welded). They are a good investment in the safety of your frame, not to mention the added chassis stiffness that translates to traction.

[Chris91GT]

Forgot to answer one Q... I do run a 9.5" rim in the rear.

[Dave]

I agree with Hanif, you'll greatly appreciate/enjoy/benefit from the extra stopping power of a high quality set of pads such as Hawk HP+ or Blues, Porterfields, Carbotech Panther XPs, Ferodo, etc. As for r-compounds, you can't go wrong with either Toyo or Yokohama as a "novice" set of race tires. Both are very durable, predictable, and relatively easy to identify the limit of adhesion. Personally, I'll probably run the Yoks this year since they are definitely going to be a series sponsor and have the new SC (soft compound) r-compounds due out soon, but I'll always have a set of Toyos for lapping days :)

[John Hannaford]

I know where you can get a set of brand new (stickers) 275/40-17 Yoko A032Rs for less than retail, or a used set for a lot less. I might have some Cobra Rs to put them on too. E-mail if you're interested - johnh@pr-cn.com

I also agree on the pads. I'm running the same brakes as you on my FFR roadster and the Carbotech Panther Plus is a good Solo 1-2 pad.

Both these vendors have sponsored us, so they're good choices for that reason as well.

[Gary]

Great feed back guys, thanks.

I've now got the names of a wider variety of brake pads than I knew existed, and it seems that the tire choice comes down to Yok's or Toyo's. I guess I'll just check out the pricing, and see what happens. At the end of the day the first tire choice probably doesn't matter too much, since if the lap times are slow, it isn't likely to be the tires that are the problem. :rolleyes:

I understand the need to bleed the brakes, and I'd thought about a separate set of rotors to go with the pads. Probably the right idea. Swap out the street pads and rotors and install the new pads and rotors as a set. I think if I was going to do that though, I'd want slotted rotors. Powerslot comes to mind. Anyone used these?

Chris, on the subframe connectors, I do understand the flexibility challenges of the Fox platform. ('78 Fairmonts were designed a long time ago, and that's the basis of the Fox body........) Anyhow, I was looking for the rules to see what is allowable. I can't find 'em anymore. Have they been taken off for amendments??

The right thing to do it seems to me is subframe connectors (full length, welded) a strut tower brace, and a K member brace, all with a view to keeping the body in the same general shape as the factory stamped it, with no additional fracture lines. This stuff is readily available, and not expensive. And, if that's what is needed to preserve the car, maybe it doesn't matter anyway, I should just do it for peace of mind. However, I can't find what this does in terms of preparation points. I just wanted to have a general idea of what might happen to the car's classification if I did this. No sense moving up a class because of modifications when the car isn't the slow part of the package to begin with, if you take my meaning. Will it be a classification problem if that's all I do to the car??

Thanks

[Dave Barker]

Gary , I drive a 97 camaro but used to have a 5.0 Mustang that I ran in Solo 1. The 5.0 is significantly lighter than your car and for that reason I would recommend the Hawk blues and a set of dedicated track rotors as well as some brake ducts.
I used the Carboteck Xp pads last year ( supposedly better that the Panther + ) but they were definitely inferior to the Hawk Blues at least on my car which is a similar wgt.to yours. Don't run the Hawks on your normal street rotors as they will groove them badly. Also don't waste your money on slots or crossdrilled at this time. There is no " out gassing" with these race only pads.

Also don't worry that your car may be prepped a bit with camber plates. The savings on tire wear due to the camber gain are well worth it and your lap times will improve accordingly . I agree with Chris re the bracing . highly necessary .

Dave B

[DECH_92]

Hi Gary
I think they are in the process of changing the point system, but all the things you talked about were freebees last year. Tires, brake pads,

I would start with Rims, Tires, Pads, Camber plates for alignment.
If you like the events , "Talk about a ADRENALIN RUSH"
which you will then get full length sub frame connectors
K Member brace ,higher rate springs, Koni DA shocks and maybe have to look into a high performance rad.

There is a lot of great guys here that will help you out alot
Dave Barker is good and you will probably see his tail lights alot in front of you, He help me out alot plus to many other guys to mention them all.

If you don`t no where to get Mustang Parts I would suggest RCO in London Ont.
They sell for Ford only.
etc. MaximumMortorsport Caster Camber Plates.
K-Members

Don`t forget there are lots of lapping days as well where you can get lots of track time

[LateApex]

I tracked an 87 extensively over the past 5 years. You'll see Greg (DECH_92) driving it this Spring....

Caster/Camber plates are very important on any Mustang, not just the Modular cars like Chris pointed out above. A ton of negative camber and some positive caster are keys to dialing out some of the understeer and preserving your tire investment.
Griggs or Maximum Motorsports are the ONLY choices here.

Once you're hooked, (and you will be) changing all of your front-end bushings to either delrin or polyurethane will limit some of the camber gain that you will experience, even if you do have C/C plates. The stock rubber bushings are responsible for much of the camber gain on Mustangs. Upgraded bushings are a logical complement to C/C plates.

Don't waste money on a Strut Tower brace. I have never heard of anyone who has quantified any performance benefit by adding one to a Mustang. If it doesn't make you faster, why do it?

Full-Length subframe connectors are a good idea. I would buy them from Maximum Motorsports, so that they will be compatible with their other suspension pieces down the road. Check thier website out and you'll see that they've done their homework.

If you have a long-term plan, buy all of your parts from one company (I would choose Griggs or Maximum Motorsports- RCO in London sells both). All of both companies' parts have been engineered to work as a system, and both companies test at the track where it counts.

If you have any more questions, post em' here. Lots of experienced Mustang guys here.....

Jordan

[Gary]

The feedback is truly awesome, and much appreciated.

Much of what I'm hearing is what I've been thinking, but which needed external validation from those who've been there, and done that.

I also appreciate the reference to RCO in London, as I'd have probably ordered direct from Maximum Motorsports. It's helpful to have a local dealer. I think I can now get on with preparations, and I am looking forward to meeting everyone at an event this year.

Now, if this cold weather and snow will just go away........

[LateApex]

Just realized I rambled about suspension ad nauseum but didn't address your tire/wheel questions.

I would suggest that a 9" rim at all 4 corners will work just fine for now. 275's are commonly available, and in Stang circles, often used, so you can save some $$$ right there. John H. already offered you a set right here...the Yok's are a good place to start, particularly if you have one set of wheels. They are durable enough for you to just install them and leave them, street or track. Once you've got some seat time, think about Toyo's or Hoosiers on a second set of wheels.

You do not want to run a larger sized wheel/tire combo on the front vs. rear of a Stang- they understeer like crazy as it is, and a larger wheel/tire combo out back will tend to make it worse.

Keeping the size consistent at all 4 corners will also allow you to rotate them at will, which you will need to do very often until you've dunped a boatload of money into front suspension and alignment parts as I outlined above.

Hope this stuff is useful.

Jordan

[Gary]

Jordan:

Hmmmm. Hadn't thought of that. I think you are saying that a front end bushing change is necessary because the stock lower control arm bushings deflect inward under a cornering load, thereby adding positive camber to the outside front tire, and if the change is enough, it overcomes your static camber settings, and loads the outside of the tire. Deflection is limited at the top of the strut with a camber/caster plate. So, in order to have consistent camber settings, you've got to limit the deflection at the control arm too, not just the strut. Interesting stuff, this.

Presumably you can identify that you've got the camber setting right and deflection sufficiently limited if you have even temps across the front tires?

Gary

[Dave Barker]

Gary , Jordan is right about the softer bushing in the lower control arms means more deflection. The question becomes street noise and comfort loses vs the gains of poly bushings . Would be even better with spherical bushings or heim joints but the streetability factor becomes even worse.

[J.C.]

I have a wheel/tire question that goes well with this post. I have a 1987 5.0 that has not seen the track in quite a few years. I intend to put it back on the track this year. However it is currently riding on 245/45/16 RE71R's . I have in the past tried fitting larger wheels but found there to be a clearance issue. I am wondering what size tires have people been able to get on the 87-93 mustang and what modifications were required if any?

JC

[Chris91GT]

JC, I currently have 275/40/17s on the 91 GT right now. Perry (the guy who built the car - Director on this board) had to roll the fenders to make them fit.

Supposedly the 87 - 89 fenders (Greg may know more...) are narrower so you may not get 275s to fit.

Whatever size you do go with, make sure that they are the same front & rear. Larger rear rubber on a Fox Stang will do nothing except accentuate the understeer.

[DECH_92]

Well this is something I will find out this year as well.
On my 92 I had 255/40/17 no rubbing at all
Now I am driving a 87 that has 245/45/16 and I put my
255/40/17 on and they seem fine, but will not no for sure till I am on the track this year.
I think my car has rack limiters on it .
Yes the 87-89 do have smaller wheel wells
What shocks and springs are you using?
DO you have the Simmon 16 by 8 in wheels from Dech?
There lighter then any 17`s out there

[J.C.]

Yes I have simmons 3 piece. I did not know there was a wheel well size difference from one year to the next like that. Maybe its best then if I just stick to the smaller wheel/tire package.
Atleast its cheaper.

Almost forgot the other question yes DECH springs & Koni shocks.

[LateApex]

Anyone interested in learning about tuning a Mustang chassis should get their hands on the latest issue of Grassroots Motorsports. They are in the process of transforming a stock Mustang into a competent autocrosser with the assistance of several tuning companies.

J.C., on the tire size issue, more is not always better on a Fox-body Stang. Derek and Peter Hanson (DECH) did extensive testing of the various tire and wheel sizes available, and I believe they found that 245/45/16 was the quickest combination. You may want to get in touch with one fo them to verify.

Jordan

[91_DECH]

I ran simmons 16"x8" F90 rims with 245/45/16 RE71 on my 91, then switched to 255/45/17 on a simmons 17"x9" FR17 rim.

When I was running the 16" rims I noted 2 areas (well 3 sometimes) of rubbing; 1 front and 1 rear (before I went with the ASG on the back). Front passenger rim would rub at full lock to the right on the lower control arm, when moving slow while backing up. Forward didn't seem to cause any rubbing. In the back I noticed rubbing on the horizontial shock (on both sides) after being on the track, without the ASG. Sometimes the front would also rub at the fender lips when the car was going into dips / bumps at road speeds. This problem went away when Derek changed the rubber stops to a stiffer material (can't remember the name of the stop of the material).

When I switched to 17"x9" my biggest problems where with the rims rubbing the front lower control arms at both full lock left and right. I had to install rack stop limiters 2 per side to start with, then I went down to 1 per side. Turning radius suffers, but it saves the rims. Out back with the ASG I have not notice any rubbing any more.

Hope this helps some what.

[DECH_92]

I realy like the 255/40/17 on ROH 8.5 in rim with 5.5in back spacing on a Fox body
The 255/ 40 is not as tall a tire, helps up the rear gear a bit to.

No fender rub at all, maybe a little on the front control arms , but very little and did not have any rack limiters installed .

OH where can you pic up Grassroots Motorsports mag, don`t think I have ever seen them.

Hey Dave B , what tires did you run on you fox?

[LateApex]

17's look great on a Stang, but unless you're forced to use them due to brakes (Cobra brakes for example with 13" rotors), you're further ahead to run 16's.
Cost savings are substantial in any respectable R-Compound tire. 17's will also be heavier, and extra weight is the last thing a Mustang needs.

17's are for looks. Looks don't make you faster.....

Greg, are you taking good care of my car?:D

Jordan

[DECH_92]

Jordan
The 16`s are alot lighter yes this is true
WOW when I picked up your 16`s with the hoosiers on compared to the 17`s with Kumho`s , there must of been at least 10 pounds different per wheel.

The side wall on my 255/40/17 was about half that of the 245/45/16, that must help in the performance some.

But can`t argue with price difference.
And yes I am taking very good care of the car

Why you here, did you put in rack limiters in and still would be nice if you could find that stuff, you no ,ripe you house apart again lol.

:D

[Dave Barker]

Greg , I always ran 245/45- 16s and never had a rubbing problem. Sometimes the higher sidewall helps with the bad attitude of the rear axle but I 'm not sure with the Dech type rear end. I agree with Jordan that the wgt penalty is significant ( although Hoosiers always were very light)

[squeekyracer]

the stock tire/rim combination on the 1998 GT fit on my friends 1990 GT with lots of clearance i can't give you the specs though. I Don't know them. Sorry i drive a honda.

[squeekyracer]

Choose a budget first then make the decission. R compounds are far from cheap in respect to a street tire, especially for a mustang and its wheel size. Not only that the durability is much different.

[DECH_92]

Actually R tires are cheaper then good street tires, but don`t last as long