Still debating wheels/tires/brakes setup for our build - please help us decide

[Alec]

Hey everyone. We are expecting our MK4 Complete Kit delivery in September. Our build plan (its myself and Cobramarco, my BIL) seems to change every time we talk about it. Please help us nail down a setup that we will be happy with.

Power plant is a Mike Forte 427 windsor (Boss block) with Mike's mechanical throttle setup, edelbrock EFI, gas'n touring headers/sidepipes. We ordered IRS and stock coilovers, power steering.

We are debating the tradeoffs between vintage looks, and driveability/performance. We love the look of knockoff 15" hallibrands (Vintage Wheels in san diego, e.g.), and tall rubber (mickey thompsons or similar). But that means a narrower rear tire, fewer tire choices without options for really sticky tires, and smaller (4-piston calipers) brakes all around (correct me, please, if I am wrong about those limitations).

With 500HP, I want to make sure we maximize grip, and that we can stop without stomping on the brakes. I would prefer to use good brakes rather than add components like hydroboost.

SO how do these tradeoffs play out in real-world driving? This will be a driver: Car shows, twisty roads in north georgia, cruises, evening out with a girl. Maybe we try autocross, but racing isn't a goal. It's looks, but also driveability and safety. I read on here that stupid power is still very driveable with the right wheels, sticky tires, and big brakes. So can the look we want coexist with the power we will have, and still be fun to drive and not terrifying? If so, tell me the setup that will best achieve those goals.

Thanks in advance, and we are sooooo excited to get started. The waiting is miserable.

[Jeff Kleiner]

…So can the look we want coexist with the power we will have...

Sure—-as long as you don’t try to use that power. Short of a purpose built drag radial there isn’t a 15” DOT tire in an appropriate size that will hook up half of that 500 HP (and drag radials aren’t suitable for“twisty roads in north Georgia”).

Jeff

[Alec]

So Jeff, I am hearing that my goals are not compatible in your experience. If that is the conclusion then I would prioritize driveability, and we would go with 17" wheels and sticky tires. What brakes, then? If we don't use the FFR-supplied wheels and instead used knock-offs like the Vintage Wheels version, what brake packages should we use assuming we want to use the largest/best rotors and calipers that fit? Or are the knock-offs also a tradeoff and cause limitations that I need to be aware of?

[rich grsc]

First off, you can't have 'knock off's' with the new IRS, but you can still get 15" wheels and tires that have the same look, from Vintage Wheels. If you have no plans to track the car then you don't really need giant brakes, I don't have them with my 15" setup, and am comfortable with the power brakes that I have. You CAN get great 15" tires. I'll put my Avon's up against any street tire out there. They have a rating of 80 for traction, and do very well with wet roads. I'll have to disagree with Jeff on handling 500hp, they hold 400 hp just fine, ;) so they can take 500 on the street.

[CaptB]

What is the mission? In other words is this a fun to drive carshow car or a drag/other racer?

If it is a fun to drive car/carshow, the 15" are fine, the more narrow rear tire is not a show stopper, you can't even tell unless you get underneath and look.

Just my .02 cents and that's what it is worth (or less).

Capt. B

[GoDadGo]

Unlike Jeff, I'm A Back Road Cruiser Not An Auto Crossing Bruiser!

Like you I wanted 15" wheels but went down the path of 17's because of the better tire selection.
The best handling option with 17 inch wheels is 255/40-17 up front with 315/35-17 out back.
Since I wanted that 15" look, I went with the taller Nitto 245/45-17 and 285/40-17 instead.

https://youtu.be/9WEe6-wdNtA

As for brakes, I'm running the stock 2000 Mustang disks up front with 1995 Explorer in the back.
My wheels are 17X9 and 17X10 and were purchased from OE Wheels LLC but are now discontinued.
Late Model Restoration still makes a very similar looking wheel which can be viewed in the link below:

https://lmr.com/products/94-04-Mustang-SVE-Anniversary-Wheels#320

Good Luck & I'm 100% Sure You'll Figure It Out!

[BradCraig]

I really enjoy ~500HP with really sticky 18" tires (R888R). I started out with the unboosted FF brakes and found that they didn't stop well at all with the provided pads. I could have gone with a better pad choice that a lot of folks swear by here but decided to upgrade to Wilwood instead. Couldn't be happier with the decision, stops on a dime! And they look great!

[KDubU]

I had 15”’s and they were fine but I did not “race”. I drove the backroads, occasionally on the interstate and the MT’s did fine. I agree you cannot beat the look. Also you will not use 500hp on roads so keep that in mind.

165777

[CraigS]

500hp is fine. Setup the Forte linkage for a long gas pedal travel and you can modulate the 500hp easily.
https://fortesparts.com/product/mechanical-throttle-linkage-kit/
See that the levers have long slots in them rather than holes. The slots allow you to set the ratio of pedal travel vs actual throttle travel. Brakes are not that difficult. Use the FFR standard front brakes and buy your IRS parts from a salvage yard selling the complete rear suspension and be sure you are getting the OE brakes. Get the FFR supplied balance adjustable master cylinder assembly. Search a lot here on pads or just get HAWK HP plus. They dust a lot but you will have brakes that the pedal pressure required is very managable. I compared my FFR brakes to my Tacoma pickup truck. Use this to help w/ the dust.
https://www.armorall.com/product/outlast-brake-dust-repellent/
I am not a fan of 15inch wheels. Rich mentions Avon tires which I understand are quite good, but those and the Mickey Thompson are the only ones you can say that about. 17s or 18s give you a much wider choice of tires. GoDad mentioned a good compromise to get somewhat of a 15 inch look but I could never bring myself to go narrower than the max that will fit. 315s on the rear will be the best for traction.

[Avalanche325]

At 500hp you want all the grip you can get. 315s in the rear and 200TW max.

As far a brakes go, when is that last time you drove a car that stopped too fast? Wilwoods are the way to go. If you want 500hp in a 2200lbs car, you had better be able to stop. That is tires and brakes. Wilwoods are manual, so you do have to step on them. There is thread after thread about people trying to improve the stock brakes. I drove one with donor brakes way back.....absolutely terrifying. Wilwoods are awesome on the street, autocross and track.

[john42]

Any one have actual real testing data on brakes? Measured topping distance from 60mph for donor brakes vs FF brakes vs Wilwood?

I have 13" Cobra Mustang brakes with Hawk racing pads. I find that the car stops extremely well, but I have no basis of comparison, as I've never driven a Cobra with Wilwoods.

[Alec]

Thanks everyone for the replies. I am learning, mostly, just how much I don't know. I think making things complicated for myself is just stupid, this being my first major car build. So I think I am going to stick with the stock FF 17" wheels with tires: 17” X 9” Front and 17” X 10.5” Rear & Mickey Thompson Tires, 245/45R17 Front and 315/35R17 Rear" $3500 already mounted and balanced. I will also order the FF Wilwood package. It should grip well, stop well, and most importantly, I know it will all work together with my IRS - NO SURPRISES, No creativity or fabrication or major problem solving needed.

THe next questions involve: which pedal box, which pedals (a number of aftermarket kits I am seeing), which master cylinders - and should I have 3 reservoirs? So many choices without a context or knowledge to make them.

[Jeff Kleiner]

THe next questions involve: which pedal box, which pedals (a number of aftermarket kits I am seeing), which master cylinders - and should I have 3 reservoirs? So many choices without a context or knowledge to make them.

The complete kit includes the Wilwood pedal box and masters. No reason to not use it. Combine that with a Russ Thompson gas pedal and then the only question is cable or hydraulic clutch. You’ll get differing opinions; I’ve done both and really don’t have a strong preference either way although for hydraulic I’m still not sold in the hydraulic throw out bearing. Just one guy’s opinion…

Jeff

[GoDadGo]

THe next questions involve: which pedal box, which pedals (a number of aftermarket kits I am seeing), which master cylinders - and should I have 3 reservoirs? So many choices without a context or knowledge to make them.

If you don't want 3 Reservoirs, you could consider a 3 Chamber style like the one in the link below:

https://www.summitracing.com/parts/til-72-576

I've got this one on my car and like the fact that I can see the fluid level in each chamber since the unit is somewhat translucent.

[Avalanche325]

The complete kit includes the Wilwood pedal box and masters. No reason to not use it. Combine that with a Russ Thompson gas pedal and then the only question is cable or hydraulic clutch. You’ll get differing opinions; I’ve done both and really don’t have a strong preference either way although for hydraulic I’m still not sold in the hydraulic throw out bearing. Just one guy’s opinion…

Jeff

I agree that a hydraulic throwout bearing is an engine-pull waiting to happen.

I went from cable to hydraulic. That was from a problem with the old design, not an issue now. I also agree that there is not any real world difference.

[CraigS]

Get a hydraulic setup w/ an external slave cylinder. I 'think' Forte sells them although I don't see them here so call.
https://fortesparts.com/kit-car-parts/

[Alec]

Get a hydraulic setup w/ an external slave cylinder. I 'think' Forte sells them although I don't see them here so call.
https://fortesparts.com/kit-car-parts/

That is exactly what we are doing.

[Mike.Bray]

THe next questions involve: which pedal box, which pedals (a number of aftermarket kits I am seeing), which master cylinders - and should I have 3 reservoirs? So many choices without a context or knowledge to make them.

My two cents. The Wilwood pedal kit is fine and their brake packages are very good. I've used them for decades and never had an issue. Wilwood master cylinders are another story, too many issues with them especially lately. I don't know the root cause but there's obviously some sort of quality issue going on. Maybe related to outsourcing them. I'm going with Tilton 76 series for peace of mind.

Personally I think the hydraulic clutch is more elegant than the cable model and gives a more precise "feel". I've used the hydraulic throwout bearing before without any issues. It's certainly simple to install. Yes, in the rare instance of a failure you have to pull the engine & trans to replace it but they are reported to be very reliable. I now I've never had any issue with them.

I'm planning on using this reservoir.
https://www.summitracing.com/parts/sxh-rr-3003p