[kenco]

I have a 88 Fox, I am contemplating going to a rear disc brake setup similar to the package offered at Summit (Stainless Steel Brakes A112-1 - Stainless Steel Brakes Rear Disc Brake Conversion Kits - Overview - SummitRacing.com). Has anyone used this product, if so, were you happy with the results.
Overall I would like to improve the handling and suspension of the car, so any input would be appreciated.

Kenco

[fogged306]

I had a complete SSBC kit on another car that worked great in dry weather. To the point where I had so much stopping power I was afraid that people would slam into the back of me if I had to stop too hard in traffic, but in the rain, they were actually worse than my stock brakes.

[ReverendDexter]

Hi Ken!

You're starting on a dark path, one that few of us on this site travel (most of the guys here are drag racers only).

There are a lot of good threads regarding fox-chassis suspension, so get'a searchin'. Suspension is the same for '79-'04 (other than New Edge Cobras), so don't be afraid to hit the mod-motor section when you're looking.

Regarding the specific kit, I can't speak to it, as I haven't done the rear brake conversion on my car... it seems a little pricey relative to a junkyard conversion, but with all the little parts involved having them all at once certainly would make life easier.

[ReverendDexter]

Originally Posted by fogged306 I had a complete SSBC kit on another car that worked great in dry weather. To the point where I had so much stopping power I was afraid that people would slam into the back of me if I had to stop too hard in traffic, but in the rain, they were actually worse than my stock brakes.

Sounds like you need an adjustable proportioning valve. Rain makes for different braking conditions, and you need a different braking balance because of it.

[kenco]

Thanks for the replies! Some background, I had the car on the dyno last year and I was very happy to see 501 RWHP with 460 torque. At present I am running the stock rear suspension setup, with the power I'm making, I was was thinking to do some upgrades, rear upper and lower control arms seem a good place to start, the disc brakes are really a "nice have" thing. The steering is also a little sloppy, due to the rag joint, I should replace the whole steering shaft with a good aftermarket.
All it takes is a big bag of money and a well equiped garage (luckily I have the garage issue covered)
The car is in very good shape so the upgrades are worth it.

Kenco

[fogged306]

Originally Posted by ReverendDexter Sounds like you need an adjustable proportioning valve. Rain makes for different braking conditions, and you need a different braking balance because of it.

Makes sense, so you're saying the braking power was probably too much in the front and not enough in the rear?.. or something similar.. The car that the kit was on is long gone now anyway, but it's always good to learn something new.

[jessemachone]

Originally Posted by fogged306 Makes sense, so you're saying the braking power was probably too much in the front and not enough in the rear?.. or something similar.. The car that the kit was on is long gone now anyway, but it's always good to learn something new.

too much pressure in the rear

[ReverendDexter]

I was actually thinking the opposite - in the rain, the grip is lower, therefore when you get on the brakes it takes less effort to lock them up. That means that you want relatively less power up front, as the lock up point has less weight shifted forward, which means more weight is actively on the rear tires, meaning they have relatively more grip, meaning they can take more braking power. Now, if the rears were locking up first, that shoots my theory all to hell - you want the fronts and rears to lock up at the same time, and if the rears go first that means they have too much power.

Ken - sounds like a healthy motor, hahaha. At the VERY least, what I would recommend to you is full-length, weld-in subframe connectors. Foxbodies are very flexy, so you need all the help with chassis rigidity you can get. If you can afford 'em get over-and-under SFCs... much more expensive, but much more rigid. Also helpful is a proper rollbar, get a 6-pt if you don't mind the door bars.

Control arms would certainly help, though you have a decision to make whether you want to keep the 4-link (cheaper, stronger) or ditch it in favor of a setup with significantly better geometry such as a torque arm or even the Cobra IRS. Really depends on your goals and budget.

Take a look at the Maximum Motorsports grip boxes to get an idea of what you're getting in to, Griggs Racing is the other company I really recommend for a handling car. These are the guys on the far extreme of handling and show you really what's possible with these cars.

Like I said, depends on goals and budget. How fast do you want to spend?

[fogged306]

It actually took quite a bit to lock them up in the rain, it felt more like brake fade than anything. I always thought it might have been poor rotor design and water was getting inbetween there but that was just an uneducated guess. So lets say you have a street car that will see rain and shine, where would you say would be a good starting point to set brake bias on your average set-up.. I've heard that factory set-ups are in the neighborhood of 70%F-30%R, any truth to that?

[ReverendDexter]

Originally Posted by fogged306 It actually took quite a bit to lock them up in the rain, it felt more like brake fade than anything. I always thought it might have been poor rotor design and water was getting inbetween there but that was just an uneducated guess. So lets say you have a street car that will see rain and shine, where would you say would be a good starting point to set brake bias on your average set-up.. I've heard that factory set-ups are in the neighborhood of 70%F-30%R, any truth to that?

You know, that's honestly outside my knowledge, but I do know that the usual given figure is that your front brakes do 80-85% of the work, and that it's "safer" to have the front brakes lock up first, as that would create an understeer condition. Based on that, I'd guess that 70/30 is actually low, and that factory brakes are probably more like 80/20. Especially in this day of ABS, overpowering the front brakes isn't much of an issue, they'll just start pulsing.