Precision Brakes

[Supra7MG]

Has anyone here had any experience with the current Precision Brakes MKIII front kit that utilizes the 4 Pot Wilwood Forged Dynalite Calipers. I have just installed this kit on my car and am a little sceptical. These calipers appear to be quite small as compared to what I have been accustomed to. We have a MKIV with Brembo's and a WRX with Rotora's. You can pretty well imagine how those perform and I'm looking for the same performance with the MKIII. I would think that the 4 Pot Wilwood would work very well on the rear, but I'm concerned that it is enough for the front. I'm in PA. and do not drive my cars in the winter which is the reason for this post.
I've been waiting on the rear kit for 5 months and had intended to do all 4 corners before I drove the car. I'm growing a little weary about that also.
Please let me know.
Also, I purchased the front kit form Horsepower Freaks and was very impressed with their service and pricing. I would highly recomend them.

 

[bluemax]

I wouldn't worry about the size of the caliper. In comparing brake systems, the deciding factor on how much stopping power the brake system has, assuming the friction coefficient of the pads and rotors are the same, is the size of the pistons. The more piston area you have the more force on the pads you get and the more friction on the rotor from the pad you get. The size of the caliper isn't necessarily an indicator of the actual piston sizes. A manufacturer can space the pistons further away from each other to accomodate longer pads.

Do you know what model calipers you got? And what piston sizes they are?


Your MkIII won't stop like a Mk IV or a WRX. The Mk III is considerably heavier. If you want to increase maximum braking, get wider tires.

Post some pics. I'd be real interested in seeing them.

 

[Adjuster]

I have PB brakes in 14" rotor size front and back. (14x1.38" front, 14x1.25 rear. Calipers are GNIII 6 piston front, and Billet forged dynalite 4 piston rear.)

Took forever to get them. The rear kit was custom, with only a few made at the time.

Then when I finally did get them installed, they pulsed almost from the start, and are out of balance, so I now have a vibration over 60mph that was never there before the brakes were changed.....

Can you tell I'm not really very happy with PB? Yep, they have great prices, but the advantages stop there. (Excuse the pun.)

Speaking of stopping, even with the pulse, and vibration, these brakes ROCK. They stop very fast, with little or no fade. (They are dang loud when cold however... takes some getting used to when they screech so loudly when cold.)

Good luck.

 

[Supra7MG]

Thanks for the replies guys. Bluemax, I'm running BFG Comp TA KDW's 235/45/17 Frt. 275/40/17 R. HKS Hipermax coilovers with Suspension Tecniques sway bars. Car is a hardtop with Sparco interior, no back seat and battery relocated to the rear where it belongs. I am going to weigh it soon. I would have to estimate it will come in about 3,400 lbs. I agree with everything that you have said. I guess the size of the pads is the source of my concern. The calipers are Pt.#120-6841 Wilwood Forged Billet Dynalite's. Piston size is 1.75x4. The rotors however are really hot. 12.8x1.25 2 piece. The vents look like they could devour a chipmunk. I'm probably being overly concerned but I never leave anything to chance. Adjuster, I've read of your experience before. That is a shame, and quite frankly is a bit of a concern to me. I will say that the front install went fine without any red flags. The brake lines are lame though. No provisions for securing them to the factory brackets . I fabbed some pieces and lined things with rubber hose and all is fine. I am probably setting my expectations a little high as the MKIV has the Brembo 14" 2 piece rotors and F50 calipers. Good thing there is Schroth Harnesses.
I will shoot some pics when the weather breaks and post. I've owned this 88 for 16yrs. 38,600 on the ODO right now. I think that you guys would approve.

 

[bluemax]

Wooooooo......
You've had the '88 since around 1993 and its got under 39,000 on it!

You've really lightened up the car.

FYI. I read in a R&T or Car and Driver mag. a couple of months ago that did a comparison on tires...... the Yokohama AD06 tires are by far the best braking tires. All the other tires were close to each other, but the AD06's had something like 10% shorter distance. If I find the mag again, I'll post the actual results.

Adjuster, I've got a set of the 6-piston 14" rotor F. kit. I haven't installed them yet. I hope I don't have your problems. Is the problem the rotors?

 

[Supra7MG]

bluemax, thanks for the tip on the tires. I'm almost ready for a new set as mine are getting old. I bought my 88 the first week of April, 1990. It had 7,800 on the ODO when I titled it. It belonged to a middle aged couple with no kids. They only used it on the weekends for pleasure and traded in every 2 yrs. The toyota dealer that I bought it from said that they traded it in on a new Buick Reatta. (Owner also had a Buick dealership) Is that sick or what. Oh well, I guess that means that it was never hammered. I've only driven it in good weather since I purchased it. In 91 I did a Full HKS Turbo conversion. Intercooler, Oil cooler and all. At the time it had 10,800 on the ODO. I'm still running the same Garret TO4B. I've never had any problems. My son will get the car when I auger in as I will never sell it. We bought the 94 for him last year. One of my best friends bought it new. He lives in Santa Monica. We had the car shipped here in an enclosed hauler. Rhyes Millen did most of the prior work on the car. It's BadAss. That one has 28,000 on it now. We love cars, especially Supra's!