CentralCoaster

Seems like if it displaces more fluid, I'll need a larger M/C to compensate.

I have the 85 master cyl, which has two reserviors, so that may do the trick... The stock single pistons look bigger than the ones on the Wilwood calipers, so will this work?

My plan is to put Wilwoods superlites 6-pots up front and keep the stock 11.5" rear brakes to avoid losing the parking brake. Nobody needs 13" or 14" rear brakes anyways.

I assume I can balance between 13 or 14" fronts and 11.5" rears by using a proportioning valve... and that comes with the kit.

eguyett1985

You shouldn't have a problem...the stock master cylinder should work fine with the Wilwood 6 piston calipers...I'm gonna do the same conversion in a few weeks on my 85..I'm having to make my own caliper brackets and hats though since I haven't found anybody with a kit for the 84 to 87's..what are you doing on yours?

BAM92

So how much is that set cost anyway? And where did you find them?

silver84

Does anyone know the stock brake piston diameters
(F and R) for the '85?
.....
My concern is ...putting calipers with more piston
area in the front--> the back brakes don't do anything.
...
From the factory, what is the front/back braking ratio?

CentralCoaster

My plan is to buy the C5 setup and use Edsalinas' adapters.... this all assuming they'll work.

DREGSZ

Hi,
Let me help on this a little.
Ed Salinas C5 adapters to my knowledge DO NOT fit a Wilwood Superlight 4 or 6 pot caliper mounting holes.

I'm told from Wilwood tech that the stock M/C is fine for a front only conversion, But Dave at Melrose T Top, (very experienced and opinionated C4 racer) and one other racer who I can't remember told me that the trick set up is to get the 4th Gen F Body M/C and bore it out a size and that is the ticket for higher volume M/C

You can buy a complete kit from Wilwood, but the "word " is their mounting bracket is crap, (I have trouble beleiving that but I haven't seen it) I don't know of any racers that will use it, but it may be fine for the street.

If you buy their package, then it includes aluminum hats and rotors and nonstock offsets that fit but the rotors are $350 each and that, for me is a hard pill to swallow when C5 rotors are $25 each. And the total package is $2500

I am planning to have some Caliper mounting brackets custom made from a top race fabrication shop for at least the 4 pot Superlites.

I have it from good sources that they get Zero fade on the four pots in a 3400# blown F body w 750 hp and a professional driver, (Damn most impressive ride around Thunder Hill I've ever had and I have a full race '88 Vette and rumor has it I can drive, (at least onto the podium).

My '88 has Z52 front spindles which took a factory 13" rotor and LT1 (PBR) front calipers stock, they will take that spindle, and build a mounting bracket that accomodates a C5 13" rotor, and mates to a Superlite caliper, (same mount dimensions for 4 and 6 pot, 3.5" center to center)

Sooooo. if you want (or can) swap in a Z52, ZR1, or (maybe) a ZO7 front spindle that had a PBR caliper (LT1) and a 13" rotor, then we could have 2 sets made and that will drive (hopefully) the price down into the $350 per set range.

Summit sells the Forged Billet Superlite 4 pots for $125 ea and the 6 pots for $375 ea

Since you are a neighbor, NASA has an open track event at Thunder Hill on Wed Sept. 22 for $149 per car and I am the Event Director.

Come put in some hot laps with us!!
Thanks

CentralCoaster

Thanks for the details Evan. It doesn't seem wise given the rotor prices... maybe I'll try a tad softer pads, I dunno.

My reason is that I can supposedly get the whole setup for cheap, (I wont say how cheap yet) because I don't want the whole world knocking on my door... but it could very well be false promises from this guy. I've seen one set already, so I know he has the hookup.

I guess I don't understand how C5 aftermarket brakes won't fit the c5 adapters... The holes HAVE TO line up. Maybe there's some beef in areas the C5 calipers don't have it, which would mean it's a matter of clearancing the adapter if possible. The other possibility I can think of is that the rotor hat will push the disc inward, so the adapter will need to be offset accordingly. Having a prehistoric vette with zilch for aftermarket gets pretty frustrating.

Sounds easier to upgrade to new spindles and get Wilwood's C4 kit.

Jeffvette

The Willwoods, Brembos, Alcons mount completely different than the stock system.

DREGSZ

Caliper Mounting bolt hole locations vary from manufacturer to manufacturer. Adapters must be specific to each model of caliper. there is no universal standard.
Also, offset is a consideration so the mount bracket must be of the correct thickness for correct orrientation.

You could upgrade to the late C4 HD spindle, but the Wilwood kit again includes pricey rotors and different offsets.
I'm doing my fabrication to make the calipers work on a stock C5 rotor with a custom mount bracket.

Simple, relatively cheap
Thanks
Evan

IBEAM700

Luvmy92 has a truck MC on his Vette. Maybe he’ll chime in here.
I still need to get together with him someday and take a look at that setup.

luvmy92

I have the 6-piston Wilwoods up front but they aren't the Superlites. If I were you I would go with the GN III's instead if you plan on doing any heavy-duty road racing with it. These work fine with the stock MC, although there is much more pedal travel before they bite. This also makes it difficult to heel/toe because the brake pedal is so much lower than the gas pedal.

I bought mine thru DRM with their front brake kit... this includes the GN III Calipers, 2 piece rotors with aluminum hats, SS Lines, Grade 8 bolts, PFC 01 pads, anodized aluminum caliper mounting brackets, and spacers to push the wheels out to clear the calipers.

This is not a direct bolt-on. You will have to cut off your existing eyelets on the spindle and then grind down the knuckle about 1/4" for clearance. Not a big deal though.

I have since bought the 4-piston Superlites for the rear, and went with a truck MC from Corey Henderson and the Wilwood proportioning valve. You have to do a little work here with the brake lines to include the PV into the mix, but again, it's not too difficult if somebody knows what they are doing (CorvetteZ51Racer did mine).

Since I am in the middle of a 383 build-up I have not had a chance to test this yet, but this setup should be pretty stout for my purposes. I can hardly wait to see how much of a difference the rears are going to make.

Regardless, you will be very pleased with the brakes, and if you can get them for a good price even better.

Mike

2manyfuncars

I have GN-III's on the front of my car and have been to the track with them last week. They are a good choice. I haven't put the superlites on the rear yet, but they are needed. The rears still get a little mushy after a hard session.

GN-III's have a big pad and the pads are very reasonably priced. I made brackets and hats myself, but I have access to a CNC mill and a TIG welder. I would recommend buying something off the shelf. I also run a dual mastercylinder with a balance bar that I fabricated but it was way too much work. It works great, but a dual inline M/C with a proportioning valve is much easier to deal with and sounds like it works fine too.

The one piece rotors are cheaper, but transfer more heat to the front wheel bearing assemblies. Maybe a thin spacer between the hub and rotor would reduce that. The other advantage to two-piece rotors is the ability to use the thicker 1.375 wide 13 in stock car disks. You can get them from Coleman and others.

Lots of trade-offs to consider.

luvmy92

Once you have the massive 2-piece rotors, you only need to order the rotor itself from coleman, and they are pretty reasonable. It's the initial cost for the hats that get you. You should also always buy another hat bolt kit everytime you replace the rotors.

The C5 rotors are 1.25", whereas the GN III can handle a 1.375" rotor. My rear rotors are 12.72" x 1.25" with the 4-piston superlite calipers, which are much bigger than the existing 12" x .80" stock rotors.

Either way, these brakes will be a major improvement over stock and/or the C5 brakes available to you. It really comes down to how you are going to use your car, and whether or not they fit into your budget.

Mike

CentralCoaster

I guess I was under the impression that the aftermarket C5 caliper brackets would have to fit the stock C5 spindles, just as the stock caliper brackets. How could it be otherwise?