Dynomite

ZR-1 (90' and 91') Wilwood Rotors and C4 to C5-Z06 Front Brake Conversion with A-Molds

Specific Brake Parts by Wilwood
see ZR-1 (90' and 91') Wilwood Rotors and C4 to C5-Z06 Conversion

The KEY Element is the offset of the Rotor to match the offset of the Caliper Bracket.

1. Rotors.
Wilwood SRP Drilled Performance rotors 12.8 inch diameter and 1.25 inch width with 12x7.06 Rotor Bolt Circle (160-7744-BK RH and 160-7745-LH).


2. Hats.
Two Wilwood Big Brake short offset (offset 1/4 inch) Hats (Aluminum Aloy) with 5x7.45 Wheel Stud Circle and 12x7.06 Rotor Bolt Circle (#170-7746) will fit the Wilwood SRP Drilled Performance Rotors.


3. Brake Pads.
Four (4) 15Q-8012K PolymatrixQ pads for a C5-Z06 (Wilwood is souce).

4. C5-Z06 Calipers and Brackets.

C5-Z06 Calipers Ebay
C5-Z06 Caliper Brackets Ebay

5. Bracket Bolt Kits.
#14121 (Caliper Guide Pin) and Brake Hardware Kit (spacers and seals) #H5634Q at O'Reilly Auto Parts.

6. Adapters.
(Corvette C4 to C5-Z06 conversion brackets, late spindle) C4 to C5-Z06 Conversion Adapters (Ebay)
(Note the countersunk surface for Bracket Boss)



7. SS Brake Lines.
C5 SS Brake Lines (Ebay)

8. Adapter Washer Spacer.
One Washers (about 1/16 inch thickness are used on each of two adapter bolts) between the Adapter and
Wheel Assembly. This setup centered the calipers on the rotors having 1/4 inch offset.

9. Performance of the Wilwood SRP Drilled Performance Rotors with Hats.
I have this same Wilwood SRP Drilled Performance Rotor brake set up on my 91' and I can tell you there is no fade.

Also the Bearing Hub does not see near as much heat on a high speed stop.

The trick with the Wilwoods is the Hat. As you can see there is limited transfer of heat possible from the Rotor to the Hat. That keeps the Hub cooler than a solid mass Rotor/Hub. So the front end Hub Bearings do not see near as much heat when I stop in my relatively short 1/4 mile runouts from 120 mph



10. Wheel Dimensions that will fit on this brake Set-Up.

This would be the limit of a wheel inner dimensions which would fit/clear this Brake Caliper Set-UP.
Rather than try to measure the offset and the maximum radius of the Caliper it was easier just to measure the A-Mold wheel which just clears the spokes as well as the Caliper outer radius as shown below. I would say this is Minimum Clearance. The clearances of this Set-Up is on the order of 1/4 inch on spoke and 1/8 inch on wheel inner radius so very close. There is slop in the Caliper pins riding in the bracket so this clearance is definitely required.



A. Spoke Offset.
The Spoke Offset from hub surface is 1 inch at the widest part (outer edge) of the Caliper.
The wheel weights are located on the inner rim and single stacked.



B. Wheel inner diameter.

Two Inner wheel diameters are shown. The one on the left is the wheel diameter at the hub surface which is 15.25 inches (this would coincide with the the radius of the outer part of the caliper . The Second wheel diameter on right is the wheel diameter at 4.5 inches up from the spoke where the inner (larger radius) part of the caliper which is larger radius sits which dimension is 15.75 inches.

Vette Daddy

Neat stuff. Love the rotors

ghlkal

Wow - impressive, and looks great too.


You might be missing a lug nut or two ....

Dynomite

I was waiting for someone to notice the missing lug nuts....I just set that up on my 91' temporarily to check offset

bamawrx

Anyone try a setup like this on road course?

LT5corsa

Cliff

We should set up some type of track event for 1/4 mile drag and stopping???

Maybe a zero to 100mph to zero? That would be magazine material!!!



David

Dynomite

Ok....next week in South Dakota after I get these mounted on my 90' I will do a couple 120 mph stops for you and see if the brakes catch fire

USAFPILOT

what is the cost of that setup? any idea if it will fit under Shelby Series 1 wheels?

Dynomite

I forget the specific costs (which will vary with time) but all the sources are in the first post for prices (click on underlined link). The A-Molds shown are as tight as you can get with 3/16 inch clearance on the radius. Wheel weights cannot be stacked. Go to Specific Brake Parts by Wilwood and search for the Rotor Part #s (160-7744-BK RH and 160-7745-LH).

I think each Rotor was around $270 more or less and then you have Adapters, Hats, Calipers, Brackets, SS Brake lines.

I think what you need is to compare the inside diameter of the wheel (or the outside radius of the Caliper) which I can measure tomorrow for ya. I need that information in the first post anyway....I will put a tape measure on the wheel Hub and Caliper for you. Actually the Caliper to spoke clearance is very tight also so I will measure out from the face of the rotor to the outside of the Caliper. Actually you need from the inside hub of the A-Mold to the flat of the spoke.....Anyway....you get my drift

Then you can just measure any wheel you have in mind and compare.
It will be difficult to get much tighter than this however.

ghlkal

Maybe that will melt some of the snow you guys got

Seriously, I'd like to see the numbers. I bet they would be impressive

Dynomite

LOL....you know about the 33 inches of snow in higher elevations around Rapid City and 10 inches on the lower elevations...and I90 closed for a while a week ago

I was going to drive through there last week but decided to wait a week....so am driving through later this week thinking/hoping all that will be melted

Actually I will do a 120 mph run tomorrow with my 91' to a quick stop and see if the brakes (identical set up) catch fire....which I know they won't since I have done that several times already down the street

More seriously I will take note of brake fade but I have done that already also and there is none that I can detect. I did not stand on the brakes however........What I really really like are the Aluminum Alloy Hats and the separation of the Hats from the Rotors (they are bolted together but definitely not a solid mass). The Hubs are definitely isolated from the Rotors much better than stock.

I am thinking on my 91' the Hats are steel being an older variant of Wilwood Hat...but will verify tomorrow. Still the isolation of the Hat from Rotor is the same.

One more item.....the adapter which I had originally got (for my 90') from one vendor (not the most recent one on Ebay) did not counter sink the holes for the caliper bracket boss on the adapter (even though his adapter photo shows countersink). So had to get the adapter on Ebay which DID have the proper countersink. This makes a difference in the caliper alignment with the Hats having 1/2 inch offset. I was going to countersink those holes but just went and ordered the adapters on Ebay. One can adjust the location of the Adapter with a washer or two but using washers is not my way of aligning things that should be machined without the use of washers.

The adapters I have on my 91' from the original vendor DO have the proper countersink for the bracket boss.

(Corvette C4 to C5-Z06 conversion brackets, late spindle) C4 to C5-Z06 Conversion Adapters (Ebay)
(Note the countersunk surface for Bracket Boss)

Dynomite

Measure your Shelby Series 1 wheels as shown below and compare dimensions
The clearances of this Set-Up is on the order of 1/4 inch on spoke and 1/8 inch on wheel inner radius so very close. There is slop in the Caliper pins riding in the bracket so this clearance is definitely required.

Wheel Dimensions that will fit on this brake Set-Up.

This would be the limit of a wheel inner dimensions which would fit/clear this Brake Caliper Set-UP.
Rather than try to measure the offset and the maximum radius of the Caliper it was easier just to measure the A-Mold wheel which just clears the spokes as well as the Caliper outer radius as shown below. I would say this is Minimum Clearance.



A. Spoke Offset.
The Spoke Offset from hub surface is 1 inch at the widest part (outer edge) of the Caliper.
The wheel weights are located on the inner rim and single stacked.



B. Wheel inner diameter.

Two Inner wheel diameters are shown. The one on the left is the wheel diameter at the hub surface which is 15.25 inches (this would coincide with the the radius of the outer part of the caliper . The Second wheel diameter on right is the wheel diameter at 4.5 inches up from the spoke where the inner (larger radius) part of the caliper which is larger radius sits which dimension is 15.75 inches.