Wilwood aluminum rotor hat

68L71

Well-known member
Joined
May 13, 2008
Messages
749
I have Wilwood front rotors but I am concerned with the thickness of the hat. I will be running aluminum wheels so the hat is thicker as well as the mounting surface of the wheel. I have stock length studs. The hat + wheel mounting flange = 7/8", not including the conical seat. I have not measured how much stud protrudes. The Wilwood rotors are stock size, I was surprised how there seems to be little weight difference, maybe the difference is more than I think as I did not use a scale. Currently I am using stock rotors.
 
Install some longer 1/2" studs, the stock 7/16 are pretty weak. What hat & rotors do you have? Do you, or anyone else, know the hat offsets for front & rear?
 
Larry, is that front or rear? they are different in offset too.


Good question. It's what I had here at work. I'll check when I get home.

I can't imagine that the Wilwood hats are thicker than the stockers. C3 roteors seem thicker there than any I have ever seen. 68L71, you should have at least 1.25 stud length (beyond the hub face).
 
Stock = 1/4"
Wilwood = 1/2"

With steel wheels the wheel is thin but aluminum wheels have thicker mount flange. The only reason I am concerned is I would be using both thicker hats and wheels. If I upgraded to longer ½" studs it would solve the problem, but if I don't need too, I do not want to go to the trouble of adding ½" studs. I need to measure how much stud protrudes but I need to pull the caliper to test fit.
 
Stock = 1/4"
Wilwood = 1/2"

With steel wheels the wheel is thin but aluminum wheels have thicker mount flange. The only reason I am concerned is I would be using both thicker hats and wheels. If I upgraded to longer ½" studs it would solve the problem, but if I don't need too, I do not want to go to the trouble of adding ½" studs. I need to measure how much stud protrudes but I need to pull the caliper to test fit.


Stock should be at least 3/8". 1/2" hub face thickness for an alumunum hat is thick.
 
I`m using this one on the front...HD series fixed mount. please note, they measure offset kinda funny...you can (I think) get longer 7/16 studs, I don`t think I would use a 7/16 stud in a hat with a 1/2" hole...redvetracr

8 x 7.62" rotor circle

5 x 4.75" bolt pattern


1.50" offset


.51" stud hole

2.85" center hole

.50" face thickness

6.51"

.323"

Wilwood #170-0176
 
Last edited:
...you can (I think) get longer 7/16 studs, I don`t think I would use a 7/16 stud in a hat with a 1/2" hole...redvetracr

Thanks for posting this...the hat I have has 7/16 holes…I think I may need to get longer studs to feel comfortable using them.
 
...you can (I think) get longer 7/16 studs, I don`t think I would use a 7/16 stud in a hat with a 1/2" hole...redvetracr

Thanks for posting this...the hat I have has 7/16 holes…I think I may need to get longer studs to feel comfortable using them.

is that a Wilwood hat? or possibly a Coleman hat? I don`t dispute you I just don`t see any hats on the Wilwood site with 7/16 stud holes. I think Moroso offers a longer 7/16 stud......
 
redvetracr; is that a Wilwood hat? or possibly a Coleman hat? I don`t dispute you I just don`t see any hats on the Wilwood site with 7/16 stud holes. I think Moroso offers a longer 7/16 stud......[/QUOTE said:
I just checked the hats definitely have holes 7/16. They may be special order. The rotor is definitely Wilwood. The hat says on the back CU or GU 2234.
 
The rotors are the same ones this guy sells…. http://store.corvettengineering.com/index.php?act=viewProd&productId=43

I would like ½" studs, but is it really necessary on the street with street tires?

I installed aluminum hat wilwood 13 inch front rotors with stock 7/16 studs and Centerline aluminum 17 X 10 wheels The stud threads went through my taller lug nuts.

My rotors became blue from heat except near the aluminum hat attachment points. So it appears that the aluminum is conducting heat away.

I am now able to run all three run sessions and still have great brakes at the end of a hot day where my stock brakes with 600 degree fluid would be gone in about 10 minutes before I finished my fourth lap on the 4.2 mile course.
 
Top