Real Fiero Tech

Anyone using 12" Wilwood two piece rotors with the stock 1988 calipers?



EDIT
Checked title to correct inch size.

I believe a friend of mine is, let me email him this link, he rarely posts.

CincinnatiFiero wrote:I believe a friend of mine is, let me email him this link, he rarely posts.

Thanks CF.

My bad, they are NOT 13", those are 1.1" thick. The stock Fiero 1988 rotors are about 20mm (about 0.8") thick. I think I found them.

Wilwood GT Series Directional Vane Rotors
Diameter: 12.19" (309,7)
Width: 0.81" (20,6)
Weight LBS: 9.3

Part # for those?

I used corvette rotors on the rear, with stock 88 calipers. they work pretty well, you can also use the corvette rotors on stock 88 fronts too.

I have wilwoods on the front.

I am stupid, I mixed your car up, my bad.

coinage wrote:Part # for those?

Don't have the exact part #. I will have to call Wilwood.

Rotors are about $130 each. x 4 = $520
Rotor Hats are $200 each. x 4 = $800
Total for Wilwood $1320.

The advantage is the weight is about 10.7lbs vs 27lbs for the stock C4 front rotors (should help the unsprung weight). This setup requires four FRONT rotors. The bolt patern has to be redrilled for the '88 Fieros 5x100.

I saw the guys @ West Coast Fieros sells them for $1100. Not sure if this includes the brackets.

I also found another brand called Power Slot of the weights 14lbs @ TireRack for $79.00 each. They sell separate one for the LEFT & RIGHT side (directional rotor vents?).
http://tinyurl.com/q54hrl

They also have Cryo-Treated Rotor for $110. Not sure on the weight of these. Both are slotted.


http://www.zeckhausen.com/Chevrolet/Corvette_C4.htm

Power Slot Power Alloy Rotor for your 1988-1995 Chevrolet Corvette
Front Left fitment
Style: Slotted
Finish: Black Rotor Hat
Note: (Left Front) Slotted vented rotor. For models with 12" rotors. Excludes heavy duty models.
Price: $79.00 (each)
Estimated Availability: Fewer than 2
Manufacturer Part #: 126.62040SL


Front Right fitment
Style: Slotted
Finish: Black Rotor Hat
Note: (Right Front) Slotted vented rotor. For models with 12" rotors. Excludes heavy duty models.
Price: $79.00 (each)
Estimated Availability: Fewer than 2
Manufacturer Part #: 126.62040SR

-------------------------------------------------------------
Power Slot Power Alloy Cryo-Treated Rotor for your 1988-1995 Chevrolet Corvette

Front Left fitment
Style: Slotted
Finish: Black Rotor Hat
Note: (Left Front) Slotted vented rotor. For models with 12" rotors. Excludes heavy duty models.
Price: $110.00 (each)
Estimated Availability: 06/19/09
Manufacturer Part #: 126.62040CSL

Front Right fitment
Style: Slotted
Finish: Black Rotor Hat
Note: (Right Front) Slotted vented rotor. For models with 12" rotors. Excludes heavy duty models.
Price: $110.00 (each)
Estimated Availability: 06/19/09
Manufacturer Part #: 126.62040CSR

this is te only thing that interests me...

Wilwood GT Series Directional Vane Rotors

The better deal for the Wilwood's seems to be @ West Coast Fieros.

from FGT
to sales@westcoastfiero.com
date Sun, May 24, 2009 at 10:57 PM
subject 1988 rotor upgrade
Hello,

Need a quote for the 12" Wilwood rotors and bracket for a 1988 Fiero using the stock calipers.

Thanks

On Tue, May 26, 2009 at 11:45 AM, chris west <sales@westcoastfiero.com> wrote:
(p/n BK12/1288MH) - Brake mounting hardware only. $215.60

p/n BK1212UGR) - Set of four rotors

$1,100.00

Call with questions 661 822 8111

Chris

I'm going to go with the Power Slot brand. 14lbs directional vane rotors is better then the 27lbs non-directional Stock C4 front rotors and more economical then the Wilwood 10.7lbs directional vane rotors.

coinage wrote:this is te only thing that interests me...

Wilwood GT Series Directional Vane Rotors

This is not to be confused with the "asymmetric" slot pattern that's supposed to reduce vibration. The Wilwood GT Series Directional Vane Rotors use curved vanes inside the vented portion of the disc, vs the regular straight vanes of some of the other rotor series. This is important because the curved vane rotors are designed to rotate in a particular direction. The GT-36 and GT-48 designations refer to the number of vanes. Researched all of these for my StreetCart project. Shown here the curved vane GT rotor vs the straight vane ULS (scalloped) rotor:





And the Wilwood illustration:
http://www.wilwood.com/Products/002-Rot ... GT/dwg.gif

FGT wrote: I'm going to go with the Power Slot brand. 14lbs directional vane rotors is better then the 27lbs non-directional Stock C4 front rotors and more economical then the Wilwood 10.7lbs directional vane rotors.

Stock C4 front 12" rotors are 14 lbs.

Series8217 wrote:

FGT wrote: I'm going to go with the Power Slot brand. 14lbs directional vane rotors is better then the 27lbs non-directional Stock C4 front rotors and more economical then the Wilwood 10.7lbs directional vane rotors.

Stock C4 front 12" rotors are 14 lbs.

I was thinking the same thing. I'm will to be that 27lbs number he got was for a pair.....

Series8217 wrote: Stock C4 front 12" rotors are 14 lbs.

AkursedX wrote: I was thinking the same thing. I'm will to be that 27lbs number he got was for a pair.....

Thanks guys. I must have misunderstood the info on WCF web site re: 2 piece Wilwood rotors.

http://www.WestCoastFiero.com/brakes/brakes_12.html wrote: These rotor and hat weigh in at 10.7 lbs per unit as compared to 27 lbs for the one piece rotor. This greatly reduces your unsprung weight.

Yesterday I got together with one of the guys from CFF and reviewed the '88 - '95 Corvette C4 front rotors and the '88 calipers. They didn't feel 27lbs at all.


We had a three way call with blackrams (Ron) @ P F F and he answered several questions we had about the brackets. (blackrams email photos of his brackets for visual reference)


On P F F I found a thread with a diagram and CAD files (bracket & hub-centric rings) for the DIYer.

Originally posted by Spiff:
I have the cad file around here somewhere. Let me see what I can find.
I used winace and zipped them.
http://www.MegaShare.com/542313
Hope this helps out, and the password is fiero

You can use ExtractNow (free) open that ACE file & Free DWG Viewer to view them.

Topic: 88 C4 brake bracket diagrams
http://www.fiero.com/forum/Forum2/HTML/096791.html

I'm going to give this a shot. Looks like fun!

Made a wood template and the above design (PFFie) didn't fit on the '88.

This design works (Hi-Res scan). Note since this is a trace the bolt holes might be a bit off. Thickness is 3/8" steel.


FIRST and THIRD hole should have a thread or nut for a grade 8 bolt (M12-1.75 x 30).

That clocked caliper design works OK in the rear, but in the front, with the calipers raised up, they can come into contact with the upper A-arms... especially on lowered cars (I clearanced my upper A-arms to reduce this, but it is still present). The fieroaddiction method pushes the calipers out w/o clocking them, but to do so requires countersinking 2 holes.

More details about this and how to build your own are in this thread about 2/3 down page 16 :
http://www.fiero.com/forum/Forum3/HTML/000017-16.html

Thats odd that you're haveing problems with the cad dimensions. I don't have any fitment or contact issues with the control arms and my car is lowered 2 inches. They fit perfect for me, front calipers get clocked up and rears get clocked down.

Doing a search for an upgrade and I cam across this oldie. I was checking out wilwoods site, and they have a pretty cheap rotor.

http://www.wilwood.com/Rotors/RotorProd ... o=160-0277

Also it appears that wilwood makes a 5x100 hat, but I don't know which one I need. There are a few dimensions I don't know. Center reg diameter, offset, and stud diameter

http://www.wilwood.com/Hats/HatList.aspx

I used the wheel stud cir of 5 x 3.93 as 100mm converted comes to 3.93 so I am assuming thats what I need?

WCF still sells this setup, but I don't know which rotor they use so I might be able to piece it together for a tad bit cheaper. Just trying to price it out. Yes its more than Gurus kit with his rotors, and I know his 12" kit only adds 3 lbs per wheel, but I want to keep unsprung weight added to a minimum if possible. it appears an upgrade is available without adding weight.

Will, tell me how much 3 lbs per wheel makes a difference or not. should I not worry about it?

Basically any delta in unsprung weight is worth worrying about. The Fiero has about 100#/corner of unsprung weight stock, so 3# is 3%.
Of course the actual metric regarding unsprung weight is the sprung/unsprung ratio, which is about 6 in a 2800# car with 400# of unsprung weight (and thus 2400# of sprung weight). That goes up to 6.18 or down to 5.83 with a +/- 3# change in unsprung weight at each corner.

Wheel, tire and brake weight adds up. Between that and a few other mods to The Mule, I think I have a good chance of getting it from ~2900 down to ~2700#. The few choice mods would be sunroof delete, fixed headlight conversion and Tilton clutch (which drops 18-20#!)