Wilwood/ST205 guys, master cylinder issues?

Simba

New member
If anyone is running the Wilwood 120-8466 4-pot front calipers with the ST205 rear calipers, I'd like to hear from you regarding pedal travel and feel. I'm having a few issues with my setup and am wondering if it's a master cylinder capacity issue that other people have run in to, or if it's the evil air spirit randomly filling my lines. :twisted:
 

Simba

New member
I'll update my post from a million years ago as I've had a couple questions about this setup-- short answer is it doesn't work. Not enough volume to drive both the 4-pot wilwoods and 2-pot 205 rears. Tried both masters, all possible permutations of booster, no dice.

Probably needs something like a 1-1/8" master with an ABS delete to run it effectively.
 

ALLensTRAC

New member
Well Shit! That is the exact setup I have in my garage. Just curious but does your car have the ABS deleted? I thought from reading on a couple different forums that the master was ample? Is there any aftermarket options available i.e. Wilwood? Our master is a 1" correct? I will have to do some more research now that you brought this up. My setup is Revolution fronts(superlites with supra rotors redrilled) and 205 rears just for reference. I have yet to drive it with this setup so I don't have any comments on feel to contribute yet.
Allen
 

klue

New member
ABS MC is 15/16s, non abs is 7/8s
Ive got the willwood 4 pots in fron st205 in the rear, I ended up completely removing all the stock lines, PP valve EVERYthing and ran my own set up. pedal travel is very slightly more than I like but its easy to modulate which is good, makes it easy to roll onto the brakes.
 

Corey

Active member
^^ Win Win ;)

I'm curious how René's car is coping with his setup. I think it still had ABS installed while the AP and 205 rears were bolted on.
 

phattyduck

New member
I am running the Porsche Brembo fronts with ST205 2-pot rears on a 7/8" master cylinder without any troubles (no ABS though)... What are the piston diameters on your Willwood fronts?

-Charlie
 

ALLensTRAC

New member
Maybe this an issue with track cars only? I know that klue tracks his car and I think simba does as well. I hope mine ends up ok.
 

underscore

Well-known member
Corey Darling":ic7171ia said:
^^ Win Win ;)

I'm curious how René's car is coping with his setup. I think it still had ABS installed while the AP and 205 rears were bolted on.

Well I won't be deleting it until next winter when I pull the motor. And my parts car up and ran away! Oh well.
 

Corey

Active member
Keep an eye on the gt4oc for "kits" people sell when they part out their cars. They are actually pretty common over there. That's where I bought mine.

And it can be done in half a day with the motor in the car.
 

klue

New member
My track issue with the brakes is that I have to push the pedal to far to properly heel and toe, street issue is I just prefer a taller pedal(mostly for the same reason LOL)

If you had a 1" MC i think it would be perfect. Saying that its very hard to properly bleed the brakes and eliminate all the air. I use standard 2 man bleeding first, along with reverse bleeding to get the best results.
 

underscore

Well-known member
I've never been on GT4OC but I'll have to sign up. If it's only a half day job I may as well do it sooner rather than later.
 

GT4_DRED

New member
Has anyone tried this on a 165? I'm currently running the Wilwood 4pot kit on the front and have had the 205 rears sitting forever. I'm thinking it's time to install them, but I'm not sure of the 165s MC size (no abs)?
 

lumbercis

Moderator
Simba":30kdjnjs said:
I'll update my post from a million years ago as I've had a couple questions about this setup-- short answer is it doesn't work. Not enough volume to drive both the 4-pot wilwoods and 2-pot 205 rears. Tried both masters, all possible permutations of booster, no dice.

Probably needs something like a 1-1/8" master with an ABS delete to run it effectively.

Then how do ST205's run 4 and 2 pot brakes with ABS? I don't think their master cylinders are unusually large. The MKIV Supra has 4+2pots w/ABS and their master cylinders aren't over 1" AFAIK.
 

GT4_DRED

New member
klue":3pq9mcnf said:
My track issue with the brakes is that I have to push the pedal to far to properly heel and toe, street issue is I just prefer a taller pedal(mostly for the same reason LOL)

If you had a 1" MC i think it would be perfect. Saying that its very hard to properly bleed the brakes and eliminate all the air. I use standard 2 man bleeding first, along with reverse bleeding to get the best results.

Did some more searching on here and found that the st165 master cylinder is as follows:

non-ABS: 15/16"
ABS: 1"

Can anyone confirm this? Seem like the abs mc would make the setup work? I'm gonna throw the rears on anyway and go from there, as it seems that most of the info I'm finding is for fitting on a 185.
 

klue

New member
I have a st165, and 1 " cylinder now. Pedal travel is still a bit much, but on the track with the racing compound pads it works great once up to temp.
Had to buy new pads for rear.
 

Meenya

New member
I have AP front (6 piston) and 205 rear. Pedal feel is firm like stock. Those brakes make a big difference compare to OEM set up. Bleeding manually took some time especially the fronts as there are 2 bleeder on each caliper.
The car is 91 RC originally non ABS.
 

GT4_DRED

New member
klue":1mzlfp04 said:
I have a st165, and 1 " cylinder now. Pedal travel is still a bit much, but on the track with the racing compound pads it works great once up to temp.
Had to buy new pads for rear.
That's great news! So a 165 abs master cylinder, but without using the abs? BTW, did your car come with abs from the factory? Do you also have a project page for your 165, I only saw the one for your 185?

Thanks!
 

klue

New member
I had a project page for my st165 but I never updated it, to busy working to be taking a photo blog. I do update my facebook frequently

https://www.facebook.com/xiiimotorsports

Yes I orginally had ABS, so 1" bore.

I got rid of the ABS, replaced all the hard lines with PTFE -3 SS. I run a Prop valve, st205 rears new pads, willwood 4pot fronts with race comp pad, motul rbf fluid. Since using the rbf on other cars I have noticed that this can play a roll in the pedal feel. It seems that when the fluid comes up to temp along with the brakes the pedal is much better. Originally when I was complaining it was with the street comp pad, and the RBF fluid. You can also adjust the pedal from the brake switch a bit. I had done this driving up to the track, a few laps in my brakes were up to temp and would not release, so I had to back it off. I will be making a modified set up this season
 
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