Wilwood Dynalite Brake Upgrade

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H2OSB
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Re: Wilwood Dynalite Brake Upgrade

Post by H2OSB » Wed Aug 02, 2017 8:22 pm

Subarus have a parking brake set up identical to the 944 except the brake shoes are 170mm diameter as opposed to the 180mm diameter of all of the Porsche (and BMW) brake shoes. Well, at least the cars with that type of parking brake. I am unfamiliar with any Subarus that use a different system.

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Piledriver
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Re: Wilwood Dynalite Brake Upgrade

Post by Piledriver » Wed Aug 02, 2017 8:51 pm

Nevermind about the Subaru stuff then.

the 4 front 1.75" pistons/side provide 19.2 sq in per axle piston area.
I don't know of any "off the shelf" parking brake caliper that would be at least 70% of that area.
Even the 45mm piston Mustang calipers are only 50%.
The commonly used Mk4 calipers are only 38mm~7 sq in/axle

You would be far better off returning the ones you have and getting a usable size, which would probably be 1.38".
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kangaboy
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Re: Wilwood Dynalite Brake Upgrade

Post by kangaboy » Wed Aug 02, 2017 10:14 pm

Piledriver wrote:
Wed Aug 02, 2017 8:51 pm
You would be far better off returning the ones you have and getting a usable size, which would probably be 1.38".
That's not gonna happen. I have already put quite a few miles on them, and the place that I purchased them from is Sketchy at best. I'll just try to bleed them the best that I can and put the largest set of compatible rear disks on it that I can.
'74 Standard- 1776T, MS3X3
'76 Westy- Stock 2.0L L-Jet

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Piledriver
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Re: Wilwood Dynalite Brake Upgrade

Post by Piledriver » Wed Aug 02, 2017 11:45 pm

I would suggest scouring Ebay for a set of the right ones... wilwood 120-6808
Then sell the wrong ones to somebody with a Camaro.(then they are the right ones)
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kangaboy
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Re: Wilwood Dynalite Brake Upgrade

Post by kangaboy » Thu Aug 03, 2017 9:49 am

That seems more doable. Two questions regarding that then: Would the calipers that I currently have still be too big for my Westy? Secondly, would the swap be as simple as removing the old and bolting on the new ones (just swapping calipers and using current rotor and mounting bracket)?
'74 Standard- 1776T, MS3X3
'76 Westy- Stock 2.0L L-Jet

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Piledriver
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Re: Wilwood Dynalite Brake Upgrade

Post by Piledriver » Thu Aug 03, 2017 10:37 am

They would be much closer to ideal for a westy, and they identical to the too-big dynalites except for piston size.
(taller vehicle, more weight transfer under braking)

It has been awhile but IIRC bus rotors are a bit thicker.
The Dynalites width is set by spacers between the halves, 3/8" has no spacers.
If the bus rotors are thicker, buy the 1.38" ones width sized for the bus and swap the spacers and bolts over.
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kangaboy
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Re: Wilwood Dynalite Brake Upgrade

Post by kangaboy » Thu Aug 03, 2017 12:22 pm

I like the way you think.
So just to be 100% sure, I want these ones, the 1.38"x4 pots for my beetle? (just talking about pot size, not rotor width)
https://www.amazon.com/Wilwood-120-6808 ... alite+1.38

I'll have to check rotor width on my current beetle rotors before I order, but will have to wait for my new Dial Caliper to come in the mail (this weekend). I am not convinced I want to put the current 1.75" wilwoods on the bus, because who knows what kind of issues that will cause in that braking system, but if I do then ill go ahead and measure the bus's rotor thickness and order the 1.38" accordingly, and then switch out the spacers in between the calipers.

Jezusss, all this time and money for a new set of brakes....
Just have to take is as a learning experience I guess.
'74 Standard- 1776T, MS3X3
'76 Westy- Stock 2.0L L-Jet

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Piledriver
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Re: Wilwood Dynalite Brake Upgrade

Post by Piledriver » Thu Aug 03, 2017 3:00 pm

Std Ghia rotors are ~3./8" or close enough.

You will probably want 2 lb residual pressure valve for the front disc circuit, 10 lb for the rear drums and the larger late front wheel cylinders for the rear.

The only metric RP valves I ever found were EMPIs...
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