Wilwood brake proportioning valve - Page 2 - Alfa Romeo Bulletin Board & Forums

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post #16 of 23 (permalink) Old 11-07-2015, 06:23 PM
But Mad North-Northwest
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Not sure if I understand the question? Fronts should always lock first: the proportioning valve cuts pressure to the rears to prevent them locking up before the fronts, which would be bad. Mine was leaking and the original Alfa valve is NLA, hence the Wilwood part.

Right now as far as I can tell I've got it set the same as the Alfa valve and it seems to be working okay. I guess I'm just wondering what other folks have found with regards to optimization.

Tom

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1963 Giulia Spider (1750 engine)
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post #17 of 23 (permalink) Old 11-07-2015, 06:59 PM
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Ideally all wheels would lock at the same time. The fronts will lock up first if there is insufficient pressure to the rears. You may want the fronts to lock up first, but only just.

Ed Prytherch
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post #18 of 23 (permalink) Old 11-08-2015, 01:20 PM
But Mad North-Northwest
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Ah, I get what you were asking now. You're absolutely right that best stopping is when both front and rear lock simultaneously. But the rear pressure setting where that happens varies depending on speed and road conditions, so you need to be conservative in setting the bias. You've only got one setting on the valve, and you never want the rears to lock first in any conditions.

Anyway, I think I answered my question on optimization because it actually rained today in SF. Doing some panic stops in the wet, the rears were grabbing with my original setting of two turns in. I dialed it out one turn and it performed much better. I'm calling it good.

Tom

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post #19 of 23 (permalink) Old 11-08-2015, 04:34 PM
Del
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"best stopping is when both front and rear lock simultaneously"

But for vehicle stability in braking, usually it seems that the rears are set so that the fronts lock first.

Del

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post #20 of 23 (permalink) Old 12-03-2015, 07:45 PM
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I am looking to do this but have an S1 with a single circuit and standing pedals. Is there any risk in mounting this in a different location than the stock valve which is in a rather inconvenient spot under the rear seat? I need to bend a new rear brake line anyways and could delete the old valve in the process mounting the new valve in the engine bay near the T.

I plan to road test until the rears lock then back it off from there. Each turn on the Wilwood is 4% with a max of 57% reduction.

Last edited by BostonBertone; 12-04-2015 at 05:42 AM.
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post #21 of 23 (permalink) Old 12-16-2015, 09:06 PM
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probabilities of securing up the shocks in wet conditions when going around an area. Best of luck but don't be afraid.

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Last edited by melansonc98; 12-18-2015 at 02:22 AM.
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post #22 of 23 (permalink) Old 12-17-2015, 08:38 AM
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Quote:
Originally Posted by BostonBertone View Post
I am looking to do this but have an S1 with a single circuit and standing pedals. Is there any risk in mounting this in a different location than the stock valve which is in a rather inconvenient spot under the rear seat? I need to bend a new rear brake line anyways and could delete the old valve in the process mounting the new valve in the engine bay near the T.

I plan to road test until the rears lock then back it off from there. Each turn on the Wilwood is 4% with a max of 57% reduction.
I think you're overthinking this.

Put it in an accessible location, delete the old one, have fun.

Rob
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post #23 of 23 (permalink) Old 03-13-2017, 08:17 PM
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I finally got around to installing my Wilwood valve and wanted to thank everyone for the info and knowledge regarding this swap. I started with the valve at 1 turn from full reduction but the brakes felt not as good as stock. I tried a quick lock test and the fronts locked pretty quickly so I tried another turn which really seems to help braking. I didn't really do a lock up test yet but under normal to hard braking, it felt great with the car not diving as much as stock. Hopefully the rears won't lock prematurely with the two turns and I can leave it.

Also, I mounted the valve upside down (or rotated 180 degrees is probably a better explanation) as seen in the pictures in this thread. That way, the bending of the rear brake line out of the Wilwood is minimal. All i did was rotate the short line from MC to the Wilwood valve 180 degrees so it goes in from the bottom and then comes out on the top. I'll post pics tomorrow as it's dark now.

Anyway, it's nice to be free of my leaky valve.


Pics:




bob

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Last edited by superloaf; 03-14-2017 at 06:01 PM.
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