help setting up booster delete and retain ABS

[Sh3rpak!ng]

What application is the 20/20 and is it aluminum or cast iron?

Cast iron. It was actually listed (realoem) right under the PN for the 17/22 MC that was originally in the car. So I guess the application would be a 325i, though I never knew them to have that MC... kinda doesn't make sense.

Also, the price for a new ate unit was like $170 at bmaparts so I decided to go with a cardone rebuilt unit from NAPA for ~70. Then the guy at NAPA mentioned that a new NAPA branded one was cheaper with a lifetime warranty so I thought what the heck, I'll give it a try. Opened the box to find a genuine ate unit :) $65, with 10% AAA parts discount (didnt know there was one), it came to $58. SCORE

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[Sh3rpak!ng]

20/20 MC feels great. Got a little more travel, and a little less effort. It's very nice. I think this is the final solution for me. I bet it could use a little more bleeding after my hasty MC swap saturday.

[e30_302]

If you haven't yet, buy a set of speed bleeders. Worth every penny.

[Sh3rpak!ng]

If you haven't yet, buy a set of speed bleeders. Worth every penny.

On the list. Ill swap them next time I bleed. Thanks!

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[Jaker]

Still like the 20/20? All working good?

[Sh3rpak!ng]

Still like the 20/20? All working good?

Yup! Works well so far. It really shines in the aggressive driving when the brakes have some heat in them.

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[Sh3rpak!ng]

Following up to add some closure. Still liking the 20/20 very much. I bled the brakes again after an autox and got quite a bit more air out of the system yielding a very consistent pedal feel and travel. Now it's all up to pad selection.

Regarding speed bleeders - they are not available for the wilwood calipers (wilwood calipers use a brass bushing with a tiny bleeder inside of it to avoid wearing out the threads int he caliper), but I did install them in the rear - awesome.

[e30_302]

You can get the speed bleeders for a Wilwood caliper, I have them. Or figure out what size the bushing is and see if there's a speed bleeder to match.

But back to the master cylinder, I have a 20.6mm from a Fox Mustang and it's great. Don't even notice that it's un-boosted now.

[Sh3rpak!ng]

You can get the speed bleeders for a Wilwood caliper, I have them. Or figure out what size the bushing is and see if there's a speed bleeder to match.

But back to the master cylinder, I have a 20.6mm from a Fox Mustang and it's great. Don't even notice that it's un-boosted now.

hmmm any chance you have a part number or info? Here is the listing on the wilwood site for replacement wilwood bleeders: 220-0627 described as for "Calipers w/ 1/8-27 Bushing & 1/4-28 Bleed Screws". My concern is that since the caliper is aluminum, repeated tightening and loosening of a bleeder directly mounted into the aluminum would wear out the threads over time

What pads are you running? And do you drive on the street or only track?

[e30_302]

https://www.amazon.com/Speed-Bleeder.../dp/B003TL2QNG

Track only: Raybestos ST-43 front/45 rear. The slightly more aggressive rear pad really helped the brake bias.

[Sh3rpak!ng]

https://www.amazon.com/Speed-Bleeder.../dp/B003TL2QNG

Track only: Raybestos ST-43 front/45 rear. The slightly more aggressive rear pad really helped the brake bias.

Thanks, figured it was track only

[potatomash]

How did you find the rear bias after all this? Do you think the prop valve actually allows more rear pressure? Got same setup and wondering if prop valve worth is going to help me or not

[Sh3rpak!ng]

Looks like I never updated after I sorted it all out... I actually returned to boosted brakes. New 944 booster feels really awesome. I was doing far more street driving than I intended, and never really got the strong brakes I wanted, especially for the street. Also I think I misunderstood the function of the bias valve when I initially installed it. It's only useful if you have MORE rear bias than you want, you can cut pressure to the rear to decrease it. At the very least, make sure the oem bias valve is removed.

If I understand correctly, there are two basic ways to increase rear bias; increasing mechanical advantage. Either decrease the size of the rear MC, or increase the total size of the rear caliper piston surface area.

That said, with my wilwood front kit, rear oem calipers/disks, and oem 17/22mm MC, bias is not that bad. ~67% front iirc.

I'm testing out a new setup soon though utilizing a Nissan z32 rear 2 piston caliper and a Toyota ma61 rear vented disc which ought to drop front bias to ~60%.

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[TobyB]

And just because it's both pertinent and not particularly obvious,
there is an early 318 master that has a slightly stepped bore (19/20? I forget).
It gives 'just a bit more' rear brake, if plumbed properly, and then the bias valve
can be used to prevent rear lockup, if needed.

I found different valves worked differently- some are pure pressure limiters, others
have a 'knee' above which they reduce pressure at a ratio, and few were particularly
consistent. As in, a stab at the brake got you a different rear pressure than a gentle
squeeze did.

hth,
t

[Sh3rpak!ng]

And just because it's both pertinent and not particularly obvious,
there is an early 318 master that has a slightly stepped bore (19/20? I forget).
It gives 'just a bit more' rear brake, if plumbed properly, and then the bias valve
can be used to prevent rear lockup, if needed.

I found different valves worked differently- some are pure pressure limiters, others
have a 'knee' above which they reduce pressure at a ratio, and few were particularly
consistent. As in, a stab at the brake got you a different rear pressure than a gentle
squeeze did.

hth,
t

That't good to know. Found the PN for the 19/20 MC 34311156273

And regarding the prop valve, this is a good explanation:

"one helpful thing to keep in mind when setting them up is the knob/lever adjusts the SPLIT POINT PRESSURE.

Before the split point rear pressure rises 1:1 with front pressure. After the split point, rear pressure rises 0.57:1 with front pressure (on all the common proportioning valves I've seen, Summit, Tilton, Wilwood etc.). So the least amount of bias you can have is the rear pressure being 57% the front pressure with the split point all the way down. As you raise it up you change where the "knee" occurs so your rear/front bias will be greater than 57%, but falling at increasing pressure. This is an inherently stable setup, since more brake pressure without a lockup means more weight transfer, so your bias moves in a "safe" direction for any setting that performs well in the dry."