abs delete? worth it?

[browntown]

Yes the bias is determined by the master unless you add an adjustable proportioning valve. What he was saying is the front and rear pressures are different between abs and non abs because of different master cylinder sizing. So to get proper pressure you can either add a proportioning valve or swap masters.

This never occurred to me before, but I wonder if my m5 master cylinder changed the abs properties in my car and is causing my dislike of *my* system?

[u3b3rg33k]

Select low is a wonderful thing, hmm? almost like a reactive version of the electronic-prop valves they use now.

The ABS delete question has been discussed ad naseum with no single "answer". Thought I would give you my take on the question so lighten up Francis.

Sorry, but Francis is being excessively irrational to improve his chances of survival. All your base are belong to us.

[homegrone30]

Yes the bias is determined by the master unless you add an adjustable proportioning valve. What he was saying is the front and rear pressures are different between abs and non abs because of different master cylinder sizing. So to get proper pressure you can either add a proportioning valve or swap masters.

[Bearmw]

So is the non-ABS factory cars bias controlled by the master or the proportioning valve or both?

[homegrone30]

Damn tapatalk! Your right. But i think the easier solution would just be to swap in a non abs maate

[homegrone30]

[QUOTE=nrubenstein;3034709]You read that wrong. The bias of the non-ABS cars was different - i.e. more front biased. This has nothing to do with the ABS unit itself.

So, a factory non-ABS car will have lots of front bias for "safety." If you're going to insist on fucking with your brakes, you should at least set them up properly and get the bias right for your car.

[Bearmw]

schtozo, start your own thread, and pull the ABS fuse.

WTF is this? You come into this thread and post about how not having an opinion is cool? grow a pair. no communal CYA needed.

Thanks so very much for your time, it's been a pleasure. Wait, I'm sorry. i mean STFU.

The ABS delete question has been discussed ad naseum with no single "answer". Thought I would give you my take on the question so lighten up Francis.

[nrubenstein]

I don't think so. To the best of my knowledge there is no proportioning in the ABS unit on an E30. There is a bias valve for the rear brakes, which is responsible for the proportioning.

I've added ABS to a car and removed ABS from from a car. In neither case was there any difference in brake bias.

You read that wrong. The bias of the non-ABS cars was different - i.e. more front biased. This has nothing to do with the ABS unit itself.

So, a factory non-ABS car will have lots of front bias for "safety." If you're going to insist on fucking with your brakes, you should at least set them up properly and get the bias right for your car.

[homegrone30]

I don't think so. To the best of my knowledge there is no proportioning in the ABS unit on an E30. There is a bias valve for the rear brakes, which is responsible for the proportioning.

I've added ABS to a car and removed ABS from from a car. In neither case was there any difference in brake bias.

Ding ding ding!

[jlevie]

because the proportioning of the ABS system is different than a non-ABS one.

I don't think so. To the best of my knowledge there is no proportioning in the ABS unit on an E30. There is a bias valve for the rear brakes, which is responsible for the proportioning.

I've added ABS to a car and removed ABS from from a car. In neither case was there any difference in brake bias.

[nando]

because the proportioning of the ABS system is different than a non-ABS one.

[homegrone30]

Anybody who deletes ABS without adding a bias valve is an idiot, IMHO. :)

How so? A proportioning valve only adjusts line pressure. Cars have ran without abs or bias valves for years. So why is it moronic to not use one with an abs delete? I cut my abs out and have not had one problem since. Of course I would love to install a proprtioning valve but I dont see why it is needed.

[nrubenstein]

I've raced E30s with and without it. It's OK. It DOES prevent square tires.
It DOESN'T alter physics.

However, the E30 into '86 had a 20mm master cylinder, with and without ABS.

With a 33 mm rear and 48 mm front caliper, that put the brake split at 70% front,
30% rear, which is safe on the street, and according to Tilton (who sell racing brakes)
also a good starting place for a race car with sticky tires.

Sometime during '86, or in early '87, the ABS cars get a split 17/22mm master, changing
the balance to 44% rear, 56% front. This is good at stopping the car in moderate- force
stops, but when you get toward threshold braking, the rears will now lock first.
ABS catches this, unloads the rears, and lets the fronts keep working.
With an E30, you can still ADD a bit more brake pressure, and you'll still get more front brake
even though the rears are thumping away. This took some laps to get used to.

If you now unhook ABS, you have a car that will lock the rears first in a panic stop.
This means you either have to modulate brakes or spin the car. The first results in a longer
stopping distance, the second results in the possibility of turning a frontal impact
into a side impact.

So if you decide to delete the ABS or leave it non- functioning,
it's probably a good idea to make sure you have the earlier 20mm master. And the
accompanying check and restrictor valves.

jus' sayin'...

t
who measured things himself.

Anybody who deletes ABS without adding a bias valve is an idiot, IMHO. :)

[TobyB]

I've raced E30s with and without it. It's OK. It DOES prevent square tires.
It DOESN'T alter physics.

However, the E30 into '86 had a 20mm master cylinder, with and without ABS.

With a 33 mm rear and 48 mm front caliper, that put the brake split at 70% front,
30% rear, which is safe on the street, and according to Tilton (who sell racing brakes)
also a good starting place for a race car with sticky tires.

Sometime during '86, or in early '87, the ABS cars get a split 17/22mm master, changing
the balance to 44% rear, 56% front. This is good at stopping the car in moderate- force
stops, but when you get toward threshold braking, the rears will now lock first.
ABS catches this, unloads the rears, and lets the fronts keep working.
With an E30, you can still ADD a bit more brake pressure, and you'll still get more front brake
even though the rears are thumping away. This took some laps to get used to.

If you now unhook ABS, you have a car that will lock the rears first in a panic stop.
This means you either have to modulate brakes or spin the car. The first results in a longer
stopping distance, the second results in the possibility of turning a frontal impact
into a side impact.

So if you decide to delete the ABS or leave it non- functioning,
it's probably a good idea to make sure you have the earlier 20mm master. And the
accompanying check and restrictor valves.

jus' sayin'...

t
who measured things himself.

[u3b3rg33k]

schtozo, start your own thread, and pull the ABS fuse.

There is no right or wrong to having ABS. All human activity involves risk and all humans are at time irrational or we wouldn't survive at all.

Now ask these and other questions: Do I smoke, do drugs, get too much sun, eat poorly, consume too many carcinogens, drive an old classic car without modern safety features, ride a motorcycle or bike, insult the wrong person, hike in the mountains, get enough sleep, save enough money, drive too fast, follow too close, exercise enough, have unprotected sex, have poisonous reptiles as pets, have the right partner, inspected my tires.....

Do your own cost/benefit analysis and realize you may be wrong whatever your decision but just be mentally prepared to live with unintended consequences.

If I get rearended by someone regardless of whether they have ABS or not I hope that I'm not seriously injured and they have deep pockets.

If I rearend someone I hope they are not seriously injured and.....see ya;)

WTF is this? You come into this thread and post about how not having an opinion is cool? grow a pair. no communal CYA needed.

Thanks so very much for your time, it's been a pleasure. Wait, I'm sorry. i mean STFU.