has anyone ever tried to convert to a vacuum assisted brake system?
08-25-2005, 08:04 AM
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has anyone ever tried to convert to a vacuum assisted brake system?
using parts from a 100cs should make the job very easy and remove quite a bit of hydraulic hose and the prone to failure bomb.
this is how audi runs all their turbo cars now, and how every other manufacturer does it as well.
this is how audi runs all their turbo cars now, and how every other manufacturer does it as well.
08-25-2005, 08:47 AM
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Yah, I'm generally not a fan of the hydro brakes
But I'll probably leave them alone on my //S car. If it aint broke...
On my CQ v8 4.2 project car the pump failed on my way up to NH a few weekends back. I was planning on doing something about the brake master cylinder anyway since it is too long for the v8 and would hit the left bank. Prime opportunity to switch to vacuum brakes and steering only PS pump (I already have parts from a 90q that I'll use).
On my CQ v8 4.2 project car the pump failed on my way up to NH a few weekends back. I was planning on doing something about the brake master cylinder anyway since it is too long for the v8 and would hit the left bank. Prime opportunity to switch to vacuum brakes and steering only PS pump (I already have parts from a 90q that I'll use).
08-25-2005, 10:58 AM
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yes i do...details within
AFAIK all modern cars run vacuum assisted brakes, even turbo vehicles. It works because you'll never be boosting and hitting the brakes at the same time.
my plan is to fit the vacuum booster and hydraulic pump from a 100cs in the s4. This will eliminate the bomb and several hydraulic hoses. you need to replace the hydraulic pump because the S4 unit will generate too much pressure for the steering rack. I'm pretty sure Elijah Allan has vaccum brakes in his car because he swapped in a turbo motor. Most guys who swapped turbo motors into NA cars will have the same brake system.
my plan is to fit the vacuum booster and hydraulic pump from a 100cs in the s4. This will eliminate the bomb and several hydraulic hoses. you need to replace the hydraulic pump because the S4 unit will generate too much pressure for the steering rack. I'm pretty sure Elijah Allan has vaccum brakes in his car because he swapped in a turbo motor. Most guys who swapped turbo motors into NA cars will have the same brake system.
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08-25-2005, 04:38 PM
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"It works because you'll never be boosting and hitting the brakes at the same time. "
Correct! You will be hitting the brakes immediately AFTER boosting! (And, using WHAT to help you?)
IMHO â€" I would never try it without a LARGE vacuum reservoir AND a secondary vacuum source. (Much like a Diesel). 10V's have a secondary vacuum pump for the brakes. (At least my 88 80Q did!)
As always â€" I am absolutely delighted to have my opinions proven wrong.
(A trait I learned working with engineers for years.)
IMHO â€" I would never try it without a LARGE vacuum reservoir AND a secondary vacuum source. (Much like a Diesel). 10V's have a secondary vacuum pump for the brakes. (At least my 88 80Q did!)
As always â€" I am absolutely delighted to have my opinions proven wrong.
(A trait I learned working with engineers for years.)
08-25-2005, 04:57 PM
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every subaru, mistubishi, and all new audis run a vac brake assist without any auxiliary parts
think about all the NA cars out there with aftermarket turbo kits; nothing extra is required, I promise.
In racing situations vacuum assist can cause you to lose assist because of the frequent transitions between accelerator and brake; but in racing situations you shouldn't be using assisted brakes anyway.
So unless you're trying to race, there is no situation that will cause you to have a hard pedal.
In racing situations vacuum assist can cause you to lose assist because of the frequent transitions between accelerator and brake; but in racing situations you shouldn't be using assisted brakes anyway.
So unless you're trying to race, there is no situation that will cause you to have a hard pedal.
08-25-2005, 05:37 PM
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I remind you - at least some 10V engines had a vacuum assist pump. Just for brakes.
And for all I know - all of 'em (non turbo) did - I have no clue - or desire to find out. I only know mine did.
And the last aftermarket kit feeding some Detroilet V8 POS I read about went to 5 lbs boost. There is also 4+ liter of SUCKtion going on. Huge difference to an AAN.
I have no doubt you are correct on the rice.
(Reading between the lines - I am claiming complete ignorance on the other vehicles. Don't know - don't care. OTOH - I really DO want you to prove me wrong - really! (I just found a vendor to rebuild my pump to bomb hose today - I am NO fan of hydro assist brakes.) My OPINION - I don't see that happening. I have been wrong before - I will be wrong again. I am not claiming it cannot be done - Just that AAN's don't suck. Literally.)
Boost gauge people - how much time is spent in the neg?
And the last aftermarket kit feeding some Detroilet V8 POS I read about went to 5 lbs boost. There is also 4+ liter of SUCKtion going on. Huge difference to an AAN.
I have no doubt you are correct on the rice.
(Reading between the lines - I am claiming complete ignorance on the other vehicles. Don't know - don't care. OTOH - I really DO want you to prove me wrong - really! (I just found a vendor to rebuild my pump to bomb hose today - I am NO fan of hydro assist brakes.) My OPINION - I don't see that happening. I have been wrong before - I will be wrong again. I am not claiming it cannot be done - Just that AAN's don't suck. Literally.)
Boost gauge people - how much time is spent in the neg?