AAN into Ur quattro, 400-450 Bhp Target

[20Vcqdriver]

We considered that but I've tracked it a couple of times and experienced no issues so fingeres crossed

How are you finding your turbo? Have yo had your car dynoed?

Mine on SORN at the moment and undergoing some improvements to both main and chargecooler water rads and pipework and head presently away getting perfectly matched to new Wagner exhaust manifold and porting on inlet too....
Hope to get it mapped properly later in year once a new job secured...

[DamoM]

We considered that but I've tracked it a couple of times and experienced no issues so fingeres crossed

How are you finding your turbo? Have yo had your car dynoed?

[20Vcqdriver]

Thought I'd give a quick run down as to how we got vacuum brakes into my ur.

We got the vacuum servo from a MK4 VW golf, the bolt pattern is the same as the Quattro. The push rod from the old unit had to be cut off and welded to the new servo

The master cylinder and reservoir is off the MK4 golf

The high pressure hose from the power steering to the rack needed to be made to bypass the hydraulic brake booster. Pirtek did this for £60. We replaced the old power steering reservoir which had too many ports with a Noble M12 reservoir which is the same as a BMW, Landrover, ford etc.......

We removed the ABS module (although you can keep this) and fitted a brake bias valve.

Fitted a 'rigid' vacuum pipe with a one-way valve to the inlet manifold.

We made brake pipes from the master cylinder down to both front callipers. A pipe from the master to the proportioning valve then a pipe from there to the t-piece just in front of the rear diff.

You could probably get away with bending the existing pipes to fit but it will not look great and there is a chance the pipes will crack on these old cars.

Think that was it!

I went and added an electric vacuum pump and switch as I found with a lot of heel and toe work and lots of short burst acceleration to brake to acceleration i lost vacuum in the servo and had a few scary moments with reduced brake performance, no issues since though

[DamoM]

Thought I'd give a quick run down as to how we got vacuum brakes into my ur.

We got the vacuum servo from a MK4 VW golf, the bolt pattern is the same as the Quattro. The push rod from the old unit had to be cut off and welded to the new servo

The master cylinder and reservoir is off the MK4 golf

The high pressure hose from the power steering to the rack needed to be made to bypass the hydraulic brake booster. Pirtek did this for £60. We replaced the old power steering reservoir which had too many ports with a Noble M12 reservoir which is the same as a BMW, Landrover, ford etc.......

We removed the ABS module (although you can keep this) and fitted a brake bias valve.

Fitted a 'rigid' vacuum pipe with a one-way valve to the inlet manifold.

We made brake pipes from the master cylinder down to both front callipers. A pipe from the master to the proportioning valve then a pipe from there to the t-piece just in front of the rear diff.

You could probably get away with bending the existing pipes to fit but it will not look great and there is a chance the pipes will crack on these old cars.

Think that was it!

[AndyP]

Anyone care to give a brief summary on a conversion to vacuum, what parts need to be swapped. Ive just fitted new WR rear discs and calipers, wish id gone RR now I know the difference.

Have a read of this:-

http://www.s2forum.com/forum/showthread.php?t=50533&highlight=vacuum+brake

[adam g]

Anyone care to give a brief summary on a conversion to vacuum, what parts need to be swapped. Ive just fitted new WR rear discs and calipers, wish id gone RR now I know the difference.

[AndyP]

Yes, he has changed to the 0.82 housing

http://www.s2forum.com/forum/showthread.php?t=59305

[URquattroGus]

Yes, I think so, think there is a thread? Seem to remeber he was happy with the change. I'll have to make do with my weedy little turbo for now

[DamoM]

Looking to change the MD357 on my car (see seperate thread) and wondered if djones managed to change to the 0.82?

[DamoM]

Vacuum has transformed the brakes on my car. They were axactly as you described before despite me havng a porsche caliper front setup and 20v rear calipers. Going ot vacuum was the single best improvement to braking that I have ever made on the car.

It wasn't even that much work to be honest.

[ralleyquattro]

According to the brakes international website;

WR:

Disc Thickness: 10mm
Disc Diameter: 245
Piston Diameter: 36.1

RR;
Disc Thickness: 20mm
Disc Diameter: 269mm
Piston Diameter: 42.8

A bigger Upgrade than I thought then! an 18.5% increase in piston area to be precise...

I had put this off for a while as the rears were replaced when I first got the car, and people seem to constantly harp on about the fronts doing nearly everything.

However, bigger pistons mean that I will probably gain a bit more pedal travel? and so may also want to try a bigger MC still?

I have vented in the back and Sport Quattro AP calipers up front, with standard WR master, no issues and minimal pedal travel, very happy here.
I also switched to vacuum assist.

Hope this helps.

[URquattroGus]

According to the brakes international website;

WR:

Disc Thickness: 10mm
Disc Diameter: 245
Piston Diameter: 36.1

RR;
Disc Thickness: 20mm
Disc Diameter: 269mm
Piston Diameter: 42.8

A bigger Upgrade than I thought then! an 18.5% increase in piston area to be precise...

I had put this off for a while as the rears were replaced when I first got the car, and people seem to constantly harp on about the fronts doing nearly everything.

However, bigger pistons mean that I will probably gain a bit more pedal travel? and so may also want to try a bigger MC still?

[jsws3]

Yes it was a 10V and the master cylinder is on the passenger side, but I think that all RHD quatto's have the master cylinder on that side.

As you and Acidburn say, there is a long rod that goes over from the pedal to the passenger side, a la heath robinson style.

There is a little play in this linkage, I managed to order some of the pins which I mean to change when I get round to it.

I want to avoid converting to vacuum really, as I would have to re package quite a lot of things, and I have spent a lot of money on renewing the Hydraulic assist circuit.

I think I need to find out whether the 20V RR rear calipers are actually that different appart from being vented, ie, bigger piston area or clamping area?

Wouldn't be too hard to try a bigger MC though and see how it feels. Having said that, the system is a real bitch to bleed!

If you ask Pete nicely to have a look at my rear brakes next time he goes over to aidens and measure the pistons on them for you as they are 20v rears .

[Acidburn]

yes they are bigger. Thats why they can be used on s2's for brake upgrades

[URquattroGus]

Which side of the car is your master cylinder, if you converted from a 10v im guessing the MC is passenger side. Ive heard moving it back over in conjunction with a 20v swap (which creates the space needed) reduces losses and gives better performance. There is a blanking plate on the body to plug it into.

Yes it was a 10V and the master cylinder is on the passenger side, but I think that all RHD quatto's have the master cylinder on that side.

As you and Acidburn say, there is a long rod that goes over from the pedal to the passenger side, a la heath robinson style.

There is a little play in this linkage, I managed to order some of the pins which I mean to change when I get round to it.

I want to avoid converting to vacuum really, as I would have to re package quite a lot of things, and I have spent a lot of money on renewing the Hydraulic assist circuit.

I think I need to find out whether the 20V RR rear calipers are actually that different appart from being vented, ie, bigger piston area or clamping area?

Wouldn't be too hard to try a bigger MC though and see how it feels. Having said that, the system is a real bitch to bleed!