Modern Technology in your Retro

[Tarka]

I've been thinking about what direction to go with my Audi. If I end up with more power, i'll obviously want to run MUCH better brakes.

Because I don't want to end up with 18 inch wheels, I was thinking of ways to improve the standard set up but retaining certain features like small (13 inch) wheels etc.

If I were to adapt the braking system from say a basic modern VW Polo, which isn't complicated by trick traction control etc, would it be a case of simply lifting the system i.e hydraulics, pedal box, hubs, master cylinder etc and transplanting it?

Has anyone got any examples of this working?

PS. My thoughts of extra power revolve around one of these new 1.4 Turbo & Supercharged VAG engines. (Not enough sleep again!)

[xbo11ox]

I'm not sure if fitting modern polo brakes would gain you anything really. the pedals pipes and calipers are probabl;y no more effective than your existing brakes. Polo brakes may be 'better' if a modern polo is much heavier than your audi, but that will be pretty much exclusively down to the layout and size of the calipers and discs.

Unfortunatley if you are wanting to go faster, you are going to need to convert more kinetic energy into heat, therefore you will need bigger brakes to convert it all.

You could probably get some small improvements with modern pad materials like.

[Lewis]

What you want is to see if you can find any larger calipers & discs/pads that will fit under your wheels - for example, I can just squeeze Sierra calipers, GTi discs and pads behind Sprint alloys (and they're ridiculously tight) and this offers modern stopping power. A lot of the racers find they're able to outbrake stuff on the track with a setup like that!

It does require custom brackets and lines, but something worth thinking about.

Have you considered just refreshing your system with new parts and service items?

Some of this older stopping kits not too bad either, my 1500 with rebuilt brakes generated more stopping force than a 306 that was in for the test on the same day, so I was told

[Mr K]

i say uprate what you have there, better pads, better discs, better hoses and fresh fluid.

lewisk78 said:

my 1500 with rebuilt brakes generated more stopping force than a 306 that was in for the test on the same day, so I was told

the point he might have been getting at is just how pee poor 306 brakes can be even with red dot road pads, brand new discs and it all fully functioning you will have trouble locking wheels. but on most 1997/8/9 cars the rear drums will be so soaked in brake fluid they wont be doing much anyway.

[rangerbob]

AAT offer a bigger disc conversion for 13" wheels...

Quote

"Big brakes for little wheels. A complete calliper and disk kit for the Polo that allows 255mm disks to be run whilst still keeping 13" wheels ~ the ultimate stopping power for a Euro-look Polo. We also offer brake kits for the Golf that allows the use of 13" or 14" wheels but offers competition callipers and disks upto 256mm"

www.advancedautosport.com

give them a call!!

[Lewis]

all fully functioning you will have trouble locking wheels

On the Pug or the 1500? Sharp stab on the brakes has always locked the wheels on all of mine

[Mr K]

lewisk78 said:

all fully functioning you will have trouble locking wheels

On the Pug or the 1500? Sharp stab on the brakes has always locked the wheels on all of mine

the pug!

[Aaron]

You don't have to use modern stuff, some older cars had small wheels with 4-pot calipers which may be an improvement over your Audi's standard setup. Princess 4-pot calipers were a popular conversion for Fords and some Volvos had 4-pots.

Before I fitted the larger enine to my Toyota, I spent some time at a friendly local breaker's looking at brakes to see if I could adapt anything. I ended up with Mk2 XR2 vented discs and MG Metro 4-pot calipers. I bought a cheap knackered one of each to build a mock-up and when I had the disc and caliper mounted on the hub, with the wheel on, I bought a good set and had proper brackets made up. The discs needed re-drilled to suit my hubs, and I had 10mm spacers machined up to mount them further in (disc mounted behind hub) to allow clearance for the caliper inside the wheel. I spot welded caliper mounting brackets out of heavy plate and had them TIG welded and milled to make sure they were true. For the hydraulics, I had to use a small Girling master cylinder to clear the new engine so made brake lines from Aeroquip as I could buy the correct fittings for each end of the line to suit the calipers, T-pieces and master cylinder.


Aaron.

[Lewis]

Just a comment here - if you're thinking of buying Princess calipers, try to avoid. Get some HiSpec ones that have Princess fitment, instead.



Princess calipers are a bit overrated, cost a lot, have to be rebuilt all the time and last about 3 stops before they start widdling fluid everywhere.

Just me 0.2c

[slater]

2 calipers per disc?

[Paul H]

slater said:

2 calipers per disc?

Why not? That's what an R-R Silver Shadow has on the front

[Lewis]

Depending on your setup - not necessarily a great idea - tried that on one of mine, just warped the discs all the time. A lot of heat energy, not enough area or cooling to dissappate it.

Stopped well, a few times, though ;D

[Stu]

What size and type of front discs does the Audi have as standard?
Presumably something like a Mk1 Golf or Polo, so probably 239mm solid discs - in which case a good improvement can be made with vented discs of the same diameter with GTI calipers, still fit behind 13 inch wheels.

In a lightweight car, that set up with good pads, new fluid and well setup rear drums should give good stopping power.

Does it have a servo as standard?

I fitted 280mm front discs to my Mk2 Golf but retained the original calipers mounted on carriers from a VR6 Corrado to space them out, they just squeeze behind 15 inch wheels and offer much improved stopping power over the original 256mm setup.

[arthurbrown]

I was just thinking servo too.... I know that VAG were a bit stingy with fitting servo's to some 70's / 80's low-end bilge...

[surprisingskoda]

aaron said:

You don't have to use modern stuff, some older cars had small wheels with 4-pot calipers which may be an improvement over your Audi's standard setup. Princess 4-pot calipers were a popular conversion for Fords and some Volvos had 4-pots.

Before I fitted the larger enine to my Toyota, I spent some time at a friendly local breaker's looking at brakes to see if I could adapt anything. I ended up with Mk2 XR2 vented discs and MG Metro 4-pot calipers. I bought a cheap knackered one of each to build a mock-up and when I had the disc and caliper mounted on the hub, with the wheel on, I bought a good set and had proper brackets made up. The discs needed re-drilled to suit my hubs, and I had 10mm spacers machined up to mount them further in (disc mounted behind hub) to allow clearance for the caliper inside the wheel. I spot welded caliper mounting brackets out of heavy plate and had them TIG welded and milled to make sure they were true. For the hydraulics, I had to use a small Girling master cylinder to clear the new engine so made brake lines from Aeroquip as I could buy the correct fittings for each end of the line to suit the calipers, T-pieces and master cylinder.


Aaron.

skoda rapid 4pot = mg metro 4pot
pads for " = pads for "

[berendd]

my derby was on standard stuff all a bit old"ish"

changed the front to mk2 calipers and disks which have slightly bigger pads, renewed the brake shoes and cylinders in the back and bled the whole system... braking is not an issue any more..

doing the same to my swift just now, replaced the rear cylinders for new ones also changed the shoes and bled the system (changed fluid). this weekend the frontend will get new disks and pads fitted and i guess the brakes will be fine for road use..

most old cars haven't had service on things as brake cylinders for years, bleeding the whole system and checking the cylinders never does anything wrong..
also pads may be old allthough they are not worn out, changing them for new ones mostly gives good improvement..
on old VAG cars fitting a servo will help a lot in reducing the force needed for the pedal but.

as long as you don't push the car to it's limit a standard brake system with all components in good shape will easily be able to cope with a couple tight and fast hairpin's..

cheap and easy mods are fitting of performance brake pads, they will reduce the fading when you push it a bit..

[Aaron]

skoda rapid 4pot = mg metro 4pot
pads for " = pads for "



I didn't know that. Haven't had any trouble getting Metro pads, but will keep that in mind, thanks!