What options exist for vented front brakes?

[ruldal]

As far as i've read, people use the volvo calipers on the std 323i discs. So you'd need to use some sort of adaptor/extension plate to mount them for a larger diameter disc, similar to the ones I've just had made for my new wilwoods.

Ben

Yeah but the thing is that the 323 discs are too small i diameter, that is why you need to offset the caliper. This is something i would want to avoid by putting on a bigger disc. Also the bigger disc gives a better breaking momentum as the pads are located further from the centre of the hub.

I will try this during the summer and see of 284mm discs can sit inside the volvo calli´s. If not it should be possible to get them machined down in diameter.

[e21-Mark]

What engine / power are you running? What weight is your car compared to stock?

I found regular 323 discs & 4 pot callipers coped fine doing 20+ quick laps at Brands Hatch in a car with about 160 brake.

[ruldal]

What engine / power are you running? What weight is your car compared to stock?

I found regular 323 discs & 4 pot callipers coped fine doing 20+ quick laps at Brands Hatch in a car with about 160 brake.

As up now its completely stock. But it won´t stay that way forever.
Anyways, i know for a fact (its simple statics) that big brake disc diameter gives you a larger braking area to work with, otherwise all cars would run Ø120mm brake discs with circular pads The key to a wide range of braking workspace is connected to the distance from the center of the hub to the pads. The further out theese are placed on a given disc the more you can fine adjust your braking. The closer they are to the center the less a work area you have when braking.

Dont misunderstand, i have the outmost respect for your car and your brake solution. But personally (and you can call me a bit strange ) i would prefer larger diameter brakes than the original ones. I have done this on almost all cars i have owned ( Manta A 71´ fitted with 296mm Carlton GSi brakes, Monza fitted with the same, Manta B 79´ fitted with Volvo 4 pots and Calibra discs, VW Derby Mk1 fitted with Polo G40 vented discs and calipers etc etc) ..

So this is just what feels right to me

[Duracel79]

In that case have a look at what I'm doing in my thread with 296mm discs and caliper brackets. You could probably use a volvo 4 pot on the discs I'm using with a similar bracket.

http://www.bmwe21.net/forum/viewtopic.p ... &start=225

Although worth mentioning that I raced my car with ~200hp and the std brakes with just braided hoses better pads and racing fluid. Had no issues at all. The std setup can cope with a surprising amount of work. Its only since I've more than doubled the original cars power that they became an issue.

Ben

[ruldal]

In that case have a look at what I'm doing in my thread with 296mm discs and caliper brackets. You could probably use a volvo 4 pot on the discs I'm using with a similar bracket.

http://www.bmwe21.net/forum/viewtopic.p ... &start=225

Although worth mentioning that I raced my car with ~200hp and the std brakes with just braided hoses better pads and racing fluid. Had no issues at all. The std setup can cope with a surprising amount of work. Its only since I've more than doubled the original cars power that they became an issue.

Ben

That looks awsome

That could be a future solution, but right now i am looking to simple and economic solutions. A set of wilwood calipers cost the bahoolah here, and there are alot of places on the car i could pour money into that would be equally justified. In that aspect almost everything will be changed, bushes etc. So alot of work and money needed A set of 4 pot volvo calipers can be salvaged from the scrappers easily, redoing them myself, i even have a media blasting cabinet so they can end up looking and driving like new, steel braided hoses, and some fitting size discs will be good for "stage 1". If as you and others say the stock 323 brakes are that good, then i wont have to worry about brakes for a long time with this sort of setup.

Are rear discs easy to fit ? The car is a 320-6 so drumbrakes only

[petebaurseller]

hello everyone

I am considering a brake upgrade among other things, for my 1981 e21 Baur 320/6. As I have standard solid front discs and rear drums. There is a lot of info on various sites and getting to grips with it all, is a bit confusing? But here goes front only

1. I can upgrade my 255mm solid discs to 255mm vented discs with the brakes and callipers from the 323i
2. I can upgrade the 2 piston callipers to Volvo/girling 4 piston ones using the 255mm vented rotors
3. I can upgrade the 255mm rotors to mini cooper 276mm rotors with hub centric spacers

I have read somewhere in a thread at http:// the320i.blogspot.co.uk Willwood v Volvo/girling brake upgrade.
It says ".. .. The stock 320i rotor diameter (vented and unvented) is 255mm. The volvo caliper (a cast iron girling 4 piston) would fit perfect on the e21 with no modification using a 276mm rotor. There is a larger off the shelf rotor that will work. The mini cooper uses a larger 276mm vented rotor (compared to 255mm 323i rotor) that fits but the rotor hat is shorter. the Volvo 240 4 piston girlings sat on 263mm rotors."

"You can run 276mm new mini (2003+) rotors which are 21mm larger than the stock 255mm 323i rotors. The rotor height is 44mm, thickness is 21.9mm, and the hub bore is 64.1mm (compared to 63mm for the e21 hub bore) so you'll have to use hub centric spacer rings to center the rotor on the hub. You may also want to drill the rotor for the hold down bolt. In this picture you can see the gap between hub and disc center bore and a new hole for the hold down bolt:"

SO if i am correct i can use the 276mm mini rotors + volvo/girlings + make copprer pipes, utilise a brake splitter and use the original brake MC?? (Instead of a costly E12 MC and 323i disc and callipers, or Wilwood conversion)

what pads do you think i should buy for the 276mm girling application??
I know i will have to have 14" or 15" wheels possibly 16". ?
Will this increase in wheel size effect my 320/6 acceleration or gearing??
Will i need to increase the capacity of engine, by putting a different crank(2.4td?), longer rods or rebore into the engine to compensate??
I am hoping to make some performance upgrades to the engine/head/exhaust system at some stage(cash Willing) as it has a standard solex carb and 2x up pipes off the 2x 3 into 1 manifolds.
What carb(Weber side draught?)or carbs, manifold and exhaust can I use to extract some extra ponies?? or does it have to be custom made?? (there are some great manifolds being made at the moment, including turbo ones)
Do I need to put discs on the back immediately, or can i wait until upgrades to the engine??
How far can I lower the car with 14/15/16" wheels?? what suspension upgrades or shocks should I consider??

I know a lot of people have looked into all the Pros and Cons to every possible permutation be it costs, acceleration, handling, top end, fuel economy etc...etc
Any help and advice as to keep the costs down and performance and thrills up, would be most welcome.
I hope this article and my understanding is correct, and who knows it may help a few others considering this brake upgrade?

Thanks Pete