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280mm disc conversion.... Update 20/06/07

Posted: Thu May 03, 2007 9:11 pm
by jmc330i
All the recent threads on massive brake conversions got me thinking about something I thought about ages ago - a budget 280mm disc conversion using the standard E30 calipers.

The plan would be to use the VW 280mm 4 stud disc. This would obviously need a bracket made up to mount the caliper to suit the larger disc and thats what stopped me before now - not having the means or know-how to make up the bracket.

At work today, I met a guy who runs a small company tuning Rovers (someones got to I guess :P ) and was having a good look round his 2.0ltr turbo converted Rover 200 track car. The bit that got me chatting to him was the massive discs fitted under the 15" Compos (324mm I think he said) with Wilwood 4pots.
He makes up and sells the kits by using Wilwood rotors and calipers and machining the bells himself - this got me interested, but thats a different story.

Anyway, I mentioned to him about using the VW discs on the E30 and needing a custom bracket etc and he said he should be able to make them up no worries - his business partner does the same thing in the VW world.

This got me thinking about how many other people on here would be interested in the same thing. I know we would all love massive discs and 4pot calipers, but either money or wheel size doesnt always allow.

Just an idea at the moment, but any comments??

Re: 280mm disc conversion....

Posted: Thu May 03, 2007 9:17 pm
by Andy335Touring
Depends on the details like cost but i'd like to upgrade my brakes with out having to change my 15" wheels(more cost).

280mm discs should make a nice improvement.

Re: 280mm disc conversion....

Posted: Thu May 03, 2007 9:22 pm
by liam012
would be nice allright - would it make all that much difference i wonder?


i just snapped up a pair of rx7 4pot clipers for 50 quid (just trying to sort out a bracket at the moment), i 'll be using them with a 750i master cylinder and corado g60 discs - hoping to keep it cheap too though it will be interesting when all that adds up to see how far of 380 i am which is the wilwood 4 pot kit tried and tested, i'd hate to think my odds and sodds setup will end up costing me 350!!

if your way is possible and makes a noticable improvement then tha might have been the way to go.... keep us posted

Re: 280mm disc conversion....

Posted: Thu May 03, 2007 9:23 pm
by maxfield
By upgrading the disc and not the caliper.

That doesn't seem to make sense to me as it wouldn't be an improvement because your not increasing surface area of the pad there for would be almost iidentical to the normal setup.

Or am i talking aload of bull :? :?

Re: 280mm disc conversion....

Posted: Thu May 03, 2007 9:30 pm
by billgatese30
maxfield wrote:
That doesn't seem to make sense to me as it wouldn't be an improvement because your not increasing surface area of the pad there for would be almost iidentical to the normal setup.
but by increasing the radius of the rotor and gripping it further out from the centre you increase the leverage you have, so the stopping power is increased

Re: 280mm disc conversion....

Posted: Thu May 03, 2007 9:30 pm
by Andy335Touring
You gain extra leverage from the disc being bigger/further away from the hub, bigger discs will also dissapate(sp?) the heat slightly better too.

[edit]too slow :( :)

Re: 280mm disc conversion....

Posted: Thu May 03, 2007 9:30 pm
by jmc330i
Andy335Touring wrote:Depends on the details like cost but i'd like to upgrade my brakes with out having to change my 15" wheels(more cost).

280mm discs should make a nice improvement.
TBH mate, I didnt talk to him about cost - I was working and only get 6mins drop time for each delivery, but left his after 20mins :roll:

I will be going to see him again, but we did talk about me taking a strut, caliper and wheel over for him to measure up and see whats possible.
maxfield wrote:By upgrading the disc and not the caliper.

That doesn't seem to make sense to me as it wouldn't be an improvement because your not increasing surface area of the pad there for would be almost iidentical to the normal setup.

Or am i talking aload of bull :? :?
The extra leverage will make the difference, ok it wont be as good as say the Wilwood or WMS kits, but then it wont be £400 either.

Re: 280mm disc conversion....

Posted: Thu May 03, 2007 9:31 pm
by maxfield
Ah the rules of physics :) :)

Thanks makes sense to me.

Re: 280mm disc conversion....

Posted: Thu May 03, 2007 9:49 pm
by tezk
I'd definitely be interested.. Dependent on price of course.
The price of those Wilwood kits make my eyes water! And would no doubt be over kill for my needs..
I'd be more interested for the aesthetics than the performance.. But then better brakes would never be a bad thing :D

Re: 280mm disc conversion....

Posted: Thu May 03, 2007 10:50 pm
by jmc330i
Well there will be some sorting out to do, but I know this sort of thing is done in the VW world and I dont see why we cant do the same.

As I said earlier, I only spoke to him for 20mins so we will need to talk in a bit more detail, but first step will be seeing if its possible.
I will try to sort out a spare strut this weekend and I have some calipers, but I will need to buy the discs in - stupid question, but do ECP sell discs as a pair or individually?

Re: 280mm disc conversion....

Posted: Thu May 03, 2007 10:56 pm
by tezk
ECP sell individually.. Strangely enough?
Got a mate at work with a mk2 GTI and he's always on about doing a 280mm G60 brake conversion.. Would love to beat him to it :cool:

Re: 280mm disc conversion....

Posted: Thu May 03, 2007 11:00 pm
by old_skool
James,

Nice topic,

I like the logic there and like you say if the VW guys do the same thing then why not. Same calipers but increased leverage - surely this make sense? No outlay for new calipers, same M/C arrangement....

Win win.

8)

Re: 280mm disc conversion....

Posted: Thu May 03, 2007 11:11 pm
by jmc330i
old_skool_2002 wrote: No outlay for new calipers, same M/C arrangement....

Win win.
Exactly my thinking mate. If people need to replace the discs and pads anyway, then getting some larger discs and paying a bit extra for some brackets seems like a good idea to me (depending on cost obviously).

The only downside Ive thought of is, I seem to remember something about the VW discs needing some modding to fit the E30 hubs - Im not 100% sure whats needed, but I will get a disc ordered next week and go from there - I do have a new set of ATE Power Discs to compare with that I never got round to fitting :roll:

Re: 280mm disc conversion....

Posted: Thu May 03, 2007 11:16 pm
by tezk
I cant see how they'd need modding? Unlike the Audi disks, mk2 golfs are 4x100 pcd so it shouldn't be drilling.. And from what I saw on gsf, standard 280mm g60 disks are cheaper than the ATE's?
Got my fingers (and a few other things) crossed :D

Re: 280mm disc conversion....

Posted: Thu May 03, 2007 11:42 pm
by Martinaston
Center hole may be bigger because of the front wheel drive on the VW.
Bigger than 66mm then forget it, smaller then its off to the laith £Â£

Posted: Fri May 04, 2007 2:32 am
by DRIFTBOY
The Corrado discs will need 1mm taken from the centre bore.

Should be a quick and easy job for a machine shop.

Martin.

Re:

Posted: Fri May 04, 2007 5:16 am
by DaveD
As liam012 knows i am interested in this and woild be interesred in a group buy for the brackets..the corrado discs DO need 1mm out of the centre ..i have the original link which i will post on return of the guy from e30tech who did it already also there is a section in e30.de about brakes which makes interesting reading

Re:

Posted: Fri May 04, 2007 3:42 pm
by ChrisBarns
I'm defo interested.

Re:

Posted: Fri May 04, 2007 3:54 pm
by ed325i
Me too.

Re:

Posted: Fri May 04, 2007 4:11 pm
by jmc330i
DRIFTBOY wrote:The Corrado discs will need 1mm taken from the centre bore.

Should be a quick and easy job for a machine shop.
I thought that was the case, but wasnt sure if it was 1mm too big or too small. That shouldnt be a problem as the guy has all the facilities.
DaveD wrote:i have the original link which i will post on return of the guy from e30tech who did it already
I think Ive seen one or two threads on e30tech, but Im not sure what calipers were used.

Picked up a strut today, so just need to get hold of a disc.

Re:

Posted: Fri May 04, 2007 10:49 pm
by Morat
Does using the same pad on a larger disk really give much advantage? I can see that it might help with cooling and therefore preventing brake fade, but does the extra leverage really matter?

Re:

Posted: Fri May 04, 2007 11:58 pm
by tezk
This is exactly the principal breaker bars use - get a lever long enough and they say you could lift the earth! As a gross over exageration, imagine a bike wheel.. You could rub your hand against the spokes on the outside of the wheel and stop the wheel no problem.. Try the same thing near the hub and you'd more likely lose the skin on our finger than stop the wheel..

Re:

Posted: Sat May 05, 2007 12:21 am
by munky30
I'd be interested in this.

Re:

Posted: Sat May 05, 2007 5:37 pm
by lenny-d
check out the group buy section they are tryin to get a group buy for the brackets to hold calipers from a 750i to fit on 280mm audi tt discs it'd prob only cost an extra £50 or so to get the bigger calipers of the 7 series from a scrappy

Re:

Posted: Sat May 05, 2007 7:47 pm
by jmc330i
lenny-d wrote:check out the group buy section they are tryin to get a group buy for the brackets to hold calipers from a 750i to fit on 280mm audi tt discs it'd prob only cost an extra £50 or so to get the bigger calipers of the 7 series from a scrappy
They will require 16" wheels (at extra cost if you dont already have some), the idea behind using the E30 caliper is to be able to keep the standard 15" BBS wheels.

Re:

Posted: Sat May 05, 2007 7:53 pm
by old_skool
As an alternative you could have the hubs machined just as easily as the discs. The front hubs are very easy to remove, unlike the rears.

That way discs can be sourced/swapped off the shelf. Ideal if you need to swap-out a damaged disc or don't want to be beholdent to the machine shops. Hubs could be machined and then offered on an exchange basis too. Reverting back to E30 fit is just a case of bolting the original disc back on. If you were planning on keeping the car then this wouldn't be such a bad idea.

Just trying to add some out of the box thinking :)

While I'm at it - anyone fancy a new adjustable rear beam finished in powdercoat with new genuine bushes and eccentric adjusters on an exchange basis too - bye bye neg camber ?? 8)

Re:

Posted: Sat May 05, 2007 9:04 pm
by ed325i
While I'm at it - anyone fancy a new adjustable rear beam finished in powdercoat with new genuine bushes and eccentric adjusters on an exchange basis too - bye bye neg camber ??
I would, I was going to make one.

Re:

Posted: Sat May 05, 2007 9:14 pm
by beardymat
old skool thinking too, nice :wink:

id be up for a beam too if its done to your usual exact standards :D

Re:

Posted: Sat May 05, 2007 10:36 pm
by old_skool
Cool. It didn't want to hijack the thread, just thinking out loud really.

I have most of the resources 'on site' to be able to do the beams but will need to research the whole thing and more importantly speak with zone admin first of all :) If it looks good then I'll see if I can start something up :)

Back on topic, the 750i stuff sounds great, is there a wide selection of pads available for that caliper though? Also will they work with 15" BBS?

Re:

Posted: Mon May 07, 2007 8:22 pm
by DaveD
this was one of the original threads i mentioned but i am sure i had another with pics ..I'll keep searching

http://www.e30tech.com/forum/viewtopic. ... 7&start=75

Posted: Thu May 10, 2007 10:22 am
by jmc330i
old_skool_2002 wrote: Back on topic, the 750i stuff sounds great, is there a wide selection of pads available for that caliper though? Also will they work with 15" BBS?
I think thats 16" minimum because of the size of the caliper. Fitting 280mm discs with the standard caliper is going to be tight inside the 15" BBS wheels.


Im just waiting on the discs now. None of my local motorfactors will sell me a disc without a Reg or VIN number for the car - WTF is that all about???
I can get a single disc from ECP, but would prefer to wait until they have the ATE Power Discs in stock, as thats what Im going to be using and I dont want to pay out for and get stuck with a single disc.

I have Emailed ECP about the Power Discs but not got a reply yet.

Re:

Posted: Thu May 10, 2007 10:42 am
by ste
Bear in mind that not only will you need to open up the Corrado 280mm disc centre bore, the disc mounting face is also 2mm thinner, so you reduce the wheel offset to ET26 which will probably mean you need to run with a 2mm spacer at the front to return to standard offset (you really don't want to reduce front track) and to clear the calliper.

Another thing to note is that the disc retaining screw on the VW 280mm discs does not align with the screw hole on the E30 hub. Not the end of the world but it's worth a mention.

Great idea for cheap bigger brakes though, hope you get it sorted.

Dameon - I like the idea of the rear subframe- keep me informed please. 8)

Posted: Thu May 10, 2007 1:31 pm
by keri-WMS
If it helps anyone we do 280mm Corrado discs (selected to NOT have the "cast holes"), bored to E30 spec AND SHAMFERED to E30 spec as well (as the VW shamfer is smaller) for £85.18+vat / pr.

Grooves are an extra £48+vat/pr and 48h UK shipping is £10+vat. Stock is limited (3pr grooved, 1pr plain from memory) and that'll be it for now until we get the next big batch done.

Any zoners who buy a pair can have free shipping and free "2mm" wheel spacers, can't say fairer than that! :cool:

Keri

Re:

Posted: Thu May 10, 2007 4:59 pm
by Niggy
James.
Give me a call, just spent winter doing the big brake thing for my race car that has M3 on the rear but still 4 stud.
The front has 305mm x 28mm disks with 4 pot Brembo, cost £220 off fleabay but still running 15", sadly not BBS.
Got lots of info and VW disk if you want it.
:wink: Nigel
mob 07990557979

Re:

Posted: Thu May 10, 2007 5:12 pm
by ed325i