E30 M3 Brakes

I think there`s no doubt they offer an improvement, probably not in outright braking ability but in braking consistency over a number of laps and less brake disk wear. But it comes down to "do you really need it" at £2000 or whatever, when just brake ducts on a std setup removal some of the advantage large brakes have over std ones. And of course if you take the extra weight of large brakes into consideration and also the fact that you will probably need larger heavier wheels too over the much prefered 15" wheels for track use. Having said that, i prefer the handling on 16`s than 15`s with the 205*55 tyres but have yet to try a 50 tyre on a 15

 

 

 

There are options which allow you to retain 15" wheels... but for example with AP this is only possible running with spacers which is not a desired option for many.

The cost is an issue to me in so much as attempting to decide which modifications to the car would give the best relative performance increase per £ (does that make sense)....  i.e with a standard car would I like to spend £1400 on brakes or on bigger cams, or on coilovers etc etc...

I liked the idea of bigger brakes but have to confess I've not found the limit of my standard ones (using ferodo pads) so would rather spend the money elsewhere for now.

I'm no expert but isn't another reason for uprating brakes (aside from braking performance) a consideration of unsprung vehicle weight?

Tom

Roops

Where did you get the G88? gona give em a try as need to changed them, hopefully for Sunday as off to Keilder, if i can't get them by then i'll get a lift with Gary.

 

Well it was following our curry house post Brands discussion on suspension that I decided the next job on my car will not be engine based (read Carbon Airbox & Motec or equivalent) but will in fact be Leda/Camber plates.

I recognise that I'm nowhere close to using the power I already (235) have effectively with my current setup...

Increasing track experience will make the biggest difference to my times though methinks.

I'm not sure how much if any difference unsprung weight makes on cars at thislevel, but I understood that lower unsprung weight effectively improved the time (due to momentum) in which the shocks and thus keep the tyres incontact with the road more of the time (huge over-simplification by me I suspect) - call me sad but I find all this stuff quite interesting!

Tom-H

Tom, if you like all that stuff. The book "How to make your car handle" by Fred Puhn is a good read. The technical sections about roll centres, unsprung weight etc. help you understand why certain cars work better than others ie. double wishbone v mcpherson strut.

Roops

Tom,I have a copy if you want to borrow it.

   Jon

on the subject of brakes, dave gamble has just fitted some very nice 6 pot hi-spec brakes that came in i think at around £1000 not fitted, his car is up at bexleys for a few days i think while they get his 2 litre race engine going, should be interesting to see this car go.

Have you checked Gustave's site Tom? There's plenty of great info

http://e30m3performance.com/index.html

 

TMS do a 4 pot caliper set up that will fit under 15" I believe. They're suppose to be pretty good.

I have been following this thread with some interest as I have shortly to replace mine (pads & disks) I was going to continue with the mintex fast road pads as they have suited my driving up till now (no  track use though - life always manages to get in the way... ) but I was going to go for grooved disks (G88's due to board members experience).

Questions I have are: is it worth getting grooved disks on the rear aswell?

and why are 15" rims favoured? I had noticed that all track prep'd cars tend to run them and again people here seem to prefer them, but I wondered why, as I would have thought that a lower sidewall (as on a 16") would provide less tyre deformation on turn-in etc.  Or have I missed something?

Any answers would be welcome.

Thanks.

The reason the track guys like 15" firstly the tyres are cheaper, but the main reason I think is that  lighter is better.

Your car has to move mass in order to go. The more mass the more HP it takes. Another problem is where this mass is. With a bigger rim it moves the mass out more this needs more HP to get it moving.

 

Think of a weight of a piece of rope. Let say you a 1 lb weight in a  1 foot piece of rope and swing it around your head, now put the same weight on a 3 ft piece of rope and it will take much more effort to swing the rope. Exactly the same principal with wheels, the further out the weight the harder it is to get it moving, hense slower acceleration.