Dave25

Am thinking of upgrading my P1, and preferring to keep to standard / warranty compliant upgrades.

I like the look of the Prodrive brake kit, but just wondering if anyone has info about the weight of the kit. I know brake discs aren't light so wondering how much of a penalty the ( larger disc ) kit would have over the standard fitment.

The Prodrive blurb says they are lightweight aluminium calipers, but anyone have anything concrete?

Thanks,

Dave.

MARK MORRIS

from what i remember when i swapped alcons back to 4 pots the alcon kit is lighter then the subaru kit, at least the alcons are alloy whereas the subaru calipers are iron
mark

Hoppy

Dave, I've not got anything concrete. This is not a good material for brakes

I don't think there's anything to choose between the APR, Brembo or Prodrive/Alcon alloy calipers. They are all fantastic.

But the Prodrive discs use an integral iron bell, I believe, which makes them both heavier and inferior to alloy-belled discs from APR, ScoobySport, or Godspeed.

I posted an explanation on here a few days ago about alloy bells. Scroll down a bit and you'll find it.

Hope it helps.

Richard.

Fat Boy

Oh no they don't The Alcons have a one piece alloy bell and disc. I have them on my P1. No noticeable difference in weight although I do use OZ Super L's on the road now so the unsprung weight is probably the same as before overall. They look great but there have been a lot of warped discs replaced under warranty - mine seem to have gone as well despite a meticulous bedding in procedure

MartinM

Oh yes they do . The Alcons are a one piece iron bell and disc. There is no alloy part at all - the main disc surface is definitely not alloy!. If there was an alloy part, it would be the bell, and you would see it attached to the disc via a ring of bolts - just like my APs as shown in:

http://www.scoobynet.co.uk/bbs/threa...threadid=60669

<<They look great but there have been a lot of warped discs replaced under warranty - mine seem to have gone as well despite a meticulous bedding in procedure>> Another vote for APs then - although if anyone has had 330mm x 28mm AP discs warp, I'd be interested to know


[Edited by MartinM - 12/28/2001 12:12:40 PM]

Hoppy

Martin, thanks for bringing that excellent link back to the top Oops - I've just done it again

Richard.

Fat Boy

Mea culpa
Misread your post and thought you meant a separate bell & disc (not bright enough to understand integral!). Thought htye were alloy but then that explains the rusty brown colour of the bells, I guess. Doh!

I wavered horribly between APR and Alcons before plumping for the warranty backed kit. If I was to do it again I would probably go for the APR 6 pots , but i don't think they fit under the Super L's.Grrrr.

Theo

Prodrive/Alcon disk : 7,5 Kg

standard disk : 6 Kg

MartinM

Hoppy - yes it is an excellent link - especially your post within it...I'm so sad I have it on my favorites menu!!

...but to pick up a point you made (thread hijack, sorry)...
<<An APR disc has a separate alloy bell ... In addition, the alloy bell is much lighter and has superior heat conducting properties>>

If the alloy bell has superior heat conducting, surely that makes the heat from the disk dissipate more quickly on the 'bell side'...so you get asymmetric (sp?) heat levels in the disk and therefore still prone to warping?? Or is it just an Nth degree effect not worth worrying about?

Mike Tuckwood

The alloy bell will not transit heat anywhere near as much as a one piece iron disk.

The benefit there also is that it is being kinder to the hub/bearing area by massively reducing the amount of heat it will be subjected to.

APR 6 pots will fit under 17" Super L's).

Mike.

[Edited by Mike Tuckwood - 12/29/2001 12:31:47 AM]

Hoppy

Hi Martin. Thanks - you are not sad at all

Heat doesn't pass through a mechanical joint at anything like the rate is passes through continuous metal, therefore it's an Nth degree effect, as you say.

But also the joint allows a miniscule amount of movement between the disc and bell so that the disc is free to expand at it's own rate without warping.

Arguably, the benefit of alloy is more evident in the calipers which shed heat more quickly, keeping the fluid cool, and they are dramatically lighter than the standard steel jobs. I don't have my comparison figures to hand but they're something like a third of the weight (I stand to be corrected). Unfortunately, the mounting bracket needed puts a lot of that weight saving back on. Whatever, even the mighty 6-pots and big discs are lighter than stock.

The bolted-on bell is an ingeniously simple solution, which seems to work as well as floating discs, but without the maintenance hassle. Proof of the pudding is that I've yet to hear of an APR disc warping, and on a Scoob at Dono they probably get pushed harder than anywhere else at any time.

Dono is one of the world's hardest circuits for brakes, production cars are heavier than racers, and the brakes are usually poorly cooled (as they are on a Scoob). My APR brakes can take more laps of Dono at a time than I can, and they've done a few hundred laps with no significant wear yet. Done almost two sets of pads, though, and Pagid RS421s are £250 a set. But that's damn good going, really. (How many sets of Greenstuff would I have used ?) I have a set of Ferodo DS2500s ready to fit which APR tell me are at least as good and half the price. 6-pot heaven

Cheers,

Richard.

PS Edited to add that Mike Tuckwood makes a very good point about protecting bearings from heat, which are prone to heavy wear on track day cars.

[Edited by Hoppy - 12/29/2001 12:58:31 AM]

MartinM

Hoppy, Mike - right, one last clarification please

...the alloy has superior heat conducting abilities (Hoppy)
...the alloy bell will not transit heat anywhere near as much as a one piece iron disk (Mike)

So
...either one of you is incorrect
...the heat induced in the bell by the disc 'disappears' from the bell (not sure where to as they're not explicitly cooled by anything) before it gets to the hub
...or I still don't understand exactly

I think I'll get back to rocket science - it seems easier sometimes

Dave25

Seems I've started a bit of an argument here!

Thanks Theo for the info that the Prodrive kit is another 1.5 Kg per wheel heavier, so 3 Kg weight penalty overall. Think that could be offset if the driver works off the Christmas dinners.....

So, if the Prodrive kit is heavier, how are the AP kits lighter? One comment was that the majority of the weight is saved in the calipers, which are aluminium in the Prodrive kit.

Sorry, I have no idea what components of a brake assembly ( bell etc ) actually are.

Thanks for the info!

Dave.

AJF

iTrader: (1)

check with dealer ref new discs not under warrentry close to £700

Theo

Dave,...just the disks are 1,5kg more weight each !

Don't know the difference between the 2 callipers !

One Prodrive/Alcon calliper with mountingbracket is 4,5kg !

I don't know how much the Subaru 4 pots are, because they are still on the car

Hoppy

Martin, both Mike and I are right Alloy bells and calipers run cooler than steel.

Dave, I've dug out a few old notes and I can tell you that APR's 4-pot alloy caliper weighs a massive 2Kg less than Subaru's 4-pot Brembo and Prodrive calipers will be very similar to AP's weight. Also, the overall weight saving on a 16in APR 4-pot kit is 1.6Kg over stock.

Richard.