jasonius

iTrader: (1)

Basically looking for better brakes for my 05 wrx as both pads and discs are getting close to replacement time (have been running uprated pads/fluid/hoses..).

I realise going bigger is going to incur a weight penalty, but I'm really keen to keep the unsprung weight down as much as possible, so here's my question:

Given that I'm not likely to track the car, I'm thinking something like AP 4pots with 330mm discs would be a good choice to fulfill my criteria. Does anyone know how these compare (weight wise) to OEM 'Subaru' 4 pots and 294mm solid rotors.

Also, for fast road use, surely AP 4pots are more than man enough, even with the stickiest of road tyre..?

PS IIRC pads are much cheaper for the 4 pots too..!

Chelspeed

> OEM 'Subaru' 4 pots and 294mm solid rotors

Pretty (like 99%) sure that all standard subaru 4 pot calipers come with vented discs not solid.

The AP discs with either the 4 pot or 6 pot kits will more than likely be lighter than the standard subaru discs because the AP's come with alloy bells rather than being made in one piece steel like the standard discs.

The AP calipers will be lots lighter than the standard subaru 4 pots because they're alloy rather than steel. According to the AP catalogue the CP5200 4 pot calipers are 2.6kg, the CP5570 6 pot calipers used with the 330mm kit are 2.4kg and the CP7040 6 pot caliper used in the bigger disc kits are 3.7kg.

So looks like the 6 pot CP5570 is the one to go for if money's no object and you're only trying to save unspring weight. A bit surprising that they're lighter than the 4 pots but that's what it says, the difference between road and race derived calipers I guess. But overall I'd say you're right the 4 pot kit will be the one that suits you best.

Edited to say CP5570's are 3.0kg on the web which seems more likely.

jasonius

iTrader: (1)

Sorry, by 'solid' I meant one piece..

It was the alloy bells that made me wonder if they'd actually be 'any' heavier, I knew the calipers would be lighter, just wondered if anyone knows the weight of the OEM setup.

I recently considered getting the Godspeed AP 6pot kit with Ian's own 355mm disc's, but after some digging I found out that a) they come with the heavier AP caliper and (more importantly) b) the 32mm discs weigh an awful lot. Some people have even commented to me on the noticeably reduced response (turn in and acceleration)..!..

Hence my criteria not to over do it and unnecessarily effect other areas of performance, IYSWIM..?

Puff The Magic Wagon!

iTrader: (2)

AP4s and 300mm discs are perfectly adequate for road use.

I run AP4s with 28mm x 304mm Alcon discs on a Godspeed bell on track because I prefer to keep with 16s. They are more than man enough - 50 minute session at Oulton Park before Xmas with no fade (not that I was expecting any lol!). I also brake late

I don't think that you will have any problem with extra unsprung weight causing issues as I certainly don't.

jasonius

iTrader: (1)

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