P&L STI Lightweight rear brake kit

[mabviper]

Well my daily driving is pretty aggressive. So I wouldn't think about putting this on my car, but you're free to do what you wish.

Nobody would consider something like this just for daily driving, cause less unsprung weight really doesn't matter. This is targeted for the motorsports crowd and I wouldn't use it even for autocross.

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[industrial]

Originally Posted by mabviper

Well my daily driving is pretty aggressive. So I wouldn't think about putting this on my car, but you're free to do what you wish.

Nobody would consider something like this just for daily driving, cause less unsprung weight really doesn't matter. This is targeted for the motorsports crowd and I wouldn't use it even for autocross.

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You are seriously on the limit of your stock brakes on your daily drive? If so... that's awesome but I highly doubt you are anywhere close.

[jack43]

What is a sensible lightweight rear brake setup that keeps the e-brake functionality?

[Captain Insano]

Originally Posted by mabviper

Well my daily driving is pretty aggressive. So I wouldn't think about putting this on my car, but you're free to do what you wish.

Nobody would consider something like this just for daily driving, cause less unsprung weight really doesn't matter. This is targeted for the motorsports crowd and I wouldn't use it even for autocross.

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I would consider these on my daily driven car. I assure you, if you drop 40 lbs of rotating weight from your rear brakes you are going to feel it in a very good way. Even on a daily driven car. Especially if used in conjunction with other weight saving modifications.

Industrial is right, unless you are doing some crazy canyon carving for several minutes or street racing these aren't going to fail you on the street. Even then, I would be extremely interested in the "fail" point of these brakes compared to OEM rear brakes. You use your front brakes for about 85% of your stopping power. Maybe P&L can chime in with some more info on the topic.

For people scared about parking brake, put it in gear and turn your wheels properly to curb, Drivers Ed 101.

[Turdinator]

Originally Posted by mabviper

I wouldn't risk safety for the weight savings. The rotor seems like the same size as stock but only 1 layer vs 2 for the oem ventilated disk. I don't think the rotors can take the thermal abuse of daily driving, not to mention the pad size is also smaller than oem. You'll just cook them, I think.

OP has the NZ base model with the smaller solid rear rotors on it already so it would be less of a performance drop than you are suggesting.

These plus the essex sprint front brakes would make for a significant drop in unsprung and rotating mass....

[diss7]

Originally Posted by Turdinator

OP has the NZ base model with the smaller solid rear rotors on it already so it would be less of a performance drop than you are suggesting.

These plus the essex sprint front brakes would make for a significant drop in unsprung and rotating mass....

The wilwoods are even lighter (I haz them)

[Captain Snooze]

Originally Posted by Captain Insano

For people scared about parking brake, put it in gear and turn your wheels properly to curb, Drivers Ed 101.

Say goodbye to insurance.

[diss7]

Originally Posted by Captain Snooze

Say goodbye to insurance.

Bit late to start caring about that.

[utekineir]

Not advocating anything, but this seems at least slightly relevant.

From the csg long term bbk thread.

Originally Posted by Dave-ROR

Dude the rears haven't even generated enough heat to bake the paint off the pads yet

[Dave-ROR]

Originally Posted by industrial

What kind of daily driving do you do? Come on people... this will hold up just fine for commuting and the stopping power won't be any different. You don't need a parking brake if you leave the car in the proper gear and if you're real paranoid, there are other ways to have a parking brake.

The reason you'd want to do this is to drop a large amount of rotating and/or unsprung weight. People pay the same price to drop 10 pounds from the driveshaft. This kit drops 4x that weight, some of it unsprung as well as rotating. It's also further away from the center of the car which makes the weight more significant.

A couple of things.. how do you know stopping power won't be any different? What's the brake torque with this setup in the rear compared to the OEM setup given the same brake pressure? I didn't see any really detailed information on that site to determine that. If you change rear torque/mu in any way (piston sizes, disc diameter, pressure, pad) then you WILL change the brake bias. That change can result in less brake force before ABS than before.

Parking brake can be useful on hills (starting to drive) although depending on where you live that could not matter.

Also, I doubt the rear kit drops 40 lbs. I've had the rear components off a BRZ and they didn't seem all that heavy to me, even with the parking brake drums.

[mike156]

I would imagine that 40# includes all the parking brake hardware (handle, cables, mounting plates, shoes, etc.).

Maybe its just the fact I live in Utah where we have mountains, hills and sloped parking lots everywhere, but trust me, no parking brake is a pain in the ass on a daily.

[industrial]

Originally Posted by Dave-ROR

A couple of things.. how do you know stopping power won't be any different? What's the brake torque with this setup in the rear compared to the OEM setup given the same brake pressure? I didn't see any really detailed information on that site to determine that. If you change rear torque/mu in any way (piston sizes, disc diameter, pressure, pad) then you WILL change the brake bias. That change can result in less brake force before ABS than before.

Parking brake can be useful on hills (starting to drive) although depending on where you live that could not matter.

Also, I doubt the rear kit drops 40 lbs. I've had the rear components off a BRZ and they didn't seem all that heavy to me, even with the parking brake drums.

You're right, I don't know how the bias is affected. I'd imagine these brakes would bite really hard just looking at the rotor. It was designed for dirt tracks and drag racers so I'd imagine they'd work fairly well.

I'd like to hypothesize that the brake bias wouldn't be radically affected by the overall system. Nothing that couldn't be fixed with a pad swap or something to that effect. I really don't know at this point. Hard telling not knowing. I can say with a large degree of certainty that 95% of the people on this forum wouldn't reach the thermal limit of these brakes on their daily commute. That's the main point I was contending with. I have little interest in running this exact setup but I do have an inquiry with P&L about using their custom brackets with a slightly larger caliper which can take a .81" thick rotor which opens up a ton of options from wilwood's catalog of rotors. From there, it will take some experimenting to see what works well.

I'm sure you know but it seems that robispec runs a similar setup on his timetrial car. Granted, it's a brakeman setup but it's similar. He has also claimed similar weight loss numbers and seems to be doing just fine racing their setup. The 40 pound figure is just for the rear brakes on the sti. I'm not sure what the figure is for us but it's going to be significant. The wrx front kit that some are running saves 32 pounds so it doesn't seem like 40 pounds is that far out there.

[Captain Snooze]

Originally Posted by industrial

I'd imagine these brakes would bite really hard just looking at the rotor.

Huh?

[Captain Insano]

Originally Posted by diss7

Bit late to start caring about that.

LOL, indeed.