P&L STI Lightweight rear brake kit
 

http://pandlmotorsports.com/shop/pl-...ght-brake-kit/

Thinking of whether to try this out. I know it says drag/auto cross only. But dem weight savings.

And how much to the rear brakes do anyway? Naff all thats how much. TRD pads in my rear poo spec brakes (base model outside US) were engaging ABS before my Wilwood Front BBK. Admitidly I had stock suspension in, so rear was getting massive unloading. But still. Has me thinking about running these brakes.

I can not determine from their picture if there is a parking brake surface inside the hat.
From their website:
"While this kit is “street-able” we strongly do not recommend using it for daily/street driving. The reduced weight also provides for less thermal mass for heat dispensation and therefore is not good for extended braking applications like a PDX/Track Days, or Daily Driving." (My italics)
I think the application is very limited.

Yes saw that, although imagine that is for an sti, the 86 is much lighter, so not as demanding on the brakes.

Hand brake?

I don't think it has one. Could live without for dat weight savings

I'd say call them monday at the shop unless you were trying to take advantage of the black friday sale.

Forty lb reduction just for rear kit or coupled with front kit? I would think the latter, but it is vague.

The rear brakes have a large iron drum brake surface inside. 40 pounds is probably just from the rear. I sent p&l an email a week or so ago about this kit. More specifically whether a slightly larger rotor would fit their bracket. Wilwood makes the same rotor with a .81 clearance which would be able to take a normal vented rotor. The weight savings would still be significant. Haven't heard anything back.

Robispec runs ultra light front and rear brakes. It accelerated well for a N/A but yielded no additional benefits for track use. With that said, not sure what you are trying to accomplish. Do you want to have the ability to trail brake? As preference, we use non-staggered brake compound to get our desired braking performance.

They were closed most of last week for thanksgiving. If you havent heard back, call them (847) 678-4311

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.

No parking brake is a bigger issue on a street car then you may think. The handle in my daily won't lock currently and I haven't had the time to fix it. I keep waiting to walk out and find my car down the street crashed into somebody else. It might not be an actual issue, but it sure makes you nervous on a daily basis.

You could likely add a hydraulic handbrake with a lock to get all the weight loss (except for the parking brake handle) and none of the downfalls of no parking brake.

I dont see any reason to put this on your car..OP what reason are you considering using this for?

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 big compromise is that you won't have an e-brake which is there for a reason and the thermal capacity will be reduced for heavy use. Track days or a run through the mountains. Things like that which is why I'd like to retain a thicker vented rotor.

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.

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.

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

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.

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....

:popcorn:

The wilwoods are even lighter (I haz them)

Say goodbye to insurance.

Bit late to start caring about that.

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

From the csg long term bbk thread.

Quote:

Originally Posted by Dave-ROR (Post 1319503) Dude the rears haven't even generated enough heat to bake the paint off the pads yet :)

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.

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.

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.

Huh?

LOL, indeed.

All I know, is that my poo spec rear brakes, will Wilwood 6 pots up front, running semi slicks at the track, barely got hot at all. I had new TRD pads in the back, and I wish I had taken before and after measurements, because they still looked new.

In the same 50 laps, The wilwood 6 pots and destroyed a brand new set of pads down to the metal.

However, I do think part of this was caused by me being inbetween suspension at that track day, so I used my oem suspension. Which heavily unloaded the rear under heavy braking, making the rears work easier than they should be.

My new suspension has arrived so I'll try go to the track again with that in, take some before and after measurements of the rear pads, and if they show little/no wear, I'll take that as that they are indeed doing naff all, and bite the bullet on this kit.

Re brake bias concerns, while valid, this is more often than not to be another thing that is over analysed and stressed about on forums. Often the arguement starts from someone selling brake kits, trying to tie you into a rear kit you dont really need.

As another has pointed out, you can toy around with compounds, and find a balance you're happy with. Heck, if that didnt solve it, its not hard to put in a brake proportioning valve; thats what I can in my ae86 before I went full pedal box.

Trying to figure out the actual weight loss potential.

Actual weights posted:
stock caliper 2.8lb, bracket 3lb, disc rotor 13.2lb, pad .8lb = 19.8lb (1 side)
x2 = 39.6lb for stock rear brakes

Anyone know what the rest weighs?

You can mess with pad choice for sure, but not all pads are consistant across temp ranges so that's not always the best choice either.

Having been on track with too little rear brake (rear pads glazed), it's something I will never understress again. Too much rear brake is just as bad of course.

Adjustable prop valve may not work well on a car with EBFD either, unless you always disable it.

People can do whatever they want, but I see a VERY limited market and usefulness for a product like this. From a track perspective I see absolutely no value in it. From a street perspective I see no value (I don't care much about street performance and having to test and tune to find proper bias again on a street car isn't very appealing, nor is the custom disk and who knows how much pad choice/selection). For an autocross car or drag race car I see value in it.

Huh? It's an iron surface. Appearance isn't all that telling in how it will perform, beyond all the additional stress risers. And that they will be noisy due to the design.

You can adjust pads. Assuming you have a lot of choice in that size. I agree that people won't overheat these in daily driving. There's very little thermal mass in that rotor, but no one should be killing their rear brakes that much when daily driving, unless they have too much power, a heavy right foot, and TCS turned on... that could heat them up quick :)

The entire rear brake system is about 40lbs, not including a few lbs of lines and nuts.. so... yeah.. 40lbs seems pretty far out there.

No track value in removing 35-40lbs of unsprung and rotational weight?

I politely disagree sir.

What Dave says is true. Our very good friend Robispec runs the Brakeman custom kits. Originally he had a 4lb setup in the rear. Blew up that rotor in a session and proceeded to upgrade to a 7lb setup. Also, his car is caged with 400lbs+ less than a stock car. If your car is at that point, then you can try it. He also changes rotors often enough because he does crack those rotors. If the cost of changing doesn't bother you, then go for it. Robi also doesn't run full sessions too. For the record, his setups usually net podium finishes all over the country so he knows a thing or two, however, he does get a little angry whenever we beat him just by a few tenths every time (all in good competitive spirits). :D

For side note, while our damper setup is superior to his (he will admit this flat out), he barely pulls on straights when was E85, big radiator/oil cooler, 400lbs lighter, stock motor, and his epic uber light brake rotors. Again, I don't see the correlation to going with lighter brakes will improved performance. There are other things you can do improve performance on your car, such as picking up high quality dampers that will improve your cornering speed and help lay down additional grip for higher corner entry speeds.

While weight matters, our tuning philosophy never compromises on safety equipment. I've seen quite a bit of brake failures with multiple setups. If you find this absolutely necessary for your application, then there's no way to stop you from doing it.

schooled

Again, the rear brakes weigh about 40lbs total based on information in this thread. If that's true, then these brakes will NOT save 35-40lbs.

And not all of that weight is rotational. About 13.2 lbs per side is rotational based on that information. If this rotor/hat setup weighs 5 lbs then it's 8.2lbs rotational, the rest of the savings is in the bracket, drum, caliper, etc.

Furthermore, ignoring the bias issues, I don't run time trials for a few laps on A6 hoosiers. I run 30-60 minute sessions. There's no way I'd track my car with these on the back. Absolutely no way in hell.

Having said that, if they meet your needs then rock on.

40 pounds not including the drum brake hardware I believe. That stuff can be pretty heavy. I don't think anyone is saying these wilwoods in question would work for heavy track use.

I just want to remove the parking brake and go with a lighter two piece rotor. Don't know why you guys are so vehemently against touching the rear brakes. Seems strange to me especially considering the op has a similar undersized setup stock.

I just said if it meets your needs then rock on. I'm just cautioning that it's not the best idea IMO for various reasons for most people.

I didn't notice that he didn't include the drum bits. Rotational weight will still be limited to the rotor though, most of that is in the hat and that weight removal is less important than weight further out (wheels for example).

I'm just curious, how is your car setup for comparisons sake? You guys don't have any weight reduction, brake upgrades or engine tuning?