Rear Brake upgrades

[coolcatracing]

I'm currently building my time attack car for this season and I'm using the 350Z track 2 piece front setup with 30mm 300Z calipers and stock 300Z rears on a 95 240. I want something in the rear to equal the new power up front. I'm not concerned about a parking brake since I never use them and none of the hardware is there anyways. Does anyone sell brackets like what I have up front to use maybe the track rotors in the rear? I've seen several setups that use the stock 240 rear caliper but that won't give me the torque I need.

[jrocslider]

i know you are new and this isnt flaming but we have dozens of threads on this same topic. just type ur title into the search bar and you'll most likely get the answer you are looking for. i did just that and found at least 6 threads regarding rear brake upgrades on the first page alone.

Danny

[garagelu]

you really dont need a bigger rotor in the rear. A awesome upgrade for the rear is the sti brembo rear. I compared the brake pad to the 300zx rear pad and it has about 20 percent more pad area.

I havent seen any other brake upgrades for the rear other than that stk kit which allows you to use a bigger rotor with the stock 240sx brakes. It wont work on the 300zx because of the ebrake.

Honestly if you are looking for brake performance, 300zx brakes are sufficient. There is really no need to go any bigger.

[pwhitersxs]

^^ That is a pretty true statement. Why is there no mention on pads from the OP? Pads can play an importatnt role in braking power.

Also, not sure on what your master cylinder is, but that also plays a role on rear brake bias. After the split point, the line pressure decreases causing less force available to the piston. So look into getting a MC with something 40 units with a .2 ratio for increased rear bias. z31 is 40 units with a ratio of .4. Sorry no units, I forget them at the moment. Not sure on what master cylinder you are using, but look into a z31 or run new lines to run another type of master cylinder that is commonly used on nissan FWD applications. Using the z32 MC will give less rear line pressure because the split point is around 30 units I believe. Sorry, not at home and don't have the fsm's to be sure of units.

[coolcatracing]

Originally Posted by jrocslider

i know you are new and this isnt flaming but we have dozens of threads on this same topic. just type ur title into the search bar and you'll most likely get the answer you are looking for. i did just that and found at least 6 threads regarding rear brake upgrades on the first page alone.

Danny

I'm not new to forums, I know how to use the search but thanks for trying to belittle me. I found lots of info on rear upgrades but nothing that suited what I was looking for. I'm trying to keep the bias in the same range as I don't want to use a manual proportioning valve on this car and the larger fronts will necessitate something more in the rear to maintain the balance. As for the 300zx brakes being sufficient, after about 10 minutes of hot laps they are fading even with Hawk HT-10 pads on my last setup so I know I need some larger rotors to deal with the heat. If they were fine then none of the time attack cars would use anything else, fact is they all do. This is not on a street 240 that sees a few track days here and there. This is a fully gutted and caged race car that weighs 2470lbs with just under 400whp. If I have to go with the same 355mm Stoptechs I run on our GTR and our S15 then I will but I was trying to pursue other options to see how they compared to the more expensive kits.

[coolcatracing]

Originally Posted by pwhitersxs

^^ That is a pretty true statement. Why is there no mention on pads from the OP? Pads can play an importatnt role in braking power.

Also, not sure on what your master cylinder is, but that also plays a role on rear brake bias. After the split point, the line pressure decreases causing less force available to the piston. So look into getting a MC with something 40 units with a .2 ratio for increased rear bias. z31 is 40 units with a ratio of .4. Sorry no units, I forget them at the moment. Not sure on what master cylinder you are using, but look into a z31 or run new lines to run another type of master cylinder that is commonly used on nissan FWD applications. Using the z32 MC will give less rear line pressure because the split point is around 30 units I believe. Sorry, not at home and don't have the fsm's to be sure of units.

This car currently has the 1 1/16 Z32 master and booster and will be using either Hawk 9012 track pads or the same HT-10 pads I used on the other car. I run the 9012 in our S15 with the Stoptech 355mm Z32 4 wheel package on it and love it and have only had fade issues once on track and they do well enough that I leave them in for street use. I use the same pads in our SC Lotus for the same reason, its brakes though are more than capable in stock form, just better pads and 2 piece rotors for a lighter setup.

[Koopa Troopa]

If you're not going to spend the time tuning the brake balance with a proportioning valve then what's the point in even upgrading the rear brakes?

[coolcatracing]

The stock balance works well. The car will eventually have a manual valve but even that won't produce the best results if the front is so far above the rear. I'm just trying to avoid having to compensate for less power in the rear with the PV.

[pwhitersxs]

Originally Posted by coolcatracing

This car currently has the 1 1/16 Z32 master and booster and will be using either Hawk 9012 track pads or the same HT-10 pads I used on the other car. I run the 9012 in our S15 with the Stoptech 355mm Z32 4 wheel package on it and love it and have only had fade issues once on track and they do well enough that I leave them in for street use. I use the same pads in our SC Lotus for the same reason, its brakes though are more than capable in stock form, just better pads and 2 piece rotors for a lighter setup.

You just answered your own question I believe. At this point, you are maxing out most brakes. I find it crazy, but I guess you are the exception. Either upgrade to an aftermarket kit with huge brakes OR read up on cooling fans and ducting.

The z32 brakes are usually more than adequate. Maybe look into getting a z33 track rear setup. Just fyi, the z33 track rear rotor is 322mm x 22.2mm. So you might want to grab some z33 brakes and see if they fit or go to a nissan dealer and peak around. Other than that an aftermarket kit will be your best best.

[Gumballf355]

Go with stoptechs... not even an STI brembos would work for what you're tryin to accomplish. Brake ducts would help out with your fade aswell. I'm sure you don't have any of those yet.

[racepar1]

Honestly I have never heard of anyone complaining about rear brake fade before. Tons of people run the stock rear brakes with 300zx fronts and have no problems. Where does this car run at? Is it a super fast track? Is the ambient tempurature like a million degrees or something? The problem is much more likely something other than the rear brakes themselves. Are you running good fluid? Are you sure the stock proportioning valve is working correctly? As far as the bias goes just get a proportioning valve! There is no point in up-sizing the rear brakes. You just don't need that much stopping power in the rear. If the overheating problem continues then just run some brake ducts, you will be fine!

[coolcatracing]

Let me clear up something. This is an expansion of a previous car. I'm using a new chassis and using parts I've used on the previous car but since this one will be in a higher class and have much more power/lighter weight I don't want to run into the same problems I had in the previous setup with just 300ZX brakes with good pads and rotors. I never had a problem on that car with rear overheating, I just want to keep the sizing relatively close as I increase the size of the fronts. I know the Stoptechs work great and are honestly overkill for this weight but I am using this car for a test bed for many things I'm fabricating and I wanted to see what options are commonly available for the rears without using the expensive kits. I have a few ideas of what I can use and may fabricate some billet brackets for doing so but I was curious as to what was already out for the rears. I see numerous options for the front but not much for the rears. Thanks for the suggestions, looks like I'm just going to have to build some brackets and move these calipers out some.

[robtheflyer]

arizonazcar.com has a wilwood setup for the rear and the front, I think it's 4 piston rears, and you can get a 6 piston setup for the fronts.

[coolcatracing]

I was looking at that setup. I've just had too many problems with the Dyna lite calipers flexing so I won't use them anymore.

[Gumballf355]

I was talking with Brian from JspecMotorsport the other day and wanted him to put Z32 and Sti/Evo brake pads side by side for a footprint comparison. (I was just curious) This is what he came up with using Project Mu pads he had in stock.

I already have the Sti calipers... have to fab up brackets... I can't wait tho.

[idriveattz32]

i've looked into this before as well. I would start with ducting and if that was not sufficient I would look into making this work:

Since you already have the 300ZX rear setup, upgrade to racingbrake.com 2pc rear 350Z track rotors, the larger size should help cooling. Then I would look into sourcing some porsche boxster-S rear calipers.

You'll have to make custom brackets to make this work and may need some hard metal shims to get the spacing of the brake pads right because the 350Z track rotor is 322x22 while the porsche is 299x24mm.

If you wish, you could stick with the 300ZX rear rotor which is 296x18mm (racingbrake.com sells a 2pc) and go with a cheaper easier to find non-S Boxster rear caliper which mates up to a 292x20mm, but again you will still need brackets and shims to place the pads rights. This should save you on some cost though.

I've looked into this before but never went anywhere with it and have no clue if this will even work, so good luck!

[LigouriRd]

Stoptech: Rear Brake Upgrades ... Is Bigger Really Better?
You really don't need to upgrade your rear brakes, the Z32 or even the stock 240 should be sufficient. If you are getting fade, it is happening up front. When you brake hard, all the weight shifts to the front wheels, that is where all the braking happens. There is very little normal force on the rear wheels at that point, more braking out back will just make it easier to lock up the rear tires.

I have the Wilwood 4 piston set all around. I regret getting the rear A) cause I lost my parking brake, and 2) I have the proportioning valve turned down so low they are useless.

Sorry, there isn't going to be a rear upgrade out there that will work with the OEM setup (Stock or Z32) without messing with proportioning.