RR Racing Brake Development -- Competition and Street

[OkieSnuffBox]

Originally Posted by Rafi@RR-racing

We are getting a lot of PM's asking about the weights of our kits. Let me summarize it here (even our solid rotor kits are lighter than stock):


Stage I -- 4 lbs lighter than stock
Stage II -- 2.8 lbs lighter than stock
Stage III -- 15 lbs lighter than stock
Stage IV -- 14 lbs lighter than stock




Rafi

Per corner? Or both combined?


And then update your OP with the info as well.

[Rafi@RR-racing]

Originally Posted by OkieSnuffBox

Per corner? Or both combined?


And then update your OP with the info as well.

Updated the OP. Weight savings is combined.


I wish we could save 15lbs per corner but I don't even think a ceramic rotor will get you there!


Rafi

[CSG Mike]

Originally Posted by Rafi@RR-racing

The only way to retain full e-brake functionality is to line the hat with an iron sleeve, but that adds weight. I understand that drift cars need the e-brake, but this kit is intended for road racing. The e-brake is functional for parking purposes.


Stage II is made for cars with substantial downforce and increases rear bias by 25% compared to Stage I, so I do not see it working on a car without rear downforce, keeping in mind that guys running track tires without rear downforce will induce more weight transfer to the front... so I think that a Stage II may induce rear ABS activation.



We are working on ducting solution, but I must tell you we have no temperature issues on Phil's car. Phil runs time attack, so he needs really powerful brakes but endurance is not an issue. Compared to stock, this setup is so robust, temperature is not an issue. The front Coleman Racing Winston Cup rotors 13"x1.25" are extremely robust for this application.


Regarding caliper service intervals -- clearly that depends on the application. Endurance racing and sustained heat will obviously require more frequent service. Replacement high temperature seal set for 12 pistons runs only about $35. They are easy to replace, just pressurize the caliper to pop the pistons, clean, and replace. Stage II and IV caliper are anodized, so the finish is really durable and will last a lifetime.


We can also rebuild these calipers with Wilwood Thermlock pistons. These pistons have a thermal shield that is supposed to reduce fluid temps by 25%. BUT, to be I do not see this as a necessity for all but the most extreme endurance application.


Lastly, we will soon offer a thick titanium shim option with these kits for applications where fluid temperature is a problem.


-Rafi

Would you be able to make the iron sleeve an option? Increased thermal capacity is my concern; weight reduction is a nice bonus, but even a mass increase is okay if the thermal capacity is increased. Overall inertial changes will likely be minimal given the location of the increased mass anyways.

Do you have any data on how the bias change benefitted Phil's car? Downforce is highly variable, even with the rear bias, the dynamic grip balance of Phil's car changes depending on speed. While the rear bias certainly helps braking at high speed, what about braking for a corner that's 45mph, such as Laguna Seca T2? As the speed diminishes, the potential for engaging rear ABS would increase, as rear downforce, drops exponentially.

Will you guys be testing this in a sprint race/hot lapping HPDE type scenario? I understand the purpose of a one (or two) lap wonder, but I'd like to know how the system can tolerate a 25 minute session. No doubt the increased rotor mass and surface area is key, but where is the actual failure point?

Cheap maintenace! Love it.

[OkieSnuffBox]

Originally Posted by Rafi@RR-racing

Updated the OP. Weight savings is combined.


I wish we could save 15lbs per corner but I don't even think a ceramic rotor will get you there!


Rafi

Thank you El Cunado. Now I just need to print off the template for the Stg II front kit to see if it fits the 18x9.5 ET 38 RPF1s......because that's a hell of a price.


Another question, if someone wanted to run different pads than the included BP-10s, would you be willing to discount the cost of those BP-10s to put toward another pad?


I know Flyin' Miata does this on their Wilwood based kits.


Are Hawk and Wilwood the only brand of pads you carry?


Thanks!

[Rafi@RR-racing]

Originally Posted by OkieSnuffBox

Thank you El Cunado. Now I just need to print off the template for the Stg II front kit to see if it fits the 18x9.5 ET 38 RPF1s......because that's a hell of a price.


Another question, if someone wanted to run different pads than the included BP-10s, would you be willing to discount the cost of those BP-10s to put toward another pad?


I know Flyin' Miata does this on their Wilwood based kits.


Are Hawk and Wilwood the only brand of pads you carry?


Thanks!

Yes, if you go to our website, you can choose a number of pad options from street to all out track pads from Wilwood and Hawk, and you get full credit for the base BP10's. We only stock Hawk and Wilwood. Between those two brands, there are so many great compound options, we don't see the need for anything else.


Stage II will require a spacer to fit with RPF1's 18x9.5et38. RPF1's are a great wheel, but they have very poor caliper clearance. Enkei PF01's are much better for caliper clearance. Stage I's should fit your RPF1s, but please verify with the template.



-Rafi

[Rafi@RR-racing]

Originally Posted by CSG Mike

Would you be able to make the iron sleeve an option? Increased thermal capacity is my concern; weight reduction is a nice bonus, but even a mass increase is okay if the thermal capacity is increased. Overall inertial changes will likely be minimal given the location of the increased mass anyways.

Do you have any data on how the bias change benefitted Phil's car? Downforce is highly variable, even with the rear bias, the dynamic grip balance of Phil's car changes depending on speed. While the rear bias certainly helps braking at high speed, what about braking for a corner that's 45mph, such as Laguna Seca T2? As the speed diminishes, the potential for engaging rear ABS would increase, as rear downforce, drops exponentially.

Will you guys be testing this in a sprint race/hot lapping HPDE type scenario? I understand the purpose of a one (or two) lap wonder, but I'd like to know how the system can tolerate a 25 minute session. No doubt the increased rotor mass and surface area is key, but where is the actual failure point?

Cheap maintenace! Love it.

First off, Phil does run full HDPE type sessions when testing, so its more than just a few hot laps.


I am not sure if you where following Phil's thread and the ABS/icemode/bias issues he had with the STi Brembo and OEM setup he was running. Once we installed our STage II rears, I know that even in the slower braking zones we had no ABS engagement issues.


Due to tire setup, power, and downforce variations, there is going to be a lot of variation in the "ideal" setup. We will work with you guys to get to the ideal setup, even if it means swapping calipers -- we will do all this for minimal cost.


For a light car like the BRZ, these rotors are massive at 13x1.25" (approx. same as Essex endurance kit). They are directionally cooled and have a wide gap for excellent cooling. They are exactly the same rotors as used on NASCAR Winston Cup and ARCA cars which are significantly more powerful and about 800lbs heavier than a BRZ... so I am 110% confidant they will hold up to a 30min HPDE session.

Rafi

[Element Tuning]

Guys I'll fill in briefly for now until I'm on a PC and have a little more time. First off the quality of the parts is amazing. When RR approached me I told them they had to build a kit that improved the bias and that I wouldn't accept any marginal or questionable components. I shared my experiences with the oem braking system, with various race pads, with Brembo front and various pads, all while running "street" track tires plus race compound, no downforce, but with suspension mods. Then we did a ton of testing with downforce, more suspension mods, and all the above senarios. At that stage of development I had a solid understanding of what was happening and what we needed. I was able to communicate and push RR Racing to step out of the comfort zone and fix the poor factory mechanical bias.

As you increase suspension modifications you will end up with less front weight transfer even without DF. That alone will allow more rear braking. Increasing roll stiffness with bigger sway bars also results in one side of the car getting less wheel pressure as the other when trail braking. The heavy oem front bias easily overpowers the front and when you lighten one wheel too much it's easy to enage front ABS because it's doing too much of the braking. Now take it up a notch and add race tires and lots of DF and you have the ability to massively compress your braking zone. The factory brake force distribution becomes much too slow at transferring rear brake torque. This is what I needed RR to fix! We had to take some of the front brake torque away and shift it to the rear to balance the system better "mechanically" so I didn't have to rely on the electronics so much....mostly because it constantly failed me (ABS turns off which leads to mostly front bias or "ice" mode which removes most brake torque). When the ABS failed the car was un-raceable and frankly I couldn't even drive it at track day speeds. Now with the RR kit the car is still raceable even when the ABS fails because it's so much more balanced.

The balance is still safe! In fact I want even more rear brake torque but I should be able to tweak the pad compound or maybe resort to a driver adjustable bias valve.

The brake power is massive and you don't need much pedal pressure and I'm only running BP30 race pads. Pads are massively thick so they are excellent in terms of wear and heat capacity.

It's nice to have a parking brake also even if you couldn't use it for drifting but if you're a drifter you don't need this kit anyway

I wanted a real redesign of the braking system and that's what RR Racing developed for us.

[Rafi@RR-racing]

Originally Posted by Element Tuning

Guys I'll fill in briefly for now until I'm on a PC and have a little more time. First off the quality of the parts is amazing. When RR approached me I told them they had to build a kit that improved the bias and that I wouldn't accept any marginal or questionable components. I shared my experiences with the oem braking system, with various race pads, with Brembo front and various pads, all while running "street" track tires plus race compound, no downforce, but with suspension mods. Then we did a ton of testing with downforce, more suspension mods, and all the above senarios. At that stage of development I had a solid understanding of what was happening and what we needed. I was able to communicate and push RR Racing to step out of the comfort zone and fix the poor factory mechanical bias.

As you increase suspension modifications you will end up with less front weight transfer even without DF. That alone will allow more rear braking. Increasing roll stiffness with bigger sway bars also results in one side of the car getting less wheel pressure as the other when trail braking. The heavy oem front bias easily overpowers the front and when you lighten one wheel too much it's easy to enage front ABS because it's doing too much of the braking. Now take it up a notch and add race tires and lots of DF and you have the ability to massively compress your braking zone. The factory brake force distribution becomes much too slow at transferring rear brake torque. This is what I needed RR to fix! We had to take some of the front brake torque away and shift it to the rear to balance the system better "mechanically" so I didn't have to rely on the electronics so much....mostly because it constantly failed me (ABS turns off which leads to mostly front bias or "ice" mode which removes most brake torque). When the ABS failed the car was un-raceable and frankly I couldn't even drive it at track day speeds. Now with the RR kit the car is still raceable even when the ABS fails because it's so much more balanced.

The balance is still safe! In fact I want even more rear brake torque but I should be able to tweak the pad compound or maybe resort to a driver adjustable bias valve.

The brake power is massive and you don't need much pedal pressure and I'm only running BP30 race pads. Pads are massively thick so they are excellent in terms of wear and heat capacity.

It's nice to have a parking brake also even if you couldn't use it for drifting but if you're a drifter you don't need this kit anyway

I wanted a real redesign of the braking system and that's what RR Racing developed for us.

Phil... thank you for this post, we really appreciate all the input you had into developing our Competition kits.


We previously worked with Phil on a Cusco sponsored Toyota GT86 Custom Borg Warner EFR Turbo we built which utilized one of the first Element Hydra EMS ecu's, and walked away impressed with Phil's support and knowledge... so when it came time to develop the brakes, it was a no brainer who we should be working with.


Phil.




-Rafi

[Panman]

Originally Posted by Rafi@RR-racing

Yes, if you go to our website, you can choose a number of pad options from street to all out track pads from Wilwood and Hawk, and you get full credit for the base BP10's. We only stock Hawk and Wilwood. Between those two brands, there are so many great compound options, we don't see the need for anything else.


Stage II will require a spacer to fit with RPF1's 18x9.5et38. RPF1's are a great wheel, but they have very poor caliper clearance. Enkei PF01's are much better for caliper clearance. Stage I's should fit your RPF1s, but please verify with the template.



-Rafi

I can verify from using the template that Stage II will not clear RPF1 17x9 +35. I'm looking to order a Stage 1 front set - I track 3 times a month - HPDE, Regularity and getting back into Motorkhana/Khanacross - the kit looks like it will do exactly what I need with good value consumables and good upgrade path. Rafi has been great to deal with so far!.

[OkieSnuffBox]

Yeah, I'm looking to ditch my 18s and go back to a 17 with better brake clearance.


Likely the TC105n.

[wizzo]

These kits look brilliant, and the price is fantastic!

Its amazing how you can initially buy the kit for a great price like the stage 2 kit, and once you are done with the first set of rotors, you can upgrade to your floating rotors and have the stage 4 kit!

So how is brake bias with only the front kit installed? To maintain break bias is the rear kit also required?

[Rafi@RR-racing]

Originally Posted by wizzo

These kits look brilliant, and the price is fantastic!

Its amazing how you can initially buy the kit for a great price like the stage 2 kit, and once you are done with the first set of rotors, you can upgrade to your floating rotors and have the stage 4 kit!

So how is brake bias with only the front kit installed? To maintain break bias is the rear kit also required?

Exactly! We wanted to make everything upgradeable because we know that everyone is on a budget, especially the guys who race (the guys who take their cars to shows don't wear out parts, so they can afford to buy shiny Brembos:-)


Anyway, bias with the just the front rotors is good because we actually undersize the front caliper piston area compared to stock (unlike STi Brembos which oversize and create a big bias problem).


A few more things to consider to maintain bias:


(1) If you have solid rotors in the rear, and you are considering some serious track time, you should really consider the rear BBK upgrade as well. OEM Vented rear rotor cars can delay the rear upgrade.


(2) If you run front pads with a friction coefficient of X, make sure you are using an equivalent pad in the rear. A lot of folks don't swap our their rear pads because they don't wear out, but you can create a bias problem if you run aggressive street/track pads up front, and street pads in rear. Look up the friction coefficient chart for your pads, and try to match up the front and rear.


(3) If you track your car, you can get away with just a front BBK for a while, but the faster you get, the more heat you will put into the front brakes.... the most effective way to reduce front brake temps (other than direct air ducts) is to shift bias rearward with one of our rear BBK's.


-Rafi

[babykwiss]

Anyone know if stage 1 will clear RPF1 17x9 +35 without running any spacers?

[Rafi@RR-racing]

Originally Posted by babykwiss

Anyone know if stage 1 will clear RPF1 17x9 +35 without running any spacers?

I am almost 100% sure the RPF1 17x9+35 will clear the Stage I's. You can download the wheel fitment template in the product description to be sure.


Rafi