Arca_ex

iTrader: (10)

With the added power and weight of the V8 swap, your brakes will be working harder than a normal RX-8. The HP+ is a compromise at best. Not that great of street manners, and they are not really that great on track.

You will quickly outgrow the HP+ if you haven't already. You'll notice that about halfway through the session your braking power just seems to disappear and this is because the pads will be too hot and outside of their operating temperature.

Before you go through all this trouble of piecing together a big brake kit, try swapping pads first. It made worlds of difference on my car even with only 175WHP.

Chezmanbespoke

Appreciate the input guys,

Looking for some recommendation on what you guys think would be the optimal pad to use for this, keeping in mind that I will only use these brakes on the track, as I have switched the OEM brakes back into it after each lapping night.

I see Arca suggested the DTC-60's from Hawk, Ive heard lots of good things about the carbotech's , but looking on their site I see quite a range of different pad's, not sure which would be the best selection, quick reading through, looks like maybe the XP12 or XP20 would be a good selection?

I do have the front brake ducting setup in it, I dont think it does a huge amount, but maybe just enough to overcome some of the extra heat created with my weight balance shift and extra 60lb.

Heres another shot of the brake ducting, has been in there for a month and a bit so far, and no damage. For what its worth, the bright red paint on the caliper was completely baked off on my first lapping night lol

RIWWP

iTrader: (2)

If you go Carbotechs, start with XP12s. Their heat capacity is far above what you are currently using if HP+ is somewhat adequate, but their lower threshhold is still reachable on the street, which means you will be comfortably in the right range on track, with lots of room to grow.

Keep in mind though that if you go with Carbotech, you WILL need a 2nd set of rotors to use non-Carbotech pads if you swap back. Alternatively, you can use their 1521(?) pad that works with their compounds, or just stay on the XP12s (I do on both of my cars). Lots and lots of dust, plenty of squealing, but that doesn't bother me. Their warnings and cautions about not using other pads on rotors that have seen their pads is very much true. OEM pads on carbotech bedded rotors = more than 50% loss of braking capacity. I thought it was just marketing and was proven wrong in a rather pucker moment.

Arca_ex

iTrader: (10)

When you are swapping brakes make sure that you are swapping rotors as well and keeping all the positions the same. I know the Hawk pads don't particularly like it when they get contaminated with other pad compound.

Chezmanbespoke

I have a set of OEM pads & rotors that I was keeping together and another set of rotors with the HP+ pads, not using the same rotor for both pads.

In regards to the rotor, the set of rotors I have the HP+ with, was the economy rotors at my parts store, they have only been used on 2 lapping nights when I glazed the pads. Think I am safe to scuff them down real good and use them with the HP+ again (once their sanded) this weekend? I will do a proper bedding procedure to see if that keeps me from glazing them.

The car will be on the track friday night, saturday night and sunday afternoon this weekend so unfortunately the XP12's are out of the question for this weekend, but it seems like thats the way to go after this weekend, Ill have to order a set of them and grab another pair of front rotors to keep them with.

I mean... its only money right?

RIWWP

iTrader: (2)

Glazing is from the heat. You are exceeding the maximum threshhold the pad was designed for. The pad material is literally liquifying. You can't solve that through rotors, you need a pad that can handle the higher heat.

Chezmanbespoke

This is what my brake rotors have looked like after the first two nights (Not my pic, but the rotors looked identical)

https://i.imgur.com/giPV5E8.jpg

Reading on other forums, some point to a bad bedding procedure making them glaze over fast. A good friend of mine has HP+ in his '05 Rotary powered RX8, on the same track he runs 1:19 lap times without hurting his pads, but I can only manage a 1:28 while cooking my brakes.

Im sure some of it is my driving technique being bad, but I dont know if I am making them more likely to glaze with a bad bedding procedure?

I will have to bring a infrared heat thing to the track this weekend to monitor temps, but I am sure I will end up glazing them again from the heat.

Thanks for all the input guys! Im going to order some Carbotech's and maybe I can get a lapping night in before the season up here ends to see how it feels.

RIWWP

iTrader: (2)

Don't get hung up on what rotors look like after track use. Even with proper pads, they will still look something similar.

Arca_ex

iTrader: (10)

Oh the rotors don't even look that bad.


Also here, take a look at this and you will see why an HP+ is not really a track pad compared to say an HT-10 or a DTC-60.

Steve Dallas

Are hauling the car to the track on a trailer? If you are, you can use virtually any track pad--just be sure to warm them up on your first 2 laps before you trust them. If you are driving to the track, you need a hybrid pad that will actually stop you on the street. That is the main reason people are willing to tolerate HP+ pads.

If you want to stay in the price range of Hawk, their new Street/Race (DTC30) pad is a good compromise, with its much higher heat tolerance. It has a little too much initial bite for me, and modulation is not as good as it could be, but I still did fine driving on them for half a season. I also found running DTC30 front and HP+ rear to be a good combination. And, DTC30s will stop you on the street with no worries.

Lately, I have become a believer in Carbotech. I am running XP10 front and XP8 rear, and that seems to work well for me. The downside is the fact that they cost twice as much as Hawk.

9krpmrx8

iTrader: (46)

An they make your car sound like a Mac truck on the street, But that is kind of funny to me.

Gravey

iTrader: (3)

We should trade 8's for a day >.>

I need to get a ride in this thing!!!

Chezmanbespoke

You guys are awesome! Really appreciate all the help!

Gravey - I'll have to meet with you soon to let you check it out!! The 4.444 rear diff ratio definitely makes it a bit of an animal on the street haha, are you going to any meets soon? I'll be at CSCS at Shannonville Raceway sunday with it!



As far as driving it to the track, the rest of this season will be the last times it ever drives to the track, partly cause I hate street driving my R-S3 tires as they were expensive as **** lol. Im going to drive it down after work tomorrow to Toronto Motorsports park from work as I dont have a trailer available, but I will be trailering it to shannonville raceway for saturday night lapping and sunday CSCS race day.

Next year, It will be trailered to the track, and Ill convert it back to street spec when I want to street drive it. The car will be going into Phase 2 of its build this winter, where it will be setup to be much more track oriented. (And caged)

Thinking of ordering a set of the XP20's for the front soon, maybe leaving my HP+ brakes in the rear of it. Would love to have them for this weekend, but no way I will have time to get them here and installed.

The HP+ brakes definitely make an assload of noise lol, nothing like stopping beside a dump truck or school bus and being the one making the most noise haha.

Arca_ex

iTrader: (10)

Nooooooooooooooo. If he is switching pads/rotors then having to drive track pads on the street to an event is NOT a reason to compromise on pads. I have had both DTC-60's and HT-10's on my Miata and I can still stop it on the street just good enough that I feel completely safe driving it to and from the track.

Also don't mess with pad compound front to rear if you don't have an obvious problem with brake bias. If you put HP+ in the rear, you can see that at certain lower temperatures it will create a much greater coefficient of friction than the fronts if you had for example DTC-60 up front. So in certain situations (mainly street driving or your first couple of outlaps before the brakes get some heat into them) it's very possible to either lock the rears, or ABS will try to keep the rears from locking but really it'll make your brake pedal rock hard and you won't slow down like at all.

Steve Dallas

It seems to be a good reason for 90% of the guys who frequent my local tracks--myself included.

I'm not sure "just good enough" and "completely safe" escape cognitive dissonance.

Those are valid concerns, but the two combinations I recommended are proven to work together and are even recommended by their respective manufacturers. And, I have personally used both of them.

Chezmanbespoke

Well,

I raced the Canadian Sport Compact Series this sunday with it, was a ton of fun! Considering it was my 4th day ever being on the track, with my 3rd being the night before, I did alright with a 10th place!

The car ran and drove excellent, but unfortunately I had a pretty narly slide off the night before during practice, that took off the lip, under tray, fender liners, and brake ducting

Oh well! I suppose it was inevitable at some point, thankfully I didnt do any mechanical damage to the car.

Brakes didnt seem to come up as quite as much of an issue for me at Shannonville Raceway, as this track is a little more wide open and most of the corners I could reduce my speed enough with light brake use and engine braking.

Have so much to learn, seeing how well this car did in the hands of myself, with very little experience, and nothing more then some verbal pointers and watching youtube videos to learn how to drive on the track, It is definitely very capable of being a force to be reckoned with on the track! Just need to learn how to drive it there haha

The result of my slide off. There was a nice ditch at the side of the track, as apparently I am not the first to slide off at that section lol. Sad to see the car hurt, but it could have been worse.




Race ready:

Steve Dallas

Here is a decent article in Grassroots Motorsports about brake bias and why you might want less aggressive pads on the rear--especially with a car that carries more weight in the front, where weight transfer is greater during braking than it is in a more balanced car.

Chezmanbespoke

Thanks for the link!!!

I tried pushing my car a little more again, and have had a 0/3 luck for my brakes surviving to the end. Cooked them AGAIN! WOOOOO!!!!

I am planning to make some changes to the car to make it faster for next year, and I think I am going to update the brakes this winter just so its not a concern anymore. Spoke to a few engineers in high end motorsports and they have recommended I try to upsize the brakes if I have the means to.

Ordered a set of 4 Brembo 4 pot calipers for an 04-06 CTS-V and will have to design and have machined out brackets to fit them, and find a rotor that will work with it. Will keep this thread updated as I try to make that work, which maybe means someone can buy a brand new set cheap when i give up LOL


Only update to this car for now, is I am dropping panels off for paint tomorrow and THE CAR WILL FINALLY BE ALL ONE COLOR FOR THE FIRST TIME SINCE I OWNED IT!!!!

Arca_ex

iTrader: (10)

Should have tried some better pads first lol, the stock RX-8 brakes are pretty large for an OEM Japanese car. Some people like S2k's and RX-7's buy aftermarket brakes just to get up to the OEM RX-8 size. The HP+ are garbage on a road course outside of maybe the first or second time you're on track and not carrying any decent speed.

When you get all the new stuff in, get proper pads or you'll still be in the same boat.

NotAPreppie

Well, it's your money so I guess it's up to you if you want to waste it.

iwannarun

RX8 rotor size is pretty comparable to a C5. Same motor/trans and lighter car. I agree with the previous posts. Compound is wrong. You have the right size rotors. If you are just bored though perhaps you can develop a bracket to adapt the V or maybe C5Z calipers to it.

Steve Dallas

You will probably run into problems with the master cylinder and valving with those calipers. The best course of action would be to try some Carbotech XP12s on the front and XP10s on the rear and the ducting you already have for additional cooling. That should be all you need.

Hawk HP+ are only good to 800 degrees, which means autocross. If you are any kind of fast at all on the track, you will cook them in a hurry. You need at least 1200 degrees heat tolerance for moderate track use.

Take your cool-down lap(s) seriously, which means drive as fast as you can without using the brakes at all. And, if possible, jump out on the highway after each session and drive 2 or 3 miles away and back to cool them further. Those things make all the difference. Much of the cooking of a good brake setup happens after you park in the paddock--assuming the pads are in the right heat range for your application.

Chezmanbespoke

Holy ****! What a badass feeling to come across this article based off this thread!!


From Tired to Triumph: LS1 Swapped Mazda RX-8



To update!

The car is off the road for the winter now, beginning phase 2 of the build!

The plans for the winter:

-Ford 8.8 Differential swap
-More aggressive aerodynamics
-Rebuilding T56
-Re fabricating mounting kit to work with some plans for the motor

On the fence right now on whether I want to setup a small front mount turbo, like a 67mm with twin wastegates to get boost on early and give control over higher rpm exhaust flow to keep from choking the motor and having boost creep.

OR, to build a high compression N/A motor, with a lower lift cam that is better set for prolonged high RPM use in time attack.

I want to bring the car to TX2K16 and try to break 180+mph in the texas mile, I know I wont be able to do so with just a N/A motor, so if I go that route, Ill need to bring nitrous to that event lol

Heres the final few shots I got of the car before it got laid onto the surgery table for round 2 to begin

tylerdurden

Nice. Still on the fence about whether I want to do this too.

9krpmrx8

iTrader: (46)

Nice man, if you come to Texas please let us know.