AP Racing, Freaky Parts, 996, Cooling? School me on BBK to help pad consumption

[Estoril]

Appreciate these pointers! I've had very little instruction at Shenandoah, and wasn't being instructed in this video, so definitely have some to learn. Interesting on T11 and T17, what you're suggesting are things I played around with but found them slower when comparing using my Catalyst. What groups do you drive Shenandoah with? Would be great to get out there at the same time and talk shop.

I'm there with BMWCCA (NJ and NCC), PCA, multiple SCCA, and in Fall with 1 MBCA. If you want to sync an event, just PM me.

[Pklauser]

Played around with some sheet aluminum today, inspired by Vorshlag. Their plates are mounted to the control arm, but after doing some playing around, I actually think it makes more sense for the plate to be mounted to the knuckle. Here's how things sit right now. I think the plate can come down slightly, or at least should probably be trimmed on the top so it's not pushing air against the surface of the rotor. This setup is painfully simple, which gives me confidence in it not causing me problems on track, though we'll have to see how well that bend in the aluminum holds up at 130+.



Initial scientific aerodynamic testing performed by me blowing at the fog-light area with my spot blower has air pushing out of the rotor vanes that I can feel with my hand. Definitely didn't have that before this plate, so there should be at least some cooling improvement here!

lol you ever do something and think, "I'm a dumbass"? Who sees what's wrong with mounting the duct to the knuckle there?

[Estoril]

lol you ever do something and think, "I'm a dumbass"? Who sees what's wrong with mounting the duct to the knuckle there?

There is no way that I'd have a sheet metal edge within shouting distance of my brake line. And I'd assume that sheet metal could be struck by debris and moved or cut.

[Pklauser]

There is no way that I'd have a sheet metal edge within shouting distance of my brake line. And I'd assume that sheet metal could be struck by debris and moved or cut.

Not entirely wrong, but not what I was going for. Fwiw in that picture the caliper is hanging and the line is out of the bracket as well, so it wasn't that close when actually put together.

I did all my testing and fitting with the damn car in the air, totally forgetting about the suspension compression effecting the alignment of the guide relative to the air guide from the bumper. ☠️ Back to the drawing board. At this point I may just pony up the money for the Vorshlag kit. Spent enough time on this.

[Fresh1179]

Here is my suggestion, and this is based on going through a couple of different BBK sets in the front. This setup takes into account some economical factors as well, because you start getting into some super expensive consumables. Chewing through pads can be a combination of factors, including brake technique etc. I remember someone on here saying that VIR is easy on pads, which is certainly not correct, or certainly not correct in my experience running 1000's of laps there. Ultimately, I would suggest that you chose a pad for it's characteristics that fit your driving style to go along with car.

For example, I went on the same route as you did with the DTC-70, DTC-60 split so I could save on consumables from FCP Euro. I purchased the StopTech rear and front rotors to go with them. I ran this setup for a couple of years. What you get from that setup is a ton of initial torque, as the pads are "grabby." Some people complain about the release and modulation characteristics, but I tend to disagree that is an issue, especially when you get used to them after a couple of years. To me, despite hating the pads for the slag and other rotor wear reasons, they are still solid pads when you consider the FCP bonus.

Here is my suggestion. Pay for the AP Radicals in the front. Make sure you get the larger thickness pad calipers, not the 18 mm caliper I purchased. That was a mistake on my part. The other caliper has a 24mm (?) pad. This will be a big financial commitment, but you will not regret it for a second. Hard Motorsport (ugh) makes a 355 backing plate that does deliver the air to the center of the rotor veins, not a spot on the rotor which is absolutely crucial for both pad wear, heat, rotor wear, and brake temp fluid. Get the Stoptech slotted rotors and a pair of DTC-60's for the rear from FCP. Install rack limiters on your steering rack and you can pipe a 3 inch hose directly from the front fog light blanks to the backing plates. You will not have issues chewing up your hose with limiters. I like SRF because of the firm pedal feel, but Brembo and Endless make really good fluid. This is the setup I ended up with, and yes, I run DTC-70's in the front. I can get 6-8 days out of an 18mm pair in the front. Is that great? No. Is it horrible? No. As an aside, I have run through about 5 sets of pads in the fronts and my front rotor rings are just now looking like they need replacement.

I think if you wanted to upgrade down the line, you could go 996 in the rear to match, but our rear brakes are actually very solid, especially with a rebuild and some bronze bushings. I think upgraded rears are more of a convenience than a pure performance issue. I am sure you probably experience this yourself, and it is alignment related to a certain extent, but you will be dancing around like no other with the DTC combo in the hard breaking zones haha.

[Pklauser]

Really appreciate your thoroughness Fresh1179, sounds like we've gone through a similar journey and you appreciate the consumable expenses. Couple of questions and comments:

Fwiw I too like the feel and modulation of the DTC-70s, I don't find it offensive, though I do agree, the dust/slag is pretty rough.

What is appealing to the StopTech rotors over Zimmerman blanks to you?

Is the reason you recommend 25mm over 18mm about pad costs, longevity, heat capacity, what exactly? I ask because my 17" Arc8s are going to require even more spacer if I go with that larger caliper. Not ruling it out, but the cost delta between a set of RS4s in 255/40R17 to 265/35R18 is nearly $500 so factoring all of this into it, not to mention needing different wheels. Swapping to the Bimmerworld 17s will give me more clearance, but again that will effect the economics of the whole thing.

Where did you buy your AP Radicals? I see Essex has their CP9668 (25mm) kit here at $5399 and CP9660 (18mm) kit here at $5099, each with 355mm rotors. I can't just walk by N15 design though who has comparable kits for $4290 $3890 respectively.

Were you running ducting throughout all of your BBKs? I hear you on limiters and hose, but I also plan to keep this car streetable and I'd really rather avoid dealing with hose. To be honest I figured going with a 355mm and those big Radicals, you would negate a lot of the need for hose, but it sounds like maybe that's not the case? What is your take on the Vorshlag approach?

[Maxhouse97]

OP referred to me in the original post, so wanted to clarify where I ended up:

- Front: FreakyParts Megane front on 360mm E90 rotors for a bigger heat sink, Volvo S60R Hawk DTC-60 pads from FCP, SS brake lines, Vorshlag brake cooling ducts. Minor rust ring, not very noticeable.
- Rear: 996 with Rally Road brackets on CSL rotors, base DTC-60 Boxster front pads from FCP on rear to prevent rust ring. SRF fluid all around. 996 are noisy under certain conditions on street, could be the pad.

This worked to 85% effectiveness (minor fade) my last track day minus brake ducts and SRF (used Motul 600), based on street experience I expect those two adds to get me to 100%. Headed to Mid-Ohio this weekend. Was about $1500 for front and about $1000 rear. Very happy and looks great.

[Pklauser]

OP referred to me in the original post, so wanted to clarify where I ended up:

- Front: FreakyParts Megane front on 360mm E90 rotors for a bigger heat sink, Volvo S60R Hawk DTC-60 pads from FCP, SS brake lines, Vorshlag brake cooling ducts. Minor rust ring, not very noticeable.
- Rear: 996 with Rally Road brackets on CSL rotors, base DTC-60 Boxster front pads from FCP on rear to prevent rust ring. SRF fluid all around. 996 are noisy under certain conditions on street, could be the pad.

This worked to 85% effectiveness (minor fade) my last track day minus brake ducts and SRF (used Motul 600), based on street experience I expect those two adds to get me to 100%. Headed to Mid-Ohio this weekend. Was about $1500 for front and about $1000 rear. Very happy and looks great.

Thanks for that update Maxhouse97, eager to hear if the ducts and SRF get you there. I've been a Motul 600 guy as well, but maybe I'll make the jump. I'll be at Mid Ohio and PittRace in May with Chin if you're doing either of those events!

[Maxhouse97]

Back from the track, brakes worked great … unfortunately it was super cold (in the 40s and a little sleet, love OH weather). So will wait for the summer for a real test.

[Pklauser]

How's people's pad taper with brass guide bushings? I've got a Bimmerworld set, and honestly they still allow for a lot of movement, resulting in some extreme taper. Been wondering if moving to one of the "long" kits like: https://www.iemotorsport.com/product...-long-version/ would help at all. 🤔

[Estoril]

How's people's pad taper with brass guide bushings? I've got a Bimmerworld set, and honestly they still allow for a lot of movement, resulting in some extreme taper. Been wondering if moving to one of the "long" kits like: https://www.iemotorsport.com/product...-long-version/ would help at all. 🤔

I've used both - neither with any pad taper issue. I used old-school Turner IIRC. Suggest you check your pins for straightness and for marks that might suggest binding/rubbing. Make sure pad "ears" are 100% seated of course. If it continues, I'd pull the affected wheel(s) and make sure pads are reasonable placed and tight after multiple braking events.

Make sure your choice of brass bushings are a correct fit for the car and don't allow for excessive movement over the slider pin.

[t44tq]

I've said it before, but the 996 based kits simply don't have enough thermal mass- they're using the stock sized rotors.

Even the cheaper AP 8350 caliper kit uses 32mm thick rotors (vs. 28mm for stock sized rotors). That's a pretty big difference. Also, the vanes are better, the floating hat, etc.

It was mentioned already that you can get a version that has 1" thick pads- far longer lasting pads. Also, brake pistons and seals that are made for track use.

I don't think you need all four corners. The other big plus is the 8350 kit will fit under 17" wheels and definitely the stock 18s.

I would get the ducted backing plates for the front and duct the rotors.

[Pklauser]

I've used both - neither with any pad taper issue. I used old-school Turner IIRC. Suggest you check your pins for straightness and for marks that might suggest binding/rubbing. Make sure pad "ears" are 100% seated of course. If it continues, I'd pull the affected wheel(s) and make sure pads are reasonable placed and tight after multiple braking events.

Make sure your choice of brass bushings are a correct fit for the car and don't allow for excessive movement over the slider pin.

Having used a couple of these on different cars from different sources, FCP, Bimmerworld, it seems like they all come from the same supplier. I wonder if quality is going downhill. Someone at the track said he had a lot more play in his Bimmerworld set than his FCP set 🤷♂️

[Nate047]

OP referred to me in the original post, so wanted to clarify where I ended up:

- Front: FreakyParts Megane front on 360mm E90 rotors for a bigger heat sink, Volvo S60R Hawk DTC-60 pads from FCP, SS brake lines, Vorshlag brake cooling ducts. Minor rust ring, not very noticeable.
- Rear: 996 with Rally Road brackets on CSL rotors, base DTC-60 Boxster front pads from FCP on rear to prevent rust ring. SRF fluid all around. 996 are noisy under certain conditions on street, could be the pad.

This worked to 85% effectiveness (minor fade) my last track day minus brake ducts and SRF (used Motul 600), based on street experience I expect those two adds to get me to 100%. Headed to Mid-Ohio this weekend. Was about $1500 for front and about $1000 rear. Very happy and looks great.

Do you by chance have any close up pics of the fronts?

Also is it safe to assume your car is a lter build MK60 car?

[mrgizmo04]

First question those with brake issues should answer is whether you use any safety net from DSC, or its cousin MDM/M track mode on later cars. Latter is still way too intrusive and will jam the grabbies many bars of line pressure full force into the rotors as you start doing fun things (braking into a corner or full throttle accelerating out), keeping you out of the walls. Sometimes it is easy to butt feel it working but sometimes it is not. It will overwork (and potentially overheat) even the better setups out there and will make the brakes pop, crackle and smoke in the pits. You will also see miserable pad/rotor wear.

DTC70 are a SUUUUUPER grabby compound, I would not run them on anything less than the super 200s (RS4 are endurance). Engaging ABS introduces full line pressure pulses and vibrations that also put more heat into the system and pulverize pads/rotors.

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