mx5cartalk.com

Hi guys

Just wondering if anyone out there is running DBA 4000 T3 Slot design with Carbotech XP Pads.

I have had issues on my SE with material buildup around the slots causing the brakes to vibrate upon application.
The pads bedded in fine(they left the multi-colour transfer layer carbotech pads make), then after a few hard track sessions they just leave massive deposits around the slots. I sand and wire brush it back after each track day/supersprint I have done, but it just keeps happening.

I'll take some pics after the supersprint this weekend to illustrate what I mean.

I drove Marks car with XP12's and it had no such problem, but it had the older 6x6 DBA 4000 design. I believe he had XP10's before the 12's as well.

I'm leaning towards the material not liking the slot design, but would like to here other experiences, unless of course I'm using a unique combo.
I have emailed Carbotech and am awaiting a response, may send one to DBA as well.


On the plus side however the wear rate is much less than the Hawk Blue's I was using before for both Pad and Rotor, while having similar braking capability. I would already be at half life on blues, and I have not even worn 25% of these things yet.

you will probably get a response to switch to blank rotors. this is what 949 recommend who sell the pads.

Carbotech XP pads are known to be dusty so accumulation in the slots shouldn't be unexpected.

I got my Wilwood kit from 949racing a while ago and the rotors were blank, now I know why thanks to the previous post.

Off subject I know but I have just received a price on the Club Spec T3 4000 for the front rotors on my NC………..$480 for the pair.

My previous DBA slotted rotors lasted 55,000 kilometres before cracking and cost me $320. From my conversation with DBA the only difference is the heat treatment the T3 rotor receives.

50% additional cost for some heat treatment. Think I’ll pass.

I've never had the slots fill or had brake shudder on the track with either pad (yes I did run the XP10's first just moved to XP12's because they have more bight). I doubt it's the rotors though , maybe Carbotech changed compound and it's softer/more malleable. If you want I can send you some hi-res pics of the last set of rotors I took off the car, they have pretty massive heat wrinkles/cracks and the slots are getting a little...unslotted but there's no build-up visible.

What are your heat markers doing on the rotors? I usually lose only the first two now, before the ducts I installed though I was seeing rotor glow and the thermo paint was actually falling off. Perhaps the heat range you sit in is having an affect. I've always been ducted since I've been using carbotechs, I think I've seen as much as a 300C drop in measurable temps (skipping cooldown and getting the infrared gun on the front rotors). With the higher power and more weight of your SE you may be seeing silly high temps.

Mark, I've not only caused all 3 heat markers to change colour, I have actually burnt them off, after only 4 track days!!! I'm pretty sure they were pretty much burnt off after just the 1st use.
So silly temps could be looking like the case. Now how to measure it? I'll see if work will let me borrow the Fluke Heat Camera and the laser heat sensor for this weekend just to see what temps I am getting.

At the last track event when I borrowed a laser temp sensor I measured my rotors for fun well after a session and they were 250c. I then measured Phils Lotus who was in the same group as me and he was down at 50c. And this was a good 10 minutes after the session.

Out of curiosity now, how do I build brake ducts. Gather remove foglights and put some sort of pvc or flexi ducting through???

Oh and I payed $330 for the pair of rotors up front from race Brakes in Wetherill Park, but I gather NC will be more expensive.

Edit:
Oh yes and I got this from carbotech

Hello Luke,


It could be related to improper bedding, going over the temp limit of the pads or the rotor design.


Can you tell me exactly how you bedded the pads in? Do the pads appear shiny right now or do they have a reduction in initial bite or torque? Do you have any ideas of how hot the front pads and rotors have been getting?


Having pics would be great, looking forward to getting them and taking them to our engineer.


Thanks-

Looks like they are leaning towards temperature as well so far. I do know the pads did bed in fine. It was just after punishing them I started getting issues.

Just by way of comparison, I've got the same slot pattern on the smaller NA8 DBA 4000 rotors but with Hawk HP+ pads. There's never any significant dust build-up on mine. On the odd occasion when I've followed you around you're not stopping any harder than I am and I'm not getting very high temps at all. It makes me feel there might be something odd going on with yours. Might pay someone to have a good close look at them.

... and Phil's Lotus stops a lot harder than mine. That's the one advantage he's got over me.

Luke wrote:Out of curiosity now, how do I build brake ducts. Gather remove foglights and put some sort of pvc or flexi ducting through???

I have just had these installed

manga_blue wrote:Just by way of comparison, I've got the same slot pattern on the smaller NA8 DBA 4000 rotors but with Hawk HP+ pads. There's never any significant dust build-up on mine. On the odd occasion when I've followed you around you're not stopping any harder than I am and I'm not getting very high temps at all. It makes me feel there might be something odd going on with yours. Might pay someone to have a good close look at them.

... and Phil's Lotus stops a lot harder than mine. That's the one advantage he's got over me.

I'm also on road tyres (Ku36) while you are on full R-specs, which makes a fairly big difference in stopping distance.
Plus I'm coming into corners at much higher speeds due to more power, have more weight and less handling, so at Wakefield I have to brake at every corner except 1 and 9 so the brakes never really get a rest. Also have to brake into Turn 1 at Eastern Creek
Carbotech guy responded after my reply and he's saying I'm pretty much going over the temp limit of the pads, and XP12's would have been the better bet. Emilio at 949 said the XP10's would be as much as I need, oh well.
I have noticed slight fade at the end of supersprint sessions since they are a bit longer.

My ducts are really simple, just some flexible wired hose like the picture above and I just ran them through the undertray and zip-tied them to the swaybar endlinks. I only use 1 foglight as an air-intake and soon the other one will be an air inlet for an oil-cooler.

I had to cut away a lot of the dust shields though so the air ran onto the actual hubs.. I don't think I have any pictures.... I'll take some if I install the wilwoods this weekend .

Here are some photos of the brake ducts installed (I supplied them from Trackspeed Engineering, MX5 Plus installed them at the same time the rotors and pads were replaced).

Luke wrote:Oh and I payed $330 for the pair of rotors up front from race Brakes in Wetherill Park, but I gather NC will be more expensive.

Yesterday I checked the price for front T3 rotors for the NC and got the following quotes from these retailers per rotor:

Race Brakes $220
V Sport $216
RPM $220
Auto One $240

Now get this, I can import a pair delivered to my door from the US with a set of Hawk Blue pads for virtually same price as a pair of T3's bought locally.

Now I like to support local retailers where possible but when we make the rotors here in AU, ship them to the US, retail them at 56% of the local AU price and then I ship them back with the exurbanite US shipping rates and still save money, the local industry has to loose out.

It's the same with lots of good aussie made parts, Phil. Try buying ACL bearings here: 75% cheaper in the states.

Give Dean a call at Motorsport Essentials in Melbourne for DBA rotors, 03 9562 1005. Tell him you run with the NSW and Vic MX5 clubs.

Also try brakes direct

Sent from my GT-I9100 using Tapatalk 2

sailaholic wrote:Also try brakes direct

Sent from my GT-I9100 using Tapatalk 2

manga_blue wrote:It's the same with lots of good aussie made parts, Phil. Try buying ACL bearings here: 75% cheaper in the states.

Give Dean a call at Motorsport Essentials in Melbourne for DBA rotors, 03 9562 1005. Tell him you run with the NSW and Vic MX5 clubs.

Thanks guys but I've already order through the US. 249USD vs 440AUD was a no brainer.

Seems like we subsidise some the costs to the rest of the world.

We left Sydney the other week and duty free at the airport Wynns Cab Sauv. was $28 a bottle. Arrived at LAX and the price....$18!!!! And DJ’s, Myers, Dick Smiths, JB HI Fi, etc, etc, wonder why no one is buying their product locally and buying on line!!!.

In the US I found that everything (apart from food) was around 50% cheaper than we pay here. Admittedly our wages are higher but not 100% higher.

In New York you tip between 15 – 20% to wait staff. In AU we tip somewhere up to 10%. But wait staff are paid $5 per hour in the States vs $25 per hour here.
So where food at a 3 star Sydney restaurant (say Quay, Tetsuya’s) would set you back $600 - $700 for two with wine and a tip, in NYC it would be less than $500 with the 20% tip. So the 20% tip really doesn’t matter when you compare actual final cost of the meal, though it was still really hard to get your head around a 20% tip.