glade

iTrader: (2)

I have 1000/500 on order to go with the new tire and brake setup. (as I develop the aero package, I might even jump up to 1200/650 ish)

I've had nothing but great experiences with V8R in the past, was just looking for more of a clarification regarding the path forward.

Thanks for the response!

HeavyD

I'm new to miatas and refreshed my brakes all around this past weekend with Centric rotors, Stoptech pads and fresh brake fluid. I adjusted the rear brakes (~6 clicks on ebrake) and bled the brakes two times with a helper. After bedding my pads I noticed a fair amount more dust on the lip of the rear wheels compared to the front. After the bedding I used an infrared thermometer on each rotor to verify I didn't have a faulty caliper piston. FWIW my overall braking isn't good.

So, it seems I have more rear biased brakes. I'm wondering how to address this. Should I try more aggressive pads up front or maybe a proportional brake valve?

This is a 95' street car with ABS that sees some auto-x. Speaking of ABS, I still cannot get the ABS to engage. Either during a drive (RS-4s) or while on jack stands. Thoughts?

ryansmoneypit

iTrader: (6)

99% sure you have introduced air into the ABS system. Or you arent pushing hard enough. do the tires lock up?

HeavyD

I read multiple threads about activating the ABS while on jack stands to free any air. I clutched off in second gear and lightly applied gas and brake. I didn't feel the typical ABS pulsing. Do the front wheels need to be spun as well or something?
I'm giving her all I got. The tires do not lock up. Maybe I should try on gravel or something. It brakes just not good. My CR-V has better initial bite right now..

ryansmoneypit

iTrader: (6)

This wont do a damn thing. If it did, we would hear abs units going off in traffic all the time. 30 mph, stomp on the pedal aggressively. Like you are trying to break the pedal. a gravel road would work well.

ABS to my understanding, will not start to pulse until it senses a wheel lock up while the vehicle is still in motion. It will not activate until a wheel stops turning when it should be.

HeavyD

I should have clarified.. I performed this while on jack stands. Not in traffic. I'll try a test or two on some gravel and re-bleed the brakes (assuming I can activate abs). Just for the record, since I'm new to these cars, the pedal should be pretty firm correct? It very likely could be air in the system since the pedal feel is kinda vague.

sixshooter

iTrader: (12)

There can be some caliper flex or there can be play between the slider pins and the caliper body allowing a twisting movement and tapered pad wear.

But ABS air can certainly cause sponginess.

Do both rears drag evenly? Sometimes I end up with earlier contact on one side.

HeavyD

The old pads that I removed had even wear from side to side. A comparison between the front and rear were about even, maybe the rear with less pad. I'm not sure if they were replaced at the same time though.
Yes both rears drag evenly. I tightened that hex screw then backed off a bit on both sides about the same. I'm hoping it is just air in the system.

codrus

Getting ABS to activate while the car is sitting on jackstands is tricky, it seems that it's got some logic inside it that watches your speed and tries to make sure you're actually moving in order to enable itself, and faking that out on jackstands is hard.

There is an ABS diagnostic procedure where you jumper a couple of diag pins together and do a little dance on the pedals. If you've got air trapped inside the ABS unit, you can use this to bleed it out.

--Ian

HeavyD

Yeah, I tried to bridge TBS and GND in the diag box. The ABS light would flash here and there, but I wouldn't physically feel or hear any indication as you would driving. The thread I saw was for an NB though, so not sure if it applies to an NA. If it is air, it's pretty frustrating. I'm sitting here typing trying think of a place close with some loose gravel.

aidandj

iTrader: (5)

When you do the diag procedure correctly it is very obvious. The pump activates like 3 times, its loud, and you can feel it.

OGRacing

iTrader: (1)

do you have the swept area of the rotor your using? pfc has a lot of 79mm wide pads.

HeavyD

This was with your NA I take it? I used a simple paper clip, ignition on, then step on brake, this sufficient? What did you do differently with the pedal or procedure?

ryansmoneypit

iTrader: (6)

These latest brake issue trouble shooting posts are ******* up the best brake thread ever.

HeavyD

Your right I'll carry this on else where.

codrus

Also, if you have codes in the ABS computer then it won't activate the diag procedure. You need to clear the codes first.

--Ian

mekilljoydammit

All right, here's a weird one... I've been driving a T4 NC MX-5 which has frankly incredible brakes for fully production parts other than pads (running DTC60/30 but open to trying the Pagids after these ones die - think that would be worth anything? That's besides the main point though) One of the things I'm seeing is that the ABS will actually handle Hoosier R7s, and apparently they ran it in the last gen MX-5 Cup cars as well. I really like not flatspotting $1k worth of tires.

So, going forwards, I'm building an NA to run on R7s in a different class with less weight, more power and with aftermarket brakes allowed. From what I can tell it should be possible to swap the NC ABS computer, given the correct tone ring tooth counts and all. Will it work with balance bar'd dual masters or am I better off using some version of the vacuum booster/tandem MC?

jpreston

iTrader: (4)

The NC ABS system needs communication with the engine ECU through the CANBUS, so I don't think it would be possible to run it as full standalone in an NA/NB. Haltech is currently working on configuring their Elite 1500/2500 ECUs to fully integrate into the NC CANBUS, so once they get that up and running, you might be able to run an Elite ECU and NC ABS in your NA with the NC ABS config settings.

Another option is the RX8 ABS. I don't know much about it, but it's supposed to be very good, and the 04-07(ish?) non-DSC cars had a full standalone ABS system that doesn't need CAN communication. (I have not confirmed this myself... just read it on the internet somewhere.)

mekilljoydammit

I should have known that wouldn't go unremarked upon, heh. I'm intending to sniff the CANBUS messages going between the ABS module and the ECU on my current car before I buy anything either way but unless I come across someone with firsthand knowledge who says otherwise, I have a strong suspicion that in operation, the ABS module is mostly just sending data. I've found forum posts from Tim Buck at Mazdaspeed saying that at least the MX-5 Cup and RX-8 ABS modules are the exact same part (I haven't looked up the part numbers yet) and another set of forum posts from someone who did integrate the ABS pump and had it work.

*edit* Part numbers don't match not does appearance - however old MX-5 Cup used the non-DSC RX-8 module. So there's that, problem solved. Still doesn't change my question on what the best way to feed it pressure is.

*second edit* OK, so the non-DSC RX-8 used a different module from everything else, and I confirmed from the shop manual that it shouldn't need CAN to do useful things, while the NC probably does. Pirelli World Challenge VTS for the MX-5 gives the right part number and pics of the right RX-8 pump (which is why it's the same PN as the RX-8) so I just ordered one. Moving on.

OGRacing

iTrader: (1)

E46 M3 ABS units can be used as a standalone. I've had many installed into Corvettes. The Corvette, ABS and bais are both tied together. They are constantly interfering with performance or going 100% shutting the brakes off and going into ice mode (crash).