OGRacing

iTrader: (1)

A fixed Caliper can promote less drag if the rotor your using is engineered correctly. i said before a solid iron rotor can move .07". that's on a rotor that is not engineered to prevent coning. a full floating rotor will allow the rotor to grow outward and not cone.

if you have a rotor that likes to move around then you need to have a floating caliper. a good example of this is the GM 10 bolt with C- clips. i have plenty of guys that club race on one of those (american iron). the axle moves around almost .5". that means the rotor moves around .5" it's impossible to use a fixed caliper with the rotor moving so much. The only option there is to run a floating caliper, or to switch to a floating axle.

PiazzaT

iTrader: (1)

Here in norway we have to use calipers that have been used on road legal cars if we want to legally upgrade the brakes (custom adapters are legal) Any recommendations for calipers that would fit under a 15" wheel?

Tommy

Jeffbucc

A little late on posting my appreciation for those DBA videos; but I am properly humbled on what I considered a "proper" rotor/pad change. I'm just glad I can cycle the ABS unit via VCDS on my Jetta otherwise I'd have been pushing nasty **** in it without an easy way to get it out when retracting the piston.

I had no idea that minor of deflection was amplified so much over time...crazy and scary.

I am considering a 4 wheel Wilwood setup fairly soon, will I be able to get a balanced bias, with the adjuster, having the same caliper/rotor size front and rear? Or am I looking at causing more problems than good by upgrading all 4 corners.

Mostly looking at it for:
-Reliability
-no brake pad taper
-ease of changing pads
-less unsprung weight
-more pad options
-get rid of the worthless parking brake(mine will not tension properly no matter what)

Anyways, appreciate it Johnny, I like being humbled, means I hopefully start making mistakes less frequently.

sixshooter

iTrader: (12)

This kit allows you to use the stock calipers with 11 inch VW corrado rotors instead of factory 10 inch rotors. It is a noticeable improvement in force and fade resistance over stock rotors. Miata M-Tuned Big Rotor Kit
If you are limited to a stock caliper that is the easiest upgrade. The rear kit offers a larger diameter rotor under the stock caliper also.

PiazzaT

iTrader: (1)

Takk for the answer.
I would like to usedvanlig a 4piston design. I have looked at the Mazda FD calipers but am unsure If I'det bedre better of with a different choice regarding strength and pad choice.

sixshooter

iTrader: (12)

The stock calipers are easier because there is a kit for them. It works pretty well.

OGRacing

iTrader: (1)

I wouldn't recommend a Fixed (rx7 4 piston) caliper without a 2 piece rotor. Ideally i want to see a floating rotor. Single piece rotors move around too much under braking to use a fixed caliper, it would be best to stick with the oem floating calipers. I'm not sure if the Rx7 calipers are a direct bolt on, but with a single piece rotor i'm afraid it would cause too much drag and hurt the performance rater than increase it. With your country's laws it seams your screwed. My advice would be to use the 1.8 brakes and get yourself a quality set of pads.

OGRacing

iTrader: (1)

Morning Jeff,
The combo that i would recommend would be the V8 roadsters kit, or the track speed kit. in the front. I would love it if someone would make the rotors floating with the addition of a rotor flange. like this one form joes racing.




In the Rear
I wouldn't recommend kits that Put a non-Floating caliper on a solid 1 piece rotor. As i said before a non Motorsports rotor can flex in excess of 2mm under braking. this Kills power, straigt line speed, and overheats the braking components. the Solid rear rotors on a miata can flex a TON!! if we are going to keep the solid rear rotor it's best to use a floating caliper.


We Run a track speed 11.75" F kit, and Good win racing upgraded stock calipers in the rear. this provides ample rear tq to trail brake a 2400lbs Ls1 miata. Generally the ls1 cars have a higher rear weight balance. (Ford 8.8, larger battery, extra mufflers). that Extra rear bias should require more rear rotor to acquire balance. we find that the Sport rotor with a Stock rear caliper gives ample performance while keeping the parking brake. a larger rotor would last longer though.

DeerHunter

I guess this wouldn't adapt to the Goodwin or V8R kit. How hard would it be to get one produced for our cars?

Jeffbucc

Agreed on the floating rotor. OR I should say I don't doubt your knowledge on the matter. Apologies for not being more specific on which kit I was looking at, but in reference to what I am currently favoring, what about the newly updated design of the rear rotors in the version-4 Goodwin 2-piece rotors Big Brake Kit?

A vented 10.75" DBA5000 rotor on the rear in a 2 piece design. Is this very obvious motorsport application rotor design not enough to dissipate it going out of "threshold"?

Not questioning you, merely intrigued on your opinion with this particular specification.

*edit* I'd love to run the TSE 11.75" kit, but unfortunately My Konig Flatout 15x8 have clearance issues in the barrel.

OGRacing

iTrader: (1)

Calipers.
FYI
Piston count means nothing. how many pistons you have means 0.00000 to performance. Going form a 1 piston to a 6 piston will not increase your performance AT ALL!! there is a knee in the graph, but generally speaking the more pistons you have the worse a caliper gets. a caliper needs not to be judged by piston count but instead by rigidity, and piston size.

Pistons,
Everyone remembers the digital Camera war of Megapixels. the marking men said this camera has 4 pixels and that's better then 3 pixel. when in fact the amount of pixels it had meant nothing. it was a trick to get people to buy the next model. Brake manufactures have done the same with piston counts. They say "OH look a 8 piston!! buy now!!". The fact of the matter is this - the more pistons you have the worse your fluid will travel to all the pistons consistently. We found that the ideal number of pistons to have in a fixed caliper is 4. 4 pistons push evenly on all edges of a pad, and it can still keep consistent fluid pressure. we have also found that more pistons you have above 4 the less consistent a caliper becomes with fluid delivery to each piston. The only time we've seen 6 pistons be better performers then 4 pistons was is the size of a caliper was an issue. in NASCAR, we use 6 piston caliper to clear that tiny 15" wheels. for 90% of the applications out there we don't need to worry about that. so that 8 piston caliper you've been eyeing... run away from it.





Rigidity
a caliper is only as good as how stiff it is. a solid caliper can be felt in the peddle. time after time the peddle can be relied on to be in the exact same spot. If your reading this and not agreeing then your system is in desperate need of improvement. flex of the caliper is the same as the flex in the lines. people go crazy with stainless brake lines. they do this because it improves peddle feel. Unknowingly, they swap the stainless lines onto a caliper that flexes. the stiffer a caliper is the less it will flex. A flexing caliper requires the pistons to travel further to apply the same amount of pressure. the extra travel in the pistons means the pistons are moving further out of the bore. they will need to travel further back into the caliper to be able to remove pad pressure off the rotor surface. A caliper, let me restate that. a Good caliper has square O rings. these square O rings retract the pistons only so much. for example lets say 1mm. if a caliper flexes and the pistons need to travel 1.1mm that means the O rings cannot retract the piston, and you will still have residual brake pressure on the rotor. that residual pressure is creates drag. The Drag is acting like the brakes are still on. imagine you heading down the back straight. how much more MPH do you think we can get if your brakes where off.



Piston Size.
we have gone over this before, so i wont go too in depth about master cylinder ratios. i will focus on the pistons themselves. Everyone overlooks the piston size. so your calipers are a 12 piston.. your pistons must be the size of dimes. that's not a good situation. When looking at a fixed caliper we want to see 4 large pistons. this gives us the best hydraulic advantage.

OGRacing

iTrader: (1)

it has an 8x7 Bolt pattern just like the rotors we use on the track speed/V8r kits.. if the rotor flanges clear the hat, and we space the calipers it should bolt on.


IF that's the kit that will fit with your wheels, and you don't want to change your wheels then.... that's the kit your going to get... right?

as a Professional brake guy.. on a miata I want to see a rigid 4 piston caliper, with the largest rotors that will fit under a 15" steel wheel, with some big nasty slicks. Thats what i want. what I want and what is piratical are two different things. For those of us that street drive we need a parking brake. you can go without it, but it would make life annoying. allot of miatas are wight conscious so we cant run steelies. on that particular kit would be good for a street driven car with slightly higher then normal hp. if your looking to make a track car with 250+hp i would recommend more rotor. it is a good starter bbk. i started with good wins full kit. I still have good win's rear rotors on my car. so you can upgrade to the 11.75" rotors later if you feel like more power. I would also recommend getting a set of race pads with it for track days. I've burned up the perter fields that come with it on a track day. I get negative props whenever i post up a link to race pads. so pm me if your interested.

drsourmonkey

Kind of a silly question, but what is the best way to bleed brakes (MC and calipers)?

I know there's people that swear by the motive pressure bleeders, and others that say they suck. I usually have someone pump the brakes while opening/closing the bleeder, but this takes time, and I'd rather use a pressure bleeder because of laziness.

Just thought it would be cool to get advice from an expert on the proper way to bench bleed/bleed brake systems.

Jeffbucc

When I make the decision...we'll have some discussions.

Also, damn your well executed common sense on not basing your stopping performance based on being cheap and not getting wheels to work for them. Looks like I'll have a for sale thread once the new 15x9 6UL's come out...

OGRacing

iTrader: (1)

I've heard only good things form the motive pressure bleeders we sell. I don't have one and just use the old "get-the-wife-in-the-drivers-seat-and-make-her-work-the-brakes" trick

I try to get straight to the point. Ever since we started this "lets ask the brake nerd" stuff, i haven't had a second to take my time with it. we posted this topic on 4 forums, and on the OG Blog. I don't have any time to sugar coat anything, i do apologize if it ruffles feathers.

Ryephile

iTrader: (1)

The Motive power bleeders make brake bleeding a quick & easy 1-man job. Once you get the hang of them they make zero mess, end up with zero air, and a perfect reservoir level when you're done. I've been using them for a decade now and haven't looked back.

Jeffbucc

Dude, this is MT.net, that is sorta the design of the website

Ruffle away. I hate sugar coating, it is a waste of time.

Landrew

iTrader: (2)

Actually when I get my Krispy Kreme hot-n-fresh donuts I get 6 with glaze and 6 right from the oil with no glaze. Make a double decker with 1 glaze and 1 non glazed and you get the perfect amount of sweetness.

Some sugar coating but not to much.
Can you comment on regular passenger cars and trucks? I know it's not race car territory but we all drive them to some degree on the streets and we expect good performance there as well.
I picked up some HP performance pads for a minivan and pickup truck and was not impressed. Can you recommend a brand with good initial cold morning bite and still some fade resistance? Let me also state that I replaced rotors but went with the bottom of the barrel brand when I did so perhaps further compounding the issue.

Jeffbucc

I have Hawk HPS pads on my TDI and love them. Good initial bite and modulation, definitely too soft for the track, but for daily driving I love them.

Granted, my TDI has stainless lines and a few other goodies helping out, but I've never had "upgrade envy".

No squealing/squeaking either.

OGRacing

iTrader: (1)

Cold bite - and fade resistance will be tough to find. dare i say not existent. If your lucky-enough for PFC to have your pad shape then i would recommend the PFC .10 compound. we had U-haul, Penski, Ryder trucks, Iowa police department, CHP, IL State troopers, ect.. all use the .10. when it gets hot it grips, really grips. it's a street pad so it doesn't dust to much. the cold bite is numb (anything under 100*), but it will take a 1600* rotor temperature before it starts to fade. 1600* is higher then the dtc-60 will take, but the dtc 60 will have a higher tq. The only problem with the .10 is that pfc only makes it for fleet vehicles. Big trucks, police cars, F-150 and so on. shoot me over what vehicle you have and i'll see if they make a pad shape for your rig. ive tried the Hawk LTB on my jeep. I am not very excited about the performance from those.