mekilljoydammit

Does Coleman's floating rotor system work reasonably well? They seem like one of the easier ways to retrofit floating rotors to existing hats.

Leafy

iTrader: (1)

Is that the "drive bobbin kit"?

mekilljoydammit

I was looking more at the T-Lock mounting setup so you can use aircraft bolts and jetnuts, but either way.

psreynol

what specification "aircraft bolt" should one use for the hat -rotor ring interface, and where do you source them? I'm planning on using hats not compatible with the t-bolts you mention but I want to use jetnuts. the thread pitch avalable for the jet nut is not compatible with bolt kits designed for willwood 2 piece rotors. just curious if you have any thoughts. I'll prob just call Pegasus and see what they suggest.

codrus

I've bought aircraft hardware from Coast Fabrication - Home

--Ian

Sirnixalot

i'm about to mount up a set of 44mm ITB's and fully expect my brake pedal to suck for my autocross events.

For a car that is street driven 1-2 days out the week and raced once a month is it worth the effort to go tandem cylinders like what Madjak did or will single 7/8 master (i already have a wilwood proportioning valve) and having it at the prescribed 5:1 to 6:1 pedal ratio suffice?

Currently I'm on a basic setup but I haven't outgrown it just yet, stock non sport 1.8 brakes all around with Stoptech street pads.

Madjak's thread for reference
https://www.miataturbo.net/suspensio...-delete-86683/

Madjak

A single booster is ok... I wanted dual masters for track work, so I can tweak the brake bias in the car and for safety due to the redundancy.

For street use I still think it's best to alter the pedal ratio and either run a tandom single or dual masters. You can actually achieve a ratio increase by going to a smaller master BUT you need to make sure you don't run out of fluid in a single stroke. With dual masters you are effectively limited by the smallest sized master which is 0.625" so you really need to modify the pedal to up the ratio for comfortable street use.

Also a side effect of increasing in either pedal ratio or smaller master size is more pedal movement which isn't ideal. You really need to choose a pad that has less compression so that you don't get a spongy pedal. I'm not sure on street pads but I'd guess they'd squish a lot more than a track pad.

Sirnixalot

Wow thanks for chiming in Madjak. I am not opposed to moving to a better pad, from the info spread around here the PFC 01 would be the pad of choice OR the MX72 from Endless (which i have experience on another car with).

My nemesis is an EG hatch which has a booster delete, stock pedal ratio whatever that is, a Wilwood 7/8" master and Hawk HP+ pads which I have felt the brakes out on. It's not horrible but it's s bit more effort than I am comfortable with (never skip leg day).

A single 7/8" master may be the ticket, for right now I have no intention on wasting money on pads for the stock front calipers as I intend to get the Stoptech front BBK through my employer.

DNMakinson

iTrader: (3)

Does it matter if I use the backing shims?

mekilljoydammit

Not a Miata but a different project... at what point do you get driven to using large calipers? Like, I understand the point of having more pad volume for endurance races and stuff, but what else do you get going from (in Wilwood terms) something like a Superlite to a W6A or GN caliper? To be more precise, I'm doodling up a tube chassis GT car in Solidworks, at around 2500 pounds, 500ish HP, and wondering if PF ZR34s on 13" brakes are adequate or if I need "more" caliper for some reason.

OGRacing

iTrader: (1)

Fantastic question.

So when I'm building a kit I try to keep the caliper as small as possible. keeping weight down is a must in everything race car related. when I start working into Larger body calipers is for when I need a larger pad (for endurance). the other reason to go to a larger caliper is to get larger pistons. when we are working with manual brakes we need to keep pedal throw very short 25-30mm max. the less the better. this has to do with pedal ratio and fulcrums in the pedal box. get into that later.

let us use my car as an example. in a standard Miata and standard kits (willwood/stoptec/afoc f33) use calipers with a 3"^2 area pistons. on my car we went with a tilton manual pedal box. we upped the size of the pistons and went with the afco 4"^2 piston F22's. we did this in order to not use super tiny master, keep the pedal ratio short, and avoid needing 250Lbs of force to stop the car. Now, this still requires a small front master of 7/8". the problem we have now is we have a large difference in masters front to rear. the rear is a 15/16". ideally, we would go up to the afco F88 caliper with larger pistons that have a 5.17"^2 area. that would allow us to use almost identical master cylinder sizes. naturally, that would require a lot of work and larger wheels/tires/ ect ect $$$$... but that would be a good example of why you would want to go to a larger caliper.

mekilljoydammit

OK, that makes sense - so for a relatively lightweight car running half hour sprint races (the example I mentioned) the PF7934 shape pads or the Superlite pads would have enough meat, but for something more like a NASCAR thing running short track, there just plain wouldn't be enough pad volume... or should I be thinking of things in terms of horsepower input instead of weight? Anyway, looking at it a little more, I had overlooked that the GN and W6 calipers don't have appreciably more piston area - around the 5"^2 area.

OGRacing

iTrader: (1)

you exactly nailed it. when I start looking into pad thickness or volume, I think in terms of top speed and weight. horsepower does effect top speed so it does have an effect. for me it's easier to just look at speed / weight combo.

OGRacing

iTrader: (1)

two kinds of shims.
one is a literal 'spacer' this helps keep the pistons in the bores and lets you use the last bit of pads.
they help and do reduce drag. the further in the bore of the piston the less brake drag you have. extended pistons are prone to lock inside the bore.

the other shim is a heat shield. @PFC we had what was called rocket nozzles. just a little stainless steel caps that sat on top of the piston, and between the pads. those also work they keep heat out of the fuid. but if you don't have a fade issue I wouldn't bother with them.

herduge

I' tried to re-read the thread but got a bit overwhelmed by the tons of info... So please excuse if it's sounds like a noob question.
i just install a front kit - 11" with dynapro caliper.- (previously oem non sport, with ferodo DS 3000 ) on a '99 NB. Tires are semi slick R compound 205/50 Nankang AR1 (that seems to be stickier than Nitto NT01, which are not availaible in europe.
front pads : Ferodo DS 3000 (on Dynapro)
rear pads : Ferodo DS 2500 (on Oem non sport caliper).

Since the "upgrade" i have a much longer pedal travel, noticed while i was bedding in the news pads/rotor. After a "long" travel, braking effort on the pads seems to be the roughly the same. I assumed that the 3 in² of the wilwood pistons vs the 3.15in² of the oem caliper would require a shorter pedal travel and more force than my oem previous setup to get the same braking effect (due to smaller piston aera)??
why i am seeing the opposite (...or did I get lost and completely misunderstood the "lecture")? Is there more fluid volume to move inside the wilwood caliper that could explain why i need more pedal travel?
Since i dislike the long pedal travel as it makes heel and toe more difficult, would a bigger master cylinder be the solution to my issue (wilwood 1in² ..)?

The reason why i upgraded is to reduce rotating mass and running cost (high perf pads for oem caliper are between x1.5 to x2 the cost of pads for the wilwood). i will eventually require for more stopping power (or more accurately more heat capacity) when i install a turbo and fit wider tires.( i least i got the "tires stop car" lesson :-) )...

OGRacing

iTrader: (1)

the longer pedal could be from air in the system from the swap. Try tapping the caliper with a rubber mallet while bleeding. or it could be a characteristic of the caliper. we find the dynalights will flex a substantial amount, the longer they are used. try bleeding the system first and report back if that didn't solve it.

glade

iTrader: (2)

So, I find myself at a bit of an injunction, with an unclear path forward.

car cliff notes
current curb weight - 2268 wet , 2800 ish with passenger during instruction
Driver weight - 300+, (i know, i know lol) usually instructing with passenger, anywhere from 100-300 pounds additional
Power - currently 130 whp, building for 300, with roughly the same empty curb weight,
Xida, 700/400 giant Racing beat, 14mm rear
current tire setup - gen 2 15x9 6ul with 225/45 Rivals (planning on stepping up to at least 15x10, with 245 super 200 rubber, and a spare race set ( likely 15x11 Or 12?!??!?? lol) with the new as yet released 295

I am interested in moving forward with the full stop tech kit, (STR42, ST21 rear) with the V8 Roadsters brackets that will allow me to run 11.750 and 11 two piece rotors, ( ALA Exact copy of @ThePass) , wilwood 1" master

As far as I can reckon, the buying process for the brake package would be as follows:

one stop shop from v8r ? (tried calling, but I anticipate a slight delay from miata at the gap)

locate independent supplier for the caliper bodies, purchase brackets from V8R, Choice of Rotor Suppliers, though current leaders are V8R and Good-win (specifically looking at the ap racing J hooks),

buy the brackets from v8roadster, buy AFCO 33(?) calipers, ALA Ogracing Miata, Sport rear caliper, ?

or....?


I have the necessary funds set aside, just trying to figure out a prudent path forward. Any advice would be greatly appreciated

sixshooter

iTrader: (12)

Regardless of brake selection I will encourage you to get stronger Springs to match your operating weights and tire selection.

And I am personally fond of V8 roadsters brake offerings.

concealer404

iTrader: (3)

No PFC fitment for Wilwood 7912?

herduge

thanks for your advice.
I did try to do a propre bleed but i may have done it unperfectly. I'll try the mallet even if the pedal doesn't feel mushy or spongy...will report back when done.