Wilwood Prop valve guys...couple questions
 

Details...

PTE Miata
2400ish lbs
205 R6
1.6 brakes Hawk DTC 60's all 4 corners (points system have to stay 1.6) and have cooling.

I bought the flying miata kit a couple months ago but never installed, the car brakes great...infact better then near everything in my class however I wonder if i can get even more out of it. Also to get a little heat away from the front to survive the 45min races.

My question is for the guys who've played with adjusting this thing a lot, I though i read someone who said even with the valve at full rear...it isn't enough to lock up the rear brakes, granted pad, tire compound etc all play a role..but anyone else share there experiences?

TIA!

Read thread...
https://www.miataturbo.net/showthrea...893#post933893

My own experience is 1999 with stock brakes PF97 pads front
& rear. Stock Front / Rear bias is ok on shorter / flat tracks. However, one track has a 110 mph off camber down hill corner. Trail braking into this one is scary without reducing rear brake bias. Otherwise, changing front/rear bias was not needed in my view. rear pads last 2x front... Wilwood prop valve mounted inside car on tunnel beside shifter, similar to FM targa car.

Actually already read that thread and feel a few steps ahead.

I've run dtc 60's in the front for about 2 years now but just changed to 60's in the rear this past season and it made a pretty big difference. I don't have a huge issue with locking up fronts anymore because I've adjusted my driving style. From what I've read the 1.6 stock valve is the least amount of rear biased out of any miata so im debating on changing it...or just leaving it be and not having another failure/leak point.

I hear you on the trail braking fast forward to 1:40 in this video, there are times im fighting a lot more then this to keep the car straight on hard braking.


I'm running a fun day in November where im planning on taking brake temps etc, but it would be a good time to try out the valve. Just weighing my options and wanted some opinions from guys on track with R compounds.

I noticed you still have a full interior... the 99 racer is a gutted out, caged race only car. So no issue with normal day to day driving (brake squeal, dust, etc.) So, no brake backing plates front or rear, no front fender liners (to increase air).

Fast track (with the fast off camber corner) 90 mph average speed, ~ 120 mph peak (near stock NB1 engine). 2.5 mile, 10 corners, 1 hard braking point per lap, 2-3 much lighter braking points. Ran successfully but front wheel bearings (grease) was showing some heat stress.

Slower track 3 miles, 20 corners, Multiple braking points, 75 mph average, ~110 mph peak. Front brakes glow red a couple of times / lap. Front wheel bearings definitely getting hot...

Added 2 1/2 brake ducts (fog light holes) on front to reduce heat on short track... Good on hot days (and heavy braking track), too cool on colder days (and less demanding track). Front now has too much cooling. Had to adjust (reduce) rear bias as front brakes never got really hot... (or red). Taped over 1/3 of brake duct inlet to adjust for cool days.

All races 1 hr to 3 hr long. Brakes are good all day long... No fade even when red hot.

p.s. change your brake fluid at least 1 time / year to reduce water content and chance of fade.

Car's been a dedicated track car for years...and is caged now. I've had some issues with too much cooling in the past on cold days, did the same thing you did. I bleed the system every event...cheap insurance.

Thanks for the info.

On my car, I've only ever tested the brakes hard up till 80. BUT on street tires I'll still lock the fronts first, but just barely, with the bias valve all the way rear. With 275 hoosiers I've only locked up an inside front, mainly because the tires werent mine and I didnt want to really push the braking and risk flat spotting them. This is 1.8 brakes with parts store front pads and pre-warmed (drag the e-brake) ebc reds in the back. I eventually want to get the car setup so that in the dry on hoosiers I can run the same pads front to back and not have the bias valve all the way rear, then be able to move the bias rearward in the rain.

Thanks for the info leafy, did it make a noticeable difference in performance?

Holy shit yes. You know how the car normally has that ho hum I kind of stop ok feel? with the prop valve its more like, thank jesus for inertial reel seat belts or I would have just eaten the steering wheel.

haha well no i don't, or I'm just use to it. I think Im going to swap it in and play..i have a traqmate so the data wont lie.

I have the prop valve dialed in exactly where I want it after about two sessions. It works and it doesn't matter which brake locks first, it matters how the car turns on the pedal.

I bleed my brakes like once or twice per year, lol. Huge brakes = awesome

I'm looking forward to trying it, bleeding mine every event is overkill as the fluid usually comes out clear...but between that and the clutch it's just good practice and takes less then 10minutes if you have someone on the pedal.

I can drink a beer in about 10 minutes whilst talking shit at the track to my friends.

who works on their car at the track?

Im in the same boat. I have DTC-30s in the front, and leftover HT-10s in the rear. Ive been thinking about putting the DTC-60s in the rear (as well as the front, for that matter).

Maybe its time to pony up for the prop valve. I cant get the car to trail brake worth a damn.

Shocks, blance, alignment, and comfort help as much as pads. It takes a lot more effort to go fast in some of the other cars I drove recently at Hallett, mine and Crusher required no thought...get in and go.

Changing your alignment will definitely help you get some trail braking action.

I have been toying with the idea of a prop valve too. I have a 97 miata. If I upgrade my front brakes to the larger MSM calipers and rotors, would I need a proportioning valve or can I just put a more aggressive pad in the rear? Or ditch the whole MSM front brakes idea? The car will be turbo as of next season.

Stock brakes in the front and sport brakes in the rear would be the better upgrade if you had to do just one and weren't already killing the front brakes when you run your chosen motorsport activity. Upgrading the front on these cars without upgrading the rear is just silly. If completely removing any bias valve still doesnt result in enough rear braking force on the stock brake setup, you dont stand a chance with bigger fronts.

Can we please not do this shit on our forum again? Really, please, stop it.

Anyone here who's going fast in a Miata runs a Wilwood prop valve and but they biggest brakes we can fit all the way around.

Only if its needed. It doesnt sound like kinavo needs it. And IMO, running just upgraded fronts will make normal stopping distances longer since you'll be locking the fronts at less pedal pressure and not letting the rears contribute enough grip. Once you get to the point that stockers are heat soaked and beyond their operating range, the bigger fronts would stop better.

Just get the prob valve and most of this shit does not matter. Please, stop knowing everything their is to know about tracking a Miata, from FSAE and auto-x. We get it, you are Steven Hawking.

Not everyone who races a miata does it on the track. My posts you currently object with are directed at kinavo, who doesnt sound like a track guy, and if he is he isnt serious.

I still have to read it. I highly recommend you formally apologize to the forum for your incredulity or no one will like you.

I'm definitely not at the same level as most people here. I'm still a noob who just has dreams at this point. I have less than 10 hpde's at this point. However, I do have much experience and local success with autocross but I'm well aware they are two very different beast.

Anyways, I'm just trying to learn. And yes I search that's why my post count is so low. Sorry to have caused trouble.

You're not causing trouble, my mother never loved me.

The answer is to get a Wilwood prop-valve from TSE, get the biggest brakes you can afford all the way around, and never look back.

This guy knows what he is talking about im running Flying miata BBK not sure i will ever have to mess with brake BS ever with this setup and i have 15+ track weekends on 1 set of pads im not fast but 2:07 at TWS is not slow either. that alone is great justification for the cost long term. Hustler is way faster BTW.

I'm slow as shit at TWS. Everyone has tons of seat time there in our "crew", I've driven each direction once.

Stephen Hawking and he can't operate a track car until mind control happens.

FSAE seems to come up a lot, wonder how many are former FSAE people here.

Biggest brakes you can afford with emphasis on hardware balance rather than prop valve is my take. Prop valve is best in transients. Spreadsheets with applied force, pistons sizes etc are nice though the issue has been figured out by many vendors already.

I have the same pads and the bias valve and i can very easily lockup the rear with enough bias. A lot of people fail to take off the OEM bias valve which is where they are running into the problem.

If you take it down to HPDE1 days and get all your braking done in a straight line you wont have any problems. I can see how trail braking would cause an issue but i havent had one... i just ease into it to adjust speed if i went in too hot instead of stabbing

'90, sport brakes, XP 10/8 F/R, wilwood prop valve on R888s........I had to dial a lot out of the rear to get to where the fronts would just lock before the rears.

How the heck do you even install the bias valve without removing the stock one? Unless you're one of those crafty buggars that puts it in the trans tunnel.

I see you've never visited the southern half of the country.

Rednecks have amazing engineering skills.

It's on the trans tunnel :giggle:

Slightly OT, but brake-bias-related: how does changing the brake bias affect behaviour during trailbraking? Would more rear bias increase the tendency to rotate, or stabilize it? The reason I ask is because my current setup - stock brakes with FM Stage 2 set up to FM's alignment and sway settings - seems very squirrelly if I brake too deep into the corner.

I don't doubt that using more rear brake would give me better braking in a straight line, but I'm afraid as to what might happen if my newb ass brushes the brakes while turning if it's going to oversteer even more than it does while stock.

It should make it more stable, up till the point where the rears start locking instead of the fronts.

Adjusting for rear tire lockup is not the only threshold. More rear brake bias will make the car less stable under braking during corner entry. But as long as it is not too much, it helps with getting the car rotated during trail braking.

This is one big reason why I have cockpit adjustable brake bias. It makes dialing in the instability an easy thing to do while on the track. BTW the bias valve does not have to be mounted on the transmission tunnel. I have a Wilwood cable adjuster which is not just useful for the bias bar dual master style setups. I have a thread about it around here somewhere.

Link to thread please...

Marc, I think you may be analyzing it too deeply (driving in your helmet) look ahead and let your body do the rest. One of the best things about the Miata is the very easy ability to correct an oh shit moment. Just remember to look ahead at the next corner (not the one you're on) and be smooth with all inputs

Its the same adjuster as the balance bar? Interesting I may have to snag one once I can get enough natural rear bias that I dont just have the valve cranked fully open. And after I double check the rules.

What you call "helping the rear" I call "properly set-up car". It's neutral, the car does whatever you want no matter how ridiculous...it's a pretty cool place.

Semantics.txt

Dam already - just do it... redneck installed, like a cracker...
Seriously, there should be no conideration of installing one... it's a must-have

https://www.miataturbo.net/attachmen...ine=1357405760

Like this...

WTF is up with your fail hand position and shuffle-shits? You look like you're crunking.

We also can't see your feet nor data so we don't know if you're braking like a man or not.

Oh, but I'm a ------ and that's not a balance bar.
/SJMarcy

lol - you jelly I got trubo

Once RacePak is in - or complete car for that fact- I'll have your data... ;)

You come try'n hustle me at NOLA sometime, if the GF lets you... I'll even drive the daily AUTOMATIC... wait, that's turboed too... oh well :fawk:

No you don't. You can swap to FC T2 rear calipers and vented rotors in the rear. I wish I could convince someone to build them, but they say they aren't needed (minus Martin at Monster Miata that uses an 11" wilwood disc). :fael: :giggle:

Quick version:

Buy this (or the like) install it under the hood as usual
Flyin' Miata : Chassis : Brakes : Complete adjustable brake proportioning kit
Very carefully cut the adjuster knob off of the threaded rod coming out of the valve. The trick is to trim around the edge of the knob so it can be split open and removed from the threaded rod, so the rod remains intact. Do not cut the threaded rod or damage its threads.

Buy one of these:
http://www.jegs.com/i/Wilwood/950/340-4990/10002/-1?sendroicid=bbef8492-2d00-41d6-b158-38db0de2603c&catargetid=1716046196&sendroikwd={key word}&gclid=CL-VrvW30rQCFQpgMgodemwA2g
Route the adjuster cable with the knob mounted on the dash, in the cab, wherever you can reach it. Thread the other end of the cable onto the valve rod (the one the knob was cut off of) and loctite it into place.

Done

Does the knob that comes with the basic prop valve kit come off any way without cutting? Or is it somehow glued on? Thanks.

nevermind, question wasn't really related to OP's topic, started a new thread.

I am just wondering, if some of the recommendations is to adjust the wilwood to fully bias to the rear, then why can I run without proportioning valve at all? That is, removing the factory proportioning valve.

Sure you can, if you know that's what you want, all the time.

Some cars/setups that works, but it means you dont have a knob to adjust more rearward when it rains or more forward when you move to stickier tires.

you can definitely get some rear lock up in some places with rear-bias all the way. depends on a combination of the track, the tires, and the spring rates you run.

I didn't notice it, but my wife noticed my rears locked up on a few occasions while at T11 CMP.

Also, similar to what Hustler said earlier, the prop valve is really helpful for trail braking, more so than lock-ups...unless you only do your braking in a straight line...

Fast forward a year and I have this rear set up and a prop valve and love it.

Also means I have the same 11" vented discs all around, so I can "rotate" discs when the fronts get low. Each time I buy 2 replacement discs, I put those on the front and move the worn ones to the rear. And taking one replacement 11" rotor with me to the track covers me for all four corners too.

-Ryan