Auto X brakes need some advice

[240sxworkinprogress]

Hi I need some advice on what I should do with my brakes. This sunday I was racing Auto x and by the third run my brake started to heat fade. I have been wanting to ungrade for a while but not sure what to do. I have good controll with my brake now they just don't stop me fast enough for my liking. I seem to only be able to lock them up as I start to turn but when I'm strait I can't lock them up with out standing on them. I'm just a little nerves about going to big with the Z32 and locking them up before the turns. I just want the best option for auto x. I was think about. New drilled/sloted rotors and pad and lines but stock size,180sx,Q45,or the most popular the 300zx. So what is everbody else doing for brake in auto X!!!!!

[Vatche]

i put 26mm z32 calipers in the front. stops like it should now im totally impressed. and i went from hawk hp plus pads and decent rotors. to z32 sized pbr crappy pads and some crappy rotors. so icant imagine how much better they would be with good pads..

get z32 and hawk hp pls pads for auto x imo

[mrmephistopheles]

If you go Z32, don't just stop at fronts. Get full 4 corners and ebrake. 26 or 30mm doesn't matter so much if you have good pads.

If you don't want to upgrade quite yet, get some drilled rotors and some GOOD pads.. Hawks, MetalMasters fuck I can't even remember the really good ones.

Even if you get blank rotors and upgraded pads you'll be better off.

Also run some dryer duct, or build some sheetmetal to redirect air to your front brakes. This is extremely cheap to do and any retard with a 2x4 and some metal shears can do.

[TheWolf]

The real difference is whether your running slicks or street tires. If your running slicks then I'd say go with the z32 upgrade. If your running street tires then I think you can't hurt a good set of rotors and pads. I have standard ebay crossdrilled/slotted rotors with pbr metal master pads. New high temp fluid and thermal dispersant coating on the calipers. I can't hurt them. I've taken this car upto deals gap (318 curves in 11 miles) twice and had plenty of brakes. Local autox same thing. With a 255 width 17" street tire I can lock them up at around 20mph and under which provides a pretty good threshold. Most likely a stock brake refreshening will do you more good than replacing your whole brake system. Slicks will provide more traction and you'll need bigger brakes. if I was on DOT hoosiers and serious about autox I'd get something bigger than the z32. You'll be surprised how fast things slow down.

[240sxworkinprogress]

I was hoping to get a set or slick for next season. I just need a brake upgrade that will cover street tire really well and slicks when I get them.

[TheWolf]

then definitly go with the z32 or a caliper bracket and a larger rotor upgrade. running hoosier slicks on my autox bmw 2002 dropped gobs of braking distance off and what was once perfectly fine became heat soaked and inefficent. Doesn't someone make some billet aluminum hats to where you can use standard race rotors and some willwood calipers?

[exitspeed]

Just for reference, my 240 is bone stock and for autox i run brembo blanks and metal master's pads. It's not really an upgrade, but it's affordible and made a big difference.

[orion::S14]

^^^ Agreed.

For auto-x...go with new rotors and GOOD pads.

Axxis Ultimates are pretty good for light track duty and autocross...easy to find, and reasonably priced.

Start there.

Z32 and Q45 brakes don't stop you any faster than stock brakes (assuming you'd be using the same pad)...but they offer MUCH more fade resistance.

However, better pads on stock calipers and rotors will be a BIG improvement over your current Autozone special pads.

- Brian

[KwKouki]

without good tires, you wont stop anyways. What tires are you running.

I autoXd my sisters z32 with brand new dunlops, the brakes still felt greasy at the end of the day.

Best bang for your buck would be better pads and stainless lines if you dont have those already

[mrmephistopheles]

LOL I'm hotspotting the stock brakes on my 180sx...

[vw_nissan]

[QUOTE=TheWolf]Slicks will provide more traction and you'll need bigger brakes. [QUOTE]

Why do you need bigger brakes if you run slicks? If your tires are stickier, than your brakes should stop the car easier already. No?

You will only need to upgrade your brakes if you have increased the power of your car, otherwise, a good set of tires, pads and rotors should help the stopping already.

[1Via!]

If you run slicks there is that much more friction, creating more heat, leading to more/quicker fade. This is where bigger brakes will help reduce fade, etc.

[240sxworkinprogress]

What about the Q45 brakes nobody has saided anything about those yet. I heard that the nismo silvia/240sx uses them. How well do they hold up. Would they be a good choice for slicks and street tires. I forgot to tell you all I running bf goodrich sport 225/50/16. I really happy with them I just need slicks to keep up with everbody in my class. Witch I'm hopeing to get late season to next season. I running in street mod agained a BMW M3 and a few str-4s. I just need some thing to help to get closer to there times.

[Gearhead_42]

My $0.02 -

Pads- Go with a high end street pad. I run Hawk HPS, but the PBR/Axxis, KVR, or EBC Greens are good too. If your events tend to be long runs with only short delays between runs (meaning more heat in the pad), the Hawk HP+ would be the next step up...

Rotors- A *quality* replacement rotor is very important. You don't want them warping after one weekend, so spend a few extra bucks. At autocross speeds, cross drilling does nothing for you, as you aren't on the brakes long enough for gasses to build up. Slots however, can be a help as they will remove any glazing to ensure you have clean surfaces to work with. So, quality plain or at most slotted rotors. I personally run plain Brembos.

Lines- Teflon inner lines, stainless sleeves with a PVC or other outer jacket. I run SPL's DOT approved lines. Get 'em...

Caliper- Here's the great debate. Obviously, greater pad area will provide greater fade resistance for the same compound, so "big brakes" help... BUT only if the balance F/R is correct, which means the correct master cylinder for the job. As was stated above, if you go Z32, go all the way with Front, Rear, and MASTER CYLINDER.

Keep in mind that certain caliper types have better pad selections than others. Z32 and Maxima/180SX brakes have excellent choices, 240SX stock is OK, but Q45 is limited...

That said, I never had fading problems on my S14 with stock calipers and KVR pads. My S13 uses the larger 180SX (still single pot) front brakes, and I don't expect any problems with this setup either.

Edit: Oh yeah, I run my SR'd S13 Coupe in SM also...

[mrmephistopheles]

Q brakes are mainly good for folks who want upgraded brakes, but either want to run superlow offset wheels or want to retain stock appearance. Like gearhead said - pad selection IS limited, but not nonexistant.
Lisa has Q brakes on her car and they're great. shitty autozone pads and stock rotors work wonders.

Z brakes... i can't stress this enough - get the whole setup. fronts, rears and BMC.
Don't skimp and jsut get the front. I have this setup on my 240sx and after driving another friend's s13 240sx with the whole shebang, my brakes feel like crap. I think a stock 240 could out-brake me since all my bias is in front.
I now have the rear setup ready to install on my car, and all i need is the BMC.
With full Z32 setup, the car will hunker down and squat when brakes are applied instead of diving.

[Replicant_S14]

Z32 and Q45 brakes don't stop you any faster than stock brakes (assuming you'd be using the same pad)...but they offer MUCH more fade resistance.


...and maybe more unsprung weight.
A stock setup in good working order... even with street pads, shouldn't fade while autocrossing.

[TheWolf]

When slick tires are used such as hoosier Autox tires or even their Race tire. The tire has a larger amount of available grip resulting in shorter stopping distances. You can lock up your tires at 30mph or so with stock brakes but you probably can't lock a set of slicks up at 20mph. They just grip so much more and thats why they're worth usually 1-2 seconds easily on an autox course which is huge. In reality, the stickier tires will help you grip better latterally which will give you better speed through the corners and you can brake much deeper into the corners. It will also lead to unbalanced braking. Such as you'll find that you can drive through some corners but need to brake for the next one while going through the current one. With the weight transfered to one side of the car only two tires are really gripping. It's important to realize slicks will let you do things streets would never let you do. Stock won't cut it on that setup.

http://www.splparts.com/Parts/Universal/Brakes/BrakeUpgrades/stoptech.jpg Someone show me where to get JUST those Black center sections on the rotors and I'll show you how to build a cheap Race/Autox brake setup that will beat anything out there.

[240sxworkinprogress]

I thought about getting the brake upgrade from heavy throttle the Z32 front rotors and stock rear. It also come with pad PBR / Axxis Metal Master and straitless steal conversion lines front and back. It 415 for everthing plus shipping. I would also get the master cylinder to go with it to.

[SlowCoupe]

http://www.splparts.com/Parts/Universal/Brakes/BrakeUpgrades/stoptech.jpg Someone show me where to get JUST those Black center sections on the rotors and I'll show you how to build a cheap Race/Autox brake setup that will beat anything out there.

http://www.wilwood.com/Products/003-Hats/index.asp

show me now! :D

[Replicant_S14]

I thought about getting the brake upgrade from heavy throttle the Z32 front rotors and stock rear. It also come with pad PBR / Axxis Metal Master and straitless steal conversion lines front and back. It 415 for everthing plus shipping. I would also get the master cylinder to go with it to.


The basic kit will put you in STX. Add the M.C. and you're in SM.

You want big brakes. It's fine. Go for it. Think about this tho: there's about a zillion auto-xers out there on o.e. brakes (and r-comps) that can blast a few sub 1 minute run without brake fade. If you can't, there's either a problem with the car or your driving. I'd get that sorted out first and then figure out if you still want bigger brakes. There are plenty of good rationalizations for bigger brakes. Autocrossing just isn't one of them.

[Rennen]

I agree with Replicant_S14 100%

If you are overheating your brakes at autocross, there is either something wrong with your stock brakes, or something wrong with your driving.

I run brembo blanks, Axxis Ultimates pads, SS lines, and well bled DOT4 brake fluid. This has always been sufficient at autocrosses, even using Kuhmo V710 r-comps on a hot day.

Bigger brakes just aren't worth the class penalty or unsprung weight addition

-Matt

[TheWolf]

http://www.wilwood.com/Products/003-Hats/index.asp

show me now! :D

Working on it. Superlight race calipers and basic race rotors pwn

[240sxworkinprogress]

So if I do a brake upgrade I'll get kick out of street mod, is that right. I need to get one of those scca book to see all I can do before I get kick out of Sm.
Is it any big brake upgrade that will kick you out of SM. If that the case then I might not get the Z32 brakes. I'll just get sloted rotors, nice pads and stainless steal brake lines. I'll have to check on the rules of street mod.

[orion::S14]

NO...in SM, you can run any brakes you like.

I run Z32 brakes on all four corners, and compete in SM...have for the last 2 years.

STX allows upgrades...but STS does NOT.

Also, make sure you use good fluid...cheap and local is the Valvoline Synthetic.

- Brian

[AceInHole]

For pure autocross I'd run an aluminum Wilwood ultralight, or on a budget, aluminum Z32 calipers. Otherwise, Q45 calipers with hawk pads (at least I think it was hawk that made mine) will be more than enough for ANY tire setup you run on the 240. Just make sure to upgrade your master cylinder as well.

As a note to upgrading all 4 corners (which I'd highly recommend if upgrading calipers), you MUST retain an e-brake to stay in SM. Rules are now available online as well:
http://www.scca.org/_filelibrary/File/2006_solo_rules.pdf


Finally, for the most part you really don't need to upgrade brakes on the 240 for autocross. A good brake pad will make a pretty decent difference. I'd say that the biggest reason to upgrade would be for better brake bias and brake feel (modulation).

Good luck with SM. It's a tough class for the 240.

Edited because Orion beats me to everything.

[240sxworkinprogress]

Good luck with SM. It's a tough class for the 240.

Yea no shit it hard I trying to keep up with everbody else thats running slicks. I'm trying to out drive them with street tire. It is hard as hell!!!

[240sxworkinprogress]

If I go Q45 what calipers would I run in the rear. Would I keep the stock ones. Also do you change out the master cylinder for the Q45 brakes or stock MC will work fine. I don't want to half ass it so i want to make sure it right. Do you all know if you have to have conversion brake liine for the caliper to work.

[AceInHole]

I ran the z32 17/16" MC with Q45 brakes all around. The Q45 pretty much uses the same rotor sizes as the z32 (26mm front i believe?) as well as a much larger pad contact area than the stock 240sx brakes. The only upside to Q45 brakes is they *sometimes* can be bought cheaper, and won't ruin your wheel selection (you lose a large selection of wheels with the z32's or any "big brake" upgrade). For both the Q45 or z32 you WILL need to redo your e-brake lines (if doing both front and rear).

[g6civcx]

For autocrossers, the first thing is to check the rulebook like posted above. Some people don't care and some are super anal about you running illegal mods and they'll hassle you non-stop just so they can get quickest time in class.

Also, I'm surprised that your brakes started fading. Autocross runs typically don't last more than one or two minutes at most, and speeds are usually really low as compared to roadracing. Plus you have a lot of cooldown time in between as well.

Several factors for you to consider before going to bigger brakes:

1) Big brakes cost more to replace. Next to tyres, brakes are the next most expensive consumables.

2) Race compound brakes need time to heat up. They have very little initial bite. They usually need to be cycled one or two laps on the roadcourse before they come up to operating temperature. By this time in autocross, your run has been over for a long time.

3) You will be surprised what a properly maintained stock braking system will do. Get good pads (Hawk) and discs (Brembo blanks) and check for leak. Flush and bleed with good fluid. Bed in and you're good to go.

[kapower]

I auto X on kumho 710's and smoked the o.e. front brakes, literally. Smoke was billowing out of the front fenders. That was with cheap pads and several back to back fun runs at the end of the event.

I'll admit there was not much time in between runs, but the brakes got so hot that the fluid boiled and I lost most of the pedal and had to call it quits early...

I'am now on Hawk hp +'s all around and ate super blue brake fluid. No more smoke and a much better brake feel.

[g6civcx]

If you're running around on 10 year old brakes that have not been maintained then you get what you get. That is not a good indicator of how well the stock system works, as said above.

[kapower]

For auto X'ng all you need are pads designed for agressive street driving or entry level track/lapping days. Anything targeted for that heat range will be ok. I think going with a more aggressive pad on the rear of the car would also benifit most auto Xer's.... trail braking.

[240sxworkinprogress]

Well I'm running 225 and I have a Sr and some of the track they are setting up I'm getting it 50 to 60 mph before I hit the next turn. At one track witch is my favorite, we race at fort knoks on a air plane runway. If you have a fast ass car you can almost hit a hundred. My brakes are going out and that why I'm trying to figure out what I sould do about them. I figure if I need to replaced my brake why not upgrade!!!!

[mrmephistopheles]

Well I'm running 225 and I have a Sr and some of the track they are setting up I'm getting it 50 to 60 mph before I hit the next turn. At one track witch is my favorite, we race at fort knoks on a air plane runway. If you have a fast ass car you can almost hit a hundred. My brakes are going out and that why I'm trying to figure out what I sould do about them. I figure if I need to replaced my brake why not upgrade!!!!


Translated:

Well, I'm running 225-width tires as well as an SR, and for some of the track configurations they are setting up I'm getting it up to 50 to 60 mph before I hit the next turn. At one track, which is my favorite, we race at Fort Knox on a runway. If you have a fast ass car, you can almost hit a hundred. My brakes are going out and that's why I'm trying to figure out what I should do about them. I figure if I need to replace my brakes, why not upgrade?

Ok, someone else answer his question - my head hurts now.

[240sxworkinprogress]

I think I going to just take mrmephistopheles advice and do the Z32 brakes up grade and do it right and replace all for corners and the master cylinder.

[jmauld]

If you are overheating your brakes on a 60-90 second course, regardless of the speeds, then you have a problem.

Fix your problems before deciding that you need to spend $$$$ upgrading.

With a good set of race pads and fresh fluid, the stock brakes can make it through a weekend of track use with speeds over 120mph.