Brake Conversion Questions

[benebob]

Originally Posted by UberRoo

I think integrating a proportioning valve would be mighty tricky without removing the ABS. The diagonally linked braking system kinda makes that a bugger to do. I was thinking about installing a solenoid brake lock, like the B&M Launch Control - you know, just for fun - but it requires two valves on a stock SVX.

Also, I toasted my old semi-metallic pads almost right away. I've since upgraded to metallic pads, but I still routinely experience brake fade during spirited driving. Then again, I really use my brakes. I would propose to drivers who don't experience brake fade that you may simply not using them enough. Some tracks aren't long enough, or have enough speed variation to warrant that much brake use, but under-utilizing the brakes is extremely common. Extremely hard, last-minute braking nets you good times, but it generates a lot of heat. In fact, as a general rule, the faster you are, the harder it is on your car. Constant full-throttle to full-braking is pretty abusive.

Change your entire fluid to a decent fluid and get rid of your metallic pads. That isn't an upgrade. Metallic pads are worse for fade as they cause more heat. After both Dave and I use our car the wheels are around 250 degrees. You don't do that on the street unless you do 150-0 stops 30 times in a row.

[benebob]

Originally Posted by NeedForSpeed

Since you have experience replacing brake fluid at regular intervals, could you post the procedure that you have found to work best for you. Like everything else, after doing a job a time or two, one learns the 'tricks'.

Thanks for the informative posts.

Sure, go buy some speed bleeders. Replace your bleeders with those (ALWAYS USE A FLARE NUT WRENCH!!!) Speed bleeders let you open it w/o having air get sucked in when you push the pedal.
1. Suck out most of the fluid with a turkey baster from the resevoir
2. Fill it with fresh fluid and put the cap on both the fluid and the top of the resevoir (don't tighten it)
3. Bleed to the ABS pump bleeders.
Slowly push the pedal in stopping about 3/4 of the way then release it. Have a friend on the other end with a clear hose and clear bottle draining the fluid until it runs clear (old fluid gets kinda nasty looking). Make sure the resevoir stays above the low mark if it goes below you need to start over.
Repete 2 and 3 for the wheels. I always do it closest to the pump first followed by the opposite rear then the other front then the other rear but have read different versions of the order. Be sure to do it diagonally though.

I also have a Mighty Vac pump that works well when you're by yourself. Costs about $30.

It'll take a quart or less of fluid and then throw that fluid out. You can't reuse it as it takes on water.

Expect to spend about 3 hours on it your first time. With speed bleeders we can do our racer (no pump) in about 15 minutes when its on the trailer as we can get axcess w/o taking the wheel off. Be sure to soak those bleeder valves for a week or so first to ensure they aren't seized. Trust me it sucks breaking one off in a caliper. If you're using the new speed bleeders then get yourself some 6 point sockets that are long enough to fit on there for the removal.

[UberRoo]

Originally Posted by benebob

...get rid of your metallic pads. That isn't an upgrade. Metallic pads are worse for fade as they cause more heat.

What options are available as an upgrade from metallic pads?

Also, I don't see how metallic pads can cause more heat. Braking should always generate the exact same amount of heat regardless of the means used to slow down. Where that heat goes, and how efficiently it's dissipated can vary. I've never heard that metallic pads cause more heat. Can you explain what you mean?

[curly2k3]

my think is definately brake fade...its really bad IMO, when i am on the course and am constantly on/off the gas to brakes i notice it really bad, especially coming out of the cicane and they throw a 65-75 to zero end poing right at you. I have been looking into stainless lines and have been trying different brake fluids, however i have not tried wilwoods yet. also, have any of you racers removed the ABS?I have a couple of friends that are EXTREMELY into auto-x adn they said removing it would give me a much better feel for the vehicle, they said next to corner weighting its one of the better things you can do to get a better overall feel on the track...any thoughts on this?

[benebob]

Originally Posted by UberRoo

What options are available as an upgrade from metallic pads?

Also, I don't see how metallic pads can cause more heat. Braking should always generate the exact same amount of heat regardless of the means used to slow down. Where that heat goes, and how efficiently it's dissipated can vary. I've never heard that metallic pads cause more heat. Can you explain what you mean?

Did ya take Physics in high school. Metal on metal isn't nearly as good as metal on say ceramic or aspestos (which was actually probably the best material for braking). Metal means your brakes last longer but they also retain heat rather than helping to disapate it. Just as the softer the pad bits better then the harder pad which results in quicker stops with less pedal feel. Metallic pads are well hard so then you have that issue going against you as well.

[benebob]

Originally Posted by curly2k3

my think is definately brake fade...its really bad IMO, when i am on the course and am constantly on/off the gas to brakes i notice it really bad, especially coming out of the cicane and they throw a 65-75 to zero end poing right at you. I have been looking into stainless lines and have been trying different brake fluids, however i have not tried wilwoods yet. also, have any of you racers removed the ABS?I have a couple of friends that are EXTREMELY into auto-x adn they said removing it would give me a much better feel for the vehicle, they said next to corner weighting its one of the better things you can do to get a better overall feel on the track...any thoughts on this?

Driving skill or lack there of it has a lot to do with cooking brakes, sounds like you'd probably cook them on a vette as well if you're cooking them on a 60 second course with at least 5 minutes of cool down between runs. No I'm not cutting on you in the least bit. Keep in mind you need to slow down to go fast. On and off of the gas to brakes does not make a very fast driver in any car. My bet is that an above average driver could go around the same course using the parking brake only in the same car faster than someone who can cause brake fade in a properly functioning system.

As for stainless lines did you not read what I wrote? They will do absolutely nothing for you as far as fade except cost you about $100 that could've been better spent elsewhere. Yes it will give you a better pedal feel but that is all.

Removing the ABS is dumb for a car that's driven on the street. It is there for a reason and again for 1992 it was a top of the line system. Better than the Vette had even! The only time ABS works is when you here it and if you're hearing it then you should be very glad you have it otherwise you probably would've just gone into a spin on the course or street.

Corner weighing does absolutely nothing for you except tell you how to set up a car, again a waste of money unless you're gonna use it for something like adjusting ride height to even out weight, setting an alignment etc. Sure its helpful to know what it is to an experienced person driving anothers car but an average driver will know after their first run which side is lighter etc.

[svxstarship]

Maybe I should have tried the Axxis pads on the many brake jobs I did on my 92. I tried KVR pads and others, with new rotors every time, flushed brake fluid, used high quality brake fluid, torqued the lug nuts, lubed the slide pins. Rotors warped ( or deposits ) every time in short order. Hard brake use might have been a factor. When I got my 96 it seemed to have a fresh brake job and they didn't last either. I seem to recall many of the intial reviews mentioning the brakes not standing up to hard driving. How about the recent review on TV by Cazzer ( or something ) on Sports Car Revolution where he mentions the car needing better brakes? How many posts are there on this form mentioning warped rotors? I could never get the abs to kick in at higher speeds.

[UberRoo]

Originally Posted by benebob

Did ya take Physics in high school. Metal on metal isn't nearly as good as metal on say ceramic or aspestos (which was actually probably the best material for braking). Metal means your brakes last longer but they also retain heat rather than helping to disapate it. Just as the softer the pad bits better then the harder pad which results in quicker stops with less pedal feel. Metallic pads are well hard so then you have that issue going against you as well.

I'm afraid they didn't cover the friction properties of ceramics, asbestos, or metal in my high school. I'm rather fond of metallic pads because they don't turn to butter after one hard stop, but rather require quite a bit of abuse before they reach the temperature of uselessness. Also, the hotter the brakes, the greater the temperature differential, and thus the more effectively they can dissipate heat. A higher temperature useful-braking threshold allows for more heat dissipation, which will prolong the onset of brake fade.

What the best available pad options for the SVX? I seem to recall that ceramics are the ultimate, but not exactly a viable option.

[shotgunslade]

I warped and cracked the drilled and slotted Race Concepts front rotors I had before. I have been using Axxis Ultimate pads on the front this season, and did not experience any deposits on the rotors. I know some drivers who practice laps with minimum brake use to perfect their line, but getting on the brakes really hard at the end of the straight is the fastest way around. Pulling it down from 120+ to 50 every 2 minutes for half an hour with several other 100-90 down to 50-40 episodes in between will definitely get your brakes hot. Like I said, my rear pads have smoked at the end of a session. The question that SVXfiles asked, "do you break loose or invoke the anti-lock often" is the real quesiton. If the answer is yes, then your tires are the limitation. If it is no, then your rotor/pads/calipers are the problem. As for anti-lock brakes, most drivers, including myself are not good enough to do as well without anti-lock as they do with it. It takes very good feel. I know, because the Porsche 911 I had before the SVX didn't have anti-lock, and it would lock up pretty easily.

[benebob]

Originally Posted by UberRoo

I'm afraid they didn't cover the friction properties of ceramics, asbestos, or metal in my high school. I'm rather fond of metallic pads because they don't turn to butter after one hard stop, but rather require quite a bit of abuse before they reach the temperature of uselessness. Also, the hotter the brakes, the greater the temperature differential, and thus the more effectively they can dissipate heat. A higher temperature useful-braking threshold allows for more heat dissipation, which will prolong the onset of brake fade.

What the best available pad options for the SVX? I seem to recall that ceramics are the ultimate, but not exactly a viable option.

Do you know where brake fade comes from? It comes from brake fluid changing from fluid to vapor. Pads and Rotors have nothing to do with fade aside from how they act when hot and the heat they transfer to the caliper and fluid when hot. Nothing more nothing less.

[benebob]

Originally Posted by svxstarship

Maybe I should have tried the Axxis pads on the many brake jobs I did on my 92. I tried KVR pads and others, with new rotors every time, flushed brake fluid, used high quality brake fluid, torqued the lug nuts, lubed the slide pins. Rotors warped ( or deposits ) every time in short order. Hard brake use might have been a factor. When I got my 96 it seemed to have a fresh brake job and they didn't last either. I seem to recall many of the intial reviews mentioning the brakes not standing up to hard driving. How about the recent review on TV by Cazzer ( or something ) on Sports Car Revolution where he mentions the car needing better brakes? How many posts are there on this form mentioning warped rotors? I could never get the abs to kick in at higher speeds.

I replaced my front rotors 2 years ago on my road SVX. They were the originals and were worn out at 140k from wear. Not a bit of warp to them. I autoxed it probably about 10 times with a 20 minute driver school using your average $15 Pep Boys pad. Now if I wanted to I could go out and warp the rotors in 15 minutes but understanding limitations and abilities do more for me then writing checks to replace things I broke while doing things I shouldn't have been.

As for test saying things need this and that. That is opinions and yes when you drive a Ferarri from 10 years ago today you'll say it needs better brakes too.

There are plenty of posts on this forum about how bad the transmission is too but yet how does it compare to an auto out of a Vette, Mitsu 3000 or a 300z? Quite well in fact!

[svxstarship]

Just some interesting sites on the causes of brake fade..

Brake fade...
http://www.tirerack.com/brakes/tech/....jsp?techid=78
http://www.spdusa.com/brake1.htm
http://www.se-r.net/car_info/brake_performance.html
http://www.stoptech.com/tech_info/wp...rakedisk.shtml
http://people.ucsc.edu/~kbrandt/mustang/brakfade.shtml
http://driving.timesonline.co.uk/art...560640,00.html

[TomsSVX]

Well here is the thing... Some of us warp brakes like there is no tomorrow, some of us get the brakes way too hot and begin to feel brake fade, and then some of us can race the car without destroying brakes... THink about it... is it the car or the driver?? If these cars were all setup the same, I have a feeling the results would match. You need to learn how to brake the car properly, then and only then ar you say the brakes are insufficient. My silver's brakes have been through hell and back since I installed them at Reading and they have seen many miles since then. They are still straight and still have plenty of meat on them. I used DOT4 synthetic fluid and habe not ONCE felt fade and they have not warped or deposited since... While some people can tear a set of brakes apart in 2 months only driving on the street. Seriously, if you ar ehaving issues with your brakes on a short course(less than 5 minutes) you should inves in a driving school. They will teah you how to use what you have much better

Tom

[UberRoo]

Brake fade is a general term for when the brakes effectiveness 'fades'.

The type of fade I routinely experience is a very stiff pedal that doesn't do a damn thing. (Pad fade.)

I’ve yet to experience the spongy pedal symptoms of boiling brake fluid. (Fluid fade.) This type of fade doesn't immediately reduce the overall stopping ability - only increases pedal travel. Once there's no travel left, then the stopping ability is affected, but symptoms should be evident before that happens.

For normal driving, the brakes on any modern car are more than adequate. For normal driving, the SVXs' brakes are exceptionally good, but then, the SVX is a sports car with a powerful engine. Usually the engineers take that sort of thing into account because they expect that a sports car will occasionally be driven like one. The SVX is not a racing car however, and its brakes are not adequate for aggressive racing. In my experience, to say marginal would be generous.

The universal limiting factor on brakes seems to be wheel size. I've seen well-funded race teams that are simply unable to fit a large enough rotor inside the wheels. They have the best parts money can buy, but still experience brake fade. Carbon pads under umpteenzillion pot calipers, with massive, drilled, slotted, uber-vented disks, and they're still glowing red hot and blowing corners 'cause they can't slow down. Whatever the case, in aggressive racing, aggressive use of the brakes is required and sometimes driving slower is the only solution.

When I got my SVX, I immediately ruined my disks by cooking them with semi-metallic pads. I had them turned, and so far, they've fared pretty well with the metallic pads, considering what I've put them through. I did a thorough break-in, and I haven't had any problems - just fade. I've been very careful never to come to a complete stop until the disks have a chance to cool. Aside from larger disks, it appears there's nothing more that can be done to improve braking unless you're willing to let carbon pads eat your rotors.

[benebob]

Originally Posted by UberRoo

Aside from larger disks, it appears there's nothing more that can be done to improve braking unless you're willing to let carbon pads eat your rotors.

... Or you could simply learn to drive right . As both Tom and I explained we don't have carbon pads, in fact I've never had carbon pads on any car I've owned and suprise suprise, I'll bet both of us could out brake you in your car set up how you want it.

FYI the average wheel size for racing is a 15 inch rim not a 20 so I don't know where you get you're thoughts on disk size aside from overcompensating for lack of size elsewhere. Lets call it Hummeritis.