Brake Conversion Questions

[shotgunslade]

If we could get past the acrimony, I'm very interested that different owners have had different experiences with their brakes. I believe that I push my brakes pretty hard on the track. The east course at Pocono is almost an AutoX course. It has a lot of turns and a lot of braking. Peak speed on the straight, for me, is a little over 100 mph, and there is a really tight hairpin. I also know my sessions are long compared with autoX. Yet, the only problems I have had are the following. Occasional smoking rear pads, One instance of boiling brake fluid (with year old fluid). One instance of being low on fluid (that day involved six 30 minute track sessions at Pocono) One cracked rotor and strange non-contact areas (showed rust ring in middle of rotor circumference) on both front and rear rotors (from that same 3 hour track day) . Both the above were solved by replacing pads, brake fluid and replacing front rotors with slotted only FrozenRotors.

I cannot say I have been aware of any real brake fading, except for a spongey pedal at the end of the 3 hour track day. I also know that I often brake much harder than others in my group (HPDE 2), because I close with those in front of me at the start of turns.

I have never been to the track with stock rotors. Had Race Concepts d&s until one front cracked. Rears are still Race Concepts, Fronts are slotted Frozen Rotors. I had Metal Masters all around for my first 2 track days, and Axxis Ultimates front with Metal Masters rear ever since. Have had Race Concepts SS lines from the beginning. Used ATE SuperBlue first (old boiling brake fluid), now Wilwood 570 (just as good and cheaper - $5.75 for 12ozs)

Braking performance is also related to suspension (not about fade, about maximum tire grip) Both Ben and I are running pretty stiff springs for our car weight. Maybe that helps us with overall braking performance. That might well explain Cazzer's observations about needing better brakes. An OEM sprung SVX is a real floater. Also, I'm running 245-40/17 BFG KDW-2's, good grip, but not slicks or R-compound. Maybe if I was running slicks, I would have a lot more problem with fade.

So, why is my perceived braking experience so much different from some others? Are you running OEM or other plain rotors? Fluid, pads, lines??? What tires are the faders running, R-compound, slicks??? Also, exactly what kind of sessions result in fade? AutoX? HPDE? Time Trials? Wheel to wheel 30 minute sprints?

[svxstarship]

I agree with everything you said. He is some info on the Dunville track where Cazzer tested the SVX. I copied it from a post on the Grassroots motorsport site...
I've been to Dunnville 7 times over the last two summers for Solo 1 and lapping days. Here are my observations:

- the track is very tight and has very rough run-off areas. you do not want to go off at this track. It has three fairly long straights that all end with very tight/slow corners, so it's murder on brakes. If you don't have race pads and good quality brake fluid, you will suffer brake fad in 2-3 laps if not less.

- the facility still needs a lot of work. the paddock area is very rough, with 60 year old pavement and gravel, so it's hard on race tires, especially slicks.

- the track is technically challenging, but it only has one medium/high speed corner. all the rest are slow/tight corners, so it almost feels like a big autocross rather than a race track.

- the track has very little "flow", because of all the straights ending in super tight corners. It's very much a "start and stop" kind of circuit, which suits lighter cars with good brakes very well (my car included), but lots of torque to get out of the tight corners works well too (some fast laps have been put down by Z06's and Mustangs here).

Of all the tracks I've competed on in Ontario (Shannonville, Mosport GP and DDT, Cayuga/TMP), Dunnville is my least favorite. I'm looking forward to Calabogie opening up near Ottawa next summer, which will be a fantastic circuit along the lines of Mosport GP or Tremblant.
_________________
Dave Pratte

I'm looking forward to some lapping days next season at Mosport and Calabogie with the SVX. Allthough they were expensive, I think if you were to try out my Movit kit on your svx for a track session you would like them. I think my problems were the result of running stock non slotted rotors. The slotted rotors with the right pads like you are running probably would have eliminated my warping issues.

[svxstarship]

I meant to say slotted, and or, drilled rotors.

[ItsPeteReally]

By now you have probably guessed that I have a bee in my bonnet about measurement. It seems to me that you probably aren't doing much wrong, apart from trying to use the SVX as a race car

But if you must race an SVX, then more power to your elbow sir.

It seems to me that if you want to gain the 'racer's edge' that you shouldn't blindly copy what all the other idiots are doing, but think for yourself.

Just looking round the web for a measurement tool I came across this item http://www.tiptemp.com/Product.aspx?...ategoryID=4413 something that allows you to see just how hot your brakes are getting. This information may allow you to select the most appropriate pad for any particular circuit. It may also allow you to see if any disc pattern does run significantly cooler than another.

Agressive stops from high speed are the real problem, they dump horrendous amounts of heat into the discs, and the only mechanism that is going to remove that heat is air, which has a pathetically low thermal capacity. The end result is that vast amounts of air are required to disperse it before the next stop, lower speed braking puts much less energy into the system, it's all about v-squared.

I remain to be convinced that any disc rotor design, by itself, significantly improves the cooling airflow, perhaps they help with outgassing from the pads, I dunno: is this an issue at all?

Brake ducts, or water cooling are a different issue. Whether or not the standard SVX wheels improve brake cooling or not - who knows? They say it does, do any aftermarket wheels claim anything similar?

[Earthworm]

Originally Posted by ItsPeteReally

Whether or not the standard SVX wheels improve brake cooling or not - who knows? They say it does, do any aftermarket wheels claim anything similar?

Now UberRoo insists on running his wheels on the opposite sides...perhaps that's why he's having issues with his brakes?

[svxstarship]

DBA mentions using a temp paint kit for analysis.
http://www.dba.com.au/dba_catalogue_...ions_Track.pdf

They also claim their tigerpaw design rotor vanes run cooler. Not to admit guilt, but I think your remark about agressive stops from high speed being a major cause is correct. For cars with drilled rotors that aid in water dispersment in the rain the removal of the brake shields is probably benificial to cooling. For non drilled rotors this is not a good idea as their can be a delay when first applying the brakes in the rain!
Does your uk car have vented rear disks? When ordering rear disks here in Canada I have twice been given "Eurorotor" brand vented rear disks. They fit of course except for the caliper carrier not being wide enough, quality looks good too. Of course I never notice this until I am halfway through the brake job. I wonder if I can find some used rear UK calipers on line? Just for the record I use fresh Valvoline Synthetic fluid.

[UberRoo]

Originally Posted by Earthworm

Now UberRoo insists on running his wheels on the opposite sides...perhaps that's why he's having issues with his brakes?

Haha! Interesting theory.

It would probably be more useful if we quantified the actual performance of our brakes. As I recall, if I do consecutive 0 - 100 - 0 runs, the first two are fine, but number three brings on a bit of fade for the last twenty MPH, and number four starts to fade around fifty. That more than doubles my stopping distance. (It may be run four and five that I start to experience fade. I don't remember.) Overall, they're damn good brakes. I'm certainly impressed with them, but I wouldn't trust them with a more powerful motor.

I think I must be punishing my brakes with more demanding conditions. After twenty minutes of hundred-plus straights and late braking for corners at half the speed, the occasional dead stop (or near stop) from a buck-twenty is just too much. The brakes will effectively knock fifty MPH off the end of the dial, but that last fifty is a hard sell.

If I just throttle off early and coast into the next corner, I rarely have to brake at all, but I lose ten or twenty from my top speeds. After the first five minutes, I back off because I know I won't be able to stop if I need to. If being able to come to a complete stop in an emergency wasn't a concern, I probably wouldn't be complaining. In situations where my top speeds are under ninety, fade is rarely an issue.

My fluid is fresh and doesn't boil, and I'm using metallic pads, which have a pretty high heat tolerance. Perhaps I can find nicer pads, but of course every manufacturer claims their product is the best. I haven't seen any evidence that the Axxis pads are any better than brand-X, but I acknowledge their popularity could be indicative of their performance, and not just their aggressive marketing. My current pads are definitely superior to the original equipment pads. I may look a little harder at my pad options when I finally grind this set down.

Carbon disks and pads with a brake multiplier would be a nice, albeit expensive, solution.

I can dream...

[Suby Fan]

why hasnt any one pointed out dayle's big brake kit?? i warp my rotors constantly! and as far as the SVX goes im not impressed with its braking ability i would definatly say its the car's weak point... and Curly... your going to need to choose between a modded out SVX that you can show off or stock SVX that you can race.... because one mod on a svx... even a aftermarket cone style filter puts you in a open class where you will most definatly get PWNED by cars that are really done up... i think... right?

[Suby Fan]

and benebob are you mocking me w/ your signature?

[newsvx]

I haven't been on this thread for a while, and I find the snide remarks a bit disconcerting (Ben). I believe this site has always been for the exchange of ideas - and yes, we all will not always agree. So let's treat each other with a bit of respect, even if we feel the other person doesn't fully understand the issue / problem / or whatever. Name calling always ends badly!

As for brakes on the SVX, yes they could be better. That said, I have never had a great deal of problems with them, to include warped rotors. What does "better" mean? Shorter stopping distance and lack of fading under hard use. They are NOT as good as say a Porsche 911 - neither did it cost as much. They won't be as good as a BMW either. There are SO many factors involved in a good braking system that is is difficult to get into specifics. Most cars don't weigh as much as the SVX (4,450 lbs, GVW - that's "gross vehicle weight", not dry weight) - I know, that's a general statement, but it must be considered when some have been talking about SVX race cars which are stripped of weight.
Seems to me there are a few things that need to be considered in talking about brakes, in general: 1) what kind of driving will you be doing? Autocross requires a different pad, as an example, than putting a car on a track (notice the different pads that a racing manufacturer sells). 2) having fresh, "high temp" brake fluid is a must. Part of our tech inspections for the track includes insuring the car has had the brake fluid changed within the past six months - seven months won't do! In addition to being sure there is no water (that "boils" easily) in the system, clean fluid, changed regularly, insures a clean system that works better. All cars should change the brake fluid every year!! At least! BTW, at a track event, as pads wear, the fluid goes "down". Pay attention to that! 3) Decent rotors are essential. Again, drilled and / or slotted rotors are best for the track ( I think the German manufacturers prefer the drilled only, if one takes the AMG's as an example). OEM (non-warped, of course) are fine for autocross, generally speaking. Proper break-in of a new set of pads / rotors will go a LONG way in ensuring they work their best, and don't warp. 4) Pads. See above re pads and different uses. 5) TIRES. Tires will make a tremendous difference in braking, but have nothing to do with fade. Both on the track and autocross, I run R compound tires. One is fooling himself if he runs street tires and expects to perform well. R compound tires will make seconds difference in your times where a tenth of a second is "forever".
I have rambled a bit, and I sorry for that. Just allow me to say what I run for brakes on my '97, bone stock SVX: For autocross, I run Axxis semi-metalic pads, front and rear with OEM rotors (if I went the slotted or drilled rotors, I am modified). I do NOT race my SVX on the track - I ain't that good. And if I were that good and serious about racing, I'd have a better (read lighter and more HP) car to run. Old guys don't have the reflexes of you young guys. But I do like to get the SVX out on a track such as Summit Point or Virginia International Raceways (VIR) to enjoy what the car will do. Personally, I think a stock SVX is very respectable in the performance arena, but a Porsche it ain't!! And as with 90% of the folks on this thread, I am not a racecar driver, and as a result, I run the car perhaps seven tenths of its capability. I don't want to wreck my car since I can't afford another one. And you can't (or shouldn't) run the car even seven tenths on the road.
So ..... bottom line for the SVX (or any car used in high performance driving (track or street)), be sure you have the best brakes (and suspension too) parts / system you can afford to put on the car. Keep it sericeable.NEVER show up at a driving event with brakes that have not been thoughly checked out.
Sorry to get on my soapbox ......
Harry

[ItsPeteReally]

Originally Posted by svxstarship

Does your uk car have vented rear disks? When ordering rear disks here in Canada I have twice been given "Eurorotor" brand vented rear disks. They fit of course except for the caliper carrier not being wide enough, quality looks good too. Of course I never notice this until I am halfway through the brake job. I wonder if I can find some used rear UK calipers on line?

Yes, the UK cars have vented rear disks. As to finding used calipers for sale, all I can suggest is 'camping' on e-bay, and waiting, and waiting. The SVX is a rare car over here: there were only about 280 ever sold and probably less than half that number have survived. I think that I'd be a little wary of used calipers, and I'd certainly refurbish the seals etc. before using them.

[shotgunslade]

Harry:

Well said. My sentiments exactly. I think I probably drive the car a little more than 7/10 on my trackdays, but I'm certainly not good enough to drive it 10/10's. Since I'm not usually competing, I don't care that my car has a good amount of mods. I think they make the car more enjoyable. The one group I run with that does Time Trials (CART) has classified me as F Street Prepared, which doesn't seem to be a bad place to be. For NASA time trials, my car would be Class E, along with stock Integra Type R's, Nissan 300ZX- NA, Mustang V-6's, Porsche 944, Subaru WRX, e30 M-3's, etc. I have driven with some of these cars on track days, and can say I'm probably in the right place. Will try to do some NASA time trials next season. All said, the SVX is a good, predictable and fun car on the track. Not the fastest car in the world, but it's fun surprising people from time to time (WRX's and E30 M-3's especially)

Looking forward to our Summit Point SVX Track Day next season.

Uberoo:

Consecutive 0-100-0's is way harsh, don't you think?

ItsPeteReally:

I'm not racing an SVX. I'm just driving fast in a controlled environment with an occasional timed performance check.

[newsvx]

Originally Posted by shotgunslade

Harry:

The one group I run with that does Time Trials (CART) has classified me as F Street Prepared, which doesn't seem to be a bad place to be. For NASA time trials, my car would be Class E, along with stock Integra Type R's, Nissan 300ZX- NA, Mustang V-6's, Porsche 944, Subaru WRX, e30 M-3's, etc. I have driven with some of these cars on track days, and can say I'm probably in the right place. Will try to do some NASA time trials next season. All said, the SVX is a good, predictable and fun car on the track. Not the fastest car in the world, but it's fun surprising people from time to time (WRX's and E30 M-3's especially)

Slade,
The SCCA has the SVX in G STOCK. What is the reasoning of placing you in F STOCK Prepared?
Harry

[benebob]

Originally Posted by Suby Fan

and benebob are you mocking me w/ your signature?

Huh?

[benebob]

Originally Posted by newsvx

I haven't been on this thread for a while, and I find the snide remarks a bit disconcerting (Ben).
Harry

Sorry Harry but I value my time. If people can't listen to others who have plenty of knowledge on the subject (when they are the ones experiencing a problem) then I feel its right to tell them.

Do you go to the doctor and diagnosis your problem?

Point is as plenty have proved that the SVX brakes are fine for moderate track use. Doing 0-100-0 will kill any braking system and in reality isn't the wisest thing to do in a non-controlled enviroment. Go put an extra 750lbs in a vette and do that you'll be in the same boat. For street cars there really isn't a safe alternative as racing pads absolutely suck of street driving. It'd be like driving with your Toyos in a snowstorm... completely irresponsible!!!

Harry, that sounds about right on classifications. Dave and I kinda screwed up the NOC with wanting to be classed so that's what we got. Once a car is classed in a prepared class its much easier to then find the fit elsewhere based on that.