Brakes upgrade question

PMUM

Enthusiast
Joined
Oct 31, 2000
Posts
322
Reaction score
0
Location
Orange County, CA USA
Professor Luc, you are a plethora of braking information! Now we need to send you to Muffler University so you can figure out how to keep that Mustang quiet at Laguna so you don't get a black flag every lap.
 

luc

Enthusiast
Joined
Oct 19, 2000
Posts
1,031
Reaction score
4
Location
Paso Robles CA
Paul,

You are right,
no point of having brake and horsepower if you can't pass sound.
BTW SCCA is 105 db at Laguna.
Luc.

The only reason that I know a lot about brakes is because my car started with a single piston floating caliper and in the process of upgrading the brakes,I made ALL the mistakes than you can possibly do and even some more,(as putting the wrong size bearing and braking the spindle)
 

PMUM

Enthusiast
Joined
Oct 31, 2000
Posts
322
Reaction score
0
Location
Orange County, CA USA
Luc, are you bringing that beast to ViperDays at Pahrump this weekend? I'm sure Skip will let you run it as long as you take it easy on most of the Vipers. I'd like to see that thing run again with the full exhaust. There's no sound limit at Pahrump and there's a huge straightaway, so wheel that baby out!
 

Gavin

Enthusiast
Joined
Oct 15, 2000
Posts
431
Reaction score
0
Location
Monterey, Ca, USA
Chuck - you have to remember that the rear brakes on the viper have almost zero stopping effect. The advantage of a balanced upgrade that Luc speaks of is that the upgraded rears working with the fronts result in very much improved stopping distances.

Also Luc's points regarding "control" or "pedal feel" are very significant. A driver of a Viper is much more likely to flat spot the fronts with a stock system than with an upgraded system. Why -because the fronts carry most of the braking load therefor reach the limit of tire grip very quickly thereby catching the drive off guard. With the upgraded system there is much more "feel" and with the rears carrying their share of the load there just is not that instant, surprise lockup that occurs with the stock setup.
Or looking at it another way - the car stops so **** quick without having to stand ******* the pedal.
My first outing with the upgraded system found me getting on the brakes hard at my usual braking point, and the car stopping so quick that I had to get back on the gas to make it to the corner.

With the upgraded package the driver is on the gas accelerating longer, on the brakes harder and shorter.

Example - Laguna Sec going down the straightaway into turn 2 - stock system I hit 120mph over the hill, lift at turn one (clip the white line and get on the brakes) three laps of this and I was into brake fade.
Upgraded brakes 125mph over the crest of the hill - stay ******* the gas - clip the white line, lift (to settle the car) brake hard for turn 2.
I am picking up speed coming onto the staight resulting in 5mph at the crest, I'm on the gas down the hill therefore still accelerating, also my braking distance is much shorter.
Confidence goes up - I carry just a little more speed through turn 2 - I think because the car has better balance from the rears doing their job.
I know next trip to the track I can move up the braking point on this turn and pick up a bit more- Another big difference - 20-30 minutes of this and the brakes hold up perfect - no fade. The tires are now the limiting factor - after about 4-5 laps they go off and require a lap or two at an easier pace to recover.

Another area I notice a big difference is turn 6 - this is not a heavy braking corner like turn 2 - This is a much faster corner with the upgraded system - again, I think because the car is in better balance after a quick stab on the brakes before turn in - the car just flies through this turn.
Night!
 

luc

Enthusiast
Joined
Oct 19, 2000
Posts
1,031
Reaction score
4
Location
Paso Robles CA
Andy,
Of course it is better to bleed the brakes instead of just removing the fluid in the MC,but replacing some of the old fluid with new one is better than nothing.
Even without a recirculating valve,fluid do move in the system from the calipers to the MC due to fluid temperature difference.
It is why even if the "aging" of the fluid happen mostly in the calipers,the fluid in the MC turn black also.

Re-circulating valve.

The valve by itself cost less than $200.
You need to add some brake lines and labor,about 2 hours.

You use the bleeder valve port to connect return lines to the MC and valve.
It's pretty simple to install but you need to make some lines,so you need a tubing bender and a double flaring tool
Paul is correct,COOLING make a huge improvment.
Luc.00GTS
 
OP
OP
A

Andrew2KRT10

Enthusiast
Joined
Apr 25, 2001
Posts
2,886
Reaction score
0
Location
New York, where else?
If this much thought is going into eliminating terrorism, we should be done with the war this week.

I think Luc, Gavin, and C.Tator should go over to Afganistan, and covertly sabotage the braking systems on the toyota trucks that the Taliban are using.

AC
 
OP
OP
A

Andrew2KRT10

Enthusiast
Joined
Apr 25, 2001
Posts
2,886
Reaction score
0
Location
New York, where else?
For what it's worth, I ran Hoosiers at Watkins Glen. Started at 33 rear and 32 front cold and ended my first session at 40 hot all around. I started with that presure according to a suggestion from Archer Racing. They said that Hoosiers like 40 PSI hot. It was a day that started at about 45 degrees, dry and ended at about 68-70.

AC
 

Gary Lashinsky

Enthusiast
Joined
Aug 1, 2000
Posts
621
Reaction score
0
Location
Orlando, Florida
I have run every race in the eastcoast in the Viper Racing League with the same Alcon rotors and Baer four piston calipers front and back this year. Other than replacing brake fluid and Pagid pads as needed, I have had no problems. The Alcon's look nearly new after 14 races. Not bad! A full season out of one set of rotors and they still look like new!
 

Gavin

Enthusiast
Joined
Oct 15, 2000
Posts
431
Reaction score
0
Location
Monterey, Ca, USA
ANDREW - I would bet any of the guys and girls on this board would go to Afganistan in a minute. One thing I know about Viper owners - they understand the Viper is built in the USA - the greatest country on the planet. (I still think you should upgrade - you have a standing invite to Monterey - open track weekend at Laguna Seca of course - come stay at my house - wife is a terrific cook and we will see what you think about the idea of a brake upgrade after a few laps)
ALSO - you may wonder why we are all so prolific on this subject - simple - Luc said it in a different way - good brakes translate into speed around the track - The Viper has ample horse power for the average, even above average driver - its the brake upgrade that will produce the quickest increase in speed (and if your name is Fred - a couple of driving schools will make you go quicker too - I'm poking a bit of fun at him but he is right - I did the schools before I upgraded the brakes - I will do school until my track days are over)

JIM - Sean Roe provided the equipment - went from stock to full upgrade - I firmly believe the rears have to be upgraded.
I experienced excessive lockup with the stock system - there were many instances of driving hard into turn two at Laguna and having the "Oh **** " experience - never made it to the gravel pit but came close. Did make to the gravel pit at the corkscrew however - climbed on the brakes and clipped the accelerator - not a smart thing to do with 500 big ones under the hood.
After the upgrade - no more such instances - as I said in earlier posts - confidence shot up and I'm very comfortable moving the braking points around - If I over do it - I'm still able to threshold brake and brake into the turn a bit, and take the corner wide - thats my safety net. With stock system I was never comfortable doing this - lockup the fronts and control is gone - all be it just for a second or two - just too risky for me.
Stoptech - nothing wrong with the setup as far as I have heard - its all been good - I think if you add their rear system you will be very surprised at the effect of that upgrade over the fronts only. When I did my upgrade Stoptech did not have a front and rear solution - I spoke with their reps at Viper Days and thought to myself that "these guys know their stuff" - they just didn't have the equipment I was looking for.

I believe you are correct when you say their system modulates better than the stock system - four piston calipers over two piston calipers??? more control. Changing the master cylinder per Luc's discussion will also help further.
Luc talks about how much he has experimented and all the thing he did wrong - that is the great thing about this board- if you need help there are plenty of folks that can get you up the learning curve quick - I made the final decision to go the route I did but is was all the input from guys on the track that really made the choice for me. I am most grateful.

LUC - Sean has done woke me up - he has spanked me good - I'm starting off with too much pressure in my Michelin Pilot Sports - 35 psi - He beleives I should be at 39-40 hot - so I have to start off at 29-30 cold see how the grip is throughout a session, go up until grip goes away, back off the pressure to the previous session, let that cool down then that is the starting temp for the next day. Going to give it a go
Will you be at Laguna Seca Nov 11th and again Dec 1 & 2?
Gavin
 

Jim Hodel

Enthusiast
Joined
Oct 18, 2000
Posts
332
Reaction score
0
Location
Portland Or
Gavin, have you said which vendor's four wheel system you installed, and did you try a front only upgrade first? I
am wondering if you experienced an excessive lock up problem with a front only upgrade, and then decided on the four wheel system, or if you went directly from stock to a four wheel system.

Thanks, I am honestly trying to separate lore from fact. For me, the Stoptech front only system seems easier to modulate then the stock system.

Jim
 

luc

Enthusiast
Joined
Oct 19, 2000
Posts
1,031
Reaction score
4
Location
Paso Robles CA
Gavin,
Just curious,you mention that after a few laps at Laguna,your tires overheat.
Which brand/type/size tires are you using and at which pressure cold?

If you are using Hoosiers,as I do on my 69 Mustang,my experience,as well than my fellows racers and CONTRARY to the manufacturer suggestions/guidelines,is that they handle and last much better with low pressure.
As an example,my car weight about 3500# with driver and gas/fluids with a 53% frt and 47%rear distribution.
I run 275/40/17 all around with a cold air pressure of 25 front and 21 rear.
I got to those #s after a LOT of experimentation with the goal of even wear and maximum footprint.(I have -3 camber in frt).

I never really check tire pressure hot since to do it correctly is almost impossible.(No cooling down lap,temperature taken in the hot pits,etc,)but I would think that air pressure go up 6 to 8 psi hot.
Luc.00GTS.
 
OP
OP
A

Andrew2KRT10

Enthusiast
Joined
Apr 25, 2001
Posts
2,886
Reaction score
0
Location
New York, where else?
Gavin:
Once again, you and Luc make great, non-arguable points for upgrading the brakes.....if I were to do the track stuff to the extent that you guys do. My problem is that I want to be able to drive street on the same equipment, and from what I read so far that is not advisable. Believe me. I am a huge race fan. When I am out on the track I can taste it in my blood ..... I love it so much. The speed, and the concept of pushing the limits further and further is instinctive to me. The thought and appreciation that I feel for those such as yourself and also the NASCAR pros when I watch a race, is soul-deep. BUT realism then sets in, and unfortunately I have to be able to use equipment that is good for street and track, and I have to make trade-offs to accomplish that. I guess I just need two Vipers.

Regards, and thanks for the invite. I may knock on your door one day. Will you be going to VOI-7 in Detroit, which we have not heard very much about??????

Andrew
 

luc

Enthusiast
Joined
Oct 19, 2000
Posts
1,031
Reaction score
4
Location
Paso Robles CA
Gavin,
That for sure,USA is #1.
I was born/raised in France(please no jokes,I know them all)and spend years in many countries before coming here 20 years ago.
For me what make this Country so great is the Freedom that we have and the fact that we are all from different backgroung,race,colors,nationality and IT WORK.
Yes, I will be there with Green flag on 11/11 and 12/3-4.
Only in America could the Viper be designed and built/sold.

In a way the Viper is like the USA,brash,bold,not for the timid and a car you have a passion for,almost love.
And peoples that criticize the car or our Country,are mostly jealous that will LOVE to have our car/way of life.
Luc.00GTS
 

Gavin

Enthusiast
Joined
Oct 15, 2000
Posts
431
Reaction score
0
Location
Monterey, Ca, USA
Andrew - My Viper is a daily driver - 26,000 miles to date - proud to say it gets driven in the wet too!
Gavin
 

VIPERSPEED32

Enthusiast
Joined
Jun 7, 2001
Posts
5
Reaction score
0
Location
arlington, tx, usa
Following up on Brake Question,

Bobby Archer Motorsports offers a T1 Approved Brake kit, which costs $749.95. We have these in stock. Installation takes about 2 hours.

Regards,

Tony Arbelaez
Marketing
Bobby Archer Motorsports
(817) 877-1772
 

StopTech Service

Enthusiast
Joined
Oct 6, 2001
Posts
23
Reaction score
0
Location
Torrance, CA, USA
As there are many different levels of driving, there are many different levels of upgrades, not only for brakes, but for every system on a car. Being involved in the brake world, I'll give my opinion on brakes and those other modifications that directly effect brake performance.

The first question to honestly ask and answer is what type of driving are you doing and what do you expect from your brakes. If you are on an open track, you should have pads suitable for that environment, period. Street pads don't work well on the track, and track pads don't work well on the street. If you are unwilling to change pads for each environment, you WILL compromise one or the other. Rotors, brake fluid and brake lines don't really care what environment they're in for the most part, pads do.

Since the thread started with a request for a simple, economical upgrade, I won't spend much time on big brake kits or 4 wheel solutions, except to state that an improperly balanced kit can actually have an adverse effect on brake performance.

There are a number of economical upgrades that will give you good bang for the buck. The StopTech 1-piece AeroRotor is designed to give several benefits. First, it might be best to spend a moment discussing the stock Viper front rotor. The Viper Engineers realized their baby would be heavy, fast and have a lot of front brake bias. They chose a rotor style that was specifically designed to absorb gobs of heat and resist warping (can you say warranty nightmare?). They succeeded, but at the cost of a stock rotor that will continue to absorb, not dissipate heat and prematurely lead to pad failure (street compounds) on the track. Even air deflectors are only moderately effective unless really well ducted to the inside of the rotor. The StopTech Viper AeroRotor flows 61% more air, which translates into approximately 15% cooler temperatures for most any given environment. They still have to absorb all the kinetic energy from any given stop, but dissipate it much more quickly, and will start each braking cycle (each corner) at a cooler temperature, hence lower peak temps. over the course of an event.

Bear in mind, they will still see temperatures well above those that a street pad can handle, but overall lower than the stock rotor. This translates into longer pad and rotor life. I won't promise 2 or 3 times the life, but we have seen 2X the life on both pads and rotors on a hard driven car (the Schley brothers out of Southern California) with a lot of track time both before and after the change out. Severity of the track, pad selection, additional cooling, driving style, vehicle setup and maintenance... all will have an effect on brake performance. Your longevity results may vary.

There are a couple other advantages. The StopTech AeroRotor is 3.5 pounds lighter per rotor than stock. That's 7 pounds saving on rotating mass, lap after lap, stop after stop, pass after pass for the entire time the rotor is on the car. Also, the use of a slotted rotor, in our experience, will result in more aggressive pad bite, meaning better stopping performance. There may be more aggressive pad wear, but rotor wear, in our experience, is un-affected. Again, pad selection, driver style and vehicle set-up are all variables that will effect your individual results.

Additional upgrades at a reasonable cost include stainless steel brake lines, which will give a firmer pedal and quicker response. They are also, typically, a one time buy that will be there every time you step on the brakes, track or street for the life of the car. Performance quality brake fluid is also a must if on the track. As important as the brand you choose is the maintenance of the fluid. Bleed as often as necessary, at least before each event, more so if the brakes are used aggressively. Opening a $12.00 bottle of brake fluid and bleeding all four corners will seem pretty insignificant compared to pumping the pedal 3 times at the end of each straight 5 laps into your first session.

One final point not yet brought up is pad and rotor break-in. You MUST properly break in your pads and rotors both when they are new, and if you are swapping from street to track pads or vice versa. Switching pad compounds means re-bedding the rotors.

I'm sorry to get so long winded, but I spend a good portion of each day addressing these exact issues. If I could make a short list of things to happen to make my job easier, it would be to educate users how to properly break in pads and rotors, and convince them to swap pads for track and street use.

Now back to the start of the thread. Upgraded pads are a must on the track, and some track pads will be more aggressive on the rotors. They can be expensive, but there are a lot of choices available. Stock rotors are about $100.00, and they will absorb heat and run hot. A slotted StopTech AeroRotor is $199.00 (non-slotted $175.00), it will run cooler, stop better (if slotted) is 3.5 lb. lighter, and will last longer. There are also 2-piece solutions available at higher costs that will also be lighter and run cooler.

Each user will need to balance all the advantages against the additional costs. Invest 30-40 bucks to flush out the brake fluid and replace it with good quality stuff. Then add 12 bucks to each weekend and keep it fresh. Pads, rotors and brake fluid are consumables, put them into your budget along with fuel, tires and feeding your crew. Stainless lines are a great upgrade, and a one-time expense. The sooner you upgrade, the longer you'll enjoy them.

OK, I'm almost done... Taking a car on the open track and sliding it around and slamming on the brakes from over 120mph takes a toll. It is not anything near the same as driving on the street, even on the most aggressive canyon roads you know so well. Parts wear out, improperly prepared or maintained parts fail, and things fall off if you ignore them. The track is different from the street, and can't be casually treated the same, even for those 1 or 2 events a year. Unless you have the discipline to putz around the track all weekend and resist jumping on it, you'll need to budget wearing out some parts and a few hours work between events.

If you have any questions about upgrades, or brakes in general, please feel free to get in touch.

Matt Weiss
StopTech Customer Service Manager
 

Tom and Vipers

Enthusiast
Joined
Nov 22, 2000
Posts
2,562
Reaction score
16
Location
Jeannette, PA 15644
Ok Ok Ok
I'm all right now.....

Sounds like the rear brakes aren't carrying their load!

Sooooo, why isn't a rear brake "correction" popular?

I've also heard the rear pads wear at 1/2 the rate of the fronts, however, on my 00 GTS, the rear pads, percent wise are wear perhaps 20% less than the fronts - could there have been a change?

My guess is that a larger rear caliper piston would balance the brakes better. And this would take some of the braking from the fronts which need the help. Sounds like this would be a big winner for the marginal stock fronts.

I suppose you could use a proportioning valve to limit the fronts but I don't like proportioning valves and when used, they are best left to adjust the less critical rears.

Sooooo, any info on rear brake modifications?
====================

Also, regarding Porsche air ducts. Are there 2 styles? I have seen simple scoopers and also full ducts that attach to the control arms.
====================
 

StopTech Service

Enthusiast
Joined
Oct 6, 2001
Posts
23
Reaction score
0
Location
Torrance, CA, USA
If anyone is interested, I would be happy to send a copy of our recommended break-in procedures. We have not yet published it on our website, but I will gladly send a .pdf file (Adobe Acrobat Reader needed) to anyone who e-mails me.

This is a general procedure that we have developed from extensive testing when we often have new components to quickly break-in. Asking your pad or brake supplier specifics about their products is probably a really good idea as well.

[email protected]

Matt Weiss
StopTech Customer Service Manager
 
Top