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Im posting this question for a freind of mine who wanted to know how good stop tech's are for hard driving and track use. I believe he just bought a 4 wheel stop tech brake system for his M5. Thanks in adavance for the info
 

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Black M5 said:
Im posting this question for a freind of mine who wanted to know how good stop tech's are for hard driving and track use. I believe he just bought a 4 wheel stop tech brake system for his M5. Thanks in adavance for the info
Black-

While I cannot speak for the 4-wheel setup, I absolutely can vouch for the original front BBK. For me, it's as clear as a night-and-day distinction.

I tracked my car extensively before taking the StopTech plunge. I did just about everything I could do to upgrade the factory system short of replacing it: race pads, stainless lines, high-T fluids, and opening the air ducts. Even so, as I picked up my pace, I always ended up managing my brakes on a track weekend. It never left the back of my mind: "when will I experience a mushy pedal?"

Since installing the StopTechs, I've had zero issues with fade, and performance has been stellar. I've surprised more than one instructor with the car's ability to haul two flying tons down to a desired corner entry speed in what must seem for them to be unreasonable distances. It usually plays out like this (over the helmet communicators):
"Wow. (pause) This thing has great brakes!" --usually uttered after we've successfully tracked out and kept four wheels on the pavement.

I'm convinced! It hit me like a ton of bricks when I finished a two-day event at a favorite track and was changing back into my street pads---I realized I hadn't thought about brake fade all weekend. For me, that sealed the deal.

Good luck, and hope this helps.

-Dave
 

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abdulla,

I had the 4wheel stoptechs on my car (slotted rotors, red calipers) and while they were good, i had a constant battle with spongy pedal (probably due to knowone around new how to bleed brakes) and I even warped my rotors from pad deposit from racing.

The pad deposit is more than likey due to my learning how to drive a high performance car in the m5, thus my learning curve was great. The brakes are quite good and i know alot of people use them on the street and track because they are good at both sides.

My master tech even commented on how the brakes felt after one of the 5 times they spent bleeding them--the last 2 was by hand. After getting the air out they felt incredible but thats when i started to have the pad problems.

Both of these issues are not conducive to stoptech brakes, and are more due to my driving (i chewed up a set of new axxis pads in 5000miles and warped the original rotors at the same time in those 5000miles) and just circumstances of brake kits.

They are great.
 

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I have the StopTech front BBK on my M5 and Brembo 4-wheel (14" front/13" rear) brakes on my 1995 M3 race car. Both set-ups work very well indeed on the track, and I see no practical difference in essential quality of construction and performance. The only qualification is that you want the "outside lower bridge bolt" modification for the StopTech front calipers, as pad changing is otherwise a big PITA. There are big differences in absolute braking performance between the 2 cars due to differences in weight and cooling (assuming both on "R" tires). This means that higher-temp-rated pads need to be used on the M5, and that more attention must be paid to freshness of fluid and proper bedding of new pads on the M5. I consider both brands to be a great choice for the track, and night-vs.-day improvement over the stock brakes. I have run the StopTech brakes on the street for almost two years with no issues there either.

Regards, Dick Roberts
 

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I also use the StopTech front BBK on my M5 for extensive track use and have had similar comments made about the incredible braking ability of my 4000lb beast. Except for all-out race cars, there is hardly ever a car that can out-brake me even at very high speeds. The difference is night and day compared to the original brakes.

Dick, what is the "outside lower bridge bolt" modification? I always have a bear of a time removing that stupid bridge and as a result, my caliper's black finish is scratched and chipped from several fouled attempts. In fact, I think I need to re-build my calipers as the dust boots are dried and cracked and the paint finish is not in good shape.
 

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Redshift said:
I also use the StopTech front BBK on my M5 for extensive track use and have had similar comments made about the incredible braking ability of my 4000lb beast. Except for all-out race cars, there is hardly ever a car that can out-brake me even at very high speeds. The difference is night and day compared to the original brakes.

Dick, what is the "outside lower bridge bolt" modification? I always have a bear of a time removing that stupid bridge and as a result, my caliper's black finish is scratched and chipped from several fouled attempts. In fact, I think I need to re-build my calipers as the dust boots are dried and cracked and the paint finish is not in good shape.
With the early M5 kits, StopTech had the bridge allen screws removeable from the inside - and the lower screw hit the steering arm. The result was that the caliper had to be removed from its mounting to allow pad changes. Later M5 BBKs - either all of them or if you requested this from StopTech (I'm unsure which) - had the front caliper bridge screws reversed so the bridge could be removed without removing the caliper from its mount. My car has an early kit, so I reversed the lower screw on each front caliper. This required machining a threaded insert to fit the inside half (where the allen screw head recess is located), and drilling out the threaded insert and spot-facing a screw head recess on the outside. Being paranoid, I also safety wire the reversed screw. This setup has worked for me without any trouble.

I don't have serious difficulty removing the bridges, but I use anti-sieze on the screws - and don't overtighten them (this will pull the StopTech threaded inserts into contact with the bridge, making removal more difficult according to others I have spoken with). The titanium heat shields available from StopTech will significantly reduce burning the rubber piston dust seals under heavy track use.

Regards, Dick Roberts
 

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Thank you, Dick. Mine are removeable from the front, so that's good. I try not to overtighten, but anti-seize is a great idea. I need to have mine rebuilt like new so that they will last longer. I had not used the titanium heat shields until after the dust boots were fried. :(
 

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RRoberts said:
Later M5 BBKs - either all of them or if you requested this from StopTech (I'm unsure which) - had the front caliper bridge screws reversed so the bridge could be removed without removing the caliper from its mount.
I think anyone with a newer StopTech kit owes Dave Zeckhausen a debt of gratitude for recommending this design change! Of course, it does Dick and me little good now, but at least Dick has engineered a fix. I, on the other hand, have to remove one caliper mounting bolt and loosen the other in order to pivot the caliper and change pads. Every time!

It's three extra steps that I can do fairly quickly, but you don't have to go back too far in the archives to read where I didn't tighten those bolts sufficiently with my last pad change, and one of the caliper mounting bolts backed all the way out! grrrrrrr

So Redshift, now my black calipers are scraped clean in parts due to contact with my three-pc wheels.

-Dave
 

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Discussion Starter #9
Thanks everyone, your feedback is always valuable :M5thumbs:
 

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Black M5 said:
Im posting this question for a freind of mine who wanted to know how good stop tech's are for hard driving and track use. I believe he just bought a 4 wheel stop tech brake system for his M5. Thanks in adavance for the info
This press release should answer your question. http://www.stoptech.com/press_releases/laguna_wins.htm

StopTech equipped cars have totally dominated this year's SCCA SPEED World Challenge Touring Car series. The brakes used on the Turner Motorsports cars are exactly the same brakes I installed yesterday on a customer's supercharged BMW 323i.

Grinding casting flash off the 323i knuckle before bolting on the StopTech caliper bracket

My customer snapped the photo above while I was installing a set of StopTech 4-wheel brakes on his car.
 

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Guys,

this is a good thread for someone like myself about to pull the trigger on a set of front Stoptechs after driving mcouling's car last saturday. (thanks Mike)

Can someone recommend a set of track pads to be used with these?

I track around only twice a year, so changing shouldn't be an issue.

I believe the kit comes with Axxis Ultimates, which i presume are good for the road, but what track ones do u use/recommend.

many thanks as ever
Foxy :thumbsup:
 

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foxyboym5 said:
Can someone recommend a set of track pads to be used with these?

I track around only twice a year, so changing shouldn't be an issue.

I believe the kit comes with Axxis Ultimates, which i presume are good for the road, but what track ones do u use/recommend.
Regardless of how many times you track per year, the Performance Friction 01 pads are the ones I strongly recommend. Of all the pads I support, this one results in the most positive customer feedback and the least number of judder complaints. Very good cold bite, so you can run them at the track when the ambient temperature dips below 40 degrees. Some other pads, like the Cobalt Friction Spec VR, have trouble when it's that cool. The torque curver is flatter than PFC97 and it has a maximum operating temperature you will not exceed with StopTech brakes. PFC97 pads will last longer, but the lower bite and more variability in torque across the temperature range make it somewhat less desirable. If you were running an event every weekend, you might use the PFC97 to save money, but with only two track events/year the PFC01 pads are ideal.

When switching back and forth between your street and track pads, follow the process outlined here to make sure you always have the appropriate transfer layer on your rotors: http://www.zeckhausen.com/avoiding_brake_judder.htm

You're correct about the Axxis Ultimate pads. They are great road pads but will give you deposition problems at the track.
 

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Brilliant, thanks Dave. Are these available in the UK? If not, not sure if u can supply?

cheers
piers
 

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foxyboym5 said:
Brilliant, thanks Dave. Are these available in the UK? If not, not sure if u can supply?
I can always send you a set, if you need them. But shipping to the UK costs $48 for a set of pads, so you should try looking for a local source first. Of course, the relative weakness of the US dollar to the pound sterling might offset that.
 

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yep, i'll get the brakes done first for road use £££££ :sad2: , then sort it before tracking

cheers
 

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Dave, in your expert opinion is there any reason Stoptech went with 4-pots rather than 6 (or even 8 as in the case of the top Brembo kits)??


Thanks
Roger
 

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rogbacon said:
Dave, in your expert opinion is there any reason Stoptech went with 4-pots rather than 6 (or even 8 as in the case of the top Brembo kits)??
Yes. There are many reasons for picking a certain number of pistons for a particular application. In general, a 6 piston caliper will not be as stiff as a 4 piston caliper. (You can see this effect in the caliper deflection charts here: http://www.stoptech.com/technical/caliperdeflectionchart.htm) So that translates into softer pedal feel. In order to accomodate more pistons without compromising stiffness, one needs to add bulk to the caliper and that impacts which wheels it will fit under. And the manufacturing cost is a consideration if you want your kit to reach a certain price point. More pistons means more materials, pistons, seals, dust boots, and greater assembly costs.

If you want to generate more brake torque for a given application without increasing rotor diameter, you could increase the piston size. At some point, you run into a conflict between the size of the pistons and the shape of the pad. In order to apply even pressure across the backing plate of a very long pad, you may opt for more, smaller pistons.

When you say the "top Brembo kits" as you refer to their 8-piston front kit for the M5, you need to remember that this is their top price kit for the M5 application, but not necessarily the top performing kit for the M5 application. If your interest is bling, then the 8-piston Brembo certainly has curb appeal. But it requires 19" wheels to fit and it is significantly heavier than the 4-piston Brembo kit. It is an appropriate solution for the BMW X5 where more brake torque is required than could be provided by the Brembo 4-Piston. But it is not a "better" kit for the M5.

Some vendors have begun to prey on the lack of knowledge of certain groups of automobile owners and started a "piston war" where, say, a Honda Civic with "8 pot calipers" will supposedly stop better than a car equipped with 4 or 6 piston calipers. They try to equate the number of pistons with the stopping force of the brakes. I predict you will see some of the Asian manufacturers start cranking out 12 piston calipers in the next year to market to this crowd. There's no engineering behind this sort of thinking. It's all hype.

By the way, StopTech makes a 6 piston and an 8 piston caliper for specific applications. Lou Gigliotti had a very successful year in the SCCA Speed World Challenge running the StopTech 6-piston front brakes on his Corvette in the GT class.


I snapped this shot of Lou's brakes before his race at Lime Rock this year


StopTech has created a HUGE billet 8-piston caliper for the Hummer and other oversized SUVs. You won't see this caliper offered for the M5! It's simply not appropriate.





To give you a sense of scale, that small looking rotor is 380mm (15") in diameter!
 

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Thanks Dave very helpful. I know this subject has been covered before but I appreciate the refresher!
 

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i've been quite satisfied with the PF97s for the track (with Axxis Ultimates on the rear - you won't ever get track pads up to temp on the rear)

i've run quite a few events in hot weather at Thunderhill which is demanding on brakes and finally developed a leaky seal and did a rebuild - have started to use the titanium shims - don't think StopTech makes titanium pistons for these calipers
 

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Whew! Thanks for the size clarification, I thought the pictures were actual size!! :1:

LOL!

SCORPIO

DZeckhausen said:
StopTech has created a HUGE billet 8-piston caliper for the Hummer and other oversized SUVs. You won't see this caliper offered for the M5! It's simply not appropriate.
To give you a sense of scale, that small looking rotor is 380mm (15") in diameter!
 
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