Track forum general chit chat.

[kyippee]

Originally Posted by dparm

Have you ever done a rebuild? I looked at the guide for Brembos and decided it wasn't worth the hassle and that I didn't even have some of the right equipment.


Does your BBK manufacturer offer it as a service?

Never done it before but rotora (my BBK maker) sells rebuild kits and forged pistons. The shop I get work done at (performance Technic) will do the rebuild

Rotora did say I'm likely overdue for rebuild given the days I've racked up pounding on the brakes so I guess it's time!

[dparm]

Originally Posted by kpewpew

Never done it before but rotora (my BBK maker) sells rebuild kits and forged pistons. The shop I get work done at (performance Technic) will do the rebuild

Rotora did say I'm likely overdue for rebuild given the days I've racked up pounding on the brakes so I guess it's time!

What do they charge for the rebuild kit, and what's in it? What does your shop charge?


The Brembo rebuild kit for my OEM 6-piston fronts runs $130 per caliper (includes dust boots, pressure seals, and pistons) but the labor is about 1.5 hours per caliper, according to my previous shop. Coupled with the price to remove the calipers and reinstall, it really starts adding up.


In the end, it was cheaper for me to just replace the whole caliper from GM. I sold the used ones to some guy with a Camaro who was going to get them re-painted anyway so he didn't care about needing a rebuild.

[kyippee]

Originally Posted by dparm

What do they charge for the rebuild kit, and what's in it? What does your shop charge?


The Brembo rebuild kit for my OEM 6-piston fronts runs $130 per caliper (includes dust boots, pressure seals, and pistons) but the labor is about 1.5 hours per caliper, according to my previous shop. Coupled with the price to remove the calipers and reinstall, it really starts adding up.


In the end, it was cheaper for me to just replace the whole caliper from GM. I sold the used ones to some guy with a Camaro who was going to get them re-painted anyway so he didn't care about needing a rebuild.

In terms of labor, don't know yet 😬

Front rebuild kit just under 200, rear just under 130. I believe this is for an axle, not per caliper.

Pistons are just under $25 each. And these prices are negotiated rates below their list rate.

I suspect that going your route isn't an option unless I switch BBKs. Not a common caliper!

[ThunderMoose]

Originally Posted by dparm

Have you ever done a rebuild? I looked at the guide for Brembos and decided it wasn't worth the hassle and that I didn't even have some of the right equipment.


Does your BBK manufacturer offer it as a service?

Rebuild is super simple. I have a little fitting that connects to the caliper to pressure out the pistons. After that it's just seals and boots. I also have some some stops that go on the brake lines so you don't lose a lot of fluid. I was hesitant to do it for a while but it turns out to be easy and very satisfying.

[roastbeef]

Originally Posted by kpewpew

Never done it before but rotora (my BBK maker) sells rebuild kits and forged pistons. The shop I get work done at (performance Technic) will do the rebuild

Rotora did say I'm likely overdue for rebuild given the days I've racked up pounding on the brakes so I guess it's time!

Does this kit have dust boots? If so, how are they looking?

[dparm]

Originally Posted by ThunderMoose

Rebuild is super simple. I have a little fitting that connects to the caliper to pressure out the pistons. After that it's just seals and boots. I also have some some stops that go on the brake lines so you don't lose a lot of fluid. I was hesitant to do it for a while but it turns out to be easy and very satisfying.

If you send calipers out, or have special shops do the rebuild, they will also be thoroughly cleaned and pressure-tested. Are you able to do the pressure-testing?

[ThunderMoose]

Originally Posted by dparm

If you send calipers out, or have special shops do the rebuild, they will also be thoroughly cleaned and pressure-tested. Are you able to do the pressure-testing?

I don't have the hardware on the bench to pressure, but seriously if you see how easy this is to do, there's no reason to have someone else do it. The inside of the calipers are typically pristine, so I just pressure washed the exterior and then brake cleaned and air dried all of the internal stuff.

As far as pressure testing, you effectively function test this once installed.

I only had one piston that had enough scoring to replace. So all in cost was probably less than $60 to rebuild all four corners.

I am not trying to sell you on DIY because this is one of the few spots that if you get it wrong can certainly make for a bad day, but I try to DIY everything on my track car and this was probably at difficulty level of 3 (slightly more difficult than a brake pad change).

[roastbeef]

Originally Posted by ThunderMoose

I don't have the hardware on the bench to pressure, but seriously if you see how easy this is to do, there's no reason to have someone else do it. The inside of the calipers are typically pristine, so I just pressure washed the exterior and then brake cleaned and air dried all of the internal stuff.

As far as pressure testing, you effectively function test this once installed.

I only had one piston that had enough scoring to replace. So all in cost was probably less than $60 to rebuild all four corners.

I am not trying to sell you on DIY because this is one of the few spots that if you get it wrong can certainly make for a bad day, but I try to DIY everything on my track car and this was probably at difficulty level of 3 (slightly more difficult than a brake pad change).

What about brakes with seals? Do they just press in like an O-ring or something? Seems like it could be easy.
What about anti knockback springs? Do they attach a certain way that they could be damaged if they get stretched? Or are they just sort of floating in there?

[ThunderMoose]

Originally Posted by roastbeef

What about brakes with seals? Do they just press in like an O-ring or something? Seems like it could be easy.
What about anti knockback springs? Do they attach a certain way that they could be damaged if they get stretched? Or are they just sort of floating in there?

I am fairly certain that all brakes are functionally the same in that there is a piston with a seal and a dust boot. It's as simple as pressuring out the pistons, removing the seal, and installing the new seal. Once you have the caliper on your bench, it probably takes 5 minutes per piston. The dust boots can be tricky. On brembos, they go in pretty easy. On stock calipers, you have to pre- install them in the piston and then they pop in place.

I can't say about antiknock springs as I don't run them.

You can buy a used caliper and practice with it.

[dparm]

Hmm, sounds like my shop was making it sound overly complicated to squeeze me for a few bucks. ;-)

[dogbone]

On my AP Racing CP5555 front calipers, I did the seal swap job myself. As people here probably know, I am not a mechanic. But I’ve learned about some car stuff over the last few years.

Replacing the seals was not particularly hard. The AP caliper has a main seal that’s basically solid rubber, and a wiper seal that had edges like a windshield wiper.

You need some compressed air to push the pistons out. And you need some kind of block to place inside the caliper (acting as a temporary rotor) that can stop the pistons from flying out of the calipers if you put compressed air in the caliper. You should also have some kind of tool that can help remove the seals from the caliper that won’t scratch the caliper. Scratching the metal compromises the seal’s ability to seal. I was also advised to soak the new seals in brake fluid.

I didn’t have a way to pressure test with high pressure. I figured I would just install them and see on the street if there was leaking. It was totally fine. I’ve run them on track several times and they’ve been great.

Stillen used to do the seal swap years ago, but then said they no longer did it. So I decided to try it myself. Glad I did. Very satisfying. Of course, due to the very high importance of the brake seals, I could understand not wanting to do the job. For years, I said I would never do it. But thanks to Stillen and their unwillingness to support AP products, I learned yet another skill!

[Ximian]

Originally Posted by rhyary

I make a living of complexed data center technology. I am accustom to complexity and complexity does not intimidate me.

However, the complexity of car technology including power, suspension, grip, physics, feel, intuition is endless.

One thing in the computer field is that at some point, when you get it right, it will stay that way for a reasonable amount of time.

Managing computer networks is a bit more dynamically complexed because the interaction between streams of information may effect each other in a non linear way.

But...the fact that every track day has its own variables, the tires are not the same, you may start with a fresh set, you may start with a used set. The temp will be different, the surface will be different etc etc. Each variable has its own setting, and the interaction among the variables is not linear.

I am fascinated with the infinite complexity but the fact is that as a non professional I will have to settle for only understanding the tip of the iceberg.

Since I measure every lap, whatever I try, has a result. It is either 1:36 at NYST, or it is not. I am not complaining, I enjoy the process.

This weekend, I was instructing in the novice group. The goal was not to show them how to go fast. I am not qualified for that. The goal was to explain the relationship between the throttle, brakes, steering angle, location of the car on the track and the angle of the car at the same location.

Trying to explain that to a first timer make you realize how complex the interaction between all your body parts are.

From engineering point of view, a car is one of the great human invention. It brings so much of human ability to harness the laws of physics into a machine. Driving a car on the track heighten what the machine can do.

Last time horses, dogs, elephants and giraffes try to put together a car, it drove into a ditch, if I remember correctly.

Complex data center technology? Sounds like ServiceNow, according to the integrator my customer is using.

Going back a bit to intro to computer science courses, this is the difference between deterministic and nondeterministic finite state machines. For deterministic algorithms, the same inputs always give you the same outputs. For driving on the track, the same steering wheel, throttle, or brake inputs, don't always give you the same outputs.

One of the great things about the E9x M3s is that they are heavy, powerful cars with a few weaknesses that introduce inconsistency to performance on track as you add on laps in a session. Street tires overheat, brakes overheat, fluids overheat, and they all alter how you have to respond at a specific speed into a corner over the course of a session.

I know at the last half of a session, I need to start braking a half second earlier into the heaviest braking zones to make sure I don't run out of track as brakes are toward the bad end of operational temperatures. I also know I need to adjust my line and late apex into long corners so I'm not putting more heat into the tires. There are also corners that I know I can try to lift and coast through rather than attacking it and braking for an extra 2-3/10th of a second, to avoid adding more heat into the tires and brakes.

Without these variables, I wouldn't have a reason to learn to drive in a compromised way that actually can benefit me overall. Once you start adding track compound tires, BBKs, and cooling upgrades, a lot of those variables disappear. You're essentially removing a large part of nondeterminism from high performance driving. You don't have to adjust your line to cool the tires as they still have the same grip at the end of the session as they did at the start. You don't have to back off the brakes because they're not overheating, and you don't have to keep checking the dials (or sniffing the air) for overheating fluids. You can just take the ideal line that suits your driving style every time.

Once you learn how your car, network, or server performs over time, you know what you can start ignoring and for how long. That removes a ton of complexity and all you're left with is few variables to look at. It's a useful skill when you're troubleshooting problems in a complex environment.

If you look at some of the experienced drivers out there, a lot of them have a list of things they can ignore in the back of their minds (e.g. I can run two hot laps with this car without any one thing falling apart) and the others have blissful ignorance. One of the scariest moments for me happened when discussing the session after a ride along with an instructor. My assumption on track was that he kept pushing his car because he knew that the limits are still beyond what I thought they were. But that wasn't skillful rotation during trail braking, that was the rear trying to slide away. That wasn't attacking the corner with hard braking even toward the very end, that was the fluid starting to boil and he didn't realize it. From the outside, it looked skillful and complex. Blissful ignorance.

We're not driving overpowered and ultra sensitive race cars. My opinion is that it's only as complex as you want to make it to be or you want to think it to be. Suspension settings seem like a overly complex thing but the secret I was told by a race engineer is that they're mostly winging it. They don't calculate an ideal configuration, it's mostly set on feedback from a driver to suit their style.

[roastbeef]

Makes sense you wouldn't want to score the cylinder wall of the brake caliper pistons. Do you just stab at the seals with a pick and be careful?

[roastbeef]

Originally Posted by rhyary

I make a living of complexed data center technology. I am accustom to complexity and complexity does not intimidate me.

However, the complexity of car technology including power, suspension, grip, physics, feel, intuition is endless.

One thing in the computer field is that at some point, when you get it right, it will stay that way for a reasonable amount of time.

Managing computer networks is a bit more dynamically complexed because the interaction between streams of information may effect each other in a non linear way.

But...the fact that every track day has its own variables, the tires are not the same, you may start with a fresh set, you may start with a used set. The temp will be different, the surface will be different etc etc. Each variable has its own setting, and the interaction among the variables is not linear.

I am fascinated with the infinite complexity but the fact is that as a non professional I will have to settle for only understanding the tip of the iceberg.

Since I measure every lap, whatever I try, has a result. It is either 1:36 at NYST, or it is not. I am not complaining, I enjoy the process.

This weekend, I was instructing in the novice group. The goal was not to show them how to go fast. I am not qualified for that. The goal was to explain the relationship between the throttle, brakes, steering angle, location of the car on the track and the angle of the car at the same location.

Trying to explain that to a first timer make you realize how complex the interaction between all your body parts are.

From engineering point of view, a car is one of the great human invention. It brings so much of human ability to harness the laws of physics into a machine. Driving a car on the track heighten what the machine can do.

Last time horses, dogs, elephants and giraffes try to put together a car, it drove into a ditch, if I remember correctly.

How many track days have you done to date? Seems like you go about every other weekend.

[rhyary]

Originally Posted by roastbeef

How many track days have you done to date? Seems like you go about every other weekend.

About 50 so far?
First year about 20
second year about 22
This year about 10 so far.

since June 11th it would be a bit crazy.
June 11th open day at LRRP,
21 NYST with open track toward the end
coming up Racing School at LRP 28 and 29
and another track day on Monday July 1st.

I just heard that I might get invitation to Monticello track with bunch of McLarens for Sunday.

So it is intense schedule for sure.

[M3 Number 86]

[CorruptCommie]

Dude he almost had you though. He almost had his car.

[Richbot]

That guy is destined for a tire wall

[dogbone]

Originally Posted by roastbeef

Makes sense you wouldn't want to score the cylinder wall of the brake caliper pistons. Do you just stab at the seals with a pick and be careful?

On the AP calipers, the solid rubber seal has enough meat that I could get on it with a pick and pull them out. The wiper seal has no meat like that. It's basically hollow in the middle. Plus, the wiper seals were basically destroyed which made it even more difficult to get them out. I didn't have plastic tools, so I just had to be careful with the metal tools I had. Someone recommended trying simple plastic utensils. I didn't try that but maybe it could work.

[Chris_PDX]

Originally Posted by M3 Number 86

I don't know what track this is but I can do a 1:10 flat. FACT.

[MaximusB]

What are everyone's thought/advice for newbie driver and MDM?

I just did my first HPDE this past weekend, had a blast. I had the traction control on the whole day as it was my first time on this particular track. All my previous experience were autocross or high performance driving clinic at an air field.

The issue I had with traction control on was it intervened when I tried to power out of an apex on tight corners. This was especially apparently in the afternoon sessions when my tires got a little greasy.

So my question is, should I try driving with MDM the next time out (in two weeks)? Or I am better off keeping traction control on and just focus on being smooth on corner entry/exit? I am thinking maybe TC came on is because I got on the gas too early or too hard? But a few times my instructor was telling to hammer it but the car just wouldn't go till it completely straightened out.

Oh I also got signed off by in the afternoon to drive solo. although I am going to request an instructor the next time out, at least for the morning sessions and see how it goes first.

[Ximian]

Originally Posted by MaximusB

So my question is, should I try driving with MDM the next time out (in two weeks)? Or I am better off keeping traction control on and just focus on being smooth on corner entry/exit? I am thinking maybe TC came on is because I got on the gas too early or too hard? But a few times my instructor was telling to hammer it but the car just wouldn't go till it completely straightened out.

While DSC starts limiting you earlier than MDM would, it's better to work on smoothness than going straight to MDM or DSC off. The DSC light on the dash is a more consistent indicator (see deterministic algorithms from an earlier posts) where you can be smoother than any instructor would be. While your instructor is probably right that you can safely hammer it, the car thinks there is a significant enough risk involved so you should figure out why that is first.

Feel free to let your instructor know if there is something you do not want to do, such as if you'd rather work on on smoothness and go slower out of corner without DSC kicking in.