Stoptech ST40/328mm BBK

[teemmy]

I have a set of st40 brakes for sale if anyone is interested

 

[jmason]

I have a set of st40 brakes for sale if anyone is interested

Would be, but shipping from CA to MD is likely to be pretty stiff. Why are you selling if I may ask?

 

[Daily Driver]

Bringing this back to life.

Is there an actual difference between MK7 PP brakes VS stoptech ST40 328x28 in braking power and performance? Or not worth the upgrade?

 

[SouthFL_Mk7.5]

Bringing this back to life.

Is there an actual difference between MK7 PP brakes VS stoptech ST40 328x28 in braking power and performance? Or not worth the upgrade?

I was just talking about this with a fellow forum member over the weekend.. he ran the ST-40 at a track day and had to keep coming back in (flagged by corner workers) due to the brakes glowing hot… said the ST-40 didn’t have enough mass/heat sink to run cool- switched to Macan brakes and didn’t have the problem again.

 

[Bernb6]

I'm not doubting the report but there must be more to this story about glowing rotors.
You actually don't want the heat going into the calipers - that tends to boil the fluid (ask me how I know).

First, to Daily Driver's question: yes, there are performance differences but, frankly, you need to be tracking significantly to benefit from them.

A basic benefit is in unsprung weight. Each ST-40 caliper (and pads) is 7 lbs less than PP setup. See here: https://www.golfmk7.com/forums/inde...pp-macan-stoptech-bbk-calipers-rotors.388961/ Using two piece rotors (even 355mm) gains even more weight savings over stock.

In my experience (GTI and previous Porsches), Stoptech ST-40 offer firmer and higher pedal feel and more resistance to fade/fluid issues.

Another benefit is very easy bleeding and pad change. With wheels off, it's about a five minute job per side to swap pads and flush the calipers with a simple hex bit driver and bleed bottle.

Re heat dissipation, that is pretty much the rotor's job. Again, you do not want heat getting into the calipers - that's why some people use titanium shims to block heat from the calipers. And two piece rotors do a much better job at air flow through the rotor vanes. And 355mm rotors are much better than 328mm rotors.

If rotors are glowing hot, then the brake setup is generating much more energy to go into the rotors in the first place. Other things being equal*, the more energy you're putting into the rotors, the more energy you're taking out of velocity. *Brake pad material and proper bedding make a difference, too.

Bern

 

[acorazza]

I'm not doubting the report but there must be more to this story about glowing rotors.
You actually don't want the heat going into the calipers - that tends to boil the fluid (ask me how I know).

First, to Daily Driver's question: yes, there are performance differences but, frankly, you need to be tracking significantly to benefit from them.

A basic benefit is in unsprung weight. Each ST-40 caliper (and pads) is 7 lbs less than PP setup. See here: https://www.golfmk7.com/forums/index.php?threads/unsprung-brake-weight-comparison-–-oem-pp-macan-stoptech-bbk-calipers-rotors.388961/ Using two piece rotors (even 355mm) gains even more weight savings over stock.

In my experience (GTI and previous Porsches), Stoptech ST-40 offer firmer and higher pedal feel and more resistance to fade/fluid issues.

Another benefit is very easy bleeding and pad change. With wheels off, it's about a five minute job per side to swap pads and flush the calipers with a simple hex bit driver and bleed bottle.

Re heat dissipation, that is pretty much the rotor's job. Again, you do not want heat getting into the calipers - that's why some people use titanium shims to block heat from the calipers. And two piece rotors do a much better job at air flow through the rotor vanes. And 355mm rotors are much better than 328mm rotors.

If rotors are glowing hot, then the brake setup is generating much more energy to go into the rotors in the first place. Other things being equal*, the more energy you're putting into the rotors, the more energy you're taking out of velocity. *Brake pad material and proper bedding make a difference, too.

Bern

Are you running the 355mm or 328mm disks?

 

[Daily Driver]

I'm considering the 328 over the 355 cause I'm running 17x8.5 and ST40 328 clear no issues I need spacers for 355.

I don't really track I do alot of straight line street race.

 

[ckuhns]

I know a guy selling a 328mm kit...

 

[acorazza]

I know a guy selling a 328mm kit...

I’ve thought about it trust me. I run 17x7.5 in the winter and don’t really want to run spacers or bigger wheels. I also have the performance pack already so it’s actually a downsize in diameter even though I know the 2 piece Stoptech rotors are superior. I’m hoping to get into track days next year and some autocross this year

 

[SouthFL_Mk7.5]

I’ve thought about it trust me. I run 17x7.5 in the winter and don’t really want to run spacers or bigger wheels. I also have the performance pack already so it’s actually a downsize in diameter even though I know the 2 piece Stoptech rotors are superior. I’m hoping to get into track days next year and some autocross this year

I’d keep the larger 340mm rotor of the PP brakes rather than go down in rotor size for a fixed caliper. Combined with a 2pc rotor for better heat dissipation the PP brakes are plenty good for 90% of the track duty you’d ask them for.

 

[Bernb6]

Are you running the 355mm or 328mm disks?

355mm

 

[acorazza]

I’d keep the larger 340mm rotor of the PP brakes rather than go down in rotor size for a fixed caliper. Combined with a 2pc rotor for better heat dissipation the PP brakes are plenty good for 90% of the track duty you’d ask them for.

That's what I was originally thinking but with the price of 2 piece rotors I was considering other options

 

[Daily Driver]

I’d keep the larger 340mm rotor of the PP brakes rather than go down in rotor size for a fixed caliper. Combined with a 2pc rotor for better heat dissipation the PP brakes are plenty good for 90% of the track duty you’d ask them for.

What would your choice of 2pc Rotors and pads running PP brakes. For 90% street use and possibly 10% track.

 

[SouthFL_Mk7.5]

What would your choice of 2pc Rotors and pads running PP brakes. For 90% street use and possibly 10% track.

I use the ECS front 2pc. The Girodisc are upmarket and probably better but the ECS have worked fine. I did notice that swapping to the 2pc let me stay out longer during the sessions.

For pad I use the street/light track Porterfield R4S all around daily and autocross and swap in the track specific R4 up front for the track weekend. Street driving to/from the track with the R4 isn’t nearly as bad as other track specific pads.

You can get by with the R4S for a track day but once you push later and harder into the brake zones they will reach their limit! The R4 can take abuse.

Been using the ECS 2pc up front for daily driving going on a couple years now. 2 track days and 7 autocross days and no lip has formed yet on the unswept area. Rear factory rotors are just now showing a slight ridge.

 

[ckuhns]

I’ve thought about it trust me. I run 17x7.5 in the winter and don’t really want to run spacers or bigger wheels. I also have the performance pack already so it’s actually a downsize in diameter even though I know the 2 piece Stoptech rotors are superior. I’m hoping to get into track days next year and some autocross this year

For the record I did use them with 17x7.5 Sparco winter wheels.