StopTech ST40 or ST60 on track

[mrvedit]

Previously with stock calipers and either StopTech or Turner slotted rotors and PFS track pads I had sufficient stopping power when running street/track tires at various tracks.
However last week I decided to try R-compound racing slicks and I did not have the stopping power I have with my track C6 Vette on the same tires at the same track.. (The Vette has 6-piston Wildwoods.) It wasn't fade as it was the same stopping power from 2 minutes in to 30 minutes in.

Since StopTech is a respected brand here (and less costly than Brembo) I am leaning toward either the 4-piston ST40 355mm or 6-piston ST60 380mm kit.
I have a square setup with 18" Apex SM-10 wheels which are documented as working even with the ST60 380MM BBK. (The cheaper Apex wheels do not fit.)
However since the ST60 calipers/rotors would be a tight fit in the 18" wheels, I wonder if the ST40 kit would work better due to better cooling due to more clearance? I due like that the ST60 pads are a bit bigger that the ST40 pads.
Any thoughts or other suggestions? (Appearance is a non-issue.)

Finally for those who seriously track the StopTech ST40 or ST60, what pads do you use?

Thank you for reading.

[Ximian]

I have the ST60 front kit. They come with street pads which frankly have terrible stopping power but they work for the street. They're the 1247/DR11 pad shape. A big problem is that there are a lot of compatible pad shapes, but their backing plates do not fit our rotor hats.

I've had CarboTech XP20 in the front paired with PFC 11 pads in the rear. That combination had amazing stopping power. My front rotors also seemed to have a lot of pad transfer causing steering wheel to shake after year of use. Other people have had similar issues with this type of pad on other cars. More details here. They're the only aftermarket pad I've come across that fits the DR11/1247 pad shape and backing plate dimensions perfectly.

Weeks ago, I got a new set of rotor rings and hats and got Cobalt Friction XR2s with the same PFC 11 rear. They're great, but a step down in stopping power. Their web site states the AP5 pad shape is the right one for the ST60, but it is not. Get the AP6 instead as there is less of the backing plate to remove for the right fit.

I also purchased the PFC 83 pads (7793 shape) for a cheap price but those don't fit our with our rotor hats. You'll pretty much have to stay away from all PFC pads for the ST60 on the E9x M3 rotor hats.

I think with the ST40, you'll have far more choices with compatible pad shapes and backing plates. Might be a better way to go if you get the ST40 caliper for the rear.

My biggest issue is just the difficulty in finding reasonably priced replacement parts for the ST60. I debated picking up another ST60 because the price difference wasn't that significant with the prices I was finding for two E9x M3 rotor hats and two 380x35 rotor rings, plus the unavoidable caliper rebuild.

Long term track use, something like the Essex AP kit might be cheaper. While it's almost twice the price, at least you have someone knowledgable to talk to about issues like nthis rather than wasting a lot of money finding it out yourself.

[Davisca455]

PM received,
My track/car use philosophy might be too different from yours, so I'm not likely to have much useful info for you?

For instance, I'm going to stay on street tires because I'm concerned about the extra grief that can be applied to other bits of the chassis when using track rubber.
My car needs to remain street friendly, so if it's a choice between lap time improvement or comfort, my lap times will have to suffer.

I went to the front ST-60s (OEM rear) because…
1) OEM rotors needed to be replaced and I didn't believe the OEM system would be an appropriate long term solution for the track.
2) Supercharged.
3) Couldn't afford the entry costs of the AP Racing equipment.

I did work with a brake expert, Dave Zeckhausen, for a track pad recommendation though.
He recommended Hawk DTC-60s because he thought they'd play well with street tires.

I have zero complaints about either the ST-60s or the DTC-60s after 3 track days.

[mrvedit]

Thank you Ximian and Davisca455 !
Based on your comments, I'm inclined to go with the ST-60s and Hawk DTC-60 pads. I have used those pads before and know they are track-only pads, but easy enough to swap back to the stock StopTech pads. I also plan to stay with OEM rears using DTC60.

I understand the concerns about running r-compound track tires and the extra forces on the car. I wasn't sure if the stock competition suspension would hold up but it was fine. I was previously running Yokohama AD08 tires but felt little improvement over Michelin PS4s. Hence I tried my barely used BFG R1 tires and loved them.

On my last run a month ago with the AD08 tires a front hub became very noisy. I therefore upgraded to F80 hubs, which has been documented on this forum. Since then I have also installed a roll cage, racing seats and harness. Cat delete and tune from Alex@Alpine.

[endur0]

Does AP Racing make a radi-cal kit for the e9x? If so, I expect their calipers to be a little smaller for the same benefit. Also, if you get the right set, you can swap pads without removing calipers (unsure if the Stop Techs offer this feature).

[Ximian]

Originally Posted by endur0

Does AP Racing make a radi-cal kit for the e9x? If so, I expect their calipers to be a little smaller for the same benefit.

Yes, they do.

Also, if you get the right set, you can swap pads without removing calipers (unsure if the Stop Techs offer this feature).

The ST60 (but likely the ST40 as well) has a caliper bridge with pad retaining springs. It's four hex bolts holding it in place, pretty easy to remove.

[mrvedit]

Thanks for the additional info.
While a bit more work for pad swaps, I suspect that calipers with bridge supports are stiffer.

[mrvedit]

I tried to order the ST-60 listed on Amazon for $3500 but the seller (Gruppe-S) notified me it was out of stock, as were the ST-40 they had listed for $2950. Those prices were significantly less than what Zeckhausen was listing. Gruppe-S said that StopTech does not have them in stock and I therefore suspect that no one does. Other vendors (e.g. ECS Tuning) list this as a drop ship around late November. My season is over by then.

Plan B to finish this season is to try a different brake pad with my stock calipers; I currently have PFC "08". The PFC "15" look interesting with a lot more medium temp bite, but I don't see them for sale, only "08" and "11". I may therefore try Hawk DTC-60 all around.

I'm all ears (and eyes) for another other suggestions or sources.

[DRLane]

Originally Posted by mrvedit

I tried to order the ST-60 listed on Amazon for $3500 but the seller (Gruppe-S) notified me it was out of stock, as were the ST-40 they had listed for $2950. Those prices were significantly less than what Zeckhausen was listing. Gruppe-S said that StopTech does not have them in stock and I therefore suspect that no one does. Other vendors (e.g. ECS Tuning) list this as a drop ship around late November. My season is over by then.

Plan B to finish this season is to try a different brake pad with my stock calipers; I currently have PFC "08". The PFC "15" look interesting with a lot more medium temp bite, but I don't see them for sale, only "08" and "11". I may therefore try Hawk DTC-60 all around.

I'm all ears (and eyes) for another other suggestions or sources.

This is the move if you want ST60/40.

E9x M3 Stoptech ST60/40 BBK https://www.m3post.com/forums/showthread.php?t=1860088

[Ximian]

Originally Posted by DRLane

This is the move if you want ST60/40.

E9x M3 Stoptech ST60/40 BBK https://www.m3post.com/forums/showthread.php?t=1860088

Looks like a great deal, but the caveat with the "Front rotors should probably be replaced soon" is that it'll cost a fair amount and it'll take quite a while to get the replacements. It took me nearly a month to get some rotor rings that were in stock.

[DRLane]

Originally Posted by Ximian

Looks like a great deal, but the caveat with the "Front rotors should probably be replaced soon" is that it'll cost a fair amount and it'll take quite a while to get the replacements. It took me nearly a month to get some rotor rings that were in stock.

I'd get ask for some measurements, they could be more than enough to get someone through their season.

[Davisca455]

Originally Posted by mrvedit

I tried to order the ST-60 listed on Amazon for $3500 but the seller (Gruppe-S) notified me it was out of stock, as were the ST-40 they had listed for $2950. Those prices were significantly less than what Zeckhausen was listing. Gruppe-S said that StopTech does not have them in stock and I therefore suspect that no one does. Other vendors (e.g. ECS Tuning) list this as a drop ship around late November. My season is over by then.

Plan B to finish this season is to try a different brake pad with my stock calipers; I currently have PFC "08". The PFC "15" look interesting with a lot more medium temp bite, but I don't see them for sale, only "08" and "11". I may therefore try Hawk DTC-60 all around.

I'm all ears (and eyes) for another other suggestions or sources.

Text Adam Hume at buybrakes.com

(702) 903-1713

adam@buybrakes.com

My Trophy kit was $2860 to my door.
But had to wait 8 weeks while they built the kit.

[exVtekGuy]

Originally Posted by Davisca455

Text Adam Hume at buybrakes.com

(702) 903-1713

adam@buybrakes.com

My Trophy kit was $2860 to my door.
But had to wait 8 weeks while they built the kit.

I saw around $2800 for trophy front, $2400 for regular ST60, $2000 for regular ST40 during black Friday last year. I think wait time is the norm for 2-3 month. Not many has this stocked I think. Buy brakes price is great for sure. Not sure why other vendors prices are so much higher.

Essex has nice AP kits for track and also for street. A bit more for them than Stoptech but looks like they have been put together with a lot of thoughts.

[CHSe92]

Originally Posted by Davisca455

Text Adam Hume at buybrakes.com

(702) 903-1713

adam@buybrakes.com

My Trophy kit was $2860 to my door.
But had to wait 8 weeks while they built the kit.

I also went this route. Adam responded surprisingly fast (on a weekend) and was able to quote me a price to my door that was too hard to pass up

I ended up going ST60 front running w/ stock rears. Carbotech XP12/10 on Proxes RR's. Big improvement in performance/feel and confidence throughout the entire weekend

[jritt@essex]

Originally Posted by endur0

Does AP Racing make a radi-cal kit for the e9x? If so, I expect their calipers to be a little smaller for the same benefit. Also, if you get the right set, you can swap pads without removing calipers (unsure if the Stop Techs offer this feature).

We have some fantastic Road and Competition Radi-CAL Brake Kits for the e9x M3, that have proven to be the highest performing, most durable systems available on the market today at any price. You can see our full menu of brake products for the e9x M3 here:
https://www.essexparts.com/my-vehicl.../BMW/M3/%20E92

While our systems are the cheapest, they are the same quality as the systems we supply to professional racing teams. We continue to rack up race wins and championships at all levels every week, and a quick peek at our blog will give you a snapshot of that success:
https://www.essexparts.com/news-blog

We also find that the consumables in our systems last longer than our competitors. What people tend to overlook is that even if our system costs 25% more than a competitor, it is still the superior value if it lasts twice as long! Here's an article we published on that topic a while back, which happens to use an e90 M3 ownership experience as an example.

Is it worth upgrading my brakes for the track?

Our systems also retain the greatest value on the used market, and typically change hands at about 65% of their retail price as new. You never see them in the bargain bin with the cassette tapes and HD DVD players.

We also back our systems up with the best service in the industry, which is an important factor when considering a brake system. You can call us at any time during normal business hours, and you will immediately get a human on the phone who can help you, answer your questions, etc. No automated phone tree, no chasing people for a response, no praying for an answer when you're up to your eyeballs in brake fluid.

We should be able to get you a system in far less than two months! During normal times we typically ship within 48 hours of placing an order. Under current Covid chaos, we're backlogged about a week and a half.

We are also long-time forum sponsors and have dedicated a great deal of time to helping our M3 customers over the years.

You can find cheaper alternatives, but you won't anything that performs better, is more durable, backed by better service, retains more value, etc. Our systems are truly the best investment in brakes available today. For many people, eliminating the headaches, delays, poor service, spoiled track days, etc. is worth a few extra bucks. At least that's what all our clients tell us!

Thanks for your consideration.

[aus]

Apex 18" ARC8 wheels fit around the ST60 caliper. Been using them for years.
Another pad to consider is the Stoptech R34/33 pad. Priced nicely and last a long time, particularly the R33.
On a track that's hard on the brakes, the regular ST60 paint will fade. Laguna Seca always changes the color of my calipers a little.
.

[mrvedit]

Thank you for Aus for reassurance that the ST60 will fit my Apex SM10 wheels which supposedly have more clearance that Arc8.
I just installed DTC60 pads which David at Zeckhausen recommended to me. This weekend is is next and last track weekend at Grattan Raceway.
I will keep my eyes open for any Black Friday sales on ST60 or similar kits.

[CHSe92]

Originally Posted by mrvedit

Thank you for Aus for reassurance that the ST60 will fit my Apex SM10 wheels which supposedly have more clearance that Arc8.
I just installed DTC60 pads which David at Zeckhausen recommended to me. This weekend is is next and last track weekend at Grattan Raceway.
I will keep my eyes open for any Black Friday sales on ST60 or similar kits.

I run 18" SM10's on track with ST60's and they fit fine. Plenty of clearance between spokes and the barrel