Stoptech ST10 parking brake / emergency brake revised instructions

I am not sure why you are having these problems with the e-brake. But here is a cropped picture after it was installed on mine; I show with red arrow the space which I am guessing is at least 5mm/0.25" if not more - I can take more once I wash the brake dust from a track event.

what is your wheel diameter Hrant ? That looks like an 18" rim hence the clearance.

sparky said:

what is your wheel diameter Hrant ? That looks like an 18" rim hence the clearance.

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It's the 02+ 17" OEM wheel with 15mm spacer.

http://nsxprime.com/forum/showpost.php?p=1116505&postcount=10

Hrant said:

It's the 02+ 17" OEM wheel with 15mm spacer.

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OK, so we're all using 17" but you don't have the issue! Curious. It's a bit hard to tell from your photo, how much clearance have you actually got (approx). Not where the red arrow is, but from the two ribs on top of e-brake to wheel ?

I'll post some photos of my interference experience later today.

just realized your STOPTECHs are circa 2009 Hrant and not the "trophy" style, so I'm guessing the e-brake design has been revised and introduced the interference problem.

PS: I could get paranoid and think you are following me - seems where ever I go on Prime .... you're there too!! :biggrin:

sparky said:

OK, so we're all using 17" but you don't have the issue! Curious. It's a bit hard to tell from your photo, how much clearance have you actually got (approx). Not where the red arrow is, but from the two ribs on top of e-brake to wheel ?

I'll post some photos of my interference experience later today.

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Its difficult to tell but I think Hrant's ebrake does not have the two ribs while the new ones do.

Hrant, can you confirm if your brake has the two ribs?

Help me out with what two ribs are

And yes, mine is not the Trophy. But as far as i know, the only difference is supposed to be shaving some of the weight from the fascia of the calipers; the e-brake they supply would have been the same.

Edit: August 6 with newer picture:

I'd say the design of the e-brake calliper has been changed .... here's a picture showing the current design with two ribs, after my grinding down to fit within the 17" rim.

sparky said:

I'd say the design of the e-brake calliper has been changed .... here's a picture showing the current design with two ribs, after my grinding down to fit within the 17" rim.

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Though this is not my thread, but Sparky, You are right!

I contacted Stoptech and asked their engineer who helped us with the e-brake if the design had changed to reduce weight as well, and the ribs for added strength given the now vented caliper design (exposed to the rotor). He confirmed with the following response:

Hi Hrant,

That is correct. The manufacturing process of the caliper body has changed from very expensive billet components, to a higher volume more cost effective forged and cast components with integral cable bracket. The internal components have not changed. Because of the design change and also the change from 4 to 2 bolts holding the two caliper bodies together, ribs are added to resist flex when the brake is applied. Those grinding the ribs down could potentially be making their caliper not as stiff as designed. It is very stiff to begin with, so as long as the caliper functions as necessary, it may not be an issue.

I do agree however that our wheel fitment templates should embody this caliper clearance so that customers know what to expect.


HTH.

Hrant said:

Though this is not my thread, but Sparky, You are right!

I contacted Stoptech and asked their engineer who helped us with the e-brake if the design had changed to reduce weight as well, and the ribs for added strength given the now vented caliper design (exposed to the rotor). He confirmed with the following response:

Hi Hrant,

That is correct. The manufacturing process of the caliper body has changed from very expensive billet components, to a higher volume more cost effective forged and cast components with integral cable bracket. The internal components have not changed. Because of the design change and also the change from 4 to 2 bolts holding the two caliper bodies together, ribs are added to resist flex when the brake is applied. Those grinding the ribs down could potentially be making their caliper not as stiff as designed. It is very stiff to begin with, so as long as the caliper functions as necessary, it may not be an issue.

I do agree however that our wheel fitment templates should embody this caliper clearance so that customers know what to expect.


HTH.

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Wow! Mystery solved! Thanks Hrant for actually going all the way and contacting StopTech directly!

Although its not stoptech's issue, i wonder if they can make a design change for the ebrake? I'd be happy to loan them my car for a few weeks if they are interested. That way we can still run these brakes under our OEM wheels with spacers.

I would be more interested in buying the older design. I wonder what the weight difference is between the two.

Bright Light Tech said:

Wow! Mystery solved! Thanks Hrant for actually going all the way and contacting StopTech directly!

Although its not stoptech's issue, i wonder if they can make a design change for the ebrake? I'd be happy to loan them my car for a few weeks if they are interested. That way we can still run these brakes under our OEM wheels with spacers.

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Actually, one of the partners has an NSX but he is on aftermarket wheels with his Trophy :wink:

If you are not planning to use your e-brake in rally races, then grinding it down should be fine but I know that is not the answer that buyers want to hear.

While understanding Stoptech's need to be cost efficient, I think if they had designed the e-brake caliper so as not to be higher than the brake caliper my guess all would have been fine with fitment. Perhaps they can still do this in their future casting at minimal "change order" cost.

Well at least we know how it came about. Stoptech probably use this e-brake caliper design on lots of cars not just NSX, and not many have 17" rear wheels so it doesn't come up that often. I predict it would be an issue on any 17" rim.

I don't know how much cost for Stoptech to change the design a little, but I reckon they should look at it if not overly costly. It's really not much oversize. I probably shaved 2 - 3 mm at the inner edges of the ribs, tapering to almost zero at the outer edges. Im confident/certain this small amount is not threatening the strength of the caliper in any meaningful way (I'm not into handbrake turns on public roads, or the track for that matter !)

One thing to keep in mind though, the clearance between rim and caliper after shaving is only perhaps 2mm, so stick-on wheel balancing weights could collide if placed in wrong spot.

Thank you, Thank you! :redface: I thought i was going crazy there for a minute.

I personally think those "ribs" are pointless for an e-brake.

wah these are great info and findings!

Added a better picture in post #32.

I wanted to let you know that we are working with Stoptech to address the design change that caused the hand brake caliper to have an additional offset. I will update you as soon as I have more information.

-- Chris

good to hear. thanks Chris