Big Brake Kit Installed on Si - problem with wheel bolts

[077]

I have just installed the 27Won Big Brake Kit on a 2018 Civic Si with the OEM wheels. It required 5mm wheel spacers. There is 1 to 2 mm brake clearance with the spacers. As a result the lug nuts only engage 4 full turns instead of 7 or 8. This is not acceptable to me, especially for track and autocross use. Am I worrying unnecessarily? What to do now?

If I need longer studs, where can I get them?

I spoke to someone at 27Won, who said I did not need longer bolts with up to 15 mm spacers, but that makes no sense, You'd barely see the threads. I must have misunderstood.

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[077]

Here is what I had to do so the wheels don't fall off. Install wheel bolts one inch longer, Cut closed ends of lug nuts. Looks pretty good, I think.

 

[pinhead66]

How’s the pedal feel with the new kit? Is it firmer than stock? Does it bite right away with initial pedal travel? Good to know it will clear with only a 5mm spacer but just barely.

 

[077]

Pedal is firm, with good bite, but then I bled the brakes during the installation. Doing a track day this weekend,we'll see how the brakes work then.

 

[boibuddha]

I spoke to someone at 27Won, who said I did not need longer bolts with up to 15 mm spacers, but that makes no sense, You'd barely see the threads. I must have misunderstood.

There are two types of wheel spacers, bolt-on and slip on (seen below).

You most likely have slip on 5mm spacers. Once you go up to 15+ mm, they tend to be the bolt-on wheel spacers which use nuts to hold onto the factory studs and use their own studs to attach the wheel. View attachment 178238

 

[pinhead66]

Pedal is firm, with good bite, but then I bled the brakes during the installation. Doing a track day this weekend,we'll see how the brakes work then.

Nice... let us know how it performs on the track and if theres any pad knock back. What pads are you using for the track? Any squealing on the streets?

 

[077]

Braking is much better! The brakes stayed cooler as well. The 27Won kit comes with street pads, I don't know what brand. No squeals at any time. Next year I might try switching pads for track days.

 

[pinhead66]

Glad they are working out for you. I'm definitely interested in this kit or the Stoptech. I had a Stoptech 4 piston kit when I was tracking my 350z and they performed flawlessly on the track and streets. Very good firm pedal feel with no slop in initial pedal travel. But with my new wheels on the way (18x8 +35) I don't think the Stoptech kit will fit as it requires about 9-10mm more clearance compared to the 27won kit. Plus the 27won kit is $400 cheaper.

 

[077]

27Won instructions pdf includes a template to cut out and measure on your wheels to determine if a spacer is needed. 5mm is needed for OE wheels. No spacer needed for my winter wheels. You may not need a spacer with your new wheels.

Glad they are working out for you. I'm definitely interested in this kit or the Stoptech. I had a Stoptech 4 piston kit when I was tracking my 350z and they performed flawlessly on the track and streets. Very good firm pedal feel with no slop in initial pedal travel. But with my new wheels on the way (18x8 +35) I don't think the Stoptech kit will fit as it requires about 9-10mm more clearance compared to the 27won kit. Plus the 27won kit is $400 cheaper.

 

[racer]

While late to the party, I believe SCCA and others use a guide of "thread engagement must be equal to the stud diameter". So, it was possible that 4 full rotations would have met that goal. That said, converting to studs/lug nuts make swapping wheels easier and would allow for even larger spacers if desired. Plus you get the enjoyment of the visual of full thread engagement.

 

[077]

While late to the party, I believe SCCA and others use a guide of "thread engagement must be equal to the stud diameter". So, it was possible that 4 full rotations would have met that goal. That said, converting to studs/lug nuts make swapping wheels easier and would allow for even larger spacers if desired. Plus you get the enjoyment of the visual of full thread engagement.

I figure wheel bolts are 12x1.5 so four 1.5 threads is 6 mm of engagement, half of the SCCA requirement. You are right it is reassuring to see that the wheels aren't going to fall off.

 

[pinhead66]

27Won instructions pdf includes a template to cut out and measure on your wheels to determine if a spacer is needed. 5mm is needed for OE wheels. No spacer needed for my winter wheels. You may not need a spacer with your new wheels.

Just got my new wheels today and tested a Stoptech template and a 27won template. Stoptech did not clear and would need at least another 5-10mm. 27won had plenty of clearance. The Stoptech template seems to stick out like 8-9mm more at the furthest point closest to the spokes. Looks like I know my answer when I decide to start tracking again.

 

[Vincent@27WON]

Just got my new wheels today and tested a Stoptech template and a 27won template. Stoptech did not clear and would need at least another 5-10mm. 27won had plenty of clearance. The Stoptech template seems to stick out like 8-9mm more at the furthest point closest to the spokes. Looks like I know my answer when I decide to start tracking again.

Happy to see you found the template useful.

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