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HalfMoon |
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#1
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Senior Member ![]() ![]() ![]() Group: Members Posts: 828 Joined: 13-November 12 From: Shenandoah Junction, WV Member No.: 15,144 Region Association: MidAtlantic Region ![]() |
So which calipers (or the stock variety) are better? Late or early (and why)? Or does it not make much difference?
Also, and this may sound like an odd question....is there any reason why the rotors couldn't be drilled while on the car (other than the labor involved) and yes I have no plate. Thanx David |
Cap'n Krusty |
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#2
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Cap'n Krusty ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 10,794 Joined: 24-June 04 From: Santa Maria, CA Member No.: 2,246 Region Association: Central California ![]() |
Drilled how?
The Cap'n |
HalfMoon |
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#3
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Senior Member ![]() ![]() ![]() Group: Members Posts: 828 Joined: 13-November 12 From: Shenandoah Junction, WV Member No.: 15,144 Region Association: MidAtlantic Region ![]() |
Drilled how? The Cap'n Something like this https://www.google.com/search?q=images+dril...2B4%3B225%3B225 |
bandjoey |
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#4
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bandjoey ![]() ![]() ![]() ![]() Group: Members Posts: 4,934 Joined: 26-September 07 From: Bedford Tx Member No.: 8,156 Region Association: Southwest Region ![]() |
Drilled for 5 lug or for cooling?
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Dave_Darling |
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#5
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914 Idiot ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 15,161 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California ![]() ![]() |
The stock 914-4 calipers are functionally identical. They change in how they mount, but the pad size and caliper piston size are the same. They all go over solid rotors, they all perform basically the same.
IMHO, cross-drilling solid rotors on a street car is a waste of time. On a track car, it's probably also a waste of time. On a track car with vented rotors (the thick ones with passages through the middle), it is worthwhile. Mostly because track cars get inspected thoroughly before and after every event, so the cracks that will eventually form can be caught early enough before the brakes fail catastrophically. --DD |
HalfMoon |
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#6
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Senior Member ![]() ![]() ![]() Group: Members Posts: 828 Joined: 13-November 12 From: Shenandoah Junction, WV Member No.: 15,144 Region Association: MidAtlantic Region ![]() |
The stock 914-4 calipers are functionally identical. They change in how they mount, but the pad size and caliper piston size are the same. They all go over solid rotors, they all perform basically the same. IMHO, cross-drilling solid rotors on a street car is a waste of time. On a track car, it's probably also a waste of time. On a track car with vented rotors (the thick ones with passages through the middle), it is worthwhile. Mostly because track cars get inspected thoroughly before and after every event, so the cracks that will eventually form can be caught early enough before the brakes fail catastrophically. --DD Sage advice. Thanks for that. |
steuspeed |
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#7
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Senior Member ![]() ![]() ![]() Group: Members Posts: 1,010 Joined: 12-July 11 From: Portland, Oregon Member No.: 13,308 Region Association: Pacific Northwest ![]() |
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HalfMoon |
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#8
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Senior Member ![]() ![]() ![]() Group: Members Posts: 828 Joined: 13-November 12 From: Shenandoah Junction, WV Member No.: 15,144 Region Association: MidAtlantic Region ![]() |
They don't sell ANY drilled rear rotors so I'm not clear on why you sent me the link. (IMG:style_emoticons/default/confused24.gif) Ammendment: Duh. Because I never mentioned rears. My bad So, back to the original question: Would drilling the REAR rotors have any positive effect given I already have vented 911 fronts? |
Dave_Darling |
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#9
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914 Idiot ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 15,161 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California ![]() ![]() |
The rear rotors are solid, like stock 914-4 front rotors. So no--no positive effect. Same reasons as I gave above. Additionally, the rears do much less work than the fronts do, so they build less heat in the first place.
The 914-4 rear calipers are all interchangeable, I think the only actual difference is that some have one bleeder (put it at the top!!) and some have two, one at the top and one at the bottom. --DD |
HalfMoon |
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#10
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Senior Member ![]() ![]() ![]() Group: Members Posts: 828 Joined: 13-November 12 From: Shenandoah Junction, WV Member No.: 15,144 Region Association: MidAtlantic Region ![]() |
The rear rotors are solid, like stock 914-4 front rotors. So no--no positive effect. Same reasons as I gave above. Additionally, the rears do much less work than the fronts do, so they build less heat in the first place. The 914-4 rear calipers are all interchangeable, I think the only actual difference is that some have one bleeder (put it at the top!!) and some have two, one at the top and one at the bottom. --DD Awesome stuff Dave and thanks! My plan is to keep em and git the PMB rebuild kit as I'm assuming (from all I've read) that they most likely aren't working (or barely) and are sorely in need of a rebuild. 911's on front and probably in need of a rebuild as well (although, in a different thread we've been talking about the possibility of 928 brakes for 3.5 spacing-must check mine tomorrow-doubtful they are) |
Mike Bellis |
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#11
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Resident Electrician ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 8,347 Joined: 22-June 09 From: Midlothian TX Member No.: 10,496 Region Association: None ![]() ![]() ![]() |
For solid rotors, a groove to release gasses would be better than drilling. Drilling a rotor will make it weaker and prone to cracking if the drilled edge is not eased or rounded off.
BTW, if you try to drill rotors in the car, they will look like shit. It needs to be done in a drill press with a template. (IMG:http://www.914world.com/bbs2/uploads_offsite/www.casmoedesigns.com-10496-1415462042.1.jpg) |
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