Late Calipers W/ 911 struts 3" ? Options

[Literati914]

Was wondering if late model 914 front brake calipers will work with the early 3" spaced 911 strut set-up? ..a spacer needed maybe?


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[bdstone914]

Maybe. If M caliper spacers will fit To space the caliper haves. I dont think the 914 pad will cover the 911 rotor.
But why not get 911 calipers? Or Alfa calipers?

[mepstein]

The 3” M calipers are vented. 914 calipers are not. You might make it work with a non Vented rotor but I have a feeling there will be a spacing issue. M caliper cores are ~$100 so might as well just use the correct ones.

[Literati914]

..But why not get 911 calipers? Or Alfa calipers?

Because I have several front late model 914 calipers that won't be used other-wise.. plus this particular car will have a 2056cc engine (if not a 1911), so the other options are probably not necessary. I do have Alfa calipers already - but those are ear-marked for my 3.3L Suby car (IMG:style_emoticons/default/idea.gif) will aluminum brembos from the Alfa be enough for that (think it around 230hp)?

The 3” M calipers are vented. 914 calipers are not. ...

By vented you simply mean they have the flat spacer built in, that divides the two halves - correct?


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[mepstein]

..But why not get 911 calipers? Or Alfa calipers?

Because I have several front late model 914 calipers that won't be used other-wise.. plus this particular car will have a 2056cc engine (if not a 1911), so the other options are probably not necessary. I do have Alfa calipers already - but those are ear-marked for my 3.3L Suby car (IMG:style_emoticons/default/idea.gif) will aluminum brembos from the Alfa be enough for that (think it around 230hp)?

The 3” M calipers are vented. 914 calipers are not. ...

By vented you simply mean they have the flat spacer built in, that divides the two halves - correct?

Yes. The rotors are vented and wider that the solid rotors.

Horsepower doesn’t really have a lot to do with brakes or at least not nearly as much as weight and velocity. A 914 with 1000 hp that is moving 60 mph and weighs 2000 lbs would stop fine with stock brakes. Say you filled up the car with lead and now it weigh 6000 lbs. Now the brakes are probably inadequate to bring it down from 60mph in a reasonable stopping distance.
Venting helps cool a rotor and keep it within its normal operating heat range and help prevent the brakes from fading.

I’m no brake expert but I think M calipers will be your best bet. The Alfa calipers have an advantage of being half the weight with a larger pad that lasts longer.

I have an extra right side M caliper that you can have for the cost of shipping. You should be able to find a left side for ~$50 on pelican. Let me know if you want it.

[infraredcalvin]

I know we’re all simplifying the issue, but tire size matters as well. I’d put the brembos on the 2056, just cause you have them.

The subi is going to want bigger brakes, especially if you do flares and meaty tires.

[Literati914]

So, the main reason I asked this question in the first place was because I found a set of early 911 3" struts with hubs for a good price that I might purchase.. & thought 'hey, I have a bunch of late 914 front calipers, maybe they'd work'.

I wasn't necessarily looking for early 3" struts though... I mean if 3.5" struts and Boxster calipers are a better fit (for the SUBI conversion @ 230hp) than the Alfa brembos, then maybe that's where I need to go.

The Subi conversion I'd planned 205/60/15s (just 'cause I already have 'em) on 15x7 cookies.

The air-cooled 2056 I'd considered 185/70/15s on deep-six fuchs replicas.


Didn't the factory GT cars use M calipers and run about 230-250 HP?


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[Mark Henry]

I have the alfa brembo's on my 914/6 3.0 twin plug conversion, I'm easily 250HP.

No problems, stops excellent, try not to but I can lock it up. If I was racing maybe I'd want the bigger brakes just because they might have less fade over time, but for a street car it's more than enough brake.

BTW I have Alfa Brembo's with vented rotors up front and PMB 914 "V calipers" and vented rotors in the rear.

[Shivers]

So, the main reason I asked this question in the first place was because I found a set of early 911 3" struts with hubs for a good price that I might purchase.. & thought 'hey, I have a bunch of late 914 front calipers, maybe they'd work'.

I wasn't necessarily looking for early 3" struts though... I mean if 3.5" struts and Boxster calipers are a better fit (for the SUBI conversion @ 230hp) than the Alfa brembos, then maybe that's where I need to go.

The Subi conversion I'd planned 205/60/15s (just 'cause I already have 'em) on 15x7 cookies.

The air-cooled 2056 I'd considered 185/70/15s on deep-six fuchs replicas.


Didn't the factory GT cars use M calipers and run about 230-250 HP?


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Yes, M's, they will bolt right up in back too . I think hp was 210 on the street version.

[Chris914n6]

The only reason to use 911 struts is for the vented rotors. You can redrill the 914 hub/rotor for 5 lug.
I would upgrade the Suby to vented 911 fronts. Stock M or Alfa calipers will be fine. Box calipers bring the 911 strut assm down to stock 914 weight and have larger pads but are overkill for 99% of 914s.

[mepstein]

So, the main reason I asked this question in the first place was because I found a set of early 911 3" struts with hubs for a good price that I might purchase.. & thought 'hey, I have a bunch of late 914 front calipers, maybe they'd work'.

I wasn't necessarily looking for early 3" struts though... I mean if 3.5" struts and Boxster calipers are a better fit (for the SUBI conversion @ 230hp) than the Alfa brembos, then maybe that's where I need to go.

The Subi conversion I'd planned 205/60/15s (just 'cause I already have 'em) on 15x7 cookies.

The air-cooled 2056 I'd considered 185/70/15s on deep-six fuchs replicas.


Didn't the factory GT cars use M calipers and run about 230-250 HP?


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The GT cars ran S calipers like most of the Porsche race cars from that time. 914-6gt (vented m with handbrake) on the rear. The stock 914-6 ran m vented front and the equivalent of m solid. rear.
Remember, race cars are lighter than the equivalent street car and usually use race tires so they aren’t a very good comparison to street setups.

The stock 76 930/911 turbo ran S calipers front and M rear and weighed close to 3k.

I would use 911 struts for the ability to use larger calipers. Vented rotors don’t make the car stop better, just stop the same for longer since they help keep the braking system from overheating as quickly during constant hard braking.

[Bleyseng]

So, the main reason I asked this question in the first place was because I found a set of early 911 3" struts with hubs for a good price that I might purchase.. & thought 'hey, I have a bunch of late 914 front calipers, maybe they'd work'.

I wasn't necessarily looking for early 3" struts though... I mean if 3.5" struts and Boxster calipers are a better fit (for the SUBI conversion @ 230hp) than the Alfa brembos, then maybe that's where I need to go.

The Subi conversion I'd planned 205/60/15s (just 'cause I already have 'em) on 15x7 cookies.

The air-cooled 2056 I'd considered 185/70/15s on deep-six fuchs replicas.


Didn't the factory GT cars use M calipers and run about 230-250 HP?


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Factory race 914/6 GT race cars run 908 or 911 S

[infraredcalvin]

The stock 76 930/911 turbo ran S calipers front and M rear and weighed close to 3k.

I have this car, more like 2600 lbs, 205 fronts and 245 rears. I’m not that hard on brakes, but I can easily get them to fade with some spirited canyon driving. IMO it’s not enough brake for the 930, especially when you start adding more power and using current and larger rubber. I swapped to later 930 turbo brakes, it’s what that car should have had from the beginning.

My race 914 feels great 1984 lbs with 911 As on the fronts and vented Ms on the rear. As have the same pad as the S caliper, but they are heavier. But this combo feels excellent on the 914, I would want it even more on a street car. Race car has 205/50s (200 treadwear). The only drawback is the lost ebrake. Ideally I’d have pmbs rear 914-6 caliper with A or S calipers up front.

Finally the new 6 race car has 993 tt brakes, they are big, not sure how they compare to boxster brakes, but they have to be similar in pad size. Regardless, car is a pig at 2400lbs, runs 225s in the front and 245s in the rear, they stop on a dime, probably overkill, but they feel really nice on street and track.

[mepstein]

The stock 76 930/911 turbo ran S calipers front and M rear and weighed close to 3k.

I have this car, more like 2600 lbs, 205 fronts and 245 rears. I’m not that hard on brakes, but I can easily get them to fade with some spirited canyon driving. IMO it’s not enough brake for the 930, especially when you start adding more power and using current and larger rubber. I swapped to later 930 turbo brakes, it’s what that car should have had from the beginning.

My race 914 feels great 1984 lbs with 911 As on the fronts and vented Ms on the rear. As have the same pad as the S caliper, but they are heavier. But this combo feels excellent on the 914, I would want it even more on a street car. Race car has 205/50s (200 treadwear). The only drawback is the lost ebrake. Ideally I’d have pmbs rear 914-6 caliper with A or S calipers up front.

Finally the new 6 race car has 993 tt brakes, they are big, not sure how they compare to boxster brakes, but they have to be similar in pad size. Regardless, car is a pig at 2400lbs, runs 225s in the front and 245s in the rear, they stop on a dime, probably overkill, but they feel really nice on street and track.

Are you sure? SC’s and Carrera’s are ~2600 and the turbo has heavier everything. Engine, trans, etc. im positive the one we rebuilt was a touch over 2800. Regardless, you are right, it needed turbo brakes for spirited driving.

[infraredcalvin]

I could see how quality resto materials and any slight mods like bigger rubber and or wheels would add 200 lbs. I got mine under 2600 by removing ac compressor and swapping to headers and lightweight muffler…