Big brake under 15" Fuch?

[75Carrera]

Brother Pelicans,

While I recover from a full knee replacement (OUCH) I've started looking into a few more mods for my 75 Carrera. I've already up graded to a strong 3.2 motor with some sweet power pluses. What I've struggled with is keeping my original 7&8 Fuch wheels and adding bigger and/or stronger brakes.
If you have experience with this issue I'd sure appreciate hearing from you.
I have Carrera alloy calipers (hate to loose them) but, I need to improve my stopping power. Running with many newer and far better braking cars (Newer Porsches, Ferraris and Lotus') I am sometimes in the position of not having enough brake to stop quickly behind these cars from higher speeds.
Information about kits that will fit under the 15" wheels or pads that will actually improve stopping distances or other possibilities would be great.
Also, coil overs are becoming very popular. They appear to be not much more than "helper type coil springs". Is that true and either way what are the best options for my car with fairly new Bilstien Sport struts and shocks. And yes it's lowered.
Any experienced input would be great while I'm recovering and can't drive "my Precious"....

[Bill Verburg]

Originally Posted by 75Carrera

Brother Pelicans,

While I recover from a full knee replacement (OUCH) I've started looking into a few more mods for my 75 Carrera. I've already up graded to a strong 3.2 motor with some sweet power pluses. What I've struggled with is keeping my original 7&8 Fuch wheels and adding bigger and/or stronger brakes.
If you have experience with this issue I'd sure appreciate hearing from you.
I have Carrera alloy calipers (hate to loose them) but, I need to improve my stopping power. Running with many newer and far better braking cars (Newer Porsches, Ferraris and Lotus') I am sometimes in the position of not having enough brake to stop quickly behind these cars from higher speeds.
Information about kits that will fit under the 15" wheels or pads that will actually improve stopping distances or other possibilities would be great.
Also, coil overs are becoming very popular. They appear to be not much more than "helper type coil springs". Is that true and either way what are the best options for my car with fairly new Bilstien Sport struts and shocks. And yes it's lowered.
Any experienced input would be great while I'm recovering and can't drive "my Precious"....

I'd just install a set of '78 up 930 brakes, in front you'll need the '78-80 2 piece rotors and the rear calipers will need to be modified for use w/ 3" 911 trailing arm mounts

[75Carrera]

Thanks Bill. With your history I know all that to be strong advice. Do you mind telling me the difference in the '78-80 set and my stock? And I assume they will definately fit into my 15" wheels?

[Bill Verburg]

Originally Posted by 75Carrera

Thanks Bill. With your history I know all that to be strong advice. Do you mind telling me the difference in the '78-80 set and my stock? And I assume they will definately fit into my 15" wheels?

Yes, they fit, though you may need spacers in front, it depends on the wheel width and spoke design, 7x15 Fuchs will need either a small space and/or grind the caliper fins down a bit

specs are here

[75Carrera]

Perfect! You're one of the primary brain trusts Pelican is so popular and known for.
Now I need to find all those parts (new, used?)
Any opinions on coil overs?

[PCA7GGR]

7/8-15 Fuchs fit on my '84 factory TurboLook Carrera with no issues notrspaces. Great for auto-xs.

[Bill Verburg]

Originally Posted by PCA7GGR

7/8-15 Fuchs fit on my '84 factory TurboLook Carrera with no issues notrspaces. Great for auto-xs.

'84 factory t-look has a rotor and hub design that incorporates a 1mm spacer in it, there are also ~25mm spacers in back.

a n/b 911 cannot use the '81 up 930 front rotors /hub, they must stick w/ stock 911 stuff and use 2 piece 32x304 rotors w/ flat hats

[Bill Verburg]

Originally Posted by 75Carrera

Perfect! You're one of the primary brain trusts Pelican is so popular and known for.
Now I need to find all those parts (new, used?)
Any opinions on coil overs?

New 930 calipers will be prohibitively expensive, they show up used all the time in the classifieds,

new rotors and pads are always the best place to start, the '78-80 2 piece rotor is still available from Porsche and Brembo itself, many use the Willwood equivalents

I've never used coil over on a 911, no opinion

[75Carrera]

Originally Posted by Bill Verburg

'84 factory t-look has a rotor and hub design that incorporates a 1mm spacer in it, there are also ~25mm spacers in back.

a n/b 911 cannot use the '81 up 930 front rotors /hub, they must stick w/ stock 911 stuff and use 2 piece 32x304 rotors w/ flat hats

Thanks Bill. On the fronts, would I loose my Carrera calipers and use 930 calipers as well as two piece rotors? My alloy front calipers should have a healthy resale vale I'm told. True or false and if so about what? $$

[Bill Verburg]

Originally Posted by 75Carrera

Thanks Bill. On the fronts, would I loose my Carrera calipers and use 930 calipers as well as two piece rotors? My alloy front calipers should have a healthy resale vale I'm told. True or false and if so about what? $$

yes, both front and rear calipers will want to be 930, I'm sure that there is a market for S calipers but I am not familiar w/it you will also need a 23.8mm m/c, both boosted and non boosted versions are available

[Flieger]

If you want to stop shorter, you need more tire grip.

What did you mean by "Carrera alloy calipers"?

[5:04]

Originally Posted by Flieger

If you want to stop shorter, you need more tire grip.

What did you mean by "Carrera alloy calipers"?

QFT, can you lock them up with your current tire set up? If so like Flieger said tires will make a bigger difference than a BBK. The BBK just means you'll lock them up even easier.

[Steve@Rennsport]

JMHO, but BBK's are NOT about stopping shorter.

They are all about endurance,....stamina,.......the ability to maintain peak braking performance over time and that happens mainly on a track. Thats the only place where stock brakes do not oftentimes go the distance.

DOT-spec race tires put even more thermal loads on the brakes,......

[wildcat077]

Originally Posted by Steve@Rennsport

JMHO, but BBK's are NOT about stopping shorter.

They are all about endurance,....stamina,.......the ability to maintain peak braking performance over time and that happens mainly on a track. Thats the only place where stock brakes do not oftentimes go the distance.

DOT-spec race tires put even more thermal loads on the brakes,......

Steve is right ...
I have a friend with a stock late eighties Carrera who spent his money on a fancy racing suit and an expensive helmet because he wanted to track his "stock" car,
turns out he scrapped a brand new set of rotors and went through three different kinds of pads only to boil his fluid every time and spend more time working on the car at the track than actually driving it ...
Bigger brakes = bigger heat sinks = cooler brake fluid temps = longer pad life

I hope he doesn't recognize himself ... lol

Cheers !
Phil

[Bill Verburg]

Originally Posted by Steve@Rennsport

JMHO, but BBK's are NOT about stopping shorter.

They are all about endurance,....stamina,.......the ability to maintain peak braking performance over time and that happens mainly on a track. Thats the only place where stock brakes do not oftentimes go the distance.

DOT-spec race tires put even more thermal loads on the brakes,......

I sort of disagree w/ the first part, bigger brakes do give you more brake torque, which if you can feed through the tires will give you faster /shorter stops. There are several additional steps that can be taken to this this end too but the bigger heat sinks sure are another nice feature in their own right.

[Green 912]

Big "if" I might guess that 99% of the time the tires are the limiting factor.

On the other hand adding bigger brakes does add the worst kind of weight, unsprung and rotating. Faster stops, not likely. HP eating weight and rotating mass, likely.

I can lock up my S fronts and M rears with 245 and 315 Hoosiers.

Shorter stops are easily added via more aggressive brake pads and tire compounds.

[crashmy911]

I've done ten track days on my 911sc with hawk blue brake pads. Finally need new pads. the car has plenty of brakes. My motor is only slightly modified and I'm having a ball. haven't had to bleed my brakes once at the track nor have I had fade. If anything I just wish I could modulate them alittle bit better.

[Bill Verburg]

Originally Posted by Green 912

Big "if" I might guess that 99% of the time the tires are the limiting factor.

On the other hand adding bigger brakes does add the worst kind of weight, unsprung and rotating. Faster stops, not likely. HP eating weight and rotating mass, likely.

I can lock up my S fronts and M rears with 245 and 315 Hoosiers.

Shorter stops are easily added via more aggressive brake pads and tire compounds.

Some people need them some don't. If you do need them then the weight compromise is very acceptable. If you don't need them just consider yourself lucky.

yes, a 911 can lock up it's brakes even w/ R rubber but there are several additional facets to brake performance beyond the ability to lock, one is how many laps can this be performed for and another is how controllable is it, a third is the abilty to get the back to do more of the work.

the 930s take a nice step forward in the increased thermal mass, ie they won't overheat as easily as 911 and the increased brake torque available, more so at the rear than the front. These last 2 items are very useful in reducing braking distances because of the extra torque and because some of the additional brake effort is offloaded from the front to the rear. More can be done in this last area if the car is set up for it.

[Steve@Rennsport]

Originally Posted by crashmy911

If anything I just wish I could modulate them alittle bit better.

Well Sir,...there are better choices for pads that do just that,...

[5:04]

I'd work on pad compound changes. I can't really comment on stock brakes since I bought mine with big brakes. I can tell you from experience of driving many cars that needed "bigger or better" brakes that often the brakes were fine and the driver just used them way too much on the track. If you can lock them up then you have enough power. If you're worried about fade then switch the pad compound. To me it just makes more sense to change something easy before I went doing a major component swap.