924Board.org

Bumblebee77 · Joined: 09 May 2008 Posts: 372 Location: Brisbane

Hey all. I'm pretty sure after some basic research that in order to do a brake upgrade on my car first the wheels need to be upgraded from 4 bolt to 5 bolt.
My question is hopefully directed more at the aussie peeps in here. Is the brake/wheel upgrade a big time op. Does anyone in here know much about prices in Australia?

fezza575m · Posted: Thu May 29, 2008 7:23 pm Post subject:

Just adding to that

Does anyone know of brake upgrades without doing the 5 bolt conversion???
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Red 1977 Porsche 924 CGT...THE MORPH IS COMPLETE

Ozzie · Posted: Thu May 29, 2008 7:32 pm Post subject:

Legally?
No.
5 bolt is the only legal way in Oz and from my friend at Beaurepaires, dont think about spacers either.
Any other conversion requires an engineers cert.

Find a turbo or 944 at the wreckers and get the parts there.
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

Scorpio · Posted: Thu May 29, 2008 7:33 pm Post subject:

quite a few aussies have done it, its certainly not as cheap here as say the US.
I was thinking of getting it done as part of my full rebuild then decided against...I distinctly remember one of the more knowledable people on this forum ( forgot who)stating that for street use and for the non-seasoned racer, you wont really notice much of a differnce so long as the rears are kept maintained... I also read an article stating that the 5 stud 931 has a similar breaking force as the 924 drums..ie youll lock your wheels up the same..so it all comes down to what tyres your running.

The major benefits of the break upgrade were(correct me if im wrong)

1)they required less maintenance...ie the drums can sometimes get a spongy feel and need readjusting a lot more frequently...

2)and the disks were alot more efficient at dissipating heat, usefull for those windy mountain roads when you sit on your brake alot, or for track..

3) they fill out the wider flares nicely

4) its easier to find nice 5 bolt wheels
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1979 NA
MS1..EFI..
GARRETT T25 TURBO
BILSTEIN SHOCKS
GT BASED CUSTOM BODYKIT

Brisbane , Australia
Think mean think fast
all youll see is
my Porsches Arse!!!

Cedric · Joined: 27 Aug 2004 Posts: 2809 Location: Sweden

If your going for more power that the stock 125 it migth be an idea, else its just bling. Maybe for the maintanence part. My brakes never fade at the track, even if i drive 1 hour stints. And i have r compund tires that allow lots of brakingforce..
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1980 924 Turbo
www.instagram.com/garagecedric/

fezza575m · Posted: Fri May 30, 2008 9:25 am Post subject:

How much can brake pads and fluid come into the performance of your brakes??
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Red 1977 Porsche 924 CGT...THE MORPH IS COMPLETE

Mav666 · Joined: 16 May 2008 Posts: 47 Location: Newcastle, UK

From what Ozzie has said about things there are a lot more legal issue in Oz than in either the UK or US.

One that sticks in my mind is the illegal use of rubber fuel pipe, so I'd check on the legalities of things first, but agree that looking for an S or '44 so that you can swap everything out in one go is the sensible option.

!tom · Posted: Fri May 30, 2008 10:21 am Post subject:

The biggest advantage of disks over drums is the ability to modulate disk brakes.

Inherent to the design of drum brakes which have one wheel cylinder at the top is that one shoe is self-energizing, meaning that once the shoe is touching the drum, the rotational force of the drum causes the shoe to press against the drum harder. This does not happen with disk brakes.

This is what makes disk brakes safer than drum brakes.

Like others have mentioned, the drums work fine, but this is an additional difference between disks and drums.

The only way to get drums to not self-energize is like you see on old motorcycles with drum brakes on the front with one cam per brake shoe. To do this with hydrollic brakes you'd need one wheel cylinder per shoe.

On the 924, the brake shoe towards the front of the car is the self-energizing one. I would expect it to wear faster than the rear shoe, but I haven't looked to see if that happens in practice.
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78 924 NA
5-lug

Ozzie · Posted: Fri May 30, 2008 2:12 pm Post subject:

The biggest hassle here is if you have an accident, the car has been modified and no mod plate fitted.
Insurance will wipe you.

My wifes car originally came with no seatbelts.
They were fitted by a PO and I had to remove them because a mod plate was not fitted.
The belts were fitted to the "existing holes' provided by the manufacturer but I could not register the car with them on.
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

Mike924 · Joined: 12 Aug 2004 Posts: 2601 Location: IoW UK

Cedric · Joined: 27 Aug 2004 Posts: 2809 Location: Sweden

fluid and pads are critical. Way more importand that the size of your brakes. I run motul rbf600, its a pretty cheap fluid, and it has very high boiling limit. I run Hawk HP plus pads wich works nice, no fade at all. And at a grat price over there. Else then that its important to have the brakes in good shape so the caliper can slide and the brake piston can move as it should...
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1980 924 Turbo
www.instagram.com/garagecedric/

Bumblebee77 · Joined: 09 May 2008 Posts: 372 Location: Brisbane

Thanks all... I think i'll probably just stick with the drums then in that case. I'll just make sure they're in good nick and i use good equipment.

Scorpio · Posted: Fri May 30, 2008 10:40 pm Post subject:

Bumblebee77 · Joined: 09 May 2008 Posts: 372 Location: Brisbane

Yeah good call. I think i'll just give it a miss, maybe upgrade the front discs to a more modern unit and just keep the rear drums in as good nick as possible with good components.

Vince Ponz · Joined: 02 Nov 2002 Posts: 3581 Location: Florida

For a long time I tracked my modified car on the track and with the 14 in rims and drums. No problem as long as you keep everthing in good shape.
I ran high temp fluid, metalic pads and adjusted the brakes each time I got home.

I switched to a 944 5 bolt setup and am happy with it and the ability to find Fuchs, phone dials, etc to finish the swap.

So, the only thing I can recommend is keep the brakes in good shape and adjust often. If I am not mistaken Jim Pasha also memtioned this same topic.

As for track use remember these are momentum cars and you have to sort of keep the speed up in turns and use the brakes less.
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"Never let them see you sweat"
77.5 924 modified track car
79 931 Euro stock
88 924S SE
87 911 Targa stock