924Board.org

[Aussie Jase]

Hi guys,
Is there a bigger caliper option for the 924? I need to stay with the narrow body and wheels so I can't go to 4 piston calipers.

Is there a bigger single or twin piston caliper I can bolt onto or adapt to the 924 and remain on original narrow body wheels? The braking power of the car isn't too bad but the problem is (as you all know) the pad size is just too small for endurance racing on sticky tires. Anyone know if a Toyota or Honda or whatever larger caliper could fit on the front?

Cheers, Jason. [/list]
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1987 924S 24hr LeMons car

[ideola]

[Aussie Jase]

Thank you ideola! Car is a 1987 924S.

So in summery, these 4 piston calipers will fit behind the early offset 924S 15 inch wheels and suit the OEM sized rotor? Could be a winner.

Would a 944 turbo master cylinder and brake booster suffice?
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1987 924S 24hr LeMons car

[ideola]

Brembos will most likely require 16" rims. I can't say on the Wilwoods.

Regarding the offset discussion, I prefer to use the term "high" vs. "low" offset, rather than "early" vs. "late". The reason is that most people talking "early offset" are referring exclusively to the 944 line, forgetting about the early 2.0L 924 platform.

To illustrate:
The early 2.0L cars with five lug require an offset in the 50-60mm range (52mm is stock), depending on tire and rim width. The early (1982-86) 944 required an offset in the 20-30mm range (23mm is stock). When the late (1987-onward) 944 and 951 came out, the hub moved outboard by about 22mm, requiring the additional offset (23+22 = ~55ish). So it's misleading to say "early" or "late" offset, and better to say "high" vs. "low".

On your 924S, you need "high" offset of ~52mm, which will work with 6", 7" and 8" rims front and rear. You already have the alu trailing arms in the rear, which are setup to take high offset rims with NO spacer. (Note that early 2.0L 924 came with steel arms, and the 5-lug setups required a 22mm spacer to use the same rim that goes on the later 924S setup). For the front, simply swap on the 86 951 spindle-strut-hub assembly, and you're good to go, it bolts right up to the steel A-arms. You will then only need to worry about the speedometer, as the 924S didn't get the updated electronic speedos of contemporary 944/951.

As for rotors, you MUST get the correct rotor for the Brembos, so if you source bits from an 86 951, make sure to get the 86 951 rotor. It is UNIQUE to that year, and other setups will not work correctly.

A 944 turbo master and booster would be ideal.
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erstwhile owner of just about every 924 variant ever made

[nickthompson]

Volvo 240 calipers will work. They are four piston calipers. Make sure you get the vented brake calipers. If you get early ones you have to get a split line because they have two inputs. The later ABS equipped cars have a single input. They aren't as pretty as the 951 calipers but they are cheaper, designed to stop a heavier car, can be bought anywhere and have a wide range of pads available.

[Rasta Monsta]

P.S. There is absolutely NOTHING wrong with the factory floating calipers. Hundreds, if not thousands of people race on them every weekend without issue. Properly functioning, and with a good set of pads, they will displace organs with sticky tires.

Oh, and not really sure how "pad size" comes into it?
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Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[jason c]

[Aussie Jase]

I agree that the standard floating calipers are better than most. I have been running hawk endurance pads and they've been reliable but the pedal gets long during the day. When flushing the fluid out between days it's almost black which tells me I'm pumping too much heat through them.

I was actually considering pulling the 2 piston caliper off my Scion FR-S and seeing what kind of bracket I would have to fabricate as the rotor thicknesses are the same and the diameters are only 6mm different (FRS being the larger)
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1987 924S 24hr LeMons car

[fiat22turbo]

If they are overheating, either you need to adjust your driving style or add cooling via cooling ducts from the front of the car.

For example:

http://www.pelicanparts.com/More_Info/PELPEOSBPAZK.htm?pn=PEL-PEOSBPAZK&SVSVSI=944M

Also the titanium brake pad backing plates should help reduce heat transfer to the calipers:

http://www.pelicanparts.com/More_Info/PELSSTBS2.htm?pn=PEL-SS-TBS2&SVSVSI=944M

More braking options:

http://www.pelicanparts.com/catalog/SuperCat/944M/POR_944M_BRKprf_pg1.htm

Multi caliper pistons won't really help your overheating issue, nor will adding more pad area. You have to reduce the thermal load in the system. If you're not providing cooling of some sort then you're going to continue to have the same issue at perhaps different points in time.

Ensuring there is a way to evacuate the heat from the wheel wells helps. Ensure the leading edge of the quarter panel/nose extends past the outer edge of the wheel to provide a low pressure area near the wheel center. A splitter helps as you can use it to extend the leading edge of the quarter panel and force air into the cooling ducts.

Wheel choice matters as well, wheels with larger openings or aerodynamic designs in the spokes can help greatly as well.

Good luck.
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Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

[Cedric]

With that kind of weight/power i can't see endurance would be a problem. Are the calipers regularly serviced? That makes night and day difference in racing, they heat up quickly if there is friction keeping the pads from retracting. I assume cooling ducts are already there since it's an endurance racer?
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1980 924 Turbo
www.instagram.com/garagecedric/

[KDJones2000]

[gabo931]

[daniel]

Calipers from a early 90's A4 audi (also used on a golf GTi?) will bolt right up, Hawk also has some excellent pads for them. This allows you to keep your 4 lug setup
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Over the top of skyline, total brake failure.... hit the wall at over 200 kp/h at the dipper, so anyone who has to brake for the esses is a pussy.
1977.5 Race Car, CAMS Group S Spec
1989 944 Cabriolet

[gabo931]

[fiat22turbo]