88 Turbo S - brake calipers

[V951S]

I just noticed my Front L caliper is mismatched from the other 3.

Pics attached of my R Rear caliper with Porsche letters cast in metal, and the "new" Front L caliper with the Porsche sticker.

I read the 88 Turbo S supposedly had brake calipers from the 928 S4.

Can someone tell me more about the calipers on the Turbo S?
- 4 piston front and rears?
- Which other cars also used this caliper?
- Did the 89 Turbo onward use them? (the S2, etc?)
- Can someone share the part #?

I need to find one on eBay to make them match again.

Thanks!

[Bergerac]

The smoother one looks very much like my 993 calipers, from memory these came on the later 928s as well. Piston sizes are the same as the 88+ M030/Turbo S/S4 calipers.

[Bergerac]

Sorry not the bests picture, standard S2/Turbo rears in the background

PXL_20230113_103550292.jpg (2.38 MiB) Viewed 1002 times

[Belgian951]

OP's second photo shows what looks like standard 944 turbo brakes. I have them in my 86.

[V951S]

OP's second photo shows what looks like standard 944 turbo brakes. I have them in my 86.

They are supposed to be upgraded from standard 944 turbo on the 1988 Turbo S and 1989+ turbos (M030).

I’m wondering what the part number is so I can get the original one to swap back to.

[Latitude48]

OP's second photo shows what looks like standard 944 turbo brakes. I have them in my 86.

They are supposed to be upgraded from standard 944 turbo on the 1988 Turbo S and 1989+ turbos (M030).

I’m wondering what the part number is so I can get the original one to swap back to.

The front caliper P/Ns for a 1988 Turbo S, M758 option, are:
951-351-093-00, left
951-351-094-00, right

These have piston sizes 36/44 like the 1989 Turbo, but they are the earlier design with scarper ring type pistons, whereas there was a changeover for the Turbo during the 1989 MY to switch to pistons with seals and protection caps, which are P/Ns:
928-351-421-03, left
928-351-422-03, right [corrected number]

All these calipers have raised PORSCHE lettering.

[four0four]

Don't take this too much to heart: I have a dusty memory of reading that replacement calipers came with painted letters. Probably just what Brembo had for continuing stock once the 944 line ended...

[V951S]

OP's second photo shows what looks like standard 944 turbo brakes. I have them in my 86.

They are supposed to be upgraded from standard 944 turbo on the 1988 Turbo S and 1989+ turbos (M030).

I’m wondering what the part number is so I can get the original one to swap back to.

The front caliper P/Ns for a 1988 Turbo S, M758 option, are:
951-351-093-00, left
951-351-094-00, right

These have piston sizes 36/44 like the 1989 Turbo, but they are the earlier design with scarper ring type pistons, whereas there was a changeover for the Turbo during the 1989 MY to switch to pistons with seals and protection caps, which are P/Ns:
928-351-421-03, left
928-351-421-03, right

All these calipers have raised PORSCHE lettering.

Thank you @Latitude48 - exactly what I was looking for. I found 2 sources for the scraper type caliper.

Can you explain what the differences/advantages are between scraper piston rings and 1989+ pistons?

ie: Could I just look for the newer version to swap in and it'd perform and look identical? (Though I supposed I should try to keep it as original as possible.)

[Latitude48]

They are supposed to be upgraded from standard 944 turbo on the 1988 Turbo S and 1989+ turbos (M030).

I’m wondering what the part number is so I can get the original one to swap back to.

The front caliper P/Ns for a 1988 Turbo S, M758 option, are:
951-351-093-00, left
951-351-094-00, right

These have piston sizes 36/44 like the 1989 Turbo, but they are the earlier design with scarper ring type pistons, whereas there was a changeover for the Turbo during the 1989 MY to switch to pistons with seals and protection caps, which are P/Ns:
928-351-421-03, left
928-351-422-03, right

All these calipers have raised PORSCHE lettering.

Thank you @Latitude48 - exactly what I was looking for. I found 2 sources for the scraper type caliper.

Can you explain what the differences/advantages are between scraper piston rings and 1989+ pistons?

ie: Could I just look for the newer version to swap in and it'd perform and look identical? (Though I supposed I should try to keep it as original as possible.)

Attached are two pages from WKD 495 321, Service Information Technik for the '89 944 Turbo. They explain the difference between caliper pistons with scraper rings and caliper pistons with dust caps. Note that because these calipers work slightly differently during brake application and release, calipers of the same style must be used on the same axle.

For the front calipers, the change occurred sometime during MY 1989. TSB Group 4, Number 9310 regarding Brake Vibration Damper Application does not specify the VIN number changeover for the front (you need to inspect), however it does specify the changeover for the rear: brake calipers with dust caps are used from VIN: 95_KN150216.

The 968 with M030 suspension uses the same P/N calipers as the 1989 944 Turbo, but the Porsche lettering is not raised, which leads credence to @four0four recollection about replacement calipers.

[Thom]

the 968 with M030 suspension uses the same P/N calipers as the 1989 944 Turbo, but the Porsche lettering is not raised, which leads credence to @four0four recollection about replacement calipers.

The 1991 944 turbo (and also perhaps 1991 928 S4/GT) was the first to use "medium black" front brake calipers with the lettering as a sticker.