1980 928 Brake update > what bolts on

[aluminum]

Hello all:-) My US 1980 928 Brakes are not the greatest all tho appear to be in good shape
does anyone have the experience by chance with a Simple Update from a later model.
Was thinking that perhaps I could just install the front rotors and calipers from a latter model . Also of course new Pads
Do I need to bother to update the Rear Brakes as well ?
I expect that would be best but also perhaps that most of the stopping power is on the front
Must other things be done also ? if anyone knows ?
My Budget is low so I am not thinking the ultimate as in a race car but just some perhaps .
For example well 83 up bolt right on and work or is a later year much better ?
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well my 15 inch Phone Dial Wheels require spacers perhaps ? for the Later calipers .
perhaps this is not as simple as I expect hummm but perhaps it is .
thanks in advance for any suggestions advice

[Pete R]

The only brakes worth going to would be the 4 piston S4 Brembos. Traditionally you have to change to 86 1/2 and up front suspension ect.. A arms, spindle ect. (the rear isn't an issue) but I believe I have seen a adapter kit to use with the earlier suspension.

[MPDano]

Originally Posted by Pete R

The only brakes worth going to would be the 4 piston S4 Brembos. Traditionally you have to change to 86 1/2 and up front suspension ect.. A arms, spindle ect. (the rear isn't an issue) but I believe I have seen a adapter kit to use with the earlier suspension.

Yup, there is an adapter. Ask me how I know. I still have to mount it up to the 81 Euro. It's basically 2 Milled Overpriced plates for I think around $140

[aluminum]

Great Info Thanks much: MP Dano & Peat R
So tell me if you know ? RE: 4 piston S4 Brembos
are they the same as the humm say 92 Carrera also know as a C2 Porsche , a 911 / 964 model ?
anyone know the Part numbers for correct "4 piston S4 Brembos" and the correct "Rotors ? "
the I need ? can I just look on a say 87 928 Manual perhaps ?
I have access to all that sort of thing Just have to pull the parts but don't know what interchanges

[MPDano]

Here you go. This thread has the Part Number of the Brembos you need. Like Pete says, if you just do the front S4 Suspension then you golden, but if you do the Adapter like I did, you will need different model rotors, etc. There has to be a containing all the pieces you will need if you the Adapter route.

http://forums.pelicanparts.com/porsche-928-technical-forum/534687-s4-front-calipers-my-81-ob.html

[aluminum]

Thanks and great Link :
so you used 993 Rotors then with the adapters ( $140 ? )
I well think on this >> was hoping to just blot on some later stuff but not all the Suspension arms and the like >
Is their a lesser upgrade ? that simple enables one to use larger Pad's but in the single Pad form ?
Perhaps with the same 1980 rotors ?
Look's like to me that the Pad Size is the stopping issue perhaps ? ( they are very small ) but then again perhaps you need more rotor with a larger pad ?
I well start checking the sizes of the Pads I think .

[MPDano]

Not sure but my S has larger calipers, which in turn use larger pads. Not sure what it takes to bolt on some S Calipers. I see them all the time on eBay. Could be nice if it's just a bolt on.

Anyone know about bolting S front Calipers on an early 928?

[153bigblock]

i just did the pre S conversion to S brakes. You will need S spindles, rotors and calipers for the front. The rears are the same.

[aluminum]

Originally Posted by 153bigblock

i just did the pre S conversion to S brakes. You will need S spindles, rotors and calipers for the front. The rears are the same.

Thanks for reply
How did the Upgrade work out ? performance wise if you have tried them yet .
I expect you have new quality Pads and such .
are they for example perhaps 1/3 better then before ? or in %
talking more or less if you get my drift > not rocket science

[928gene928]

Does anyone have a decent picture of those adapters and some measurements?

[MPDano]

Originally Posted by aluminum

Thanks for reply
How did the Upgrade work out ? performance wise if you have tried them yet .
I expect you have new quality Pads and such .
are they for example perhaps 1/3 better then before ? or in %
talking more or less if you get my drift > not rocket science

I have both, so S brakes for sure stop better. Like everyone says though, the best conversion will be going to the S4 Brembos.

[MPDano]

Originally Posted by 928gene928

Does anyone have a decent picture of those adapters and some measurements?

I can measure it out for you after work today.

[aluminum]

Hello MP Dano
Yours is a Euro yes :
so is that consistent with the US Models or different ? My guess is that it would be different but only a guess . I bet they are about 12 " ? if you have 16 inch wheels original

[MPDano]

You can pretty much look at a US 79 and my Euro 81 are almost identical mechanically.

[153bigblock]

Originally Posted by aluminum

Thanks for reply
How did the Upgrade work out ? performance wise if you have tried them yet .
I expect you have new quality Pads and such .
are they for example perhaps 1/3 better then before ? or in %
talking more or less if you get my drift > not rocket science

I have not tried them yet as my car is still in project phase. I have read they are a vast improvement. The rotors are substantially thicker, with more cooling vents and the piston is noticeably larger. However, some people have noted that they wear through pads faster than S4 brakes would. A friend who did this also noted that he needed the larger booster from the S cars (8 inch to 10 inch). However, others no.

I failed to mention in my previous post that you will need to update to steel ball joints (if you have not already) and you will need two more eccentrics as one (per side) is not appropriate for the new, steel lower ball joints.

I will report back when I get my car on the road, but I think there is a lot of commentary on this subject on here and on RL.

[-Havoc-]

Originally Posted by MPDano

I can measure it out for you after work today.

MPDano, did you ever get the measurements on that adapter?

[MPDano]

Originally Posted by -Havoc-

MPDano, did you ever get the measurements on that adapter?

Here you go, but I take NO responsibility for your outcome. I also don't know how to measure thread pitch but you probably use any. They look coarse if that helps.

[-Havoc-]

Originally Posted by MPDano

Here you go, but I take NO responsibility for your outcome. I also don't know how to measure thread pitch but you probably use any. They look coarse if that helps.

Thanks for the info, MPDano.

A couple things; Can you clarify the two measurements? (red question marks) It seems you have different figures for the width.

Also, could you measure the distance noted in green?

Thanks for taking the time to do this, it's much appreciated!

[MPDano]

1st pic is correct as you can see my altered image, which i turn you need to modify other pic measurements. 2nd pic is 1" to center of hole from top.

[-Havoc-]

Originally Posted by MPDano

1st pic is correct as you can see my altered image, which i turn you need to modify other pic measurements. 2nd pic is 1" to center of hole from top.

Ok got it, thanks! What about the measurement I noted in green? I think that's about the only dimension you didn't cover.