Want to change the Brakes on my 930 to 917

[PTC930]

Hello to the Experts,

For the Winter i will start to change my Brake system to 917 / 934 specs.
I bought already a set of Brake calipers and discs but dont know what i need also to get this done.

Now i have i think 993 Calipers with 17 Wheels but like to change back to 15 or 16 Fuchs.

So please share your experience with me to get this done.

Attached are a picture of the condition it is.

[PTC930]

[gumba]

Those won't work with 15" wheels. You need the 930 calipers. I think Zuffenhaus in the US and DP Motorsport in Europe offer a reproduction of the 917 calipers. For front rotors I would go with the Rennsport flat hat adapters and 993 turbo rotors. The rotors are shaved down by Rennsport to work with the 930/917 calipers and 15" wheels. You will probably need a 1/8"-1/4" front spacer so the wheel clears the rotor fins.

[mmastro]

Yeah, Stephan those are 993TT calipers mounted with adapters and rotors. The 917 calipers should bolt right up to the front struts, but the rears are a different story since they're original 77 930 trailing arms (that were never fitted with 917 calipers). Maybe Bill Verburg will chime in, he's the Guru on this stuff. He told me how to fit 917 calipers on my 914 on all 4 corners!

I see you have the engine out, hope it didn't fail! The Kinesis wheels look good with the centers black.
Cheers,
Mike

[PTC930]

Hi Mike,

the Engine is still great working !!

Just rebuild the Transmission 2 and 3 Gear.

Now want to put back Fuchs on it. I have a Set of 9 and 11 /16
Its still a great Car but just want to fix some Things.
When i bought it from you last Year i want to put it back to stock, but i was on the Track with it and it will be a shame to bring it back to stock.

You build a great Car, thanks ;-))
Ill keep you updated.

[infraredcalvin]

I did this to my '76 930. I bougt a used set of later 930 front and rear calipers, then talked to steve at Rennsport systems, I also talked witht the guys at VCI motorsports. VCI will cut and redrill the rear calipers to fit on the forward mounting holes on the 77 trailing arms. My trailing arms had the undrilled rear mounting ears, so I shaved, drilled and tapped them (very carefully) on a drill press. So my rear setup is the same as the later 930s.

Rennsport was a bit more expensive - you are also getting different brand parts, but Steve is a wealth of knowledge, really helped me out, sent me some unrelated hardware for free next day service so I could finish up. It was worth the extra couple hundred more. I love my big boy brakes!

[Miguel Antonett]

I thought that US OEM 930s (77 ~ 79) came with 917 brakes out of the box.

[ficke]

Originally Posted by Miguel Antonett

I thought that US OEM 930s (77 ~ 79) came with 917 brakes out of the box.

78-79 had full floating rotors on the front
78-89 had 917 'like brakes' but not the same thing.

[gumba]

I thought he was referring to these.

https://www.zuffenhaus.us/cgi-bin/commerce.exe?preadd=action&key=810
Product Details

[mmastro]

Hi Mike,



the Engine is still great working !!



Just rebuild the Transmission 2 and 3 Gear.



Now want to put back Fuchs on it. I have a Set of 9 and 11 /16

Its still a great Car but just want to fix some Things.

When i bought it from you last Year i want to put it back to stock, but i was on the Track with it and it will be a shame to bring it back to stock.



You build a great Car, thanks ;-))

Ill keep you updated.

So glad you're enjoying it on the track! I built it for that! Thanks for keeping me in the loop! Obviously, I must work on letting go of it...
Have fun with it!

[mmastro]

I thought that US OEM 930s (77 ~ 79) came with 917 brakes out of the box.

I wish they had, but the 75-77 930 came with aluminum S calipers up front and steel 2-piston calipers in the rear.

[PTC930]

@ gumba

you are right, i have a Set of 3.3 1978 Calipers but not sure if they work on the track, so i decide to use the big once RSR - 934 Calipers.

@ Mike

I hope with the 16'' and Semi it will go mutch better around the track.
Get the COA and its original continental orange delivery. ;-)))))))))))))))))))))))))))

[gumba]

I run 930 calipers on our '75 Carrera race car. For the track I up graded to the Rennsport 993 front rotors shaved down to work with the 930 calipers. They worked great. A coupe of changes I made was to add a dual master cylinder set up for better brake balance. I was getting front lock up due to running 255 fronts & 315 rears. The front brake bias with the smaller tires was the issue. A good up grade for the rear would be C2 turbo calipers.
I kept the 930 calipers so I could run 15" wheels on the street, and 16" & 17" wheels at the track.

[Ds1]

Hey, when you sell your 993 brakes let me know, I would be interested!

[PTC930]

Thanks i keep you updated about selling the 993 TT Calipers.

Will get next week a set of original 930 3.3 Brakes from a 1979 turbo as well.
So i have the Repro 917 Brake and the 3.3 original Brake.

Whats your experience with the original 3.3 Brakes on the track ?

[JFairman]

Originally Posted by ficke

78-79 had full floating rotors on the front
78-89 had 917 'like brakes' but not the same thing.

Correct.
Someone started that myth a while back and then all the hearsay freaks repeated it over and over until the average 930 guy thought it was fact.

I've seen Porsche 917 calipers and they have larger cooling fins cast into them. They don't look like '78-'89 930 calipers.

[onboost]

Originally Posted by JFairman

Correct.
Someone started that myth a while back and then all the hearsay freaks repeated it over and over until the average 930 guy thought it was fact.

I've seen Porsche 917 calipers and they have larger cooling fins cast into them. They don't look like '78-'89 930 calipers.

Yes.. I think that myth was started by some of the "experts" over on F-chat.

Another hearsay/ term that I hate which is continually repeated is "sunroof delete option." How could that be, you either ordered a car and specified the optional sunroof, or you didn't... kinda light metallic paint, you paid extra for that as an option.

Ok, sorry to go off topic.. back to the regularly scheduled program!

[tonypeoni]

Originally Posted by onboost

Yes.. I think that myth was started by some of the "experts" over on F-chat.

Another hearsay/ term that I hate which is continually repeated is "sunroof delete option." How could that be, you either ordered a car and specified the optional sunroof, or you didn't... kinda light metallic paint, you paid extra for that as an option.

Ok, sorry to go off topic.. back to the regularly scheduled program!

Sunroof delete is a very real option and a very rare one. Almost no U.S. 930 and very few RoW 930 would have been built without a sunroof unless the dealer or customer requested.

[ficke]

Originally Posted by onboost

Yes.. I think that myth was started by some of the "experts" over on F-chat.

Another hearsay/ term that I hate which is continually repeated is "sunroof delete option." How could that be, you either ordered a car and specified the optional sunroof, or you didn't... kinda light metallic paint, you paid extra for that as an option.

Ok, sorry to go off topic.. back to the regularly scheduled program!

I remember very clearly when the 1978 930 came out, I remember going to the dealer and drooling and reading about them and talking with my friends about them, it was our dream car. The ads said the brakes were patterned off of or inspired by or like the 917 and in 1978 people just called them "brakes from a 917" So that myth was started way before Ferrari chat or the internet.

It gets frustrating keeping facts straight around these cars because they are so myth inspiring and the 1970's Porsche went from the "little car that could" to dominating all and the 930 was part of that.

[ficke]

Originally Posted by tonypeoni

Sunroof delete is a very real option and a very rare one. Almost no U.S. 930 and very few RoW 930 would have been built without a sunroof unless the dealer or customer requested.

Sunroof was an option.
US dealers pretty much ordered all 930's with that option.
Here is a picture of the COA of my German market 930 which does not have a sunroof and no mention of it in the options but note how the fog lights were ordered deleted and noted as an option.