Turbo or NA?

 

Hosram,

How much are those 100mm turbo pistons? pm, if you don't want to post it.

 

Hosram would like to get 104mm 16v turbo, but quite happy with 16v 104mm NA too.
thanks
mike

 

Arash, sure it could have been high compression low boost that caused it but 9M have been running higher boost on the track with no problems....also there is no sign of detonation in the plugs or pistons, nor ever any audible det whilst it was boosting. I will certainly share if the reason becomes clear.

Patrick your right it was only a matter of time for more boost, I'm happy to continue to play and see what it can do...

Tom if I was pulling the engine the 105mm would have been good, this time round I will just do in car engine in changes, next time....

rgds
mike

 

Tolerance group 0 for 951 (99.98mm) with rings, pin & clip, Kolbenschmit brand.

PM sent.


Sent you a PM.

 

So Hosrom, are you selling factory pistons these days? Which pistons do you have available?

 

As I remember he came across a stash of these at his local dealer a while ago at a very competitive price and bought them all up.

Smart thinking!

 

For the 951, got the stock tolerance group 0

I know i have some 100, 104 and 104.51 for the NA (2.5 and 2.7) and the S2 (not sure about the 968 YET.



Right, i came across a local VW parts store, he had these lying around and i noticed "PORSCHE 944" on them. Found out they were pistons for our cars, for a good price. I did not buy them, but i did take a 1.5hr drive down to him to take pictures since i had a lot of people saying "i want them" where no-one was realistically interested.

 

So what if any are the differences between 968 n/a & turbo pistons? I'm guessing the crown pattern would vary but assuming they're both Forged what else?

 

Having just spent six hours searching a reading every post I could find on replacement pistons I am left with a very nervous feeling on the success rate of replacement pistons.

There seems to be a number of failures of the aftermarket pistons due to the 'coatings' to enable them to run in the Alusuil bores. However balancing that are comments on them working well, so is this a lottery?

I have had respsonse from Racer Edge quoting $900 for a new set of S2 Wossner made to specification $225 each including rings. However I expect these will be machined and locally coated - possibly back to the lottery situation, anyone running Wossner on 944 turbos?

My current thinking now, if I cant get a second hand set of 968 factory pistons, the safe bet may be to stay with my S2 factory pistons, but add the 951 forged rods, bearing, rings etc. Maybe ceramic coat the stock piston tops. and keep the boost down to 1bar.

regards
mike

 

Try HMR in south Florida.

 

Mike,

I installed a set of Wossner coated pistons for a S2. I was not impressed to say the least. Thats just my opinion. I don't wish to say what I thought was wrong with them as I don't want to spread bad press. Also, others may have had better luck.

 

many thanks for sharing, that adds more weight to my concerns, hopefully a SH set of 968's will turn up otherwise its looking like the orginals will stay in. I still have to strip the engine so hopefully something will turn up within the next few weeks.

regards
mike

 

Here is what I did with my 968 piston to use in a two valve. CC'ed after and should yield 8.5-1.

john

 

^^This gentleman is a good source for pistons, contact him and see what he has to offer.