Euro Spec Pistons

[PhillysMostWntd]

is there a difference between the US pistons and the euro spec ones??

[seaboltman]

compression, the Euro spec pistos have a higher CR ration, but i cant remember what it is. fast924s made a thread about geting a set, and im sure he probably listed what the CR was, if you search for it you should find it easily.

[rudidelange]

The euro spec pistons are 10:1
Power output for US spec vehicles are 116 KW, Euro spec 120 KW.
The Euro spec pistons are flat on top, except for a small recess for the valves.

[PhillysMostWntd]

yeah i saw a picture and was wondering, im looking into getting a set

[fast924S]

Euro Cr is 10.8-1. Stock US is 9.5-1 and 1988 US 944 pistons are 10.2-1

[fast924S]

I did found a euro set on rennlist but they where too much moeny, Plus Im not sure if the DME would take well to a 10.8-1 Compression ratio and might get some knock. SO I went with a set of 1988 pistons with the 10.2 cr. Also when buying pistons make sure you get the tolerance groups right. Its a number stamped on the pistons. Most are group 1 but there is also group 2 and 3 I believe

[Porsche-O-Phile]

You can also shave the head a bit.

[944SpecRacer]

And all this for 1-3 HP!! Get real!! See the 924S chip page for more info. Save your money or spend it on suspension or driving skills. No HP to be found other that getting the motor up to stock specs!! Trust us we know!! Go towww.nasafroums.com and check out the 944 Spec page!!
LIVE AND LEARN!!! INFO is out there trust us if there was power to be found we'd have it!!!
Live, race, learn,

[fast924S]

Isnt there like a 10hp difference between the US and Euro model?

[Dean924s]

Originally posted by 944SpecRacer
And all this for 1-3 HP!! Get real!! See the 924S chip page for more info. Save your money or spend it on suspension or driving skills. No HP to be found other that getting the motor up to stock specs!! Trust us we know!! Go towww.nasafroums.com and check out the 944 Spec page!!
LIVE AND LEARN!!! INFO is out there trust us if there was power to be found we'd have it!!!
Live, race, learn,

I have to disagree. The whole point in "tuning" these cars is to get one or two horsepower here and there. You are correct that chipping is for all intensive purposes a waste of time if you are looking for HP but it may help the drive-ability of the car.

Case in point. I added a chip to my car. Not for the hp but to change the power band. I wanted more power down low as my local track has several turns that are right in between 2nd and 3rd gear. By lowering the torque curve in the motor a bit I can keep the car off the rev limiter in 2nd. By changing my braking point and my line I "glide" the car through the turn keeping my speed / momentum up, keep it in third and am able to pull the hill on the exit of the turn instead of having to shift just at the end of the track out of the turn. Saves half a second a lap as I am faster through the turn and my top speed into the next turn is 5-7 mph faster. Did I add horsepower to my car? No I added drive-ability and speed based upon careful analysis of the problem and I have corrected it the best I can with the resources available to me. A side bar to this is I only did 4 laps. I have to put the car on a dyno with a wide band O2 to make sure that it is not going lean with the chip. After the 4 laps I swaped the chip and went back on the track. I did this in the middle of a test and tune day.

Same goes for adding pistons / changing compression ratio. It by its self will not be the single add 20 hp to your car mod that we all would like. However, I would bet that there is a master plan to what he is doing. He is asking a single question related to a single part. Most people don't go changing pistons with out addressing all the other possibilities. Decking the head, port and polish, change/porting the AFM.... . The list goes on. Each by its self may not be worth the effort some may not do a dam thing by them self but combined the numbers start to add up. We all know that these cars are not like the old V-8's of the 60's and 70's where you added a set of headers, a cam a intake and an exhaust and you would pick up 100 hp. We as Porsche owners understand this but this should not stop us from getting all we can. We also understand the Hp in a Porsche is not cheap. Part of owning one of these cars is the thrill of trying

For the record I have taken plenty of driving schools. I try to have some on ride with me at least one a year just to get a second opinion on things (I pride my self on that I try to learn something from every instructor that gets in my car). I have raced wheel to wheel, time trailed and just go to the track to blow off steam (funny how diving into a corner at 100 mph trying to brake 20 feet deeper than you have ever braked before can make other things become unimportant). I concur that there is allot to be gained by investing in a 944's suspension and brakes and making sure that all the original systems are at there peak (these cars are after all getting to be 20 years old) as well as improving a drivers skill but this should not preclude us from the quest of getting that 1-2 hp more that we so desperately want. Rember that most of the fun is the thrill of the hunt not the kill at the end.

[Zero10]

Most of the power difference comes from the different maps in the ECU, not the compression ratio.

[PhillysMostWntd]

like dean924s stated this is just a small part of my plan

im not just changing out my pistons there has been tons of planning done and im just seeing where i could squeeze a bit more power out of, i dont mean to make anyone angry.

ultimate plan includes a combo of port and polished head, euro spec pistons, fr wilks hfm5, and hopefully motec m4 engine management, those are the biggies in this project, and please i know this is going to cost a lot of money, so please no negative comments, i know i can use the money and get a 944 turbo and end up with a better car, but thats true with any car. i plan on keeping this car for a long period of time so i dont mind spending money on it because im going to enjoy driving this car for a long time.

im blabbing on now so ill stop


ANYWAYS... does anyone know the exact hp difference between euro and us 944's? maybe ill just search some more for it, i should find it but any help would be appreciated

[fast924S]

Right on DEAN. Im with you all the way.

Zero10, I believe it is a combo of different EURO maps and the higher compression. The maps are changed to alter ignition timming and A/F ratio to get the best gain from the compression ratio. So if you swap from a 9.5 CR to a 10.2CR you might not see the same increase in HP as you would in a 1988 944 that has a 1988 dme that is mapped for a 10.2CR. That is unlees you find a way to control the A/F ratio and a way to control/advance timming witch is easy to do. Infact Im beting That I might have to play with the FQS after Im done installing my 10.2 cr pistions since I am running a PowerProm 2 which has the igntion timming advanced. But we shall see in good time.

[fast924S]

http://www.pelicanparts.com/944/tech_specs/944_model.htm

http://www.pelicanparts.com/944/tech_specs/engine_specs1.htm

those 2 links are US models only

And according to my "THE PORSCHE 924/944" Book by Peter Morgan the US 944 puts out approx 143bhp at 5500rpm and 137 lbft at 3000 rpm
The EURO version puts out 163bhp at 5800rpm and 151 lbft at 3000rpm

[fast924S]

Philly. If your gonna run a Motec why even have a MAF setup, I believe the MOTEC supports MAP setups and that would be the best in low restriction intakes

[Zero10]

Running a MAP setup on a N/A 944 is tricky. The signal is not even remotely smooth. A few people have tried it, and in the end, it was decided that it is a very difficult setup to make work, and the gains are very minimal over a MAF setup.

[fast924S]

What maKes it so hard? Toyota has done it on there four bangers, The turbo 944's do it all the time, Infack alot of cars run it. I dont think there would be a problem if your running a MOTEC, I have seen problems with piggy back systems, but not a full stand alone MAP setup

[Zero10]

I don't know about a standalone, but I was told that the signal varies so quickly and wildly because of the intake design that it's very difficult to get an accurate reading of the current manifold pressure.
I hate to spready myths like this, but I'm just going on what I heard.

[fast924S]

You could be right, But I havent hear of it yet. I do know guru racing was having problems with their MAP piggy back system and since its a piggy back it might run a little slow so they might be running into what you are talking about. I guess we wont lnow for sure until someone tries or post some true data

[PhillysMostWntd]

ya im still researching it trying to find the best route to go,

fast924s - i would go with a map setup but like zero10 stated (i also read this during my web browsing) that the map setup on a n/a 944 can be difficult to work with.

im trying to figure out which one would be most benificial while being easy to use and fail safe, from what im getting, the MAF route might be the winner

"And according to my "THE PORSCHE 924/944" Book by Peter Morgan the US 944 puts out approx 143bhp at 5500rpm and 137 lbft at 3000 rpm
The EURO version puts out 163bhp at 5800rpm and 151 lbft at 3000rpm"

20 hp?? i didnt think the euro models were making quite that much more then us...