Porsche Enthusiasts Club Forum

What should the compression figures be for a 944 turbo? I just tested mine and are as follows.

From front to back figures in PSI,

1) 130
2) 125
3) 130
4) 130

I'm slightly concerned about the 125 reading but on the whole happy with how even they are. But are they all to low? I know the turbo's have a lower compression ratio to N/A but again, do i have anything to worry about?

The car goes like a rocket by the way, i was only testing it out of curiosity.

Cheers,
Stu

Doesnt anyone know what the psi figures should be?

Stu

i wouldnt worry too much on the 125 one was that hot or cold?

The engine was up to temp when i tested it. Burnt the crap out of my hands getting the plugs in and out!! LOL!

well i'm not sure about porkers but i know that a gto compression is around 125-130 cold and 145-150 hot so if pork is the same as sushi then yours seem a bit low.

Mine were checked by Hartech shortly after buyingthe car last year and were reported as 150psi across all 4 cylinders.

It's a '91 Turbo with 135000 miles on it btw.

Not too bad in my view, 5PSI difference is around 3% so not worth worrying about.
Was it throttle oppen whilst cranking? You should do that & also try with some oil down the bores to see if it improves.

The throttle was closed when i tested it. Il go and test it again as i have to put some new plugs in anyway.

Thanks all.

Well after trawling the net for info it seems 130psi is the norm and a very healthy figure for the 220 951's.

I re did the test with the throttle fully open anyway and had 130psi in all cylinders this time.

So im happy

I just have to sort out the leak from the front crank seal now. Oh and spend lots sorting out the rusty sills!! LOL!! And sort out why it seems to stutter/judder sometimes just before it comes on boost.

Isn't boost addictive

ah boost must admit its a great feeling when it throws you back in your seat.
but when you get used to it Stu you will want more and more.
Dave

I know what you mean Dave. Im wanting more already and this thing is chipped up already LOL.

bigger injectors, hybrid turbo and remapped ecu..... is the way forward

boost is adictive - i got my 89 44 Turbo up to about 290BHP and it was immense but still not enough. I worked out it would be cheaper to buy a 911 than carry on spending money on getting a lunatic 44 !!!