924Board.org

dwak · Joined: 03 Nov 2002 Posts: 839 Location: Eastern Ontario

After 2 years of being parked (my 1981 931) and going through a seperation (me), I am slowly getting my 931 back in order. It seems to be mechanically in good order and I can't remember why I parked it. My mechanic thought the turbo response was odd compared to 914's and 911's which are his forte. He said the turbo seemed always to be on and not kicking in at, say, 4000 rpm. Again, I can't remember how it used to respond but will start driving it to refresh my memory. Is this a 931 characteristic or is it the plumbing (wastegate?).

dwak
_________________
2x924NA's for parts
931
924S

Paul · Posted: Thu Aug 24, 2006 11:38 am Post subject:

Boost should appear by 3000 RPMs in first gear and even quicker as you shift to higher gears.
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

924RACR · Posted: Thu Aug 24, 2006 10:44 pm Post subject:

Yeah, even in 2nd I can feel the boost start to build once I pass 2000rpm. I seem to recall hearing that the Series I turbos were later and harder...
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Smoothie · Posted: Fri Aug 25, 2006 1:39 am Post subject:

It may well be and probably is just the difference in feel between a 914-911 and a normal 931. I've never driven either a 911 or 914 turbo, so don't have personal experience, but do recall reading that the 931 has a smoother transition from non-boost to boost.

I wouldn't conclude there's a wastegate problem because if stuck closed (torn diaphragm or loose/disconnected control line), you'd have unlimited boost and plastered back in your seat power up until the cutoff switch activates or your engine goes boom - whichever comes first. On the other side - if the wg were stuck open (broken spring), you'd have the equivalent of a low compression engine with no boost - so say what? 50-60 HP?
_________________
"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

dwak · Joined: 03 Nov 2002 Posts: 839 Location: Eastern Ontario

Current performance of the 931 is about the same as my 924S which is running strongly.

dwak
_________________
2x924NA's for parts
931
924S

Tigger937 · Posted: Fri Aug 25, 2006 12:53 pm Post subject:

dwak · Joined: 03 Nov 2002 Posts: 839 Location: Eastern Ontario

Drove the car home from the shop (Mike's 912's) this evening and was pleased.
The turbo kicks in very smoothly at 2000rpm + and when I laid into it on a familiar stretch she took off very quickly and no complaint. I think it's a lot quicker than the 924S I have but I do have the euro motor I bought from wreckers in England. ($1500CAN delivered)
If it continues to behave, I'll install my intercooler, sway bar and rebuild the punky brakes.

dwak
_________________
2x924NA's for parts
931
924S

flosho · Posted: Sat Aug 26, 2006 10:19 am Post subject:

Drive it for a couple weeks, definately install the intercooler... You will be very happy you did!

_________________
[This Space For Rent]

Devam · Posted: Sat Sep 09, 2006 10:11 pm Post subject:

Does an intercooler make a big difference?

What about K&N filter?

Thanks.

flosho · Posted: Sun Sep 10, 2006 1:45 am Post subject:

Intercooler at stock boost wont make as noticable difference as you'd think, but having an intercooler allows you to up the boost safely. You could run 1 bar (or more if you have the balls, and the supporting upgrades) with an intercooler because the intake temps are at a safe level still..
_________________
[This Space For Rent]