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Brockoli

Why is there a difference in HP between the euro 924 and US/Canada 924? I think the euro has 9.3:1 pistons and less emissions stuff but that cant make 15HP, can it? Is it the camshaft or timing?

The reason I ask is that I plan on doing my rebuild in the summer and want to find some euro pistons. While I am in there what other euro parts can I use to get more power?

Also, how much does a euro car weigh? I know the toofah guru's on this board will probably know everything that is different

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'80 924 M471,Wideband O2, Full coilover susp,23/19 sways,Bilstiens,KLA Strut Brace,Roll Bar,Test Pipe,BBS RS, Willwood BBK

25% of a '87 944 Chumpcar http://straightpipe.ca/forums/showthread.php?t=2454

'79 924 Sebring Edition(Sitting)

xpernet · Posted: Thu Dec 24, 2009 2:36 pm Post subject:

The North American cars came with a different distributor if im not mistaken... i didnt swap out a euro dizzy, but when i switched to EDIS i got a nice punch in power. Nothing big, but doesnt feel like a 95hp engine at all.
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1977 Porsche 924
Sunroof Delete
Megasquirt II EFI & EDIS
Carrera GTS / 944 Body

"If one does not fail at times, then one has not challenged himself." Ferdinand Porsche

!tom · Posted: Thu Dec 24, 2009 4:08 pm Post subject:

I believe the big differences are distributor and pistons. Some US/Canada cars had smog pumps too which rob a bit of power.

My understanding is the pistons are the biggest difference.
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78 924 NA
5-lug

Scorpio · Posted: Thu Dec 24, 2009 4:47 pm Post subject:

Power to weight...Dont Americans weigh more than Europeans?

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1979 NA
MS1..EFI..
GARRETT T25 TURBO
BILSTEIN SHOCKS
GT BASED CUSTOM BODYKIT

Brisbane , Australia
Think mean think fast
all youll see is
my Porsches Arse!!!

Brockoli · Posted: Thu Dec 24, 2009 7:13 pm Post subject:

xpernet - I think i might and source a euro dizzy but I bet the timing is different too. Something for me to look into...

!tom - i took off my EGR valve system. The only smog component left is the cat. which I will remove soon. I think the only cars with an air pump were the ones sold in california. Canada still isnt too strict on smog, alberta does have any smog testing

scopio - lol, I have already started a modest weight reduction. A/C, EGR system, sound deadening carpet in the back, spare tire. More to lose tho.
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'80 924 M471,Wideband O2, Full coilover susp,23/19 sways,Bilstiens,KLA Strut Brace,Roll Bar,Test Pipe,BBS RS, Willwood BBK

25% of a '87 944 Chumpcar http://straightpipe.ca/forums/showthread.php?t=2454

'79 924 Sebring Edition(Sitting)

D Hook · Joined: 02 Nov 2002 Posts: 3158 Location: Omaha, NE

PORSCHEV · Posted: Thu Dec 24, 2009 9:37 pm Post subject:

It is the higher compression ratio and the lack of smog gear that gives the power. The euro dizzy is only good WITH the higher compression ratio. The euro dizzy just has more advance sooner with a different curve then the US spec.

PM me if you want a set of Euro Pistons for the standard bore. I have a set I will sell for $100.00 cdn.
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1976 924
5 lug conversion, 17'C2 wheels,custom body work,327 vette engine.

1978-#53 "D" track racer.

Vince Ponz · Joined: 02 Nov 2002 Posts: 3581 Location: Florida

Weight is one problem. Here in the US we wanted more accessories. Air conditioning did not come standard in 1978 when I bought my car new. It was a very poor add on which did not work well.

Smog equipement would add weight, maybe the euro tranny was lighter, no sunroof=less weight, MUCH lighter front and rear bumpers and shocks[US total weight front and back about 48lbs vs 23lbs Euro] and stock wheel metal rims?? and thinner tires, wind up window equipement lighter than electric, smog parts, smaller rubber on the front bumpers [US 3lbs ea=6 lbs/Euro 8 ounces and some other items that I cannot think of.

Cam and pistons made up the difference also.
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"Never let them see you sweat"
77.5 924 modified track car
79 931 Euro stock
88 924S SE
87 911 Targa stock

Harm · Joined: 02 Apr 2009 Posts: 1378 Location: Holland

Porsche 924 ('76-'85) Haynes (#397)
Info on page 4, short…

”From 1976 through 1977½ model years, North American versions of the 924 had engines of 95 hp. This was a result of fitting low compression pistons and the addition of emission control systems. The emission controls which were used vary according to the sales market. (…
…
…) A redesign of the emission controls and the higher-compression pistons brought the engine output to 110 hp in the 1977½ through 1979 models.
(…
…) with the 1980 models. Changing the emission controls (…) and an additional raise in the compression ratio has lifted engine performance into the 120 hp range. Removal of pumps, valves and other emission control components has had the additional result of improved gas mileage figures.
(…)
Specifications for the European version of the 924 have remained nearly unchanged for the entire run of production. The engine produces 125 hp and is connected to a 4-speed, 5-speed, or optional automatic gearbox.
(…)”

Joes924Racer · Posted: Fri Dec 25, 2009 6:25 am Post subject:

Dish size in the top of the pistons and the dizzy.
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1979 porsche 924 Na
1980 porsche Turbo 931GT Replica
Have u ever driven a turbo.

CorsePerVita · Joined: 25 Jul 2008 Posts: 1992 Location: Redmond, Oregon

Rich H · Posted: Sun Dec 27, 2009 8:42 pm Post subject:

Slam · Posted: Wed Dec 30, 2009 5:59 am Post subject:

All the above, plus the ignition advance. My Euro runs at 10 deg BTDC. The stock US cars are 3 deg ATDC in some cases! You'll also benefit from losing the cat and going with a pre-muffler. Dump the emissions junk. I actually would source a Euro dizzy for the difference in the advance curve. You'll notice it.

Back to back, Chrenan's old yellowjacket is faster at its top end than my Euro but the Euro is snappier. The yellowjacket actually feels like a less powerful version of my 944, which is saying a lot.
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'88 944 Auto - may or may not resurrect

Brockoli · Posted: Thu Dec 31, 2009 3:08 pm Post subject:

Slam - I have already got rid of the EGR valve, and I will eventually get rid of the cat. I am still on the fence about how far I want to go during my rebuild. The big valve head is always in the back of my mind...
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'80 924 M471,Wideband O2, Full coilover susp,23/19 sways,Bilstiens,KLA Strut Brace,Roll Bar,Test Pipe,BBS RS, Willwood BBK

25% of a '87 944 Chumpcar http://straightpipe.ca/forums/showthread.php?t=2454

'79 924 Sebring Edition(Sitting)

!tom · Posted: Thu Dec 31, 2009 6:28 pm Post subject: