1980 911 SC performance

[Jelle1986]

Hi everyone,


I've just started a complete Restoration (body + engine) on my 1980 911 3.0 (204HP) SC (euromodel).

I Bought both the engine rebuild and 101projects books and am reading them like my life depends on it.

I do have some questions about performance enhancement tough.

in the engine rebuild book there's summary of low and high performance (can't tell the page ,I'm at work right now)

they recommend in the "low performance enhancement" to go for the je pistons and the ssi heat exchangers.

Does anyone have experience with these?

Do you really notice a difference?

How can i increase torque and upgrade my transmission with better performance? (i have to take it apart anyway because the synchromesh has a problem)

Are there other performance upgrades i can do that get me in the 250-270 HP range without having to place carbs. (the laws are very strict here and an engine with a weber on it is a definite no-no for insurance companies and car controls)

Best regards!!

[lindy 911]

The reason for changing the pistons is so you can use a higher lift cam. When you change the cam and piston the CIS goes by-by. You can however add EFI which in some circles is better than carbs performance wise and certainly emissions wise. Do you have to retain the catalytic converter? If so you will need a more modern version that is freer flowing. If you can swing it, the 3.2 SS engine is nice but the pistons AND cylinders will need to be replaced to 98mm. You can dig a pretty deep hole in no time...I did.

I have a 3.0 SC with 10.5 : 1 JE pistons and no problems to date. I tried SSI but they are too restrictive to let my engine rev. SSI with 9.5 : 1 JE, GE 40 cams and a hotter ignition source will definitely make a difference, but you'll still have to change the induction. 250-270 hp? No way.

[Josh D]

Wayne's recommendation is to increase compression on the low compression 3.0 SC motors, install 964 grind cams, and SSI's.

If you have the '81-'83 930/10 motor ('80 Euro SC had the 930/09 low compression 188 hp motor), you already have the 9.8:1 compression pistons, so the JE pistons don't buy you anything.

From what I've read, adding the 964 cams and SSI's to your motor would be good for 220-225 hp.

[dede911]

Hi Jelle,

I too own a204 hp euro, with 250K km on the clock.

Stock engine with SSI

A few months ago I got it on the (calibrated) dyno from Kempower.

Result 218 HP...not to bad with this mileage...

I think that with 964 cams 230 should be possible

My friends engine is almost ready...we will get it on the dyno soon (I hope) to compare. (Complete rebuild done by Van Beurden)

To get serious HP with CIS (yearly car control could be an issue if dumping CIS) best way is to increase cubic inches...3.5l should give 260-270 hp...same figures as a 3.6...

P and C are expensive...

Is this a track or street car?

André

[Jelle1986]

Thx for the info. I've been abroad for work and haven't found the time to reply until now.

The engine is definitely the 80-81 model not the 188 hp version, i've opened it up and as expected the pistons had black on them but apart from that everything looks fine, i got it running with a new fuel pump and it just started right away.

So the je's wouldn't make a difference then, but the 964 cams would. can you enhance the injection by swapping it for an ECU on the CIS?
Catalyc converters are illegal but the car is registered as an oldtime and doesn't have to go through mot.

The car is for street use but it drives 3000 km a year tops!
I do change the oil, etc.. complete maintenance every year before driving it.

Oh, just a small side question , a friend of mine was arguing that i should swap the paper air filter in the box for a k&n racing filter, now i now that this is gives just a few hp and is usually done for that weezing sound it makes ( not that that's going to be audible above an old boxter engine ) but a lot of new cars have problems with their air mass meters after installing it because the oil these filters have to be lined with gets on the sensor and gives of a bad reading to the ecu. Is it considered an upgrade (slightly better air intake)if i would install it or just some nifty thing that has more of an placebo effect on the driver?

@ andré: hallo, alles goed!! i'm curious to see what the dyno will give, is it a standard rebuild or did he increase any parts or cylinders?
I'm not building a racemonster just something classic with a little more push, my goal is/was 250 hp max!! And the car is registered under an o-plate as you will know what this means .

[gavinc69]

I found a lightweight flywheel and a complete free flow exhaust system (mines a fabspeed) made a nice increase, revs really free and fast and pulls well.
Then I installed MSD coil and MSD 6AL ignition with 0.45 gapped plugs and Magnacore wires, again it improved things a little. Im just sending the engine now to be rebuilt, going to have 964 profile cams and flowed heads. See what happens then.

[dede911]

Jelle,

the engine builder had some delay.

Car will be picked up this weekend.

The only mods are SSi and 964 cams.

I expect around 230-235 HP

For higher figures, forget CIS because other cams are necessary.

Another way is more cubic inches...3.4 or 3.7...

Why are you looking for 250hp for a street car?
More important is an engine with a nice torque curve (IMHO)
Good brakes
predictable road holding (suspension)

torque = acceleration
power = speed

André

[Jelle1986]

Hi, i just want a good increase in power. if 250 is not manageable by upgrades then i'm not doing it. (want to keep it original)
But i am planning to put the 964's in. not sure about the ssi's though.

everything else is gonna get revised or upgraded as the book recommends to get a good long running engine.

btw is there anyway of increasing the torque on these cars?

@ gavin : where did you find the lightweight flywheel?

btw does anyone have experience with the airbox for te 911 from fabspeed?
grtz

[914efi]

Andre' hit the bullseye, good comments, very practical, ignored by most.