Opinion of PMOs or Webers on an SC

I have a 79 SC. I am close to ordering the GHL headers and exaust for my car. I am also thinking about carbs and x-ing the CIS. I have heard good things about carbs, but my mechanic says the piston design does not lend itself to carbs. How true is this? 3.2 P&Cs are not in the budget at the moment.

Drew Reed

Not to sure about the carbs on a 3.0 but I went with a crank fire setup with a programmable fuel injection setup on my 3.0. Completely tunable to however/wherever you drive. Internal engine stock, with the exception of 964 cams with B&B exhaust, put out 239HP at the rear wheels on a dyno. Not bad for an SC with only 180 BHP stock! I dont know how to post a picture , but check out http://members.aol.com/rattlsnak/ignfuel1.jpeg
and http://members.aol.com/rattlsnak/ignfuel2.jpeg
Marc

WOW!

Thats a nice set up Marc. What did something like that set you back? How many miles on the motor when you did the work?

Thanks

Drew

Ditto Marc, how does that thing work?

Joe
'80 SC Targa

No offense Marc, but I don't understand how you can get so much "free" horsepower for just adding a fuel injection system and some headers. I mean it seems very high.

Marc,
Come on, you may have just cost me what looks like about $3to 4K. Where did you get teh system? Who installed it? How does it increase the HP so much? Can you lean it out for smog? Since many of the CIS systems are getting old, your experience could really help in the decision to start replacing piece by piece or upgrading. Inquiry minds want to know.

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Paul
78SC Targa

Marc,

That injection setup should be good for 255+ hp with the appropriate pistons and 'S' or GE-60 cams, or maybe even GE-80 cams ... it should be able to better the '83 3.0 SCRS 930/18 engine that had 255 hp DIN at 7000 rpm!

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Warren Hall
1973 911S Targa

You can buy the kits in as many pieces as you wish. It really depends on what kind of software you want, and what parts you can get on your own. The crankfire setup was @$2,100. (tecII system, with PAFB software)But you can get them for @$900 with a not so vesatile software. The fuel setup was @$2,500. I am a former tech who worked at a dealer for 15 years or so, so getting some parts(sensors, connectors, etc.) was no problem, and installing it was no big deal. Programming the software was challenging but not too hard, as long as you have time, patience,understand fuel mapping and spark curves, data logging, and sensor operation.(it comes with a complete manual)You can check out the some of the pieces at the electromotive website. http://www.electromotive-inc.com/home.htm. You have to go through a parts distributor. I used Richard Clewitt Engineering. There is a link on the site to his page. http://www.electromotive-inc.com/rce.htm
Great operation, great help. If you call him, tell him I referred you.The system is completely programmable, so you can run it lean or rich or whatever, whenever you want. I have a track, street, and "emissions" program! Takes a whopping 2 minutes to change over with a laptop. I did have some problems getting it to pass a tailpipe test at first, but I finally just brought the laptop with me, and right before my turn, leaned it out, passed the test, and before I left the parking lot, fattened it up again! As far as HP gains, what changed between the 78-79 SC's and the ROW or 80's and up SC's? not much besides Lambda control, and different fuel rates and they gained 20 HP. And what about the 3.2's? Most of that 20 HP gain was because of the new Motronic fuel system, not the bore increase. The exhaust adds @24 HP alone. I did put some 3.6 cams in it, which helped some I'm sure. But that free flowing fuel system has to be the biggest gain. They advertised a @40HP gain with exhuast,and it damn sure did it! There are some issues with it, it doesnt run that great during cold startups, and kinda spits a little(just like Webers), but thats minor. Overall I think it is a great system, but not for everyone. Many friends I know just have the crankfire portion and love it. Hope that helps out!
Marc

That is a nice system, but $5000 also will buy you a supercharger.
As for carbs, you can run them with stock SC cams and pistons, but all you may notice is increased throttle responce. You really need to upgrade to hotter cams and pistons to allow the carbs to function at their best. Of course all that will cost you - around $5000. Power could be somewhere similar to the above injection setup depending on the cam and piston choices.
So -- for the same money you can go many different ways to arrive at the same level of power. I would love to compare rear wheel dynos of all three setups vs their real world costs vs drivability. THIS is the information we need!

Marc,

Tell us more, how has it changed the sound of the motor etc?

240 hp is almost near the 930 output without the lag, hows the low end response ?

You must be able to throttle steer and spin your wheels with ease.


Jeff
78Sc

Jeff, The throttle response is crisp throughout the entire range. It pulls strong form start until redline. The new sound of incoming air was very noticeable , sounds like a huge vacuum cleaner back there!! But the exhaust sounds great too. I don't get much wheel spin due to the fact that I have 335/35/17 on the rear. That also might effect the HP readings on the dyno, Thats alot of rubber/=weight to spin up. If I put a tiny spare on, I could pull another 10 HP !!
Marc

We need to see more pictures of this car!

Wow!

I have almost got my monitor completely wiped off!

My wife is really starting to wonder about this BBS.

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Steve Eidson
81 SC

Steve I agree with you.

Oh-oh this thread might get locked too.

Dean

Marc:

If you had to break the performance down into components, how much HP would you figure each modification bought you? I'm particularly interested in the cam mod (you don't seem to praise it too much).


TIA,

Bill Wagner

Bill, I'm honestly not sure. I had the engine out of the car putting a new clutch and chain tensioners in it, and before it went back in, it ended up having the exhaust and fuel/ign setup on it. The exhaust seems to be in the 22-25 HP range, and the people at electromotive seem to think the fuel setup is worth 40..(seems modest, but possible). I dont have a clue as to what the cams brought in. The lift on the lobes was not that much greater, but the duration was significant. I bought them from Andial. They have all the specs. Maybe a call to them would help.
Marc

I talked to Richard Clewett on Friday. I am very interested in doing something like this to my 79 SC. I ordered the GHL headers and exhaust yesturday as well. Part of the reason Marc's engine compartment looks so SWEET is, no heat or AC. Those throttle boddies look nice too but big $$$$. You can acheive a similar set up by using a Carrera intake manifold (about $700-1100 used) and going with the tech11 system ($2345) which gives you the programmable FI and the crank-fire ignition. And not really suffer in performance loss in comparisson. Won't look as nice but should feel the same. I like the idea of the programmable FI because in a year or two I will go through my motor and upgrade to 3.2 P&Cs. as well as a larger cam(bigger the the 964s) This should really make a "sleeper" out of my old P-car

Drew Reed