I have a rebuilt 83 sc. I put in new Mahle 98 P&C, dual plugs, Tec3, 120/104 cams, carrera intake. Like Steve says, it won't idle well until it's hot, it won't run smoothly below 3000 rpm. I love how it runs above 4000 rpm though.

As you have found, the 120/104 does not mix all that well with a common plenum intake. A switch to ITB's will make all the difference in the world.

Cheers

One can even put ITB's under that Carrera intake (deleting the throttle and AFM) for excellent effect,...:) :)

I would like to know how you do that :)

Its quite simple,...:) :)

One needs to modify the intake manifolds to accept rubber sleeves, install some Jenvey's, design & build the linkage, remove the single throttle & AFM replacing them with custom plumbing and an air cleaner.

Then, one programs the Engine Management to suit.

The result is incredible throttle response (like carbs or MFI) with a VERY broad, flat torque curve (unlike carbs or MFI). :) :)

LOL - you make it sound so easy. No doubt the devil is in the details.

I may be wrong, but I think some of the Motec 964 engines from 9M are running without any AFM. Would ITBs with the common plenum intake on top of ITBs be more efficient - more hp and tq - or less?

Sorry to go OT.

Like the 993 RSR then. :)

Indeed, the devil IS in the details,...:)

The only way you can make a common-plenum intake work with ITB's is by positioning them in each runner and the final height is dictated by the required hardware and space for linkage.

Its very similar in concept to the 993 RSR intake system which makes those 3.8 race engines pretty docile for what they are.

Its all about generating the most "area under the curve",...:)

Steve:
I saw the Gulick/Fordahl 914 run at the Packwood NT event last summer with that set-up. I'm a believer....and if I ever hit the lotto......:D

edit:
As I was standing there looking at the motor (2.8L), Fordal said it made 285 hp on the dyno. Someone asked why the Carrera intake plenum. Fordahl said "That's where the torque comes from". Hp is all well & good, but for AX a nice wide torque band is killer.....IMO.

I don't suppose there are any pictures of the set-up?

I know what the 3.8RSR intakes look like as a friend has one, but this is something I have never seen or even heard of until now.

Here is a rough shot from the Freisinger web site.

Steve, do you have a bigger picture than the one on your site?

http://forums.pelicanparts.com/uploa...1197996795.jpg

Here we go.

http://forums.pelicanparts.com/uploa...1197996899.jpg

http://forums.pelicanparts.com/uploa...1197997120.jpg

Interesting idea. This might be a good experiment for those GXR throttle bodies I have in a box. Now who wants to supply a carrera intake for me to cut up? I can do a back to back comparison with the TWM ITBs currently on the car.

Anyone have comparison experience with the TWM's and the PMO's?