Sat we talked about injection vs carbs and how to replace the Webers or Dells with throttle bodies.

Here's a webpage that shows the throttle bodies you would need to replace the carbs.

Here's one for the guys who were talking about the high mounted "Madonna" injector setup for the 911 engine.

Madonna Injector Setup

those are nice......I'm guessing for the /4 motor $1000+ not including the injectors for the t/b's, linkage, extentions and mounting hardware??

those high mount units are neat, I'd hate to have a backfire thru the intake

If you are switching over from dual webers or dells, you will already have all the linkage and intakes.

And I have no idea how much they cost......

fuel injection

there is also this, kinda pricey.

QUOTE (ClayPerrine @ Feb 7 2006, 10:24 AM)

If you are switching over from dual webers or dells, you will already have all the linkage and intakes. And I have no idea how much they cost......

retail of just the throttle bodies is $328 each (2x).....

That is still cheaper than the 500 or so that CB wants for the same thing.

QUOTE (tdsmoonchild @ Feb 7 2006, 10:26 AM)

fuel injection there is also this, kinda pricey.

kinda crappy as well.....not enough tuning parameters, it's sorta like an electronic carb that cannot adjust too well to differeing conditions.....they work, but for that price, there are better solutions...

TWM stuff can be had cheaper still from the pony car guys.

Something like $250 per body including fuel rails from Top End Performance.

-Josh2

Ah ha, oh guru with the knowledgable speed racer wife....
I like it but you know I'm a cheap bastard too.
Hmmm I think I can hobble something together from some stock parts. Good info and it gives me some ideas too.

I think you can drill a bung in weber manifolds and use the car as a throttle body... but what do I know?

QUOTE (tat2dphreak @ Feb 7 2006, 05:08 PM)

I think you can drill a bung in weber manifolds and use the car as a throttle body... but what do I know?

yep, just remove the venturi....I've seen some people take a carb and just put a sleeve in it to clean it up.....

With the throttle bodies they offer I think that the injector placement could be better, i.e. closer to the valve. Gut an old dellorto and mount an injector bung into the mainifold so that it sprays the back of the valve.


I think that would work better.

Spraying on the back of the valve is good for emissions only. Moving the injector farther up the intake tract is better for power (more time to swirl/mix/cool/evaporate). The TWM placement is about as high as you can get w/o putting them above the butterflies. The jerry woods/madonna setup is best but there are the obvious fire risks.

SMD

Edit: FWIW, I've got TWMs on my 911 (which will probably end up on the /6 and I'll get biggger ones for the 911).

See, I like this idea. You could use some carbs that other wise would be tossed out. Add a ms to manage it...

here are some interesting throttle bodies. Ive seent then used on the Mad Scientist 944 Turbo. I bet you could use a pair of these on a 914

I've tried both high and low injector positions on my 914-6 injection. The high works, but it is best for higher rpm work, the low gave much better driveability. The high is a lot easier to build a manifold around though.