VW Pro Stock - HELP - fuel injector location brain storming!!

[BlownV6]

I have a VW Pro Stock car that Im working on. I have never had or used EFI in any way , but this is going to be my first experiance with it. This whole thing is kind of under wraps but I need help deciding on where to put the fuel injectors in the manifold. Most will say WTF is that and WHY are using this kind of intake setup. I have my beliefs and reasons to try this so lets leave it at that.
Question is where in a NA application , and what type of injector should I try???? The manifolds bolted the heads have injector bungs in them but I dont think that is the best location. The air supply tubes feeding the intakes is where Im prone to put them. First choice would be about 6-8" above the manifolds right in the middle of the 90 degree bends shooting straight down into the manifolds. Second thought might be to put them under the air feed tubes close to the plenium tube.
My thought is to maximize atomization of the fuel before entering the heads. Also to help move the air charge towards the cylinders. OK call me crazy!! But you can see Im dead serious!!! Let the beating begin!!! Mike

 

[blackgn1]

That's a awesome car!!

 

[bogies87]

I dont have answers and not even ideas...... all i can say is DAMN......

 

[gnpoweredrail]

If the injector bungs where on the outside of the intake then it would be awesome...at the top where the 90 is at is going to be too far away and the fuel will just run down the pipe...



awesome car....Pauter?? what size??

 

[TurboBob]

what fuel, what displacement? What is your target AFR? What controller are you thinking of using?

low speed will run better with the injectors closer to the head, but at high RPM higher up in the runner will be better. (similar to the mechanical methanol injected midget engines)

Bob

 

[BlownV6]

Pauter block , 3" stroke x 4.250" bore = 170 cu. Right now its either a Fast or Holley system. I have the parts to turn 11,000 rpm if necessaey. Hopefully normally can stay 9500 rpm or less. Mike

 

[chopped39]

This might sound crazy Bob, But could he run eight injectors. Four in the head and four farther up the runners. have the four up high come in at a higher rpm. Isnt that kinda how the seventh injector worked on the buick engines? I know my corvette has 16 injectors and thats from 1990. I saw how the pro efi will run up to 12 or 16 injectors. That would be a wild setup on a wild looking car

 

[TurboBob]

sort of what I was thinking. Or at least make a few sets of runners and try it several ways. Its a drag engine, so low throttle / low speed operation is not very important, so I would try the higher up location first.

B

 

[turbobitt]

OK, My opinion....
I think maybe just above the flange on the piping but on the outside so that the injectors will angle the flow towards the intake charge.

Allan G.

 

[gnpoweredrail]

I agree on the multiple injectors...smaller ones down low and some bigguns up top!!

 

[BlownV6]

Basically its either idleing or on its way to 8000 rpm launch and hopefully not drop blow 8000 rpm on the shifts. The dyno will tell the story of what really needs to happen as far as rpm. Clutch management will need to be a high priority.
I have some help with that aspect but I have absolutly no experience with any of this - period!!!
My thought is to put the injectors in the polished air supply tubes on the outside (tire side ) about half way up (at 45 degree point) in those 90 degree bends. This would put the injectors at a direct vertical to the ground and be spraying fuel straight down into the opening of the intake manifolds. In my mind this would help push air/fuel into the intakes and be far enough away to benefit high rpm power. I assume that they make different injectors with varying spray patterns. I would want one that sprays a fairly tight pattern so as not to cut off the air , but to help accelerate the air.
Mike

 

[Chuck Leeper]

Mike, there's an advanced engine section over at www.speedtalk.com. Some really savvy, "outside the box", guys hang there. [Including VW types.] Might get additional input from them...

 

[Reggie West]

Why not run the injectors inside the pipes? Say 1 to 2 inches after the throttle body? I cant imagine having an atomization problem with the kind of rpms you will turn.