Autonomics TBI guys that re running

mobythevan · Post by **mobythevan** » Fri Nov 18, 2005 1:16 pm

Are you having any issues with the injector spray above the throttle plate. I am getting ready to order injectors for mine and I need to decide if I want to run a more normal EFI fuel pressure like 35psi or lower like 15psi. How has your experience been?

woh · Post by **woh** » Fri Nov 18, 2005 1:35 pm

TBI injectors are typically designed for installation above the throttle plate. They spray a cone of fuel that goes to the outside of the plate where the air is at maximum velocity. These are typically 14.5/15 psi injectors.

Injectors for MPI generally have a narrower cone spray.

I have used two different Bosch injectors for TBI with no fuel distribution problems and very good idle characteristics.

werner

mobythevan · Post by **mobythevan** » Fri Nov 18, 2005 1:37 pm

I should also clarify that I will be using port injectors in the throttle body. And specifically the auto nomics TB which has an angled injector placement above the throttle plate.

Mk1rocco · Post by **Mk1rocco** » Fri Nov 18, 2005 2:31 pm

Here's the throttle body he's refering to.

Derek Fitzpatrick · Post by **Derek Fitzpatrick** » Fri Nov 18, 2005 5:08 pm

I'm running the Auto-nomics TBI on my 454 and it seems to be working fairly well. I am using 84# venom injectors, at 34psi, supplied by Auto-nomics, however I would NOT recommend this as in the first 4 he sent me one was faulty (spraying approximately 8 times the fuel as the other 3 injectors) then in the replacement set one leaked. Fortunately I was able to pick 4 good ones out of the 8 and they seem to be working fine now. I am having a little difficulty with the idle setting as the only way I can get it to idle were I want it is turning the ideal screw all the way out, the retarding the timing at idle (MSII 8-pin HEI) more then I would normally like. However I have not looked to hard into this to see if I can get the throttle shafts closing more so it could be an easy fix. Check out my success story (GM section) for pictures.

mobythevan · Post by **mobythevan** » Fri Nov 18, 2005 5:45 pm

That is good news. You have almost the identical setup I have. I am going to run a B&M 250 on top the 454. I was going to go with a set of 150# injectors and run them at a lower pressure, but I may use a smaller set at 35psi like you are doing. It will be interesting to see how the supercharger affects the idle issues.

mobythevan · Post by **mobythevan** » Mon Nov 21, 2005 10:13 am

Here is a pic for you of the setup so far

GotDart · Post by **GotDart** » Sat Nov 26, 2005 8:51 pm

Wow. That seems like a lot of motor for a single 750cfm thottle body. Or did you bore it out larger? Doesn't that supercharger come with a dual carb top plate? What are those bosses on the intake runner of the lower manifold?

mobythevan · Post by **mobythevan** » Mon Nov 28, 2005 8:31 am

I had the TB bored out to 1000cfm. The manifold has port injector bosses, but they won't be used. The supercharger comes with either single or dual top plate according to the manual.

eliotmansfield · Post by **eliotmansfield** » Mon Dec 05, 2005 6:45 am

mobythevan wrote:I had the TB bored out to 1000cfm. The manifold has port injector bosses, but they won't be used. The supercharger comes with either single or dual top plate according to the manual.

What diameter did you bore it out to? - the full 44mm? Ive just taken mine out to 41mm.

Ive got some photo's of how to convert them to progessive throttle action on my site if anyone's interested:
http://www.mez.co.uk/turbo9.html

Eliot.