GR EFI?

I'm considering electronic fuel injection or Weber IDF carbs for a SBF project. I know of several sources for this type of system, and could go and just buy one, but like the idea of coming up with my own. Anyone have any ideas for a GR system that would similar to the one in this picture? For the purposes of this discussion, please assume I have the knowledge and skills to do this, and that I am talking about a sequential system, not batch fired. I'm just looking for ideas of economical components and controls to use, but any imput would be great.

Why are you locked into sequential vs batch?

To avoid the obvious limitations of batch firing. If I'm going to do it, I'm going to do it the best way possible.

It is my understanding that sequential firing only improves idle, and perhaps only idle emissions. What other obvious limitations are there? At WOT up in the rev range, most injector systems are running all the injectors for most of the cycle. Do the math. If you have a 300 HP V8, 8 injectors, that's 300/8 HP worth of fuel each injector is dumping every 2 revolutions of the motor (4 stroke). That's a bunch of fuel and the injector needs to be open more than the intake valve is open to let air/fuel in. So at that point, it doesn't matter if you're batch or sequential.

If you want a setup that looks like the one in the picture, find some throttle bodies that will bolt on like that and the manifold to accept them. After that, MEGASQUIRT that sucker.

bravenrace wrote: To avoid the obvious limitations of batch firing. If I'm going to do it, I'm going to do it the best way possible.

What limitations? FWIW, most factory stuff goes batch fire about halfway to redline (or sooner)...sequential is only used for idle quality and emissions output, as the Doc says, there aren't any power/torque/driveability tradeoffs that you'd notice on a vehicle you're tuning yourself.

Bryce

Guys, please read the post. I'm not asking about sequential vs batch. I'm asking for suggestions on creating a ram tube sequential system from scratch. Thanks.

The thing is that firing 8 injectors sequentially is a PITA and not needed. You can make a ram tube batch system and fire the injectors in 2 banks and it will perform identical, look identical and for all practical purposes the only difference is that you say "batch" instead of sequential. If you just insist on being able to say "sequential" then pick up your debit card and get a $2-4K computer and go for it. Otherwise, get a $200 computer and say "Ram Tube."

I've seen people build ITB setups on four banger engines using motorcycle throttle bodies attached with rubber tubing to cut down stock manifolds. Unfortunately not that many stock V8 manifolds can be cut and give you eight separate runners, so you'd probably have to weld the manifold together from plates and tubing.

I was thinking of using a manifold set up for weber carbs, and then modifying it to accept the injectors.

I have seen Hilborn injectors set up to be a "Real" FI system. If you can find the components, it's a glorious start. Finding an appropriate manifold for the SBF will be a challenge, I'm sure. Maybe check some of the roundy round guys.

In reply to cwh:

I know what you mean about the manifold, which is why I was thinking of starting with a weber manifold, as they are not uncommon for a SBF. I could design all the hardware and have it machined, but I'd rather not have to do the throttle bodies, which is the main item I'd like to find a donor for. I can make the ram tubes, make the mods for the injectors, and there are many options for the electronics. The hurdles for me seem to be the throttle bodies and the linkage, which I will likely design myself. However, my mind is wide open at this point. Your idea of the hillborn mechanical system would solve the throttle boy issue, as long as I can find something that is in the correct size range. I'll be adding that to my search list, thanks!

TWM should have some throttle bodies that will bolt up to a Weber manifold. Bring your big debit card.

Dr. Hess wrote: TWM should have some throttle bodies that will bolt up to a Weber manifold. Bring your big debit card.

These guys do, too, and it's likely a lot less:

http://extrudabody.com/index.html

In reply to MadScientistMatt:

Now were talking! Thanks for the link, Matt. I'll check it out. Anybody else have any ideas? Is there a good online source for finding used racing parts, like injection manifolds or throttle bodies? Thanks again, Matt! Jim

Classic car parts and racing parts on ebaymotors or do a nationwide search of craigslist.

Quite a few of the higher end dirt track racers used mechanical fuel injection setups that could be adapted to efi fairly easily as well.

I know there was a guy on ebaymotors selling adapters for Hilborn stacks to use Bosch EFI injectors. You'd just need to hit up Ross Machine to get fuel rail blanks, etc. http://www.rossmachineracing.com/

Personally, I would go to Pierce Manifolds and buy everything you need from them as they have the SBF Weber intakes and the Weber style throttle bodies which include fuel rails and they can supply the necessary linkage parts to boot. It will be a large check, but you'd save so much time that it might be worth it in the long run.

In reply to fiat22turbo:

Thanks. That brings up another question I've had - How do you do a nationwide search on Craig's list?

nation wide CL search