×

Sale ends todayGet 30% off any course (excluding packages)

Ends in --- --- ---

Old School BBC with Twin Turbos and combo throttle body and multiport fuel injecion?

Build Threads

Forum Posts

Courses

Blog

Tech Articles

Keep everyone up to date with how your project is coming along. 

= Resolved threads

Author
1309 Views

Okay, so here's what I'm working on. As I work through the courses towards becoming a local tuner, I have my own project as well. It's a 71 Monte Carlo sporting a 468 BBC engine, twin s366 turbos, non-intercooled and running e85 and a Fitech throttle body EFI. The current engine has some blowby so I'm in the process of building a better replacement. It will be replaced with a 489 stroker plant, fully forged rotating assembly, about 9.5:1 compression ratio, and also running E85.

Here's where it gets interesting. The Fitech EFI system I have will not support what this combo will be capable of. However, it operates as a 2 stage batch fire injection with 8 injectors in the throttle body (4 running the first stage, all 8 running at higher load and throttle position on the 2nd stage). That being said, my plan is this; rewire all 8 injectors in the throttle body as either the 1st or 2nd stage, and add 8 more injectors into a multiport intake and wire those into either the first or second stage. Now you may ask why not just add bigger injectors and scrap this idea? The answer is because I like to do things just a bit different and be unique with my builds.

Couple questions. Is this idea completely ridiculous? And if it's not, which injectors should I wire on the 1st stage of injection and which injectors should activate on the 2nd stage of injection?

What kind of intake manifold are you going to have? A downdraft style or plenum style?

Injector staging is a big pain in the ass. The plumbing, getting a smooth injection transition and transient response are a lot of work. If you want a pain in the ass, go for it.

The manifold is open plenum style single plane with an injector bung built into each runner.

Yeah, it'll be a pain in the ass, probably, but so has everything else in this build and I welcome the challenge.

We usually reply within 12hrs (often sooner)

Need Help?

Need help choosing a course?

Experiencing website difficulties?

Or need to contact us for any other reason?