I emailed GMPP about the ZZ572/720.....

[skorpion317]

I emailed them asking what fuel-injection system would work best on the 572...i figured a TBI or TPI setup would work, but TPI runs out of breath at high RPMs. so, I asked, and here is what I received:

"Thank you for visiting the Performance Parts website.

Thank you for your inquiry regarding the ZZ572/720 engine and which fuel
injection would best work. Due to the nature of your inquiry, we ask that
you please visit your local GM Performance Parts dealership for assistance.
Due to all the variables involved, it has been our experience that it is
very difficult to offer accurate repair suggestions without a hands-on
examination. Please be aware that not all questions can be answered by your
authorized GM Performance Parts dealer or by General Motors.

The trained professionals at your local GM Performance Parts dealership are
equipped with the latest technology and information and would be in the
best position to assist you with your inquiry. To locate a GM Performance
Parts dealership in your area, please visit our website at
www.gmgoodwrench.com, select GM Performance Parts then enter your zip code
in the "find a dealer" window. All GM dealerships are independent
businesses, so the expertise, services, and prices may vary from dealer to
dealer.

PLEASE NOTE: Not all GM dealers are authorized GM Performance Parts
dealers. Authorized GM Performance Parts dealers are more knowledgeable in
the technical aspects of our GM Performance Parts and have the latest GM
Performance Parts product information.

When you contact us via email you are contacting the GM Goodwrench Internet
Support Team. We assist with general GM Goodwrench inquires, (e.g: part
number requests, information, etc.), however, we are not certified
technicians. For this reason we ask you to contact your nearest GM
Goodwrench Service Center and speak with the technicians. Sorry we could
not assist you further.

Regards,
Goodwrench Internet Response Team"

WTF is that?! All I asked them was a simple question. "I'm going to switch over to fuel injection. What should I use?" And they said "We don't know." Big help they were....

[12secondv6]

Working for a car company.... I'll defend them on this.

It is true..... sooooo many factor's involved.... "it would be virtually impossible to comment via correspondence" <---- uses at work.

Seriously...... how could they say "Use TBI or TPI" w/o knowing what supporting mods you have, hood clearance, style of car, fuel delivery system, your ability of install.... I could go on and on

Catch my drift?

[Slow Z]

why on earth would you ever think about putting TPI onto a 720HP BBC? Secondly, HOW would you manage to do such a thing? TPI was designed for a 305, I couldnt imagine the same system (somehow magically modified to fit onto a BBC) trying to run on a motor like that ...The motor would probably make 300HP - if it even ran at all. The best EFI setup for that motor would probably be a "custom" one ...being a carbed intake modified for fuel injectors and some sort of throttle body. As for an engine management system, who knows... either way you'll be forking out a ton of cash for little to no gains.

Secondly, why would you want to spend over $14k on a motor THEN spend another $4k on an EFI setup?

[enRo]

You should ask a GM dealer, just as they asked. Agreed with James, and a TPI I would imagine would strangle the fking thing.

[SteveR]

Look into the F.A.S.T. system, it's designed for high HP motors. It uses a rail design like the LT-1s.

[NJSPEEDER]

there are a bunch of port injection systems that you can run. motec, accel dfi, f.a.s.t., big stuff, .....the list goes on and on.

you coudl even use a stock computer most likely. the hardware is what would be all different. you would need a converted carb intake, big throttle body, large capacity fuel rails, big fuel pump, much bigger injectors.

the displacement/power output is really meaningless when it comes to engine controls, that is what your intake and fuel delivery are for. any computer will regulate whatever is there and take care of ignition timing.

later
tim

[Koll]

2x4 bbl 8 or 900 CFM should suffice :)

[jims69camaro]

why on earth would you ever think about putting TPI onto a 720HP BBC? Secondly, HOW would you manage to do such a thing? TPI was designed for a 305, I couldnt imagine the same system (somehow magically modified to fit onto a BBC) trying to run on a motor like that ...The motor would probably make 300HP - if it even ran at all. The best EFI setup for that motor would probably be a "custom" one ...being a carbed intake modified for fuel injectors and some sort of throttle body. As for an engine management system, who knows... either way you'll be forking out a ton of cash for little to no gains.

Secondly, why would you want to spend over $14k on a motor THEN spend another $4k on an EFI setup?

this is not an atypical response to people wanting to put fuel injection on a BBC. i can imagine the guy who received the email sharing it with his co-workers, as in "look what THIS guy wants to do..."

telling you to go to the dealer is the quick way of getting rid of you. it would also set you straight if you were a crackpot or a bench-racer with no wrenching experience who wants to jam a BBC into a volkeswagon or something... basically, having the dealer handle your situation would weed out all of the unnecessaries and save them some time.

p.s. there is no "out of the box" fuel injection system for a BBC. even if someone were to put one in a box for you, like a kit, it would still be a custom piece.

[BigAls87Z28]

I dont think Pat means TPI as in the small block form, but something like TPI.
I assume you could adapt the RamJet 502's intake set up, but getting the right injectors, large enough TB, as well as tuning the computer for pretty much a one off combo would be pretty crazy.
IMO, it would probably be a bit easier if you took a 502 RJ, and added a turbo or supercharger then tuned the computer that way. Just my .02

[IROCdan330]

I dont think Pat means TPI as in the small block form, but something like TPI. Â*
I assume you could adapt the RamJet 502's intake set up, but getting the right injectors, large enough TB, as well as tuning the computer for pretty much a one off combo would be pretty crazy. Â*
IMO, it would probably be a bit easier if you took a 502 RJ, and added a turbo or supercharger then tuned the computer that way. Â*Just my .02

i agree with Al. If the ram jet FI system works on a 502...why couldnt it work on a 572? Also...i dont think finding a throttle body big enough would be a problem, as I believe the Ram jet uses a 48mm just like a stock TPI unit would. maybe its a 52...its nothing bigger though. a 58mm and would probably flow enough...but like Al said injectors are an issue.

[BigAls87Z28]

I gues a 58 would flow enough. I forget what the CFM the 48/52/58 equate too. I think 54 is about 1000cfm? Not sure, and my brain is so fried from work that I really really cant do math right now.

[skorpion317]

i was just throwing ideas out there....

i forgot about the F.A.S.T. system....i may have to look into that.

[NJSPEEDER]

edelbrock has a drop on system for big blocks, they also still sell the accel big block system, both are pricey for but the most part are drop ons.

later
tim