Which unit for TBI swap?

[Green79Scottsdale]

Kicking around the idea of doing a TBI swap onto my 400 sbc. My first question is what throttle body would be better to go with, V6/Small block or Big Block? Logical sense says to use the one that closely matches the stock application, but my 400 is between the 350 and 454 applications. The V6/SB ones seem to be much more easily acquired. And my engine is in stock form, so I assume the small body would feed it just fine. Thoughts? Over thinking it am I?

 

[350runner]

454. if you search the web most sites say to use it as an performance upgrade over the 350 tb on a 350.

 

[bucket]

Get a dual quad intake and run two 4.3 tb's

 

[PrairieDrifter]

I liked the fast system it has a computer and tunes the system the first few times you take it on a drive all you really have to adjust is the fuel pressure

 

[skysurfer]

Agree that the FAST system is the cat's ass, but at $1800+ it's beyond most of our budgets. The bbc tbi will provide more than enough air/fuel but will require a custom tune, ideally done on a dyno as opposed to the chips you get through the mail. Last time I checked, shops were getting around $500 for a dyno tune.

 

[Green79Scottsdale]

Holy hell, just spent some time reading on tuning a TBI system... my head hurts and my eyes are crossed. What kind of tuning software (if any) are others here using for their system? I know you need chips and burning equipment. So much to take in.

I liked the fast system it has a computer and tunes the system the first few times you take it on a drive all you really have to adjust is the fuel pressure

You talking about the EZ-EFI system? If I had the money, I would be going a similar route. I don't have a couple grand to do this. I was hoping to do a nice swap for well under $1000. This is the planning stages to see how much of a reality this may be. I am even hesitant to do it for that much.

 

[PrairieDrifter]

Yeah these systems are expensive, but they are getting the best mpg and performance out of your motor, and with the fast system it has a self learning computer, i cant remember if we had the program the computer with the basic settings but it should just be plug and play and it should learn the proper adjustment to make after driving it a certain amount all we had to do was adjust the fuel pressure and it was a nice gauge that went on the firewall.

We did it on a 63 impala with a 427, 500 plus horsepower, they had it dynoed I think it was like 550. It was badass, but yes it's out of my price range if I ever wanted to do something like that

 

[Wreck]

Hey guys, sorry to hijack your thread but I have a similar question regarding these aftermarket self-learning TBI systems. I know the OEM systems really don't like a cam change without reprogramming. What about these aftermarket systems? Do the self-learning and programming capabilities open up your cam options or do they still have the same issues as stock?

 

[bucket]

Hey I just came across this on CL. It doesn't have much info, but I can find out more if it interests you.

http://columbus.craigslist.org/pts/4875365958.html

Hey guys, sorry to hijack your thread but I have a similar question regarding these aftermarket self-learning TBI systems. I know the OEM systems really don't like a cam change without reprogramming. What about these aftermarket systems? Do the self-learning and programming capabilities open up your cam options or do they still have the same issues as stock?

They work with non-stock cams.

 

[PrairieDrifter]

They're designed to adapt to your motor and fine tune the system, and with all of the options and differences between each motor, these aftermarket systems have to be able to be used on a wide variety of setups, or they won't sell for **** so yes your cam will work

 

[Wreck]

Awesome. Thank you!

 

[Green79Scottsdale]

Hey I just came across this on CL. It doesn't have much info, but I can find out more if it interests you.

http://columbus.craigslist.org/pts/4875365958.html

Let me do some research on it. I just got done looking at the Mega Squirt II. Looks promising and has the ability to grow from simple fuel only TBI type EFI control, to MPFI control and also boosted applications, with full ignition control at every level if desired. I also found a 454 TBI unit locally for $75. Didn't call on it, but the guy has both a 350 and 454 unit, looked like with intakes too.

edit: From what I found that AFI system is intended for stock engines. You would still need a way to burn a chip for modified applications, which means you need a burner or someone who does. You can get into a Mega Squirt controller and used TBI for less than that price. Right now the MSII is looking like a nice affordable controller.

 

[Green79Scottsdale]

Well... I acquired a 454 TBI today. Wasn't necessarily intending to, but I did. A couple of guys and I were discussing various swaps at work one day, and TBI on my '79 came up. One of the guys says, "Hey, I got a 454 TBI and intake at home. Wanna buy it?" I said, "Maybe, if it was $25 I might." So he brought it in for me today. Mine now. I obviously can't use the intake, but now I have a piece to the swap if I do it.

 

[bucket]

You stole that TB for 25 bucks!

 

[Green79Scottsdale]

I haven't even paid him yet... but he knows where I work and live!