My documented TBI-to-Vortec 350 conversion!

[jdyates]

Bump for updates !

I want to know your power differance ? I just picked up a vortec 350 with 15000 mi on it and was just thinking about throwing the carbed intake with the tbody adapter right in my truck . I bought it to take apart and build a race motor but can't bring my self to cut up such a low mi engine !

It's a beast, but it needs the custom chip, fuel pump, and i think my timing chain in stretched.

 

[TylerZ281500]

mines getting a supercharger soon teehee.

 

[jdyates]

mines getting a supercharger soon teehee.

You'll DEFINITELY see some serious power if you swap to Vortecs. We Whipple'd a TBI 350 and after thousands of dollars it still doesnt run right. The Vortecs will free up some SERIOUS flow and it'll play very nicely with the supercharger.

 

[gmcyukondriver]

mines getting a supercharger soon teehee.

Be prepared to spend a lot more than you expect. There's more involved than just buying the supercharger. What kind are you looking at? At the very least, you will need a tune. It will definitely help with power, though. I'm only making small boost and I can feel the difference. If I went with a different pulley for more boost.....hold on to your seat.

You'll DEFINITELY see some serious power if you swap to Vortecs. We Whipple'd a TBI 350 and after thousands of dollars it still doesnt run right. The Vortecs will free up some SERIOUS flow and it'll play very nicely with the supercharger.

That's weird man. Like I've said, mine runs fine (aside from running so rich you can smell it). Rather than just swap with Vortecs, though, I'd do some research behind heads if you're going with forced induction. Sure, the Vortecs make better power for less money, but usually when you add a supercharger, your focus isn't really on being as thrifty as you can (at least, my goal isn't necessarily). I would look at some heads with larger cc chambers to bring that compression ratio down and help avoid detonation.

Sorry for the thread jack, but here's a good resource if you're looking to get into supercharging. http://www.summitracing.com/expertadviceandnews/chartsandguides/supercharging-basics


Joseph, as for your fueling issue. Here are some resources for fueling and injectors. You might want to go with larger injectors, or add an adjustable fuel pressure regulator. I would go with Mallory or Aeromotive for that, just do some research.
http://www.tbiparts.com/techinfo.html
http://www.csgnetwork.com/fiflowcalc.html
http://witchhunter.com/injectorcalc1.php

The last link is for WitchHunter, which does a lot of servicing for our injectors (which is kind of tough to find). I'm thinking about going with some 90#/hr injectors so that they don't have to cycle nearly as often to fuel it and hopefully can be tuned to run leaner and still fuel at full throttle. But that's my project. Sorry for the derail. Hopefully this stuff is useful.

 

[94Sierra4x4]

Joseph, I think GW has an ExtremeFI adjustable fuel pressure regulator....... he had one for sale a while back..

 

[TylerZ281500]

Be prepared to spend a lot more than you expect. There's more involved than just buying the supercharger. What kind are you looking at? At the very least, you will need a tune. It will definitely help with power, though. I'm only making small boost and I can feel the difference. If I went with a different pulley for more boost.....hold on to your seat.



That's weird man. Like I've said, mine runs fine (aside from running so rich you can smell it). Rather than just swap with Vortecs, though, I'd do some research behind heads if you're going with forced induction. Sure, the Vortecs make better power for less money, but usually when you add a supercharger, your focus isn't really on being as thrifty as you can (at least, my goal isn't necessarily). I would look at some heads with larger cc chambers to bring that compression ratio down and help avoid detonation.

Sorry for the thread jack, but here's a good resource if you're looking to get into supercharging. http://www.summitracing.com/expertadviceandnews/chartsandguides/supercharging-basics


Joseph, as for your fueling issue. Here are some resources for fueling and injectors. You might want to go with larger injectors, or add an adjustable fuel pressure regulator. I would go with Mallory or Aeromotive for that, just do some research.
http://www.tbiparts.com/techinfo.html
http://www.csgnetwork.com/fiflowcalc.html
http://witchhunter.com/injectorcalc1.php

The last link is for WitchHunter, which does a lot of servicing for our injectors (which is kind of tough to find). I'm thinking about going with some 90#/hr injectors so that they don't have to cycle nearly as often to fuel it and hopefully can be tuned to run leaner and still fuel at full throttle. But that's my project. Sorry for the derail. Hopefully this stuff is useful.

8 psi its on old spintech i can datalog it myself, my tbis have larger vlaves and are ported a metric ton, not that it makes a difference up top but down low it does.
its came of my bosses truck his ran fine so im stealing all the stuff he has for it.

 

[Murd450]

I'm just going to drop in the complete vortec engine with a carbed intake with a tbi adaptor on it an a 454 throttle body . Then take the engine that came out of my truck and build a 13.5:1 race motor for …

 

[jdyates]

Joseph, I think GW has an ExtremeFI adjustable fuel pressure regulator....... he had one for sale a while back..

Not necessary. Mine is adjustable.

And thanks for all the info, Brian! Personally I don't think I'll ever supercharge mine. Definitely a fun idea, just not possible at this time. And my fuel issue is that the stock tbi pump can't supply the needed fuel for my heads and intake. 11psi is a joke on anything, even stock. Need to get the new fuel pump in soon and get my chip from Mark.

Also, i have reason to believe my timing chain in stretched after about 110k.

 

[gmcyukondriver]

Not necessary. Mine is adjustable.

And thanks for all the info, Brian! Personally I don't think I'll ever supercharge mine. Definitely a fun idea, just not possible at this time. And my fuel issue is that the stock tbi pump can't supply the needed fuel for my heads and intake. 11psi is a joke on anything, even stock. Need to get the new fuel pump in soon and get my chip from Mark.

Also, i have reason to believe my timing chain in stretched after about 110k.

Did you pull out the stock regulator? I wonder if the pumps are different between the years or models. I left my regulator alone, just added an adjustable on the return line, and I can get my psi up to 20 no problem.

 

[94Sierra4x4]

Did you pull out the stock regulator? I wonder if the pumps are different between the years or models. I left my regulator alone, just added an adjustable on the return line, and I can get my psi up to 20 no problem.

How would adding a adjustable one on the return line allow for more psi to flow through the stock regulator?
Not questiong you, just wondering how that works.. isn't the regulator...supposed to regulate it?!