I'm new to this forum, and this is my 1st post. To start i'm young and poor (For now). So I don't have $5000 for a supercharger kit or anything like that. So what i wanted to ask of you older and wiser gearheads is about cheap turbocharging. The truck is a 89 chevy c1500 short bed reg cab. It has mild Tbi 350/5.7. Some head porting, shaved heads, comp friendly cam, open long tude headers ( it's loud), throttle body spacer and turbo city adjustable MAP sensor. Now I know I mock up piping and set everything up, what about the fuel. Will FMU work on a Tbi injection setup. Someone told that the TBI will hold 5 to 8psi no problem before it leans out and blows bone stock. Is this true, if not what can be done and how would i go about. Will everything work fine with a custom chip. Or can I just use a FMU and MAP to tune. If anyone has any info or website to go to let me know. Also any Exp with the Turbo city adjustable MAP would help.

 

I never had good luck with my TBI. If I were you, I'd see if I could ditch it in anyway possible. Or get one of the aftermarket conversions. You can score them on ePay cheap. I don't think a MAP sensor and an FMU are going to help you tune your truck. You should probably have a custom chip burned....perhaps while on a dyno. Look into to Tunercat. Its a software program that will allow you to tune a TBI truck. Also if I'm not mistaken the TBI engines run at about 12-15psi for fuel pressure.

 

You would definately need to go with 454 injectors and a custom tune. Getting too agressive can cause problems with TBI none the less. Check out Brian Harris @TBIchips.com he has been doing the tuning on my 383 TBI truck via mail and I know has had experience with centrifugal chargers on TBI. He has software you can download for logging with a laptop that will be essential in getting the tune nailed down. Tell him Mark Howard sent you.

 

I built another standalone system, 2 extra injectors, and its own computer. That way the vehicle remains in a pure stock until the boost starts to come in, total programable.
Ricky

 

Thanks for the info. Right now I have turbo from a dodge diesel around a 2000 or so, and some piping just sitting around. I think im going to fab everything up, and see how it works on 4 or 5psi. the only thing i need to buy is FMU.

 

I also might try to a extra injector with a boost ref switch

 

FYI, your going to need a small FMU, like 2:1. TBI only run about 14 psi of fuel pressure, and will lock up around 35 psi. I ran a 5:1 and had to put a restrictor in the boost reference line to the FMU and a bleeder valve to let some of the boost out of the ref line to get it down to about a 2:1 before it would work on the TBI s-10 I turboed.

 

That's what I need to know. thanks! I'm going to start on it in a few weeks. right after i put the motor back in my blazer so i have something to drive if i blow it up. I'll post some pic when i start.

 

I used an adjustable MAP from turbo city before on my TBI. Nice unit actually. Allowed my SBC S10 to EASILY pass emmisions with a 230 duration cam. I think I kept mine at about 1.5 volts idle for everyday driving and 1.2 ish at the track.
Also, if you use the 454 throttle body you have to use a stock intake. You can use a Edelbrock but when you bore it you hit a few passages under the mounting pad and have to weld it closed again.