Outer Limits 4x4 Board

As many ppl on outer know I run a mazda 121(bubble) throttle body on my serria. But I have been in the search for more hp. I have decided to turbo it using a a import pajero turbo. I am thinking that the single injector is going to struggle to put engough fuel in. I was thinking of mounting another injector just before the throttle body. Would any injecter do or do the run off a different signal? If they run on different signals wich ones are the same as a mazda one?

It may be possible to do what you want using a boost sensing pressure regulator - as boost increases, so does fuel pressure, hopefully injecting extra fuel through the stock injectors.

NFI if it will work for your application.

I got a bid on one on Ebay. I will only put another injector in if the fuel restrictor don't work. Better to be too rich than to lean

My understanding of fuel injection is that all the injectors fire off the same signal. The fuel presure is kept cnstant with respect to the manifold pressure (or vacum) so the only variable in how much fuel goes in is th injector open time.

I'm guessin gthat whatever you do, you'l need to get the efi re-mapped ona dyno so speak to whoever is doing the tune bout your options. Maybe u can get higher flow injectors... maybe u can run a different pressure regulator for the fuel pressure. Maybe 1 extra injector into the manifold will work as a crude fix

Also, some efi systems had a cold start injector. Basically the efi answer to the choke. You ma be able to tap that.

V8 Middy wrote:My understanding of fuel injection is that all the injectors fire off the same signal. The fuel presure is kept cnstant with respect to the manifold pressure (or vacum) so the only variable in how much fuel goes in is th injector open time.

I'm guessin gthat whatever you do, you'l need to get the efi re-mapped ona dyno so speak to whoever is doing the tune bout your options. Maybe u can get higher flow injectors... maybe u can run a different pressure regulator for the fuel pressure. Maybe 1 extra injector into the manifold will work as a crude fix

Also, some efi systems had a cold start injector. Basically the efi answer to the choke. You ma be able to tap that.

Throttle body injection - only one injector/throttle assy where tha carbie should be.

TBI also use a lower pressure injection system than (sequential) multipoint injection systems (14 psi vs 30-45 psi, and usualy ~4 psi for a standard carbie setup IIRC)

Pajero turbo may be a bit to large and take too long to spool up (turbo lag). Good for power when it's sceaming it tits off, but little else. Try for something smaller and a better match for flow rates.

As long as you put the MAF sensor between the TBI and the turbo and the TBI has the extra capacity reserve (in pressure and volume) in the injection there shouldn't be too many calibration issues regards a couple of pounds increased manifold pressure.