I didn't find any discussion of this using a search, so I'll have to ask.

What is the internal difference between a lower rated flow TBI injector and a higher rated flow one, and is it possible to modify the lower rated injector for more flow?

Paul T.

 

With tbi injectors you can increase the flow or LBSHR by increasing the pressure to them. Most of the performance oreinted guys around here tend to be running around 20 to 30psi wich will increase the flow of your standard injectors a fair amount. What are you trying to do?? Do you need more fuel for your current combo?? Or just a general question?? Im sure that someone on the furum will have a technical explanation for you but hope that this helps a little.

 

I currently have an L03/305 with its lower flow injectors but once I get a handle on bin tuning and burning chips a 383 will be replacing the 305 but I need to pass smog so I have to keep the appearance of the stock TBI system.

In addition to bumping fuel pressure I'll need the higher flow big block injectors and buying some is the likely way to go, but I'm somewhat curious as to the difference between the various injectors. I have a machine shop here so if we're talking about just accurately enlarging some orifices that's something I could do here. Probably more likely there are differences in the coils used in the system, but I'm curious if anyone has scoped this out, it would be sweet if the smaller injectors could be modified for more flow without trashing the spray pattern.

Paul T.

 

I'm not even sure you can get the injectors apart, might be worth looking into. I know there are a few guys modifying MPI style injectors.

I saw no less than 5 BB chevy TBI with large injectors on Ebay just yeterday. They all were going for around $100.