502 efi
 

What is the max hp you can make on a 502 mpi before you max out the injectors.
Also can these injectors be upgraded. :D

Re: 502 efi
 

I made over 700 hp with stock 2000 502mpi micro injectors at 70 psi. I am currently running 63 lb ones that can be driven by stock mefi computer but they are physically taller so I made custom fuel rails. There are ones that are close to stock in length but I was concerned the stock rail couldn't supply enough fuel,Smitty

Re: 502 efi
 

I've got dyno sheets showing 538 and 540 horsepower on my 502 MPI's at 5200 RPM. That was with stock throttlebody, stock injectors, no spark arrestor, 45PSI fuel pressure and reprogrammed ecu w/ dyno headers.

Re: 502 efi
 

I'm making 630hp , but I'm thinking about upgrading to 700-750 range with a m3 blower.

Re: 502 efi
 

you could make 700 hp if you ran 70 psi fuel pressure under boost,I have,if your making 750 hp it will be hard to get 43 lb injectors to flow enough fuel even at 70 psi to keep your afr at 11.5-1 under boost. If your upgrading everything and getting a custom tune on the dyno (I assume you are because it will be difficult for someone to guess at) you should buy the bigger injectors at the same time. You won't have to run so much pressure either,Smitty

Re: 502 efi
 

articfriends what boost are you making and what fuel presure are you running at.
Thanks

Re: 502 efi
 

I'm currently running 9-10 psi of boost with 70-75 psi at wot with 63 lb injectors,Smitty

Re: 502 efi
 

Smitty ..... didn't I read somewhere that 502 MPI have 43lb injectors ( as you stated) but the 500 EFI's have 36lb injectors ? I am bulding a set of 502 MPI"s ... 500 EFI cams and we had to run Crane Roller rockers to get the geomtry right .... Still trying to decide if the box's need reprogramed ...m

Re: 502 efi
 

My understanding is the early mefi 1 and 2 motors used 36 lb big looking injectors,in 98-up the mefi 3 motors used the 43 lb "micro" injectors,not sure about how accurate I am or how much hp500's flowed. My micro injectors flowed 42 or 43 lbs per hour on Tyler Crocketts injector tester if I remember correctly,Smitty

Re: 502 efi
 

This guy has a couple of 502 Gen VI blocks.

502 Gen VI Block