Stock Injectors

**asshanson** · 02-05-2013

Most injectors are rated at 43.5psi. However, some specific to a platform can be rated at that pressure, like a lot of vette injectors are sold with a flow rating at 60psi, probably just for marketing purposes.

19TsiAwd90 · 02-05-2013

Quote:

Originally Posted by asshanson

Most injectors are rated at 43.5psi. However, some specific to a platform can be rated at that pressure, like a lot of vette injectors are sold with a flow rating at 60psi, probably just for marketing purposes.

s10's(aswell as all 4.3l vortec motors)use a weird type of injectors called spider injector, and they run 60+psi of fuel pressure. They are VERY picky about fuel pressure when a pump starts getting weak they WILL NOT start(i know from experiance T.T). im sure there are other platforms that use higher pressure too, i guess Vettes use the modern day injector so this might not even be related. just thought i would share something.

Alpha D · 02-05-2013

Quote:

Originally Posted by asshanson

Most injectors are rated at 43.5psi. However, some specific to a platform can be rated at that pressure, like a lot of vette injectors are sold with a flow rating at 60psi, probably just for marketing purposes.

Marketing? Which sort of marketing are we talking about? Like aftermarket or dealer...im assuming aftermarket since i dont see why they would use that in the performance spec as a point of sale dealer wise? Sounds like it would be over the head for most consumers?

I consider my self an enthusiast and i didnt even know head from tail well...

If i do ever feel adventurous though, im safe playing around with fuel pressure up untill or close to 100psi roughly...granted the whole tune will have to go hand in hand. With this new knowledge gained, I will have to decide on an injector size, for the up coming E85 season... since i sold my 1450 FIC i wonder if 1000CC will support 400WHP...but thats a discussion for another day. Not to mention i know for sure there is an equation for figuring injector size out...

I remember the first book i read called ''How to build a high performance mitsubishi engine or 4G63T'' had all kinds of interesting math in it. Again Thank you guys !

**asshanson** · 02-06-2013

Quote:

Originally Posted by Alpha D

Marketing? Which sort of marketing are we talking about? Like aftermarket or dealer...

Aftermarket. If they rate them at 60psi they look like bigger injectors.

Quote:

Originally Posted by Alpha D

If i do ever feel adventurous though, im safe playing around with fuel pressure up untill or close to 100psi roughly...granted the whole tune will have to go hand in hand. With this new knowledge gained, I will have to decide on an injector size, for the up coming E85 season... since i sold my 1450 FIC i wonder if 1000CC will support 400WHP...

1000cc injectors could probably get you close to 400whp on Shane's dyno. Your Walbro pumps won't like 100psi, they start to really taper off after 75-80psi. Look at this flow chart (13.5v brown line):

Alpha D · 02-06-2013

Quote:

Originally Posted by asshanson

Aftermarket. If they rate them at 60psi they look like bigger injectors.

1000cc injectors could probably get you close to 400whp on Shane's dyno. Your Walbro pumps won't like 100psi, they start to really taper off after 75-80psi. Look at this flow chart (13.5v brown line):

Where did the graph go? or are you referring to the previous link...didnt see one there either? Yeah its time to look into a new fuel pump set up as well i think...not to mention all the nightmare story's ive read about with one pump throwing in the tower mid pull through causing a sudden change in afr's sometimes to fast to let of and engine damage occurring.

What monster pump's do people even run now a days. I know map sells those DW300 or something weird pumps...and i also hear of import image selling some sort of Bugatti veryon pump that gtr's seem to like ect ect