Is there any post already out there that could hint as to what size injectors are needed based on current injector duty cycle and desired dry shot size? Is there a formula?

I ask because I'm trying find out what size injectors I should go up to... N/A with PE disabled on an SD tune, my car was pushing 56%. I failed to check it with my MAF on an PE enabled, but with a 25 dry everything was relatively ok (no SES, but I forgot to save the log) and with a 50 dry my injectors came to 96%! and then my car said P0140, P1133, and P1153

I have a 2002 Formula, a GT2-3 cam, and CNCed heads. My shot comes through a 52 NX jet but is limited by the Maximizer, and it's anyone's guess as to what the bottle pressure was!

 

If you already have h/c go with 60lbers... you may squeak by on 42s, but the the 60s will let you go a little bigger on your dry shot (assuming you have upgraded your pump as well), they are relatively easy to tune, and they don't cost much more.

 

How big of a shot do you want to run? My suggestion would be a set of 42s, with them you'll have a bit of room to grow.

Matt

 

dont _ever_ disable your PE!

two tools i made, they'll answer your questions:
http://redhardsupra.blogspot.com/200...readsheet.html

http://redhardsupra.blogspot.com/200...se-widths.html

 

I run the 42's and have only hit 80% with a 235 shot, and numbers in my sig. If you go with the SVO 42's they are actually about 47 or 48'ers at our pressure. Some of the others are 42lb'ers at our pressure. I don't know but seems something isn't right 56% DC n/a and 96% with a 50 dry hit. what was your a/f with the 50 shot, you may be too close and getting to good of a reading?
Robert

Edit: I do have an injector sizing formula if you like?

 

42# Delphi's from HSW here, sprayed 100 shot today IDC was 60-61% AFR was low 11's (Stock 99). Going to up the shot, saw 1° KR so am going to pull 2-3° as I work up to a 150 Dry.

 

I was thinking 60s too.


125-150 max. My bottom end won't be able to take much more than that!

Why not? I only did it for N/A tuning purposes... is that still too dangerous?

Well that 56% was w/o PE. I don't know my A/F, but according to the narrowbands, it showed up a little lean in my LTFT table, ~ +4 and in some cases +11. The mV reading for the sensors was in the mid to upper 900s. I'll have to reinstall my wideband though.

Maybe I'll do like Beer and get new injectors from HSW since I'm thinking of swining by there sometime anyway...

edit: I'm going to run and do a quick N/A log and 25 shot log now...

 

Ok my injectors are maxed out N/A already 96% w/o the bottle at 52 mph and 6000 RPM. Narrowbands are at 950-990 mV. Same deal for 2nd gear, 50 whatever till 110 mph. I don't see how! I don't have any extreme mods. So 42s you say? 55s and 65s are the same price, so unless it's bad, if I need bigger than 42s I think I'll just go to 65s.

 

i run 42's as well with a 200/250 shot heads and cam

 

Stock LS1 PCM? If yes the 55s & 65s are low z, won't work with out a driver box. I would suggest the Siemens 60s if you don't want to go with a 42 lber. Just a FYI, we carry some Racetronix fuel injectors:

http://www.harrisspeedworks.com/shop/home.php?cat=331

Matt