when are computer adjustments needed?

[kkchevy3]

im building a 4.6 stroker right now. the block is at the engine builders getting machined. my question is do i need a map adjuster or a a/f gauge? or anything other for that matter in the electronics dept

[gradon]

I have the innovate lm2 wideband o2/obd2 scanner/data logger and a psc1-002 programmable signal calibrator(map) to tune mine. My brother and I were tuning it yesterday and at WOT with the stock map and 25.5# injectors, the afr was in the 14s. I swapped in the psc and we tuned it to 12.8afr(ideal for best power in NA setups). I did run out of injector(maxed the psc) in 5th b/t 2-3K rpm and could only get low 13s, but they slowly dropped to the 12.8 above 3K. I might need to swap the lt1s for the fms(26.9# on the 49psi rail). Anyhow, I'd recommend a fuel management of some sort, even if just a wideband o2 and adjustable map.

[Flash]

What cam are you going to run in it?



Flash

[SilverXJ]

I suggest you at least get an AFR gauge and a set of injectors. In my case if I had ran the stock injectors I would have ran lean... had I gone with 5.0 performance's recommend injectors I would have ran rich.. very rich... my afr gauge only goes to 10:1 and there was a flat line at 10:1 for about 1000 RPM with the rich injectors.

[crustodd]

My 4.7 is running VERY strong and smooth with the stock computer and MAP. I have #24 Ford injectors. You can see the specs of my build on the "it's ALIVE" thread. Another 1000 miles or so and I'm off to UniChip for a piggyback chip and dyno tuning. I'll likely add an A/FR gauge too. Any recommendations on A/FR setups guys?

crustodd

[kkchevy3]

lol guys i need plain english. and i dont have the cam card infront of me. can i just put the bigger injectors in and be okay? its a daily driver

[SilverXJ]

lol guys i need plain english. and i dont have the cam card infront of me. can i just put the bigger injectors in and be okay? its a daily driver

If you can't understand then you might want do further research and reading so you can. Its not a yes or no answer. If you have the wrong injectors in your engine will have a short life.

[kkchevy3]

okay if i make my own adjustable map sensor with the bigger injectors and an a/f gauge that should be good? Can i use the o2 sensor that is in the jeep already or do i need a different one? 91wrangler 4.0 fuel injected

[SilverXJ]

The map adjuster should work. It won't be perfect as it just adjusts the map over the whole RPM range unlike other ones. And you need a Wide band O2 sensor unit, or know someone that has one, or a dyno with one.

[kkchevy3]

so what would be the proper set up and how much would it cost about. i like the map adjuster because its cheap. im sorry guys, i know all the mechanical.... give me a 327 small block and ill work on it with my eyes closed but the electronics get me running in circles