FAO Mappers (maybe fusion ed)

keastygtir

keastygtir

Well-Known Member
Hi Guys

After some advice please.

My car is basically 1 bar with all supporting mods. I have a trace log from OBD scandata and I am trying to figure out if I have have enough headroom with the MAF and the injectors to run 1.2 bar.

I did a highish speed run in 3rd gear.

max reading for injector time 16.31
max MAF reading 4.5 mv

Thanks in advance:thumbsup:
 
S

steve963

Active Member
my injectors were at 100% at 1.2 bar although it was running rich, I recon they would be at 95% even with correct fueling
 
Trip

Trip

New Member
:) i had similar readings on mine. Injector duty cycle rose to above 110% at one point was still on the rich side.
 
S

steve963

Active Member
didnt think you could get more than 100, thought this means they are just fully open all the time!

(by the way you shouldnt exceed about 80% I hear for longevity)
 
watoga

watoga

Member
Hi keastygtir,

If I remember correctly, a MAF reading of 4.5V is about 75% of it's max through-put, so your MAF should be able to handle 1.2 bar ok.

Dave
 
A

ashills

Active Member
injectors can run over a 100% in theory it doesnt mean they are constanty open as it would suggest
the maf will read to 5 volt max i think and u are near the upper limits wou will be able to run more boost even when u max it out you just wont be able to add any extra fuel to compensate so could run lean if go to far
 
watoga

watoga

Member
Yep, Ashills is correct about the MAF voltage.

However, the ECU's translation of the MAF voltage uses a rising scale, so 50% maximum throughput doesn't occur at 2.5V (ie 5V * 50%). This means you'll find very small voltage changes around 4-5V will correspond to huge changes in percentage throughput. Off the top of my head I think 4.5V is 75%, 4.7V is 82%, and 4.9V is 95%.

As Ashills says, running more boost is no problem, but you'll want to be careful the mixture doesn't go too lean, which can happen if the MAF maxes out.

I ran 1.1 bar on stock MAF/injectors for years with no troubles.

Dave
 
You must log in or register to reply here.
Top