Power Fc Tuning Question

[DVS JEZ]

ive tuned my car but this is one thing i cant seem to find an understandable answer too,

injector lag time vs battery voltage, ive noticed with my lights(or electrical drain) on im getting a richer AFR, i know why this is happening but i cant find out how to set the inj vs batt settings for my setup.

im using datalogit with LC1 and XD16 etc.

RB26 running tomei 600cc injectors 18 psi making 293kw N1 turbo's stock motor on 98

any help with settings for inj lag (ms) vs batV

current settings

16v 0.604

14v 0.772

12v 0.944

10v 1.132

8v 1.316

6v 1.396

inj settings 73.0 lag time 0.03

any help much appreciated

cheers

Jez

[JonnoHR31]

if battery voltage is the only variable causing it to run richer you can adjust the settings to suit.

your 12v figure is slighty different to the base map for rb26 but the rest are the same, they're for standard injectors tho, no aftermarket injectors are going to have exactly the same numbers as factory.

at what voltage does it run normal and what voltage make it go rich? and how rich?

[DVS JEZ]

Normally 13.2v and with highbeam on 13v

changes from 13.8Afr idle to 13.4afr or so and richer with more load.

I tried playing with the 12v setting and ur correct the rest are stock rb26 figures.

[MrStabby]

  DVS32R said:

ive tuned my car but this is one thing i cant seem to find an understandable answer too,

injector lag time vs battery voltage, ive noticed with my lights(or electrical drain) on im getting a richer AFR, i know why this is happening

Sorry for the hijack, but can you explain why its happening? I thought it was like this; lower voltage -> higher latency -> less petrol through the injector for a given input -> leaner.

[DVS JEZ]

your on the right track,

there is a an adjustment for the injector lag time in milliseconds vs battery voltage, so at a higher voltage the injector will open and close faster and needs a lower lag time = less time open

at lower voltage it will open and close slower so it needs more open time,

i just need to know the correct way to set this up so at all different Voltage there is no affect on AFR's , mainly between 12v and 14v

[JonnoHR31]

unless you can get exact firgures from an injector test or similar the only way to set it up is with experimenting. altho .2v drop is bugger and 13v is smack bang in the middle of the 12v and 14v settings, so you might find youself having to adjust both of them to get it right.

if you want to rule out any chance of problems later you could adjust it all then pull off the alternator belt and check the afr's with a lower voltage and adjust to make sure you never get a lean out if your voltage drops lower than normal for whatever reason

[DVS JEZ]

good thinking, i might have a go at doing that, just let it idle with no alternator charge and try keep the idle AFR steady, thanks mate

[Adriano]

Why not get on the freeway, unplug the alternator and adjust the values as the battery flattens

[JonnoHR31]

yer unplugging would be a much better idea. dunno wtf i was thinking with pulling the belt off

[DVS JEZ]

  Adriano said:

Why not get on the freeway, unplug the alternator and adjust the values as the battery flattens

that an awesome idea dude lol, then you can come give me a jump start aye

[DVS JEZ]

  JonnoHR31 said:

yer unplugging would be a much better idea. dunno wtf i was thinking with pulling the belt off

same shit, its gay enough trying to get to the back of the alternator

[JonnoHR31]

yer but that belt also makes water move n shit, would be kinda gay running it without it