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-   -   Injector offset? (https://www.homemadeturbo.com/engine-management-10/injector-offset-95928/)

fuse 10-06-2008 04:14 PM

Injector offset?
 
I am tuning a usdm gsr motor with crome. It is using stock injectors should I mess with injector offset? I have read you should only play with it if you are using different injectors. I also disabled the eld this should hold the voltage at a steady 14 volts?

One more question. This motor is using civic type R pistons and I was told by the owner it is very high compression. I seamed to like 4-6 degrees of timing sucked out of it. Dose this sound funny? I did set the distributor to 16 to match the ignition map and we are running 91.

lilpooh21186 10-06-2008 11:25 PM

Re: Injector offset?
 
do you have a wideband my buddy has a ls-vtec i had to ad a 10 offset with stocks to get a 15.0 idle

nascarfan 10-07-2008 08:57 PM

Re: Injector offset?
 
how do you find a close battery offset if there not listed in crome?
like rx7 460s
sorry to jump thread

fuse 10-07-2008 09:00 PM

Re: Injector offset?
 
Ya I have a wide band. The stock map ran good afcs.

lilpooh21186 10-10-2008 06:50 PM

Re: Injector offset?
 
you can make your own thats what i did crome's 880 off sets suck balls

ok so if your stock map ran good afr what are you wondering if its ok to use offset with stock injecors i would say so but you souldnt need a ---- load ill post up my ls-v map for you tonight if i can find out how mabey you can look at that an get some usefull ideas

Tom-Guy 10-12-2008 11:50 AM

Re: Injector offset?
 
Offset is affected by:

-ground system
-battery (ALTERNATOR) voltage
-fuel pressure

Sometimes stock injector cars like offset @ 0, sometimes as high as 14-15. With engine at full operating temp, and idling high enough to get a decent 13.8+ volts out of the alternator, set the offset to whatever you have to in order to get a 14.7:1 idle. Unless cam/compression is wildly different the rest of your NA fuel map will be within ~1/2 point of optimal. Sometimes it's not, seems like only dog slow useless faggot B16 fall right into place and everything else needs small tweaks. It is what it is.


Originally Posted by civiceggturbo
how do you find a close battery offset if there not listed in crome?

Battery offset aka battery compensation being COMPLETELY different (although related) from the offset I am talking about, is pretty easy. Go through the steps above to set your idle AFRs, do it with all electrical loads off. Then switch on high beams, heater fan (high), etc, all at the same time. The AFRs will always fluctuate for a second when the electrical system is loaded/unloaded, so don't make any adjustments to the battery offset tables until it has stabilized. From there it's pretty easy, and as soon as the idle AFR is the same with the electrical system loaded/unloaded your work is done.

This is exactly the procedure you need to go through with 450, 880, 1600, or one billion cc injectors on a Honda-based EMS, AFTER applying an injector recurve of course.


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