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New to tuning MAF 355 help needed

Posted: Wed Feb 05, 2014 2:34 pm
by hsv08
As above I need some help and clarification on a few things.
I have a 355 in a vt senator running the1s extended maf a6c xdf.
It's a 355 running a 234@.50 cam at +4, 36lbs sc injectors, modifyed banana mani with tb mounted forward like ls.
Standard maf.
I am haviving issues with wideband not meeting with target afr. I have my blm coolant temps maxed to get it out of closed loop. At 50k target afr is set at 14.2 but sits at around 13.6 ish. At steady throttle it always reads around .5ish out on the wideband.
When I wot it's target is 12.5 or so but wideband reads 11.5 for a second or two before going full lean ( I think this is a wiring issue as it sometimes stays on heating and doesn't read any afr. Injector pulse is still consistant and narrowbands stays in the high 800s so I dont think it's actually leaning out.
I am wondering how I go about trying to get the wideband to hit my targets. Do I have to rescale maf (no idea how) or use injector constants. If so what histogram would I set up on order to see how far I'm out?
Also getting some knock occasionally at cruise. Nothing under wot but afrs on the rich side and timing is in the low 20s. Unsure weather this is real knock or not.

Re: New to tuning MAF 355 help needed

Posted: Wed Feb 05, 2014 5:08 pm
by VX L67 Getrag
You need to have a read of the tuner guide & commonly asked questions!

But if you want a global change which sounds like that will get you in the ball park change the base injector rate till it's close to the commanded in most areas, then you adjust the injector multiplier table to get it 100% in line everywhere!

I wouldn't adjust the MAF tables unless you change your maf for higher resolution & unless your going forced induction you won't need to, you could also adjust your maf because the intake angles have changed but wouldn't advise it unless you know what your doing!

Re: New to tuning MAF 355 help needed

Posted: Wed Feb 05, 2014 5:21 pm
by hsv08
Thanks for the reply. I will re read the guides again. Just seems a lot of it is to deal with 12p and map tables.
I will try find the base injector rate. How would I go about changing the injector multiplier table? What would I set up in a histogram to log what I need to adjust?

Re: New to tuning MAF 355 help needed

Posted: Wed Feb 05, 2014 5:29 pm
by VX L67 Getrag
Like I mentioned read the guides it's not hard base injector rate will get you close as it seems it's at least 5% richer than commanded in most places!

Then the injector multiplier I mentioned there is history tables setup for either Wideband Vs Commaded AFR or STFT Vs the injector multiplier table setup & there are excel sheets made for the data logged!!!!

Re: New to tuning MAF 355 help needed

Posted: Wed Feb 05, 2014 5:49 pm
by hsv08
No worries. I am re reading them at the moment. I will do as mentioned in the Guide. Wil also try track down this spread sheet. I have seen it before somewhere so I'll just scroll through all the posts. Thank you.