Hi Guys,

Now that I finally have my LC1 installed I have begun tuning.

I have noticed that my Idle and Cruise trims are about -8 and -4 respectivley.

Anyone else find that the STOCK ROM has trims which are off?

I want to make sure it's normal before increasing the injector scaling a little

ps - my fuel does NOT have any ethanol in it... perhaps mitsu expected there to be some?

Cheers
D.

 

The stock JDMs here are usually in that range too, I've seen a few that were around -10/-7. They all seem to fall into the negative range for some reason.

 

Hmm weird, my USDM is positive. Currently cruise is +4%, don't remember what idle is.

 

stock?

does your fuel have any ethanol in it?

 

if u have an aftermarket intake it will be off as well we've seen up to 10% fuel trims

 

Yeah I am only concerned about stock cars

 

Yes completely stock. Stickers at the fuel pumps say they can contain up to 10% ethanol (but some stations have a caveat saying ethanol is only added during the winter months)...so I'm not sure...would ethanol content cause it to be positive?

 

Ethanol in the fuel means there is more oxygen - which in tern means you need MORE fuel to maintain stoich.

I am not sure if 10% Ethanol equates to 10% extra fuel, I doubt it - but its worthwhile considering!

 

Wow, so yet another thing to worry about come winter time huh? If they add more ethanol, I might need to richen up my fuel maps...or maybe the easier thing to do would be to lower the fuel injector scaling? Would that work?

 

It does seem like they expected some ethanol. I have seen close to 0 fuel trims on stock Evo X's on our 10% ethanol fuel here. With an intake on the car they are usually very far into the positive range.

 

100% stock 2008 USDM EVO X: actually I have LTFT at idle = -7%, and LTFT at partial load = -1%

 

which LTFT is that? Mid?

what fuel do you use? does it contain Ethanol?

 

LTFT means "long term fuel trim" (STFT is instead the short term fuel trim that works continuosly in closed-loop and goes to "load" the long term fuel trims).

I use 100% gasoline. It is a 98 RON gasoline (I'm in Italy), that is equal to a US 93-94 AKI gasoline.

 

lol

there are 3 LTFT's

Low/Mid/High - they usually refer to the MAF-Hz ranges...

so when you say partial load - what LTFT do you mean?

 

Sorry guy, I was in a hurry and I didn't read well your reply, I only read "what LTFT mean"? Sorry!

At idle LTFT is at -8%.
Cruising at low speeds it is (average) at -1%, so I think it's the MID: at the moment, driving normally, I have only a Greddy Informeter Touch connected, so it doesn't make difference between fuel trims, it simply shows the current "long term fuel trim" (or "slow fuel trim", as you prefer).
If you need more accurate values, I can connect Mitsubishi MUT-III diagnostic tool (not next week, because finally I will be on holiday!!) so I can check without doubts which FT is.

There are also cars with a more complex table of fuel trims, for example here some GM cars have a complete table (basing on MAP/MAF and rpm) with up to 20 slow fuel trims (fast fuel trim obviously is only 1, and goes to load the slow fuel trim for each area).

Sorry for my English... but I'm in hurry also now!
Ciao