FIC's 142lb. Is Doubling Stoich and halving IFR the wrong way to scale?

[justhereforinfo]

I already use lamba so that won't be a problem. I'm just curious is this method is the cheap, fast and easy way to scale the tune down for these big injectors. And if it will land me in trouble later.

I've read Dave's document and understand the idea. If I had to, I could spend the time necessary to dig through the tune and find all ~100 tables that needed adjustment, but I don't want to...
http://injectordynamics.com/wp-conte...SteckScale.pdf
[I feel like an ass for post an ID link in a FIC thread]

Is the method of doubling stoich and cutting the IFR in half the wrong way to scale?
Anything else need adjusting using this method?

[Ben Charles]

Works just fine... sometimes I triple stoich

[justhereforinfo]

So no need to adjust timing tables?

[Ben Charles]

Nope..

[Ben Charles]

You’re just going to run out of headroom in the spark table pretty quick in low boost.. I usually scale tune to gain more spark control

[podium]

Works just fine... sometimes I triple stoich

Just to gain more control over spark?

[TCSS07]

yes, otherwise you'll go off the airmass scale and the ecm will just use the last value for spark. so you scale the tune to get back on the airmass map

[Ben Charles]

Exactly!! So you make decent power and push a 2.25 g/cylinder on your spark ya me and last cell is 1.36... spark should be much different at 1.36 (say 4lbs) vs 2.25 (say 16lbs)

[justhereforinfo]

Exactly!! So you make decent power and push a 2.25 g/cylinder on your spark ya me and last cell is 1.36... spark should be much different at 1.36 (say 4lbs) vs 2.25 (say 16lbs)

I dont follow. Why does doubling stoich and halving IFR effect the g/cylinder in the spark table?

I?m looking to go from 15 to 18-19 psi.

[TCSS07]

i dont think you understand what hes saying. your not going to loose any power scaling your tune you'll probably going to gain power because now you will have control over your spark advance where as if you didn't scale you wouldn't because your pushing a cylinder airmass of 2.0 when you spark only goes up to 1.36. so in between 1.36 and 2 the ecm is using the same number for spark for whatever boost falls within those airmass numbers whether it be 4lb or 16lb it will be using the same number which is incorrect which is why the scaling tune method(s) becomes necessary to do.

scaling the tune method(s) are just a way to trick the ecm into thinking that the airflow is less than it actually is so you get it back on the chart when you cant increase the resolution on them such as for fuel injector size and spark charts

[justhereforinfo]

The stock spark table only reads up to 1.36. I currently see 2.0 cyl air mass, so I already have the loss of spark control. Correct?

[TCSS07]

Yes. For any boost level that falls in between 1.36 and 2.0 airmass will use the 1.36 cells for spark at whatever rpm

[justhereforinfo]

So doubling stoich and halving IFR has nothing to do with it.

I will proceed, thanks.

[justhereforinfo]

I installed the FIC142# injectors, doubled stoich and cut IFR in half. All other injector data from the FIC142# Injector data sheet is copied into the tune as is. First start shows major fuel being pulled. Did I do something wrong, or is this how it should act until I get it to the tuner?

ESS G3X DSMLIGHTS DSX Tweeked-evap+FIC145.hpt
fic142 first start.hpl

[Lakegoat]

Half the IVT Terms (AFR Term) also. Before you start it, go to the scanner special function and clear fuel trims and then let it warm up. Looks like it is adding fuel.

[justhereforinfo]

I cut the IVT terms in half, but it's still pulling a lot of fuel. I guess its not as easy as dropping in a 90# injector...


fic142 IVT second start.hpl
ESS G3X DSMLIGHTS DSX Tweeked-evap+FIC142+IVT.hpt

[justhereforinfo]

Oh shit, you're right, ha. It's adding fuel. So I must have done something wrong....

[justhereforinfo]

fic142 IVT 3rd start.hpl
I cleared the LTFT's as suggested and let it idle for a few.

After it warms up a bit, bank1 and bank2 are way off...

[Lakegoat]

log your O2's. There is something going on with bank 1.

[justhereforinfo]

O2's seem fine. I re-seated all injectors electrical connections, pulled all the plugs on bank1, checked the wires, and checked for exhaust leaks on the header and around the o2. I guess I fixed the problem of bank1 vs bank2 being different.

However I had to insert the injector data, without scaling it or the Stoich table, in order to get my fuel trims back in line. I checked some of my old logs doing highway pulls, and I never see more than 202 kpa of MAP. The injector data is below 127# (the limit) all the way up to 328kpa in the IFR table. So why do I need to scale it??? Fuel trims are nice and tight with the IFR pasted in, no scaling.



FIC142noscale.hpl
ESS G3X DSMLIGHTS DSX original tune WITH FIC142 NOT SCALED.hpt