Just ordered my FIC 850ccs...

[nightspeed87]

From here http://www.fuelinjectorclinic.com/cart/mitsubishi.htm


Anyone got good business from these guys, I know FIC is considered a well known fuel vendor. My injectors says peak and hold, can anyone enlighten me with what that means
and also they are rated at 43.3 psi i believe so therefore how would this turn out on my stock 37 something psi 1g fuel pressure.
I payed 298.20 total, in which I thought was a pretty good deal compared to some other places wanting like 350 + for 850s.
I was told they are good till around 500 whp, and rated for 85 % idcs.
Any comments, opinions.

P.s. oh and by the way for the record so no one asks, i will control them with an eprom ecu keydiver chip, not safc.

 

[Splitpi]

They will work just fine, you just need to change the offset in the supply table.

I believe the offset to global fuel supply is:

Global Offset % = ((Old Inj Size / New Inj Size) / Sqrt (New Fuel Pressure / Old Fuel Pressure)) - 1 = ((450/850) / sqrt(37/43.5)) - 1 = -42.6%

I think the fuel pressure comes into effect like I showed above due to the weaker 1G fuel pressure not feeding the injectors at their rated value, however it may not. In which case it is a much simpler equation of:

Global Offset % = (Old Inj Size / New Inj Size) - 1 = (450/850)-1 = -47.1%

So the sweet spot is somewhere between -48% to -41%.

I should note this probably makes more sense if using DSMLink/AEM/etc where you can adjust the fuel flow from the original stock amount of 0% offset (450/450) - 1 = 1-1 = 0%. So you fool the computer by removing 40 some percent of its fuel because the injectors flow 40 some percet more, thus the computer still thinks it has 450 cc inj as it would flow accordingly and behave as the computer expected ... despite having far more fuel flow and greater power.

 

[nightspeed87]

They will work just fine, you just need to change the offset in the supply table.

I believe the offset to global fuel supply is:

Global Offset % = ((Old Inj Size / New Inj Size) / Sqrt (New Fuel Pressure / Old Fuel Pressure)) - 1 = ((450/850) / sqrt(37/43.5)) - 1 = -42.6%

I think the fuel pressure comes into effect like I showed above due to the weaker 1G fuel pressure not feeding the injectors at their rated value, however it may not. In which case it is a much simpler equation of:

Global Offset % = (Old Inj Size / New Inj Size) - 1 = (450/850)-1 = -47.1%

So the sweet spot is somewhere between -48% to -41%.

I should note this probably makes more sense if using DSMLink/AEM/etc where you can adjust the fuel flow from the original stock amount of 0% offset (450/450) - 1 = 1-1 = 0%. So you fool the computer by removing 40 some percent of its fuel because the injectors flow 40 some percet more, thus the computer still thinks it has 450 cc inj as it would flow accordingly and behave as the computer expected ... despite having far more fuel flow and greater power.

Its being controlled by a keydiver chip being programmed by Jeff at www.DsmChips.com
Im not actually adjusting anything myself, perhaps your response could apply if I told him to raise the fuel pressure to 42.6 like you stated?
Is it really nessecary to run the injectors at their correct fuel pressure, like will it throw off fuel maps or injector compensation anything? ( in which I didnt think it did.)

 

[Splitpi]

I am confident that Jeff has already accounted for this when he programs your chip. I was mainly just stating the info for the record. The 850's should run great with absolultely no changes other than installing the DSMChips chip into the ECU. Jeff woudln't be in the buisness he is in if he didn't do this correctly. I here those chips work great.

 

[nightspeed87]

I am confident that Jeff has already accounted for this when he programs your chip. I was mainly just stating the info for the record. The 850's should run great with absolultely no changes other than installing the DSMChips chip into the ECU. Jeff woudln't be in the buisness he is in if he didn't do this correctly. I here those chips work great.

Yea, so far they have for me, I like to keep things simple.
I dont want to have to play around with a safc and hope my tune if half on,
or worry about not fully compensating, or over compensating something.
The chip is simple, plug and play and roll without un consistency.