Wicked E

iTrader: (26)

I bought my Evo used a few months ago and was trying to figure out what in the hell the injectors are... After some research and knowing a little history, (the guy used RRE for most all of his parts). I determined that the light blue tops of the injectors were most likely Greddy 720's sold by RRE (I hope).

I then went into ECUFlash to take a look at the RRE tune that came on the car (which was half-assed) and took a the look at the scaling and latency charts to try and get these things dialed in properly...

I have the following:

Injector size scaling = 609

Injector Latency Settings are:

4.69 = 5.424
7.03 = 3.312
9.38 = 1.68
11.72 = 1.032
14.06 = .672
16.41 = .432
18.68 = .264

Now, if you'll take a moment to notice that everything is the same as a stock Evo IX's numbers as posted in the sticky "how to tune" thread posted by Naji with the only thing changed by RRE being the 4.69 voltage setting.

I re-flashed the ROM to reset the trims and started my idle logs. All of the trims started at 100% and then the low fuel trim started to lower itself after every cycle (4 minutes or so), first starting at 85% and then 62% etc.

I attempted to read the "how to tune" thread paying special attention to the scaling section and was a little stumped. When mentioning +/- 5%, are we talking about 0% as being "dialed in" on the fuel trims or are we talking about a +/- 5% in relation to low/mid % of each other?

If you're confused let me give an example...

Say I logged my trims and they came out to 56% for low, 82% for mid and 100% for high. Are we attempting to bring these %'s as close to 0% as possible or are we trying to get the low and mid to within 5% of each other?

I tried a few of the posted latency and voltages on my flash with no success. I have wasted a 1/4 tank of gas just logging idle trims on a suggested scaling/latency posted that someone had success using with 720 injectors. These actually hogged my gas at idle and makes the car stumble while coasting. I also dropped the car into 5th and nailed the gas, the car bucked and jumped revs a few times leading me to think I'm running extremely rich and/or my clutch is slipping but that's beside the point...

Scaling: 622

Latency:
4.69 = 3.864
7.03 = 3.456
9.38 = 2.856
11.72 = 1.320
14.06 = .888
16.41 = .672
18.68 = .408

So I am going back to the original numbers (RRE) and working off of those instead since the car idled decently and didn't waste as much gas just idling.

If someone can just clear up the +/- 5% thing, I think I would be able to nail this down and get my car back to running half way decent and continue on with my tune.

for anyone that helps out...

dos531

iTrader: (2)

First of all it depends what you're using to read the trims. Evoscan reads them differently so 0% (which you want) will be 100. You can either edit the formula on evoscan to make it easier, or use mitsulogger. Basically if the trim is negative, that means the ecu is pulling fuel that much to reach 14.7, which would mean you want to increase the scaling. let it idle for like 20 minutes then see what % the fuel trims are. If its -5% then increase the scaling number by 5% and see what happens.

Wicked E

iTrader: (26)

Okay so if I'm reading you right, in Evoscan's fuel trims 100% = 0 and 0% = 100?? I have yet to see my trims equal a negative number. I will have to log it for a good 20 mins then and see what happens.

Keep the suggestions coming. I am about to dump Evoscan as its a PITA to use (saving logs and viewing logs etc (something with compatibility and Vista makes it a pita)...

I used Mitsulogger previously with good results...

cpoevo

iTrader: (1)

These setting I have used on another car and worked great. Set the injector size to 609 and use the following latencies.

4=3.312
7=2.544
9=1.8
11=1.128
14=0.744
16=0.6
18=0.312

Wicked E

iTrader: (26)

I'll give that a shot and see what happens... It seems that RRE just bumped everything down the voltages and inserted a bogus 5 number into the 4 volt box...

churchja

iTrader: (17)

Here's another setting you might want to try... I didn't tune my EVO, but I am running 720 cc Denso injectors. Idle's great and I get 240+ miles per tank... but, note I'm running 50/50 meth/water. Also running HKS MIVEC cams, stock turbo. I hope this helps... at least you have another reference for a IX...

Injector size scaling = 585

4.6875 5.592
7.03125 3.408
9.375 1.704
11.7188 1.104
14.0625 0.696
16.4062 0.504
18.6768 0.312

churchja

iTrader: (17)

Here is some numbers from my previous tune (different tuner) 720 cc Denso's (same mods minus HKS MIVEC cams). This tune... Idle was good; but MPG about 180 miles per tank. Also of NOTE: both tunes in CA.... 91 octane.

Injector size scaling = 597

4.6875 4.248
7.03125 2.616
9.375 1.632
11.7188 1.008
14.0625 0.672
16.4062 0.504
18.6768 0.384

Jorge T

iTrader: (18)

I would use the settings posted by razorlab >>https://www.evolutionm.net/forums/sh...&postcount=287 to start, he has tuned many evos and is one of the experienced tuners here.

You can chage the evoscan formulas to Eval: (0.1961*x)-25 and they will work the same as mitsulogger

Wicked E

iTrader: (26)

Okay so I left the latency and voltage the same as they were in the RRE tune:

Injector size scaling = 609

Injector Latency Settings are:

4.69 = 5.424
7.03 = 3.312
9.38 = 1.68
11.72 = 1.032
14.06 = .672
16.41 = .432
18.68 = .264

I decided to log using Evoscan for 22 mins of low fuel trims while idling...

It started out with 135% and then working its way up to being stable at 150% for the remaining 20 minutes.

The Mid fuel trim while idling stayed at 96.875% for the 22 minutes.

The High fuel trim stayed at 100% for the 22 minutes.

Can someone walk me through to how to bring the low fuel trim down to 100%?

Thanks!

Wicked E

iTrader: (26)

If you notice, those latency numbers are awfully close to what came on my car with the exception of the scaling. Why so low on the scaling for 720's? Is that due to using the 50/50 mix?

Wicked E

iTrader: (26)

I forgot to mention that I am using 91 octane at 6K feet elevation if that matters...

PVD04

iTrader: (23)

It's hard to say what you need to adjust based on idle alone. Based on the 150% low fuel trims, either your latency is too low or your scaling is too high. Think of it this way:

Fuel = (Airflow x 1/Injector Scaling) + Latency

That means if you increase your injector scaling by 10%, you will have ~10% less fuel across all loads and airflow amounts. Your latency, however, will add the same amount of fuel across all loads and airflow amounts. So increasing your latency will have more of an effect at low loads and RPMs than it will at high loads and RPMs. For example, increasing your latency by 0.1 may increase idle fuel supply by 10%, but increase cruise fuel supply by only 2%. The only way for you to know for sure which you need to adjust you'll need to go for a short drive to stabilize your mid fuel trim.

-Paul

Wicked E

iTrader: (26)

So I changed Evoscan's formula to reflect the same settings as Mitsulogger. MUCH better.

Now I then used the settings from Razorlab's post and it WORKED!! The trims are spot on and need no adjusting whatsoever. The idle is rock solid

Thanks again for all your help and suggestions guys!!

Now I just have to log WOT runs and get the fuel and timing maps done.

Cheers-
Erich

dos531

iTrader: (2)

See? it doesnt suck THAT bad.

Jorge T

iTrader: (18)

...thanks to razorlab for his will to share his work with us.