turboracer

Alright got my 91 octane tune running great. Peaks at about 22psi. Pulls great all the way through 7500. AFR about 11.2 - 11.3 and 0 knock counts all the way through. I would like to start on my 100 octane tune now.

1. Generally how much more timing can I start with over what I've got now?

2. Should I lean the AFR for higher octane? Say 11.5 - 11.6 ?

3. How much more boost?

Just looking for some starting points here.

I do have a k&n drop in, 3" TBE with HFC. I use the ECU to control boost with a smaller restrictor in the bleed line. Everything else is stock.

Thanks for any suggestions.

P.S. I thought it appropriate to post in the ecuflash forum since this is the software I use for tuning.

4doorbullit

iTrader: (2)

I dont know about a evo 9 but from 93 oct to 100oct I added 2 degrees of peak timing and 4 psi. From logs I gained 35 whp over the pump gas tune.

nj1266

iTrader: (6)

What does your current timing profile look like for the 91 octane map? Generally, on 91 octane the AFR is leaned to around 11-10.8:1 and the timing is retarded from stock. That is the case of the Evo 8.

For 100 octane I would lean to 11.5:1 and bring timing back to stock levels if it was retarded for 91 octane gas. I will do some logs and see if there is knock. If there is no knock you have three options:

1. Either lean the car to 12:1 AFR and keep the timing and boost the same.
2. Keep the AFR @ 11.5:1 and increase timing above stock levels by about 1-2* increments
3. Keep timing stock, AFR @ 11.5:1 and increase boost by about 2 psi.

You can also try a combination of all three approachs. The most important thing is to be incremental with your changes.

4WS Tuning

iTrader: (73)

im also trying to do the same thing... i posted couple fuel maps... can you check it out please https://www.evolutionm.net/forums/sh...d.php?t=246248

i put the 93 map and the first try at a meth map... idk which would be best to use with 110... is the meth map a good try? or should i lean the 93 map by .2-.3 and a count of timing over what i have and 28 pounds

JohnBradley

iTrader: (30)

For a 93 octane tune on a IX I have done the following with no knock:

1. Raised peak boost to 25psi tapering to 22psi
2. Run 4-5* at peak torque
3. Run 11.3-11.5 AFR

For 100 I would do all that plus more boost at higher rpm with 12:1 AFR's. Alot of fuel tuning changes involves knowing the specific gravity of the fuel you are switching to and the SG of the fuel you originally tuned for. Also know that not all 100 octane is going to be the same specific gravity.

Here is the approach I would use if I were you. Start by filling with 100 with as little 91 as possible in the tank. Log your A/F and see what the change was (it should richen a little). Lean it out to where you were and start adding boost. Add 4 or 5 pounds and see where you are at. At this point start adding some timing in and see how it reacts. No ones car is the same, and stuff I can get away with here in the NW doesnt always reflect what you can in Cali. Report back and let us know what you find. Remember also that there is a direct relationship between timing and what your AFR is going to be. Retarded timing means more fuel is burning as it the exhaust valves open, making your effective AFR richer appearing on a wideband.

nj1266

iTrader: (6)

Interesting...I am currently working on my CA 91 octane map. I had to fill 91 octane since I forgot my wallet @ home and when I got to work I could not do the 91+100 mix @ the pump

It turns out that my 91 octane map is knocking by about 8-11 counts from midrange to top end. I never had a chance to log this map since I did not have the Tactrix cable back when I used it.

I pulled 1* of timing from 5300+ rpm and 0.5* of timing below that to remove the 3 counts or so that I was getting.

I will see what impact the timing pull has on my AFR.

modvp

iTrader: (13)

It's interesting that your 91 oct map is knocking on 91. What boost are you running, have you tried to lower your boost to quench the knock?

nj1266

iTrader: (6)

The boost spikes to between 21-22, but that is not where the high knock counts are. The 8-10 counts are from 5300 rpm on when the boost is between 17-18 psi. The AFR is 10.8 or less in the knock area. So that leaves pulling timing as the option.

Basically, CA 91 gas SUCKS big time and the only reason I used it because I forgot my wallet at home. The upside is this will give me a chance to fine tune the 91 octane map.

turboracer

So far my results are as follows:

1. 100 octane unocal 76 gas on my 91 0ctane tune no boost increase:

Felt a little sluggish and ran about .1 to .2 richer. Was 11.1-11.3 now 10.9 to 11.1

2. 100 octane increase timing 5 degrees from base 91 tune in all 120 load and up no boost increase:

hit knock counts of 7 at peak torque area (had 0 knock counts on 91 with my tune and 22 psi)

3. 100 octane increase timing 3 degrees from 91 base tune in all 120 load and up no boost increase:

got some knock counts of 1 and 2 (adjusted map 1 degree less here and there to fix) got zero knock count now. Power feels better than 91 but not exceptional

100 octane timing same as #3 increase boost to 25 psi peak and tapers to about 19-20

Feels better than #3 but still not an exceptional difference. I do not have a dyno on me so I may be wrong.

I will run it at the track next Thursday this way and see what I get. I ran 7.9 in the 1/8th on my 91 octane tune. I should see some improvement I would hope.
Then the next step will be to lean it to 12 to 1 and see what happens.

Thanks for your input guys, I'll update this next week. My alcohol kit should be in shortly, any advice for tuning on 100 and alky?

Jason

turboracer

When I had my AFR this rich on top I would knock with less timing on 91 than when I leaned it to 11.1 - 11.3. Maybe it is a little too rich?

Jason

MalibuJack

iTrader: (5)

You can get knock if the car is running too rich, usually its caused by combustion quench. Its rare to happen as you'd have to be running really rich.. But you should also "Feel that" when your driving.

nj1266

iTrader: (6)

Correct...But I really doubt it in this case. 10.8-10.7 AFR from 5500 rpm on is fine on crappy 91 octane gas. I think the timing is a tad too aggressive. Pulling timing should do the trick. I will load the map and test. Hopefully it will work.

What amazes me is the difference in feel and power that the car has on 91 octane vs. the 93 octane mix that I do. You can see it in the power curves on DLL. This is a CA thing. Here in CA all kind of additives are placed in gas and that makes gas very bad. The 4-5 gallons of 100 octane that I add to the 91 octane does a good job of diluting these additives. This makes the mixture much more potent than 91 pistane.

modvp

iTrader: (13)

Are you using the xede to switch between 91 oct and 93 oct map...for situations like what's mentioned above?

nj1266

iTrader: (6)

Yes...That is why I am still using the xede. One map is for 91 octane and the other is for 93. The 91 is for emergencies like the one I got myself into

JohnBradley

iTrader: (30)

What is your total timing at peak torque at that boost level? What was your initial boost level? What if any changes have you made to the MIVEC table? Did you lean it back out to what the AFR's were before?

I am conducting some extensive testing with the effects of early cam advance and a peculiar lack of knock at peak torque as being a benefit. Any info you can or want to share in this regard would be appreciated.

John