I have a 93 octane reflash for a mostly-stock EVO 8 and was recently comparing it to a stock EVO 8 map. I was surprised to see that the tuner advanced the timing of the LOW octane map quite a bit (though it's still different than the H.O. map.. so he didn't just copy and paste). So, in general, would you guys recommend this? I mean, I was thinking that I should change my L.O. map back to stock, just for safety's sake. Or maybe this is normal for a "93 octane" map? In the peak-torque cells, the timing is advanced quite a bit (13 degrees) over stock.

The L.O. FUEL map was not changed from stock.

What surprises me is that some of the cells (low-to-medium rpm, highest load column) are actually running more timing in the L.O. map than in the H.O. map. Is this not really a big deal because he's making up for it with fuel instead?

I don't really plan to make any big changes until I can get a wide-band.. I'm just trying to learn at this point.

Thanks for any info!

Rob

 

Some tuners make all the maps the same, I would leave the other maps because if for some reason you get bad gas or something else that would cause the maps to change that will keep your car from taking damage to the motor. If it will not stay in the high oct map there is a different problem.

 

This tells me that your tuner was probably not paying attention to the whole map, or was pressed for time. If I was in your shoes, I'd take a look at the offsets between the stock high and low octane maps, then take your current high octane map, copy it to your low octane map and add (err, subtract) similar offsets to it. You could do the same thing with the fuel maps. Personally I really wouldn't want my low octane timing map to run more timing than my high octane timing map.

l8r)

 

So basically your low octane timing map is more advanced than your high octane map and your low octane fuel map was untouched? I would consult who you hired and ask him (her).

If you get bad gas and knock the ecu will run more agressive timing! I couldnt tell you if adding fuel in this case will keep it from damage.

 

right, noone could really advise you whether the additional timing is offset by additional fuel in that area of the map. My guess is not to point fingers at this tuner, but rather... I'd guess that it's in the area where boost is building and is set up that way in order to increase spool, even while on the low octane map, while (hopefully, this is where the "this tuner should know what he/she is doing" comes in) remaining L.O. friendly.

Just because the LO map is more aggressive than it was before, does not neccessarily mean that your engine is in any more danger than before. Remember that Mitsu must have put extra engineering factor of safety into it... (and if you really wanted to retain that, you wouldn't have gotten tuned in the first place)

 

ive been sticking to tuning the high octane maps, leaving the lows where they are...

with good results....

gotta love the 94 octane in pennsylvania

cb

 

Generally the low octane maps are alot less aggressive, if you find the axis were rescaled and they didn't "Fix" the low octane maps, then you'll experience what your talking about..

Generally the low octane maps if compared side by side should have 2-5 degrees LESS timing and almost a full point richer (according to the map).. Assuming the stock low octane map is unsatisfactory, copy the high octane maps to the low maps, and do what I said, but only worry about the "Lower right corner" portion of the map, from about 4000rpm through redline, and from the 160-260 (or higher if it was rescaled).. Remove timing and add fuel..

Generally the low load portions of the maps are untouched by the tuners, but if you might want to pull timing across the board and richen up the entire map (except the 14.7 portions) if you can't use any of your original low octane map..

If your loads were not rescaled and you can utilize the stock low octane map, in some cases if your airflow reading is much lower than what the ECU might expect, then you'd find your low octane maps in load cells that have way more timing..

Otherwise leave the low octane maps alone.. Even though I do fiddle with my low octane map, I do what I described and copy my map to the low octane, and add fuel and remove timing..

 

Also, verify your definition is actually not incorrect, and the numbers your seeing aren't off an adjacent map..

 

well this is a sensitive issue to a certain tuner. But most recommend for extra safety to leave to low octane map stock. I think the tuners logic behind changing that map is to improve drivability or something silly like that.

 

LOL @ your avatar

I wouldn't recommend messing with the low octane maps unless you're very comfortable and sure of with what you're doing. The knock detection and low octane maps are a nice safety net to have. Why mess with them unless you're absolutely sure you know you can do it right?

 

I thought low oct maps where failsafe mode to protect car from consumer in event someone accidentally fills the tank with 87 octane and goes autocrossing.

Ecu responds to whatever and can start running in grandma maps when the driver farts with AC, it looks mitsu tried to address this with the IX, maybe the X will have something decent.

I think there's sound reason behind identical low and high maps and it's a clever way of manipulating the OEM card to provide a little standaloneish control - assuming your carefull with fuel of choice but, if anyone can convince me otherwise I would be happy to learn more! I'm open to learning more about this

 

I agree that to a point identical HO and LO maps are okay (I did drive on an ecu like that for a year w/ many many exertive outtings) and had no problem w/ knock. If there ever was any, the automatic timing pull worked. However, now that I'm tuning more towards "the edge" I like to have a LO map that's actually gonna be there to fall back on. Since I never plan on running 87, the worst that's gonna happen is I'll get an extremely high pressure, hot day, where the OCT rating @ the pump was a little off and get some knock, so the extremes of the FOS (factor of safety) dialed in by the mitsu engineers is excessive for me. It all has to do w/ the end user. Do you ever forsee accidentally getting 87 in your car, or are you a set it-and forget it type of person? (not gonna log often, or "feel" the car) then... try to leave the LO conservative, but if you are the type of person that always wants to know how its running and stop every time there's a little squeek or creek, like me, then you'll be fine w/ experimenting w/ the LO map.

Only inconvenience w/ a conservative LO map is that if you are doing motorsports and do not want the computer to totally kill your performance, you have to be very cautious and do things like run 100 oct for autocrosses lol.

 

Taking 1 map and putting it the same on the other 2 is not safe at all. Here is what I think and again I own no shop nor am I a pro tooner. I think the 1st map gets knock a lot and hits the 2nd and 3rd map so instead of fixing the suck tune you just make all the maps the same and let the knock sensor go crazy and let the motor take the abuse. If it was tuned good it would stay in that 1st map 95% of the time and you would still have the fail safe of the other 2 maps.

 

I hear you, and I agree to some degree, keep in mind that my tune is totally new now and my maps are quite different from one another. I am simply saying though that it is a bit too presumpuous to say that its absolutely stupid and/or will ruin a car for them to be flat. Like I said, I ran the car very hard on maps just like that for over a year, with no trouble at all, and when logging found very minimal knock.

You do know that even if you make your maps flat, your ecu will pull timing right? As has been said onedythousand times the LO maps are for when your ecu sees the problem as persistant (such as you having filled up w/ 87) and not just a fluke (for which it simply pulls timing for a moment). So if your tune is safe enough to start, then the flatness should not be an issue. Now, I can't comment on the reasoning behind making them flat or the certain benefits thereof, outside of the fact that if they are flat, you will have much more consistent runs in motorsports (so long as you have the afore mentioned "safe tune")

For me, I'm not competitive enough at the moment to risk the motor so my LO maps ARE somewhat lessened from my HO maps, but they certainly are not stock. I have enchanced the LO maps to still encourage good spool and decent power, but able to withstand the odd, un-accounted-for, extreme (such as heat). There is just about no way my car will ever get "low" octane. I run water injection and I and only I ever drive (and fill up) the car. Lastly, I always watch and "feel" the car, if not log, and would immediatley solve the problem w/ ecu+ should any persistent problem show up.

oh, plus I have the added security of ecu+ subtracting 2 deg timing and going .5 points richer when my knock hits 2 volts on TOP of the factory ECU. I feel pretty safe, and I'd feel safe still if I were to flatten them again for whatever reason.

edit: I still don't know what to say/think about the "8 block" though lol.

 

There is nothing wrong with tuning the "other" 2 lower maps, just dont make them the same as the 1st one. The reason does stuff like that is to keep the motor from trashing itself if say a injector fails, cat gets clogged, hose blows off and boost hits 30psi. Think about it from there stand point. If the car blows up they pay for it so they have to cover there ***, they are in business to make money. Also I still think knows more then any tuner out there.