hey guys, my car has been tuned to 98 RON, my question is, when cruising on the hightway, at say 100-110, the amount of ignition timing is set to 0 at that particular engine load and RPM parameter,
the reason being, that im sure my tuner was going for power than an efficiency tune, which is fine, but can i have both? i have changed the ignition timing to an advancement of 3 units.
there is no change in power that i can feel anyway. its the green highlighted square in the photo. is this wise? or should i change it back to 0?

http://i304.photobucket.com/albums/nn177/lowridermagna/map.jpg

Your change is probably outside the engine load (PSI) parameter at that speed (2,500 rpm) and has no effect. If I read your map right you are already getting 4 degrees advance at a certain load, tapering off as the load increases. I would put it back to 0 and have a chat to the tuner. If you really want to experiment, change the 2,4,3,3,2 pattern at 2500 rpm to 2,4,4,3,2 or 2,4,4,4,3 to change timing within the working parameters, but its your engine. I wouldn't risk it without talking to the tuner first.

not quite Max...

he's changing the advance at 17.5 In Hg (i.e vacuum on low to no throttle).

is this a full replacement, or is it intercepting the stock ECU signals? either way, I would talk to the tuner and see what sort of impact this change might make.

cheers,
.wook

yeah, wook is right, im only changing that one parameter, at 2500RPM and at 17.5 Hg which is a low engine load, this is where the car sits at when driving at 100-110 km/h
i would like to take it back to the tuner, but i dont want to pay for more dyno tuning, for such a minor change.
and it is a morrisetech prosequential biggy back unit,

I am assuming you are saying it is a Piggy Back unit lol

What you have changed SHOULD NOT have any effect on engine life as you are not under heavy load at that range however i would at least talk to your tuner to see how and why he has left that part of the map, may be he has left it as the chage will make no effect (which is my summation) or he has left it because the more went for the power areas to be changed

the only way to tell if it's making much of a difference is to compare a couple of 100km/h runs (one with, one without the change). see how much fuel it actually uses.

I think the stock ECU tune would be fine for low throttle openings. it's only when you're under load and/or get close to WOT that huge adjustments are needed.

I guess it really comes down to if your tuner going to answer a question over the phone... I assume you paid him a bunch of $$ to tune it, 2 minutes out of his day couldn't be worth much more.

I have MT Interceptor as well.
That Ign Map looks weird. It should have at least couple of deg advance (from OEM timimg) from low Load and RPM to begin with. Then gradually increase to several deg accross. Your's ain't doing that and I find it baffling.
How is your Fuel Map? Noticed, how even small (on-road) changes to Fuel % makes a diff in small load and pulling up hills on level load - in other words, "normal" driving. So, even a small change will make a diff accross the RPM/load range.

Your tuner probably saved himself some time and didn't touch your low rpm tune just high rpm so you felt a power increase. I would never do this without a dyno but in your case low load it should be ok to use knock levels to set the timing around there. In terms of timing power and efficiency are matched.
Peak timing is set when the engine reaches a maximum torque value before torque falls again. Then you tuner would wind it back a few degree by there. Don't both doing it by feel of arse as you in all likelihood won't be able to tell the difference between 5 degrees of timing.

Now here's the thing you adjusting timing will not really affect the fuel usage at this point, but for your optimal timing at this position your engine will combust cooler allowing you to trim the fuel. I should explain further but i cbf'd finding the nice explaination in a book i've been reading.

So if you want to save on fuel; get the timing set at this region if you do many highway km's and then you can trim the fuel.

Note what alot of people overlook is that as you adjust duty cycle the start of injector opening is moved therefore your timing will also be altered so if you move the timing to the limit and then trim fuel your timing will be advanced further towards predetonation; so thats why you have your margin of error.

Was that for me?
I use AFR Gauge, audio aid to listen to ping - as many tuners do. I don't rely on my ass, no - it's too skinny and stupid.
My Tuner did do part TP and low RPM tuning as well, but it's never as accurate as fine tuning on the road with appropriate knowledge and equipment.
I have so far achieved good results, but work still going - hard to find ppl who want to participate in this kind of obsession...


Your tuner probably saved himself some time and didn't touch your low rpm tune just high rpm so you felt a power increase. I would never do this without a dyno but in your case low load it should be ok to use knock levels to set the timing around there. In terms of timing power and efficiency are matched.
Peak timing is set when the engine reaches a maximum torque value before torque falls again. Then you tuner would wind it back a few degree by there. Don't both doing it by feel of arse as you in all likelihood won't be able to tell the difference between 5 degrees of timing.

Now here's the thing you adjusting timing will not really affect the fuel usage at this point, but for your optimal timing at this position your engine will combust cooler allowing you to trim the fuel. I should explain further but i cbf'd finding the nice explaination in a book i've been reading.

So if you want to save on fuel; get the timing set at this region if you do many highway km's and then you can trim the fuel.

Note what alot of people overlook is that as you adjust duty cycle the start of injector opening is moved therefore your timing will also be altered so if you move the timing to the limit and then trim fuel your timing will be advanced further towards predetonation; so thats why you have your margin of error.