Map Tweaking Questions

[Badgaz]

couple of questions...i'm sitting here going through some logging i did the other night in my car...here is the scenario and i'm wondering what is the best option...being first time road tuning.

on wot i'm running 11.4 afr's in p15 n17 with a knock reading of 18.

my question i'm pondering is ....should i pull fuel or add a degree of timing? timing in this cell is 18degrees @6100rpm

my mods are in my signature

any advice would be great

thanks.

[GTSBoy]

Scientific method says to try both, report back with results.

[Don Dada]

What is the problem? You find knk reading is too low?

[Badgaz]

no problem just trying to get maximum efficiency. can you not get detonation with too much fuel? conversly with too much ignition? seeing as this is at the high end of the rpm scale i tought perhap a degree more timing might help.....this is where my thinking was going on both.....might have to do what gtsboy suggests

[89CAL]

Im a bit confused as to why your timing is going up in the bottom right cells. It climbs from left to right be a degree every few cells. It should be the opposite.

[zebra]

I wouldn't trust the pfc knock reading.

Only true way to get the maximum efficiency for that cell.

Is to load it up on a dyno and hold it at the poad point and play around with timing and fuelling

[Badgaz]

Im a bit confused as to why your timing is going up in the bottom right cells. It climbs from left to right be a degree every few cells. It should be the opposite.

as rpm increases the time between spark is reduced...which is why i advance the ignition as the rpm climbs.

[89CAL]

as rpm increases the time between spark is reduced...which is why i advance the ignition as the rpm climbs.

Isn't that what IGN Dwell vs RPM is for

I dunno, now that I can look at my old map it seems I had more timing up top anyway. It starts dropping but did start higher. I havent done any tuning for quite a while now

[Lithium]

Isn't that what IGN Dwell vs RPM is for

I dunno, now that I can look at my old map it seems I had more timing up top anyway. It starts dropping but did start higher. I havent done any tuning for quite a while now

IGN dwell versus RPM is for charge time, to make sure the coil is charged before the spark event happens. As a real rough rule the timing will typically be at it's lowest at low rpm and equal/highest at the highest rpm - the flame has to chase the piston, funnily enough at 7500rpm the piston will pull away from the start of the flame 3x faster than at 2500rpm.... if you used the same ignition advance the flame would be left for dead and just generate heat for no useful reason.

[89CAL]

This makes sense

The map looked weird for some reason doing this, but noticed mine is similar when I looked.

[Badgaz]

I wouldn't trust the pfc knock reading.

Only true way to get the maximum efficiency for that cell.

Is to load it up on a dyno and hold it at the poad point and play around with timing and fuelling

i agree, its not accurate but its all i've got at the moment. i'm saving for a knocklink.

[Badgaz]

whats the optimal AFR up the end of the map? is 12-12.5 still optimal?

[Dose Pipe Sutututu]

whats the optimal AFR up the end of the map? is 12-12.5 still optimal?

how much boost are you running? and I suggest you run less and less timing as load increases (incase your actuator hose comes off OR you get a massive boost spike).

12-12.5 is consider ok up top, however most prefer to keep it under 12.

I usually like peak torque (roughly after max boost) around 11.5 then it tapers up to 11.8 all the way to redline.

[Badgaz]

16-17psi perhaps its already optimal then....... i'm going to take it to the dyno to do a power run shortly.

[GTSBoy]

"Optimal" is whatever the engine is happy with. It takes a dyno and knock ears to decide what that is. Some engines might like a little more fuel to keep knock under control, some might like a little less timing. It really so very much comes down to the specific combo of engine (age, condition, components, settings), turbo (compressor efficiency range it's operating in, back pressure on the turbine side) fuel and a bajillion other things that you can't tell if it's really happy unless you can watch its reactions to different settings.

For example, with a certain "tune" at a given load point the engine might be pinging a little bit. The dyno operator can choose to either richen up a tad or reduce timing. But which one he chooses will depend on whether the torque suffers more on one change than the other, or if the exhaust temp starts to become a bit wild and so on.

[Dose Pipe Sutututu]

what's your base timing locked at?

appears you've got quite a bit of timing, especially for a small turbo

[Badgaz]

base timing is set to 15 degrees. thats a lot less timing than is used to have...stock they are up around 20 at wot.

i hear what you are saying gtsboy.....the knock ears will be a great help..... i think all cars need a happy meter.

[Dose Pipe Sutututu]

base timing is set to 15 degrees. thats a lot less timing than is used to have...stock they are up around 20 at wot.

i hear what you are saying gtsboy.....the knock ears will be a great help..... i think all cars need a happy meter.

stock is 22, however nissan never factored in 1.3bar into the motor.. the powerFC map is just to get the car going remember that

[89CAL]

Did you set up the base timing while looking at what the power FC was doing? I can see the first 4 cells are 15 but mine used to get close to or overlap cells further then that. I used to do base timing with a second person. One person looking at the hand controller timing and the other setting it with a timing gun. I think unplugging the TPS cancels the idle map timing so it wont jump around as much

You've probably done it fine but just asking

[Dose Pipe Sutututu]

best to pop it on a dyno, with those timing figures on a slow ramp you will find it will knock quite abit around 3600~4000rpm (assuming that's your peak torque).

I like to ramp the cars I put on dynos around 9km/k per second.. i.e. the car increase 9km/h each second... the shorter the ramp, the less stress and usually shoots up higher numbers.

I prefer to really load up the motor and let manifold glow.. think about a track, especially the straight at wakefield it's not a 400 metre straight it's quite long, thus more load on the motor