So I have 2 tunes from Aaron at RT from last summer but i have extensivly changed my mods(lower CR, bigger turbo, LOTS more fuel...) but all the AEM stuff has stayed the same. As im reading the initial directions i need to verify the timing the car is at is the same as what the EMS see's, correct??? So do i need to do this again since already have a map thats tuned? My gut says that i need to verify this again but i donnu...
I was going to modify the tune by putting the timing map to 0 and then adjust the AFR's....
I guess my big concern right now is the engine is at TDC. I need to prime this turbo, so the minute i turn it over the pistons will be all over the place and i wont be able to verify it...I dont really know what to do, what would you guys do?
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The purpose of ignition advance is to account for the lag time following spark ignition for combustion pressure to peak at 15 degrees AFTER TOP DEAD CENTER. A little fyi !
you should only need to do this when it is installed to make sure everything is good, if you are just changing some parts its not nessacary (spelling), doing some pulls and logs you could have it adjusted very quick, your overall VE contour shouldnt change much, unless cam/head/intake/exhaust header changes
I wouldnt make any changes to the map just yet (zeroing it out) there is a function in the configure drop down to do that ...configure<set ignition, the start advance needs to be -0- in the start screen (little box says crank advance)
and pull the ignition and fuel relay to prime the turbo, you may need a battery charger, this will eliminate the turbo from spinning but will pre oil the bearings (if the plugs are out its easy on the starter) a good 15-20 seconds should be good for pre lube
Verifying that mechanical TDC and the EMS interpreted TDC match should only have to be done once. I guess the only possibility of needing to do it another time would be if you changed the crankshaft (if only for the possibility that the Tone Ring may not be perfectly identical to another from a different crank).
But, even at that, I doubt you'll see a difference.
And, the best way to verify that mechanical TDC matches what the EMS reads as TDC is to define a mark on the crankshaft pulley and the plastic front cover, where when both marks line up, it = Mechanical TDC. Then, using a digital timing light, input the actual timing advance that the motor will be running at. The timing light will adjust the time that the light activates to come on at true TDC. If the light comes on and the marks on the crank pulley/front cover match up, then mechanical TDC and interpreted TDC are phased correctly.
And again, mechanical TDC "should" be verified by using a piston stop, and a degree wheel. The marks on the timing belt pulley and oil pump housing have been known to be unreliable when it comes to lining things up perfectly.
Verifying that mechanical TDC and the EMS interpreted TDC match should only have to be done once. I guess the only possibility of needing to do it another time would be if you changed the crankshaft (if only for the possibility that the Tone Ring may not be perfectly identical to another from a different crank).
But, even at that, I doubt you'll see a difference.
And, the best way to verify that mechanical TDC matches what the EMS reads as TDC is to define a mark on the crankshaft pulley and the plastic front cover, where when both marks line up, it = Mechanical TDC. Then, using a digital timing light, input the actual timing advance that the motor will be running at. The timing light will adjust the time that the light activates to come on at true TDC. If the light comes on and the marks on the crank pulley/front cover match up, then mechanical TDC and interpreted TDC are phased correctly.
And again, mechanical TDC "should" be verified by using a piston stop, and a degree wheel. The marks on the timing belt pulley and oil pump housing have been known to be unreliable when it comes to lining things up perfectly.
Thanks chuck.
We used the arrow on the oil pump, but we ALSO rotated the crank with our finger in the spark plug hole to verify the engine was finishing its compression stroke. Therefore cyl one is at TDC. But i havent put marks on the crank pulley yet, i will do that today. Couldnt i just use marks on the cam gears as well? I will make a mark on the crank pully but still.
We used the arrow on the oil pump, but we ALSO rotated the crank with our finger in the spark plug hole to verify the engine was finishing its compression stroke. Therefore cyl one is at TDC. But i havent put marks on the crank pulley yet, i will do that today. Couldnt i just use marks on the cam gears as well? I will make a mark on the crank pully but still.
Sure thing. If you have your cam gears exposed, you can use those to check timing. But you'll get 1 light activation with the timing mark lined up, and 1 with the timing mark 180* out. Just keep that in mind when/if you do verify using the cams.
in all honesty even if it is a degree off what does that change?..nothing youre still going to need to tune it to find mbt anyway so the difference in numbers wont mean that much unless you are building a map with engine software to predetermine mbt
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5/24/09 9.30@154
in all honesty even if it is a degree off what does that change?..nothing youre still going to need to tune it to find mbt anyway so the difference in numbers wont mean that much unless you are building a map with engine software to predetermine mbt
I understand what you're getting at, and I totally agree. The EMS interpreted timing values you end up with mean very little, so long as the engine is happy, and is making the power you are looking for.
do you guys do MBT with the dyno (real time) or estimate off the knock sensor. I attempted to do it on the dyno but it was very time consuming adjusting dyno load and and boost levels. my last time i used the knock log (.02-.08) and adjusted off those values then interpret and smooth (kinda like the fuel map), i know its not the "proper" way but just wanted to ask since chuck and jay are floating around
I've never actually had the time/resources to get on a dyno (it would need to be a loaded eddy current dyno to make it really happen) and find MBT, so I have done all my adjustments based off of knock voltage and trap speeds at the track. You can do a little fine tuning of MBT on a dynojet, but you won't be able to fine tune every load vs RPM cell, but rather, make global changes to an entire row (or it can be a partial row) of load cells to see if you find increases or decreases throughout the RPM range.
The proper way to find MBT would be on a dyno, since there are some fuels out there with high enough octane that will allow you to surpass MBT which will result in diminishing returns w/out setting off the knock sensor.
MBT is maximum brake torque timing, correct? What exactly is it and what does it mean in terms of tuning?
Sorry, im trying to learn here.
My guess: This is the amount of timing at the point of top torque during the powerband of a WOT pull? This is important because we can tune down from here??
MBT timing is exactly that. Maximum Brake Torque timing values.
It means it's the least amount of timing advance required to achieve the maximum power output with no limiting factors (such as detonation) to stop you from reaching this maximum potential.
Often times, going beyond MBT timing will result in no gain in power whatsoever, and going any further may result in a loss of power.
MBT timing is exactly that. Maximum Brake Torque timing values.
It means it's the least amount of timing advance required to achieve the maximum power output with no limiting factors (such as detonation) to stop you from reaching this maximum potential.
Often times, going beyond MBT timing will result in no gain in power whatsoever, and going any further may result in a loss of power.
i see this constantly with mustangs, good point
i go untill my knock just starts to hit (.1 area) then i back that part of the map down 2*/or 3* and raise the rest 1* marking my good values so they are always 1-2* below the threshold (.1 for me)
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Initial Tuning with the EMS
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Linear Mode
