Over fueling
- Thread starter Max1957
- Start date
Yes used a calculator. The tune I got was really good and set for 60% Overs. Just had a lope at Idle in gear. Now I went to 100 overs .. Got the Idle cleaned up now. Can start it in garage and it doesnt smoke me out. It sounds and runs great as it is. Just quite smokey spooling So will try lambda to see if it spools faster and cleaner And need to watch EGT’s to see what they Are. It leaves a good haze after boost where I think it should be. Probably Pushing it quite hard but its only 10 seconds, not pulling a load.
if you have a hard time getting it cleaned up and you've exhausted all fuel related tuning you may need to look at the converter too. maybe too tight. also shift points can help tremendously too. getting it to downshift into one lower gear to help raise RPMs. the trick is to keep it from unlocking the converter. works wonderful for my tune. of course I don't have your setup either
Take this with a grain of salt because I’m not as experienced with tuning. But throw 2 degrees of timing in your spooling area. See how it reacts, listen to the motor. In my understanding you can run more timing with larger injectors and not increase cylinder pressure because you’re using less Us with a bigger injector. Not really at low rail pressure because it takes longer for the fuel to get into the cylinder when the injector opens. If that doesn’t work try going the other way and pull 2 degrees out
Thats the only Question I have is the Pulsewidth. It has the 60overs Pulsewidth in it so should that be cut backed down and add a little timing. When guys say they have “” 2900us tune”” , where are they getting that Number?? Just the highest pulsewidth on the table? I hate to adjust it as it runs so well.
they’re talking 2900 uS at the highest point of of their fuel pressure and MM3 so full throttle. Usually with injectors the pulse table doesn’t need to be modified other than the max pulse width
4L80E Torque Convertor Could be a little tight, but any looser and engine hit 4000 rpms before I get speed up. Shifting with torque locked is out of the question, I broke a shaft in about 10 minutes last time I tryed. (Custom Built, Billet, hardened everything) Also it sends me sideways when locked in at low RPMs , Because of the torque in mid range.. Torque is set to lock in 3rd gear 85 mph 3800 rpm and it will chirp tires. (Yes need to tub it.)
Does not smoke bad while moving, it will down shift and then relock torque convertor. It is just the launch which I have a feeling it needs the fuel to get turbos spinning. But will try a little less fuel , maybe it will surprise me.
Yes So im 120mm3 x 190 MPA , 2550us. Im not really smokey up there so going to leave it there.
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Ok, that what I needed to hear. Also I want to say timing is about 7-9 degrees while trying to boost , I ussually try to ease into throttle 25-50% ,seems to boost a little quicker.
You generally don't get better spooling when you reduce smoke. Spooling will probably get worse, but you might be able to make it up with less timing and more fuel pressure.
In the idle spooling area you will find the fueling if the 100’s may be less fuel than the 60’s. Especially in the 10mm3-20mm3 and lower rail pressures. That’s the main reason the engine loped with the 60 over tune. It didn’t have enough fuel so it jumped back and forth in the table to find the fuel to idle.
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yes, The reason it loped was we had truck ecu fuel pressures 40 at idle in our tune. I have a Van ecu which for some reason needs 60 at idle. As soon as we bumped it up lope is gone.
If you want better spool to launch harder, reduce timing. I reduced timing alot, from 8deg to 0-2deg in my spooling area and it helped alot. 2deg change won't be too noticeable.