So while Mike is happy with the power of the quad he is struggling to get good mpg out of the unit, unlike Tyler and myself.  Bothersome because we didn't even have to try it just came with the lack of smoke.

 

I think Tyler did 21 on his first try with his firehouse injectors and I did 24.7 without trying with my 100's

 

Mike however is struggling to hit 20.

 

We are all running the same timing map, but different tuning on the canbus fueling.

 

I am however down at nearly sea level now running Mike's tune and I am smoke free so I know Mike's tune is WAY under fueled since he has 50's.  I am betting Mike has get away with a starting point of 98 or even 100 rather than the 93 he has with his current tune.

 

Watching the timing number I can see what I get high timing at high revs and low throttle / load.  

 

At 1500 rpm 55 mph and flat ground low tps you can easily see 22 or 23*  as soon as you increase throttle to 25-30% timing drops like a rock to 14-16*.

 

Once revs get up above 2200 then timing starts getting high again.

 

 

So what makes for good mpg, I have never bothered to look or research but I am assuming we are dealing with timing advancement before TDC?  Am I off on this thinking?

 

My current thinking is since Mike is under fueled due to the low canbus tuning he is having to us significantly more tps which is dropping the timing.

 

 

So any thoughts on this?  I am assuming that Mike's issue is the under fueled tune causing him to need higher tps at cruising causing the oem map to retard.

 

 

This is one of strong reasons I've never done a P7100 conversion because the timing is static which gives the VP44 better chance at producing clean power where the P7100 is rather dirty and typically lower in MPG.

Edited October 7, 20168 yr by Mopar1973Man

I drove into work today with timing set differently.  

 

My normal tunes have timing at 8* and %100 scaling, so at cruise the quad might add ~1 or 2 * timing.  

 

I changed the tune to be 12* timing with scaling at %50.  This would make masx timing on top ~6* but gave me ~3 * at cruise.  

 

 

Again this is city driving so the oem timing never got into the cruise map, but I was seeing low load timing of ~18*.   I dont know if that hurt my mpg or helped but I am at least getting a better grasp on how things worked.  

I appreciate what you doing with this myself. It is interesting reading but far over my head. I understand what timing is but not to the degree you are taking it. I have had some of the best mileage ihave ever had while running the comp. Anything better would be gravy. Even though I dont buy my own fuel, getting good mileage is always a fun accomplishment. Keep on keeping on.

Like today I'll be packing home. So I'll fill again report what my MPG is for this tank. It will be slightly higher because drive just empty truck for the last few days. I'm sure my daily MPGs were at least 18 or so. I lost my tune with the updates of the software. I'll fix it when I get home.

Alright,

 

Some more information from driving.  

 

It seems that highest cruise timing comes when the quad reads ~15%-%20 load.  The ecm was commanding ~16.5* I noticed that  cruise EGT came down by ~100* when I turned the quads timing on which was giving an extra ~1.6-2* of timing at that part of the map.

So just an update to this thread as we learned more with more people using the beta tuning with the new Cruise timing adjustment.  

 

It seems that timing in the 20* range is getting the best MPG so far.  I know the engine really starts to rattle when you hear the timing jump.