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mpersell

Recent changes improve E85 and E10 mileage

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I have recently added a Cold Air Intake system to my 2007 Ram FFV.  This is on top of synthetic oils throughout the vehicle and a very good breathing dual exhaust system.  I have headers on the board for early next year.

 

Since adding the the cold air intake I picked up about 1.4 miles per gallon on E10.  Better yet I picked up 2 miles per gallon on E85.  I'm not trying to argue with good results...but I'm curious why the increase with the cold air intake.

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Good deal - curious what sort of time frame this is over?  Is there any chance that the increase is due to local weather patterns or the winter blend fuel shift?  I would have suspected that the last thing E85 would like is more air and/or colder air.

 

I actually pulled the intercooler off my car to purposely make for warmer intake air.  Seems to have helped maybe 1 mpg.  Though, that is one of my resolutions for the new year is to try and keep better records of mpg.

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I am guessing that you reduced pumping losses by reducing pressure drop in the intake system.

That increased brake specific fuel consumption as less work was wasted trying to suck air into the engine through a restrictive intake. Net result you need slightly less throttle to go the same speed, and perhaps save a few down shifts when pulling hills etc.

 

It may also have slightly leaned out your fuel air mixture.

 

Larry

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That may be one possibility, though I would have thought at part-throttle cruising, the throttle plates would surely be the biggest restriction in the intake.  Maybe with a super-restrictive stock intake, though...

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Mike- are you still pulling a trailer?

      - do you think the 4.7L is marginal enough on HP for the high load you pull/carry that perhaps you were operating at at fairly open throttle prior to adding the cold air kit?

      - did you happen to log MAP before and after?  LTFT's? Initial air temps?

      - could the kit have changed the way airflow is crossing the MAF sensor or did you clean it?

      - change tire pressure to max sidewall rating?

 

I agree that adding a cold air kit is counterintuitive on E85 yet if one uses less throttle does not at least the initial injection time lessen due to running lower on the fuel map? (or at least until the MAF and and O2 readings come into play). I note that the former Chrysler engineer who did alcohol work I know also added a cold air kit to his "Burb". I suppose that if the engine was always so air starved in some cylinders even at half throttle or more then perhaps a colder denser charge corrected this (could this even be?????). It is pretty warm down where Mike usually runs.

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I changed everything from the throttle body to the open air.  This system adds 400 cfm and lowers the pressure while increasing the flow. Larry's idea seemed to make sense.

 

There is only one sensor and it is a temp sensor for the inbound air.  This system also lowers the inbound temp about 20 degrees F and I have a wire extension on the inbound air temp sensor that tells the ECM that the temp is 10 degrees F than it actually reads.  This wire basically adds a little advance to the timing as does the colder inbound air from the intake kit.

 

I haven't towed with the kit on yet.  The towing is only recreational with the travel trailer and camping season just started here in Texas with the temps now down to reasonable.

 

Adding up all the mods I've done I would guess I'm at about 275 hp at the flywheel, up about 40 from stock.  It takes a lot less throttle pressure to go over smaller hills and big overpasses now and very little throttle pressure to cruise.

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Mike says;

 

"I have a wire extension on the inbound air temp sensor that tells the ECM that the temp is 10 degrees F than it actually reads.  This wire basically adds a little advance to the timing as does the colder inbound air from the intake kit."

 

Question;

 

It reports the temp is warmer than actual?

The timing is advanced due to the ECU map for AIT?

 

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Bad typing.  It reports the temp as 10 degrees lower than actual.

 

Mike says;

"I have a wire extension on the inbound air temp sensor that tells the ECM that the temp is 10 degrees F than it actually reads.  This wire basically adds a little advance to the timing as does the colder inbound air from the intake kit."

 

Question;

It reports the temp is warmer than actual?

The timing is advanced due to the ECU map for AIT?

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