Lund tune bugging me

[WildHorse]

Im going to reinstall the imrc

No need to.

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[K4fxd]

Im going to reinstall the imrc, and have properly functioning tivct for running boost. Basically look for a better thought out and stock style tune.

Turning the IMRC on, or actually the CMCV's will improve gas mileage and won't hurt performance one bit.

 

[WildHorse]

Turning the IMRC or actually the CMCV's will improve gas mileage

Does it ? Maybe, maybe not. I have CMCV & CAT delete & can tell you I get better milage than what Ford, & the EPA cert says. Though could be a combo of factors however.

 

[engineermike]

Cmcv/imrc definitely improves fuel economy.

 

[WildHorse]

Cmcv/imrc definitely improves fuel economy.

by what ? 5mpg ? .5 mpg ?

 

[K4fxd]

by what ? 5mpg ? .5 mpg ?

On my car on the freeway it is about 8, 22 vs 30. In town about 4, 12 vs 16

Obviously this will vary by car and driving style.

 

[WildHorse]

On my car on the freeway it is about 8, 22 vs 30. In town about 4, 12 vs 16

Obviously this will vary by car and driving style.

Yer kidding. When I went from 3.31 gears to 3.73, gen3 intake manifold w/ CMCV delete, gen3 airbox, cat delete, i saw a net gain of .5-.75 mpg. Assuming this is from the CAT delete.

 

[K4fxd]

I'm on 3.55's now and getting 30 when I visit my Son in Indiana. It is mostly flat freeway. In town I get 15.7 But I am easy on the gas and coast whenever possible to stops.

This is with Cats, GT350 manifold and CMCV's operational. 27 inch diameter tires.

When I run my CMCV delete tune gas mileage goes to heck. The only reason I vetted a delete tune is in case I tune a PD blower.

 

[engineermike]

by what ? 5mpg ? .5 mpg ?

You can snoop around in the factory calibration and figure this out. I spot checked a few points in a gen3 and gen4. The difference is 2 to 13%, depending on load and speed. More than 5W20 gets you, for sure. The interesting thing I hadn't realized until now is that with IMRC open, as I determined though some testing, does show improved fuel economy if the cams aren't retarded as far as stock during cruise. So you can get some of the 2 to 13% back with an altered cam schedule, just not all of it.

I also just realized that I really like the mapped point layout in the gen4. Someone at Ford had a really smart idea to set mapped points 0-9 at the same locations as 10-19, just one set with IMRC open and one set closed. So MP3 and MP13 are the same cam timing, but one is IMRC closed and one open, and so on.

 

[K4fxd]

The interesting thing I hadn't realized until now is that with IMRC open, as I determined though some testing, does show improved fuel economy if the cams aren't retarded as far as stock during cruise.

I'll have to look into this. 32 or 33 would be nice.

 

[shogun32]

I also just realized that I really like the mapped point layout in the gen4. Someone at Ford had a really smart idea to set mapped points 0-9 at the same locations as 10-19

recent hire from GM powertrain?

 

[Pistol_91]

I get better fuel economy with my IMRC delete boosted tune compared to my N/A Lund tune. 4-5 mpg increase

 

[WildHorse]

I get better fuel economy with my IMRC delete boosted tune compared to my N/A Lund tune. 4-5 mpg increase

Really ? That's pretty darn good !

 

[Forestlump]

You can snoop around in the factory calibration and figure this out. I spot checked a few points in a gen3 and gen4. The difference is 2 to 13%, depending on load and speed. More than 5W20 gets you, for sure. The interesting thing I hadn't realized until now is that with IMRC open, as I determined though some testing, does show improved fuel economy if the cams aren't retarded as far as stock during cruise. So you can get some of the 2 to 13% back with an altered cam schedule, just not all of it.

I also just realized that I really like the mapped point layout in the gen4. Someone at Ford had a really smart idea to set mapped points 0-9 at the same locations as 10-19, just one set with IMRC open and one set closed. So MP3 and MP13 are the same cam timing, but one is IMRC closed and one open, and so on.

Yes, what I've found out is the factory tune retards inlet cam way more than optimal at low throttle, the throttle then has to open slightly more. It does this to reduce pumping losses in cruise (engine not sucking so hard against a closed throttle). Then by closing off one intake valve you drastically increase swirl going in to the cylinder and fuel atomization = cleaner burn, mpg increase.

The more I learn about it, the more I'm leaning towards having a go at the tune myself.
I could go back to 3.8 pulley so I didn't break anything. But I'd like to have a play around with all this and see what I can find.

Mike, the data from the roush blow through logic, could this be extrapolated per psi of boost and used on a centrif setup?

 

[K4fxd]

I get better fuel economy with my IMRC delete boosted tune compared to my N/A Lund tune. 4-5 mpg increase

Not surprising due to the way Lund runs the cams at part throttle.

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