2015 Seneca power/torque upgrades???

[Dougk30]

I just recently purchased a 2015 Seneca, on our first trip we were driving threw WV on 77 and seemed to be a little low on power, at one point I even went all the way down to 45 mph. We were towing a Tahoe but I was hoping that the 6.7 liter Cummins with the Allison tranny would be able to over come the hills. From messing around with diesel pickup truck I know that this motor is capable of much more and I was wondering if any one here has done any tuning to their motorhome to get more power out of the engine. With the engine being in a much heavier application it makes me a little nervous to start doing a bunch of engine mods. I would hate to be stuck on the side of the road with a blown head stud or something.
Thought?? Coments??

[Mr.Oz]

Driving through the smokies last summer I was down to 50mph a couple times but only for a few minutes. I have almost 10,000 miles on ours now and it seems a bit peppier. What altitude do you mostly run at? A bit more just to bring it back to sea level power will not hurt anything. At my dyno business the people that were conservative did not hurt anything. The customers that wanted huge power increases soon found the weak links.

[krsmitty]

There are several "tuners" available for the 6.7 (truck version). I am not sure how those would work in a MH version or if there are versions for MH's. I use EFI Live myself. I could ask my tuner guy if he knows of anything...if you are interested?

[Dougk30]

I have an H and S on my 2011 Ram and I only keep it on the plus 40 setting because people say if I go higher I would have to replace head studs. If I could replace head studs on my rv and safely be able to go to the plus 80 or plus 120 I would do that. The tuner I have only tells you the plus on the horsepower but I know that it is probably double that on the torque. It is amazing what they are able to do with these diesel engines now a days. Another concern that I have is the transmission, I am sure the Allison in my rv is much heavier than the 68re in my Ram but it still worries me to put the extra through a tranny that is not designed for the HP and torque. I have a local diesel shop that I think I am going to talk to about either an H and S tuner or going with EFI live for a custom tune, but then I wonder if I would have to change the exhaust as well. What a mess. Probably should just deal with it.

[WaltW]

A Tahoe is a pretty heavy vehicle. Wonder how it would perform with a mere 4,500 lb Jeep.

[krsmitty]

Originally Posted by Dougk30

I have an H and S on my 2011 Ram and I only keep it on the plus 40 setting because people say if I go higher I would have to replace head studs. If I could replace head studs on my rv and safely be able to go to the plus 80 or plus 120 I would do that. The tuner I have only tells you the plus on the horsepower but I know that it is probably double that on the torque. It is amazing what they are able to do with these diesel engines now a days. Another concern that I have is the transmission, I am sure the Allison in my rv is much heavier than the 68re in my Ram but it still worries me to put the extra through a tranny that is not designed for the HP and torque. I have a local diesel shop that I think I am going to talk to about either an H and S tuner or going with EFI live for a custom tune, but then I wonder if I would have to change the exhaust as well. What a mess. Probably should just deal with it.

I originally had a Smarty Jr. on my 07 5.9. I was always told it was safe to run at the +100 hp as long as I did not get out and constantly race, do burnouts, etc. I normally kept it at the +70 (towing) tune for several years with no ill effects.

I have a S&B CAI and a MBRP muffler. Exhaust is still the stock 4". Was told did not need to go bigger unless going for 500-600hp.

Went to EFI Live and have 5 different tunes...usually tow and street using a single injection +75 tune.

[fam cruiser]

I Dont own a Seneca , But look into the transmission specs, I believe the allison that is used in the Seneca is only rated for

http://www.allisontransmission.com/d...k.pdf?sfvrsn=2

Not that its my place to say but I think waiting for the warranty to be over might be worth while rather than explaining to Allison the transmission was wrecked due to a tuner.

[Dougk30]

Originally Posted by fam cruiser

I Dont own a Seneca , But look into the transmission specs, I believe the allison that is used in the Seneca is only rated for

http://www.allisontransmission.com/d...k.pdf?sfvrsn=2

Not that its my place to say but I think waiting for the warranty to be over might be worth while rather than explaining to Allison the transmission was wrecked due to a tuner.

Wow I think I agree, looks like the put those inputs just to match up with that engine in its stock form. They are certainly not giving you any wiggle room. Thanks for the link that is nice to know.

[LSA376]

I to have been researching this for the past year to no avail. None of the tuners for the ISB6.7 Dodge work for the 6.7 in the Freightliner, unfortunately. I asked all the vendors at last years SEMA show in Vegas again to no avail. There are two companies, ECM Performance in Florida and J Ball Electronics in Canada that can tune the ECM if you remove and ship to them, very expensive.


I did speak with Cummins directly, the 6.7 in our Seneca's can be bumped from the 340HP/660lbft to 350/850 for a few hundred dollars with a quick software tune however; it will void the two year warranty. One more year to go for me... Then tune time...

[slideouts&sails]

what was the "quick software tune" and how or what do you need to do? Who did you talk to? Would love to know more about your information. Thanks