2015 Pentastar V6 Towing [SUPERCHARGER SUCCESS!]

[engineering]

I disagree. When you're working a truck, there's no better advantage than mechanical advantage. Who is to say that regearing won't help shift points?

I'd do 4.10s, and let that little Six spin.

I always say regearing my truck is the best thing I ever did for it.

I think the point is that the transmission is controlled by a computer program. When the input parameters are changed by a large amount, the program may not know what to do. The computer is anticipating a certain amount of performance from the engine - and now it is getting a lot more. I need to do some reading on this one.

The gearing may change the engine load at various points, but in the end, gears do not create power - they only change how the power is applied. I was hoping that the load shift would convince the transmission to shift a bit better. The transmission control module is still thinking that the engine can only muster 270ft/lbs torque at like 4500rpm so it is perhaps shooting for the engine to be in that range. The problem is that it now makes that power at 2500rpm.

 

[RLJ10X]

When I regeared to 4.10s, there was none of that. It drove just like always, only a lot snappier.

But I see your point. I have the simple old 545RFE.

 

[dearchristopher]

nice to see!! so happy that it all worked out. excellent news. can’t wait for video


Sent from my iPhone using Tapatalk

 

[engineering]

Another 7,000 supercharged miles completed......all good. Fully loaded and going up very steep hills as well as some off-road. 110F in Phoenix to about 20F. Highest elevation about 8,000ft

The biggest test, however, was today - passed the California SMOG test which I was quite apprehensive about. Fortunately, no problems.

So far, the vast majority of the use has been towing. The modest amount of unloaded regular driving shows that the mileage is still the same 22-23mpg that you get with the V6 - but you have 400hp under your right foot when you want. I will say that this truck is horribly equipped for spirited driving that uses the full force of the supercharger. It gets pretty squirly, but surprises the heck out of other fast-ish cars. The exhaust is OEM, so very quiet. The transmission shifting gripes I spoke about earlier have largely been resolved by just calibrating the tire size. Just before the supercharger install, I swapped the 20" wheels with low profile tires for 17" with high-profile tires. the overall diameter was about 1" less than the OEM wheels so the speedometer was off. The wheel speed is how the computer maps shifts so when I got is calibrated properly, it shifts better.

One of my biggest concerns was reliability and drivability. It still starts just like a normal stock truck in a very wide range of temps with no trouble while running open loop. The general driving experience is benign, but with the supercharger whine being unmistakable when the hills come in. When it starts making power, everyone in the truck knows what is under the hood. It is not bad, just noticeable.

Gas mileage is about the same, but only if I drive the same speed as before the supercharger. The practical reality is that I am able to keep my speed up even on the hills, so the overall mileage goes down a little, not enough for me to care. My wife is really happy we get to use this particular truck as out adventure vehicle even though it was never designed for it. I would guess that the towing performance is similar to the V8 Hemi's although it is very difficult to compare. When this truck completes its adventure duty - my next tow vehicle will certainly be a diesel 2500 or 3500 even if we still have a small trailer. For those that followed this thread, you will know that I like truck to be miles from its max capacity. The official capacity numbers from the manufacturer are ridiculous - they do not account for hills, altitude, or temperature. They also don't account for driver experience.

A supercharged V6 does work for towing - but not exactly the low-cost option.

 

[RLJ10X]

That was an awesome report, Eng.

Are lower gears still an option?





I have a ProCharged V6 Mustang. I love it.

 

[Robeffy]

Well done! I wondered how this would turn out, glad I had notifications turned on.
Most interesting.

 

[NOV87]

Impressive. Good job!

 

[engineering]

That was an awesome report, Eng.

Are lower gears still an option?

Yes - gears are still an option and likely to happen as a final effort to wrap this up. For the moment, I am on modification lock-down because a big 2 week trip is coming up - around 2,000 miles. In general, I don't want to make any major changes just before a trip.
I would like to get the gears done before we go to Glacier NP.

 

[Doug Ram]

I wonder.......
You spent $7,000 to turbocharge the stock 3.6L V-6 gas engine. I'd expect that Ram could have done it for less, maybe $5,000, in mass production? But they didn't, and I wonder why. Could it have anything to do with availability of the 3.0L EcoDiesel -- which has plenty of torque and power, gets 27-28 MPG and costs "only" $5,000. You say that the I gas mileage was not really affected by the your mods, lower than the ED... I wonder if that was part of the reason they didn't offer a turbo version of the 3.6 gas engine, like Ford has.

 

[engineering]

I wonder.......
You spent $7,000 to turbocharge the stock 3.6L V-6 gas engine. I'd expect that Ram could have done it for less, maybe $5,000, in mass production? But they didn't, and I wonder why. Could it have anything to do with availability of the 3.0L EcoDiesel -- which has plenty of torque and power, gets 27-28 MPG and costs "only" $5,000. You say that the I gas mileage was not really affected by the your mods, lower than the ED... I wonder if that was part of the reason they didn't offer a turbo version of the 3.6 gas engine, like Ford has.

Decisions like that are remarkably complex in a company like RAM/Dodge/Chrysler/Fiat.

The Eco-Diesel is DEFINITELY the best solution for towing. Good bang for the buck. A supercharged V6 pentastar would be a specialized high-acceleration enthusiast vehicle for people that think pickups are sports cars. That audience is really small and loves to modify the vehicle for more power, race it, break it, put back in stock condition, and then claim warranty repairs. Not a good business. Ford has gone bonkers with the Raptors and the price reflects that - they are crazy expensive. I would guess that a significant portion of the cost is the expectation of warranty repairs after owners drag race them all-day, every day.

My supercharged 3.6L will a lot less life than what you get with the eco-diesel (by my estimates).

 

[GsRAM]

Thanks for the follow up Eng. Good stuff. Glad to hear all is well so far

 

[gfh77665]

I understood your reasoning from the inception of this adventure. Personally though, I could never have had the patience you did. Best wishes to you and her. I hope many enjoyable miles/years are ahead for you in your turbo RAM.

 

[El Huapo]

WOW! What a trip! Thank you "engineering" for sharing the journey with us. I will not be doing that mod on my little truck but I am glad it all worked out well for you in the end. I salute your patience and perseverance.

 

[Bearcatrp]

Haven’t read the entire thread so maybe missed it but Cummings offers a 4 cylinder diesel crate engine. At least they used to a couple years ago. Not sure it would pass California emissions though. Could be another headache too. Glad your way worked out. Keep us posted on longevity towing. As others have posted, changing the rear end could reduce stress on your setup.

 

[ramffml]

Haven’t read the entire thread so maybe missed it but Cummings offers a 4 cylinder diesel crate engine. At least they used to a couple years ago. Not sure it would pass California emissions though. Could be another headache too. Glad your way worked out. Keep us posted on longevity towing. As others have posted, changing the rear end could reduce stress on your setup.

It's "Cummins". ******g is something you do with your wife.

 

[engineering]

Well......I found the limits of this setup.
>100F outside temperature + >6,000ft altitude + Max payload/towing + looooong steep uphill driving = too much heat.

This is predictable behavior to be clear, but I was actually rather surprised how well the bone stock cooling system kept up. Nevertheless.....I need more cooling since so many of my planned trips will see similar harsh conditions. I quickly learned how to manage the power to keep the temps in check - but that always means slowing down a lot. I installed the supercharger to keep my speed up, lol. I would like to use this truck in the worst of conditions without any practical restrictions to worry about.

With that said, I am considering a cooling system upgrade and maybe venting the the hood. It really does not need a lot, just a small increase in cooling performance should be enough. The Pentastar uses a coolant to oil cooling system, so I think that simply increasing radiator performance should keep the oil at a manageable temp. So far, I have not found any specific products.

If anyone has knowledge of any pre-engineered cooling system upgrade kits for Pentastar 3.6L RAMs - I am all ears. If not, I will design my own system Maybe the radiator from the Hemi or eco-Diesel will have more capacity?


As a side note unrelated to the supercharger - I can hear the dreaded ticking from the right valve cover. Not good, but not unexpected either from this year V6. Guessing it is a bad lifter. I have will steth-o-scope it n the next few days to get a better idea. Right now the ticking is subtle, but I want to fix it before the cam is damaged.

 

[engineering]

Another update:

I could not find any Pentastar V6 cooling upgrades off the shelf so I have been putting my own together. The original idea was to add additional oil cooling but after some investigation I decided it was too complex based on how the OEM system is designed.

The latest plan is to add an aux radiator in the huge space available in the engine bay. I will make some custom control electronics to deal with the additional electric fans based on CAN data. The radiator I chose is roughly 60% - 70% of the OEM radiator capacity. That should be enough to keep the system cool in the worst conditions I can think of and still have some headroom left over.

The cooling limitation is the only real problem so far and it is rather minor - only becoming a problem in pretty harsh driving situations. Even after the additional radiator is added - it will still look 100% stock and still be rather quiet.