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283hp versus 305hp?


jeffhoward001

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Hello All -

Looking at the Wiki for the Pentastar:

http://en.wikipedia.org/wiki/Chrysler_Pentastar_engine#US_market_versions

the 3.6L in the journey is rated @ 283hp (which is respectable) but the exact same engine in the Challenger is rated at 305hp. That's a fairly large difference that I have to assume only comes from a different fuel and/or VVT mapping in the ECU. A few questions on this:

1) I'm assuming it's possible to use the same sport tunes on the Journey ECU as the Challenger ECU, correct? I can't imagine Dodge using a different ECU for the same engine (however I CAN see them using different ECU programming to increase "driveablility")

2) The Pentastar has variable valve timing (VVT). If this works similar to german cars, this is HUGE in doing custom tunes for E85 flex-fuel. You can get 10-20% more horsepower in E85 if you have the ability to change the valve and ignition timing to take advantage of the higher compression ratios available on E85. While that may not sound like much, if you were able to tune the Challenger ECU program for E85, the potential exists to push 350hp by simply changing your ECU program and filling up on a tank of E85. That's a pretty attractive offer to get V8 performance out of commodity 3.6L engine.

I'm sure you guys will redirect me to the Challenger forums (that was my next stop) :) But just curious if anyone in the Journey camp had attempted custom tunes. I have years of experience with custom tunes on high horsepower V6's, so no need to turn this into "...it's going to destroy your car!!..." thread :) I'm well aware of the risks of custom tuning, and the fact that there are a few simple things you can do to mitigate the majority of those risks.

Thanks All,

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It's been discussed before. At present I am not aware of any tuning available for the Journey 3.6L, due in large part to the lack of interest among the typical Journey buyer (translating into lack of profit potential for companies like Diablo). Diablo has cracked the PCM for the Avenger 3.6L to allow for tuning, so there is certainly possibility of cracking the Journey PCM in much the same way, however that lack of a profitable market stands in the way.

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Does it really matter? I have raced a challenger just for fun. It must have been a V6 because I managed to beat it with two bikes on the roof, 2 passengers, and a third row full of mountain biking gear. Terminal velocity over 100mph. Evidently, there is no real difference between 283 and 305. The only difference is the cocktail party banter? I used to think a tune would be simply bad ass, but now I realize the real strength of the DJ is utility. With a little vinegar mixed in, of course. If you want a challenger, get one. Our DJs won't ever be a challenger. DJs are cooler,IMHO.

Peace.

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Does it really matter? I have raced a challenger just for fun. It must have been a V6 because I managed to beat it with two bikes on the roof, 2 passengers, and a third row full of mountain biking gear. Terminal velocity over 100mph. Evidently, there is no real difference between 283 and 305. The only difference is the cocktail party banter? I used to think a tune would be simply bad ass, but now I realize the real strength of the DJ is utility. With a little vinegar mixed in, of course. If you want a challenger, get one. Our DJs won't ever be a challenger. DJs are cooler,IMHO.

Peace.

The challenger is also a lot heavier than a DJ... That difference in weight could easily kill that 22hp. I have used a tune on several vehicles and there is absolutely a big difference using one, but as you stated the DJ's usefulness is in it's utility and that is why I bought it. Hauls kids and hockey/camping gear quite well.

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Does it really matter? I have raced a challenger just for fun. It must have been a V6 because I managed to beat it with two bikes on the roof, 2 passengers, and a third row full of mountain biking gear. Terminal velocity over 100mph. Evidently, there is no real difference between 283 and 305. The only difference is the cocktail party banter? I used to think a tune would be simply bad ass, but now I realize the real strength of the DJ is utility. With a little vinegar mixed in, of course. If you want a challenger, get one. Our DJs won't ever be a challenger. DJs are cooler,IMHO.

Peace.

Well stated sir. You will never feel a seat of the pants difference between 283 and 305.

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All fair answers :) I've always been a tuner, so it's something I really enjoy talking about, testing, tweaking, etc. So one thing to consider (especially with variable valve-timing engines) is that while the top-end power may not change much with a tune, you can move the torque curve around. I don't know much (yet) about the Mopar 3.6L VVT, but if it's similar to german cars, a big change in a "performance" mode is moving the torque curve back a bit (lower in the RPM range).

We bought a 2012 AWD Journey Crew trim last Friday, and so far we're really happy with it (with no tuning!). I think this is going to be a great family car for us. Tough to let go of my Audi, it pushes 320hp and 300 lb/ft of torque, but it's time to move on... We have too many kids and too many grandparents to shuttle around!

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The HP difference comes mostly from the air intake on the Challenger. The engine orientation in the Challenger is longitudinal rather than transverse and allows for a less restrictive intake system. Some minor PCM revisions were made to take advantage of it and the result is the higher HP number. Like RTMan and Jkeaton have stated, you'd be hard pressed to feel the difference. But the Challenger competes directly with Camaro and Mustang, both of which offer V6 engines of similar power. So, from a marketing standpoint, the Challenger has to come to the party with the same numbers. That's really the only reason for the difference.

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+1 on the transmission shifting... We took our new Journey to the coast last weekend, and while it drives really smooth, I would best describe the shifting as "sloppy". It doesn't give me the feeling like anything is wrong or going to break, but just not nearly as "crisp" as I expected. It's strange because the transmission on my '77 Dodge D200 actually feels best to me out of all the vehicles I've owned in the past 20 years. It's shift quickly and crisp. My 2002 Audi had a five-speed auto tiptronic transmission that was know for slow shifts, but not as sloppy as the Journey,

What's your take on Mopar's positioning with this transmission? They use it in a ton of rigs now, so they're clearly invested in the platform. If they could clean up the shifting with a TCU update, I'm assuming they would. Just seems strange to me given how long this transmissions been out. You'd think all the kinks would be worked out.

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Took ours to the dealer for a "checkup" after we bought it. They performed a couple of updates to some modules, but the shifting is still not as I'd like. I just shift manually. It clunks, shudders, upshifts too soon, etc. But, I just figure it's part of the package, so I learn to workk around it. I just keep driving it until I can duplicate the issues before I take it in again.

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+

What's your take on Mopar's positioning with this transmission? They use it in a ton of rigs now, so they're clearly invested in the platform. If they could clean up the shifting with a TCU update, I'm assuming they would. Just seems strange to me given how long this transmissions been out. You'd think all the kinks would be worked out.

There have been software updates to improve shift quality. It's possible that the PCM software is not at the latest release. It can be easily updated if that is the case but it requires a dealer visit. You recently purchased this car, yes? Did it come from a Chrysler Group Dealer? They *should* update it for you or at least check to see if there are updates at no charge to you if so. Even still, though, the shifting is not as smooth and precise as I'd like it to be, either. What's unusual is that, as you pointed out, this unit is used in so many Chrysler applications and it does not shift the same in any two platforms. The 62TE-equipped minivan, for instance, has much better shift quality overall than the Journey - unless it is placed in its "econ" mode. In that mode, it shifts very abruptly and early to achieve maximum fuel economy at the expense of refined driveability. I feel that if my Journey's transmission shift points were just a couple hundred RPM higher, the shift quality would be significantly improved. Like JKeaton states, using Autostick brings much better results. One thing I have to say is that it has improved noticeably now with over 25,000 miles on the clock. I still much prefer the shift quality of the 42LE four speed in my 300M. At 294,000 miles, it still shifts perfectly smooth in either Drive or Autostick.

One other thing to consider is the adaptives. Your car was driven by a different person for the first part of it's life. The transmission has certain adaptive capability, of which the process may still be ongoing as it transitions to your driving style. If your dealer does, in fact update your car's software, then those adaptive values will be reset in addition to receiving the updates.

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  • 2 weeks later...

The HP difference comes mostly from the air intake on the Challenger. The engine orientation in the Challenger is longitudinal rather than transverse and allows for a less restrictive intake system. Some minor PCM revisions were made to take advantage of it and the result is the higher HP number. Like RTMan and Jkeaton have stated, you'd be hard pressed to feel the difference. But the Challenger competes directly with Camaro and Mustang, both of which offer V6 engines of similar power. So, from a marketing standpoint, the Challenger has to come to the party with the same numbers. That's really the only reason for the difference.

The exhaust on the Journey is also more restrictive because the engine sits sideways when compared to the Challenger, as stated. Air in + exhaust out = higher HP!

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