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  #1  
Old 05-19-2011, 10:43 AM
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WK2 Performance

In a recent road test by the largest and most reputable motor magazine in South Africa, they tested the acceleration of the new WK2 with offroad option, which was slower than a WJ 4.7 and an 05 Hemi, which they also tested previously. They commented that the new Hemi motor did not impress them at all!

Is the new WK2 slower off the mark to 60mph than the above mentioned two models? Is there a difference in engine tune between the standard Hemi and the one fitted with the offroad package?

Thanking you in anticipation
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Old 05-19-2011, 11:06 AM
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Re: WK2 Performance

I have not driven an older Grand Cherokee but my WK2 with the Hemi feels like it is holding itself back on a hard sprint. It is almost like a slipping somewhere. Someone on here said it was some form of torque management, which sucks if it is that. I don't need a computer telling me how much power I need, just give it all to me.

I can't wait for a tuner to come out and get all of this big brother BS off of it.
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Old 05-19-2011, 11:24 AM
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Re: WK2 Performance

Yeah, I'm thinking the ESC and whatever computer torque management is really killing the get up and go of the new WK2.
I also think that the gearing of the WK2 is more for highway fuel economy so it lacks in acceleration... sad

I think someone started a thread around here asking about doing some gear changes.
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Old 05-19-2011, 11:35 AM
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Re: WK2 Performance

"...slower than a WJ 4.7 and an 05 Hemi..."

I would gander that neither the WJ 4.7 & 05 Hemi weigh in at a portly 5,200 lbs.
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Old 05-19-2011, 02:17 PM
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Re: WK2 Performance

Agreed the weight is a big factor, I would venture to say that the 2011 greatly outweighs the 2005.

I have the V6 and it to has the Holding Back feeling. The motor is spinning up but nothing significant happens until the Tach hits at least 4 grand. I originally thougth it was the fact that the huge 5200lb off the line enertia had to be overcome, but this thread and recent experience makes me feel different.

A quick stab on the gas or a halfway stab of the gas pedal never puts me back in the seat or gives me the acceleration feeling I want and no it is not a lag from the TB. The motor is responding but nothing is really happening. It is truly underwhelming.

If I had to put it into words I would say the motor seems lazy, especially in the low and midrange. You have to floor it to get it to launch and even then it takes a while for the rpm's to build to get decent acceleration.

My Explorer was never like this. That 4.0 Sohc was always ready to give 100% of its potential. Same with my V6 Camry.

Evan at 5200lb with 390lb ft of Torque- which is a lot of torque, the hemi should scream. I think the gearing is 3.42 which is a good acceleration gear, not the best but not a dog either. Shelby puts 3.55's in his Mustang Cobra's
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Old 05-19-2011, 02:38 PM
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Re: WK2 Performance

Quote:
Originally Posted by Lazzman View Post
Agreed the weight is a big factor, I would venture to say that the 2011 greatly outweighs the 2005.

I have the V6 and it to has the Holding Back feeling. The motor is spinning up but nothing significant happens until the Tach hits at least 4 grand. I originally thougth it was the fact that the huge 5200lb off the line enertia had to be overcome, but this thread and recent experience makes me feel different.

A quick stab on the gas or a halfway stab of the gas pedal never puts me back in the seat or gives me the acceleration feeling I want and no it is not a lag from the TB. The motor is responding but nothing is really happening. It is truly underwhelming.

If I had to put it into words I would say the motor seems lazy, especially in the low and midrange. You have to floor it to get it to launch and even then it takes a while for the rpm's to build to get decent acceleration.

My Explorer was never like this. That 4.0 Sohc was always ready to give 100% of its potential. Same with my V6 Camry.

Evan at 5200lb with 390lb ft of Torque- which is a lot of torque, the hemi should scream. I think the gearing is 3.42 which is a good acceleration gear, not the best but not a dog either. Shelby puts 3.55's in his Mustang Cobra's
The v6's I drove had the sluggish feeling but it is different than the Hemi. The v6 is sluggish because it doesn't have the power, the Hemi is sluggish because the computer is holding it back.
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Old 05-19-2011, 03:15 PM
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Re: WK2 Performance

I think it's transmission programming, ESC, computer BS, and gearing.
I believe both engines rock pretty hard, but are limited by the systems....
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Old 05-19-2011, 06:55 PM
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Re: WK2 Performance

does it make a difference if you press the Tow/Haul Button?
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Old 05-19-2011, 07:21 PM
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Re: WK2 Performance

Since having the TSBs applied, my V6 does not feel sluggish. It's downright peppy, but that 5,200 pounds is a heavy load to haul around. I can't speak for the Hemi.
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Old 05-20-2011, 11:39 AM
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Re: WK2 Performance

I agree the V6 can bring it on at times, like a full on stomp coming onto the highway- it will shoot you up to 100mph pretty quick.

I don't ever get this full revving feeling at low speeds or from a dead stop.

I am willing to bet my first child that it is a tuning problem and if Diablo made a tuner for this vehicle the engine would scream.
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Old 05-20-2011, 11:40 AM
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Re: WK2 Performance

My V6 seems tolerable low range but on the highway it is a DOG. If I have a load in the car it is ridiculous! It has to down shift on even the slightest inclines on the highway. Very frustrating. This has gotten worse after my TSB flash. I'm going to report it back to my dealership because I feel the TSB flashes and results are still a work in progress.
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  #12  
Old 05-20-2011, 11:47 AM
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Re: WK2 Performance

Done some calculations shown in the PDF.
Sorry it is in metric killowats per Kilogram.
But it does show the hemi in the wk2 is about 7% up on power to the wh/k by 7% per kilogram.

kw PER kg.pdf
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