2008 Grand Cheorkee SRT8 with 6.1L MDS engine:D

http://www.cherokeesrt8.com/forums/attachment.php?attachmentid=1857&stc=1&d=1183990079

Ummmm....more info please.

I would really like to integrate MDS on to my jeep....I wonder if it will be possible?

Well, I did some looking around and found this on wkjeeps.com:

2008 Grand Cherokee SRT8 (WKJeeps.com exclusive advance info)


Production starts July/August 2007

6.1L Hemi MDS engine 420hp (standard)

W5A580 5-speed Transmission (standard)

Redesigned instrument panel, seats, steering wheel and door trim panels

Exterior - Redesigned headlamps, grille, fascia

EVIC controls moved to steering wheel

Power outlet, 115 volt (2-prong)

Radio model RER, MyGIG Touch-screen media System with navigation
(AM/FM/MP3/DVD/HDD)

Radio model REN, MyGIG Touch-screen media System without navigation
(AM/FM/MP3/DVD/HDD)

Eight-inch rear DVD video screen

Seats, heated second row

Sirius Satellite Streaming Video (optional, requires rear DVD system)

Tilt / Telescoping steering wheel (manual)

High Intensity Discharge (HID) Headlamps with auto leveling

New interior color: Dark Slate Gray (replaces 2006-2007 Medium Slate Gray)

Exterior colors: Black, Bright Silver Metallic, Red Rock Crystal and Steel Blue
Metallic

Will it be possible to put those headlights on the previous models?

Will it be possible to put those headlights on the previous models?

Most likely not. If you look at the bottom, you will see that the bumper has been reshaped, as have the head lights themselves (much like RonConcepts "headlight covers").

Can you tell me where you found that the engine would have MDS? I know there has been talk, but I haven't seen anyone mention it with any certainty. On wkjeeps it does not list MDS, but we could be looking at different pages.

Most likely not. If you look at the bottom, you will see that the bumper has been reshaped, as have the head lights themselves (much like RonConcepts "headlight covers").

you would just have to buy the bumper also or mod yours. the headlights should be an easy swap to all who would like. afraid to see the price though

No external antenna I see......

No external antenna I see......

on the srt site there isn't one on the 07's either.. just looks better in the pics

Can you tell me where you found that the engine would have MDS? I know there has been talk, but I haven't seen anyone mention it with any certainty. On wkjeeps it does not list MDS, but we could be looking at different pages.

Here is the link to what I found:

http://www.wkjeeps.com/future_jeeps.htm#08SRT8

I had that same page up from last week and never did a refresh, it shows now. Thanks.

on the srt site there isn't one on the 07's either.. just looks better in the pics
Yep, our fixed mast antenna is alive and well and will return for 2008...

2008 Grand Cherokee SRT8 (WKJeeps.com exclusive advance info)


Production starts July/August 2007
6.1L Hemi MDS engine 420hp (standard)
W5A580 5-speed Transmission (standard)
Redesigned instrument panel, seats, steering wheel and door trim panels
Exterior - Redesigned headlamps, grille, fascia
EVIC controls moved to steering wheel
Power outlet, 115 volt (2-prong)
Radio model RER, MyGIG Touch-screen media System with navigation (AM/FM/MP3/DVD/HDD)
Radio model REN, MyGIG Touch-screen media System without navigation (AM/FM/MP3/DVD/HDD)
Eight-inch rear DVD video screen
Seats, heated second row
Sirius Satellite Streaming Video (optional, requires rear DVD system)
Tilt / Telescoping steering wheel (manual)
High Intensity Discharge (HID) Headlamps with auto leveling
New interior color: Dark Slate Gray (replaces 2006-2007 Medium Slate Gray)
Exterior colors: Black, Bright Silver Metallic, Red Rock Crystal and Steel Blue Metallic
========================

2009 Grand Cherokee (WKJeeps.com exclusive advance info)


Production starts July 2008
New Bluetec 50-state clean diesel engine
New 2nd generation 5.7L MDS Hemi engine w/increased horsepower and fuel economy
New 500-hp (est.) 6.4L-Hemi engine for the SRT8
New ignition system
Adaptive cruise control?
Cooled front seats?

dosnt the MDS hurt performance some? I thought all of the 5.7 guys changed it to regular and got like i dont know 20hp or something? Correct me if im wrong?

Thanks

When are we gonna see some real 08 pic lol!!

I had a 06 Magnum 5.7 and it had the MDS and I hated it. Most times I would just run around in auto stick. I'm now rethinking ordering the 08 but I love the new options. Is there any way of defeating the MDS? turning it off? I spoke with Don of Championjeep and he said he would have pricing on the 08 this coming week. So I need to make a decision this coming week.

Does anyone have any rundown on how the MDS works? Is this purely electronic? Does this work by alternating sets of cylinders and and keeping open the exhaust valves on the "off" cylinders open while it's on? I haven't researched exactly what it is so that's a guess. If that's the case there would have to be a physical difference in the engine... kinda just the opposite of the valve train used on a big rig during engine breaking (except their exhaust valves are more or less closed during coasting when it's engaged).

Mike

Does anyone have any rundown on how the MDS works? Is this purely electronic? Does this work by alternating sets of cylinders and and keeping open the exhaust valves on the "off" cylinders open while it's on? I haven't researched exactly what it is so that's a guess. If that's the case there would have to be a physical difference in the engine... kinda just the opposite of the valve train used on a big rig during engine breaking (except their exhaust valves are more or less closed during coasting when it's engaged).

Mike

To quote my own reply... I guess I was kinda right... just arse backwards. :o

"Don't think that the new HEMI is lacking in contemporary technology. It's the first variable-displacement engine to make it to production. The ``Multi-Displacement System'' (MDS) is standard on all HEMIs in 2005 Chrysler 300Cs, Dodge Magnums, and Jeep Grand Cherokees. Put most simply, the MDS works by deactivating the lifters in four cylinders, keeping their valves closed. No fuel is injected at that time, increasing fuel economy, and no air is pumped, decreasing energy and therefore power that would be lost pumping air. Use of electronic throttle control, electronic fuel injection, sophisticated electronically-controlled hydraulic lifters, and control algorithms makes it all work quickly and seamlessly.

It takes only 40 milliseconds (0.040 seconds) to switch between four-cylinder and eight-cylinder modes, and the process can't be felt. Serendipitously, during the week in which I had a Chrysler 300C as a test car, I attended a demonstration of the MDS system. I drove a 300C in which Chrysler engineers had attached instrumentation on a short test loop that included city streets and freeway driving, with full-throttle acceleration needed for freeway merging. I never noticed any change in the engine's response or power - there was never any lack of power - and was surprised when I saw the graph of operation after the data was downloaded to a laptop. The HEMI switched between modes constantly, not just occasionally. Chrysler estimates at ten to twenty percent increase in fuel economy, and indeed, I found the 300C to be most efficient for a car of its size and power."

Here's some more propaganda explaining the process:

"

2The 2007 Dodge Magnum Multi-Displacement System (MDS) allows the 5.7-litre HEMI® V8 engine to combine the power of a V8 with the fuel efficiency of a larger V6 engine.

This ingenious system seamlessly deactivates half of the engine´s cylinders while cruising and operates all eight cylinders while idling, accelerating and responding to heavy load conditions.

The final result is full power when you need it and up to 20% more fuel economy when cruising.

MDS: How It Works
Multi-Displacement System (MDS) deactivates four cylinders when the remaining four are enough to meet power requirements. The engine operates on all eight cylinders for:

* Acceleration
* Heavy loads
* Idling to ensure maximum smoothness

The engine operates on four cylinders:

* In city traffic driving
* Steady speed cruising, even at interstate highway speeds
* Low-acceleration
* Shallow grade climbing
* The torque requirement is less than 95 percent of the maximum available from four cylinders

Both four- and eight-cylinder configurations have even firing intervals, providing smooth operation. The MDS system operates between 1000 and 3000 rpm.

Two cylinders on each bank are active when the engine is in four-cylinder mode - every other cylinder in the firing order. Each of the cylinders that are deactivated has unique hydraulic valve lifters that collapse when deactivated to prevent the valves from opening. The pistons of the deactivated cylinders still travel through their normal cycle so there will be no wear imbalances between the cylinders that deactivate and those that do not.

Deactivation occurs during the compression stroke of each cylinder, after air and fuel enter the cylinder. Ignition then occurs, but the combustion products remain trapped in the cylinder under high pressure, because the valves no longer open. No air enters or leaves. During subsequent piston strokes, this high-pressure gas is repeatedly compressed and expanded like an air spring, but fuel is not injected. The expansion process cancels out most of the energy loss involved in compressing the air, so the net effect is a negligible expenditure of energy in the inactive cylinders while MDS is operational. This is actually more efficient than allowing the valves to operate and flow air in and out of the cylinders. Reactivation occurs in time to allow the compressed gas to exit before resuming the normal intake-compression-power-exhaust cycle. Because there is some loss of pressure with each compression cycle due to leakage past the piston rings, the valves are actuated periodically for a brief time, and then fuel is injected and ignited, restoring full pressure in the cylinders. This is done to keep the cylinders warm and to minimize exhaust emissions when they resume steady operation.

Engine oil pressure is used to activate and deactivate the valves. It is delivered through special oil passages drilled into the cylinder block. Solenoid valves control the flow. When activated, pressurized oil pushes a latching pin on each valve lifter, which then becomes a "lost motion" link. Its base follows the camshaft, but its top remains stationary, held in place against the pushrod by light spring pressure but unable to move because of the much higher force of the valve spring.

Switching between four- and eight-cylinder modes is made smooth by torque compensation algorithms in the NGC (Next Generation Controller) powertrain control module. When a change from eight-cylinder to four-cylinder mode is about to occur, but before it actually takes place, the throttle is opened and the spark retarded to maintain constant torque. At the moment of deactivation the ignition timing is advanced to continue the power output at the same level as before the switch. Upon reactivation of the eight-cylinder mode, the throttle opening is reduced, and then the timing is decreased at cylinder activation. This particular sequence of events is used because there is a slight lag between when the throttle opens and the changed airflow volume is experienced in the cylinders, whereas the ignition timing change takes place instantaneously. The entire process takes 50-80 milliseconds - less than the blink of an eye. "

The EVIC buttons are on the front of the wheel, where the cruise control buttons used to be, both left and right sides.

The cruise control functions are now on a stalk on the right side of the steering wheel.

The remote audio buttons remain in the same place, behind the wheel.

The power pedals button is incorporated into the left stalk assembly.

The horn buttons use floating switches.

I just read on the red site that the first 08s off the line will NOT have the new fascia and will still have the 07. Perty lame and this comes from Milous who most of us know he knows what's up. Not too mention Resume Speed as well of course.

I just read on the red site that the first 08s off the line will NOT have the new fascia and will still have the 07. Perty lame and this comes from Milous who most of us know he knows what's up. Not too mention Resume Speed as well of course.

What???????????????? That really stinks for the people who ordered their 08's and are expecting the new features! I'm glad that I have waited.

Milous, if this is true please let us know when the switch to the new features/design will be in production.

I just read on the red site that the first 08s off the line will NOT have the new fascia and will still have the 07. Perty lame and this comes from Milous who most of us know he knows what's up. Not too mention Resume Speed as well of course.
That's messed up. What about those of us who ordered HIDs I wonder?... I guess if that's true, then the HIDs must fit in the 07 grille.

Im have mixed feelings about the HID projectors but im waiting for the 09 or 10's to come out I need more power from the factory!

I just read on the red site that the first 08s off the line will NOT have the new fascia and will still have the 07. Perty lame and this comes from Milous who most of us know he knows what's up. Not too mention Resume Speed as well of course.
We are going to *try* and verify the information this week. Looking at the 2008 WK parts book, this is what we saw:

FASCIA, Front, [SRT-8], With Bright Insert, Not included, Up to 8/13/2007 005029989AC
FASCIA, Front, [SRT-8], With Bright Insert, Not included, After 8/13/207 05030977AA

P/N 005029989AC is the number for the 2007 fascia, P/N 05030977AA is a totally new number. The "Not included" note for the bright insert simply means that the insert is sold separately.

This is very interesting, it's possible that the parts listing is in error but that seems unlikely since they list the dates. Production starts this week, guess we'll find out for certain once one lands in a dealer lot.

I would really like to integrate MDS on to my jeep....I wonder if it will be possible?

Why would you want MDS? If your really crazy, I bet it would never be initiated. I had it on my 300c and I still got bad gas mileage, But I'm not blaming the system, Just my FOOT!!!!:D

T:cool:

I feel that this is not possible - they have released advertisements for the '08 with the new HIDs and front end in place - plus, for the people that have already ordered them - the dealership would have an obligation to tell you. I visited the dealership this weekend to place an order for an '08 - im officially placing it on friday - and they told me explicitly that the '08's will have the new HIDs, face lifted front end and new dark slate grey interior - placing an order this week should put my delivery around the last week of august into the first couple of weeks in september. Anyway - SOMEONE VERIFY THIS and i will believe it

I feel that this is not possible - they have released advertisements for the '08 with the new HIDs and front end in place - plus, for the people that have already ordered them - the dealership would have an obligation to tell you. I visited the dealership this weekend to place an order for an '08 - im officially placing it on friday - and they told me explicitly that the '08's will have the new HIDs, face lifted front end and new dark slate grey interior - placing an order this week should put my delivery around the last week of august into the first couple of weeks in september. Anyway - SOMEONE VERIFY THIS and i will believe it
The fitment appears to be identical, the HID's will fit with the 2007 fascia. I don't see any restrictions or holds on HID's so they should be available right at launch (this week). What fascia appearance changes there will be, if any, is unknown, but for some reason the part number is changing starting August 14th. In 2006-2007 models the lower fascia mesh was a removeable/replaceable part, the '08 spec's call for it to be permanently attached. This may be the change being made in mid-August.

resumespeed any update on the new rims for the export models?

the 07 export models come with embarrasingly small and thin 245 front and back wheels and tires.

wk rumours section said that they might consider changing the tires and with the addition of newer rims...but only for export models.

has there been any confirmation??

thanks in advance

It appears so but I am looking for a 100% confirmation. Is it true the 09's will in fact have a 6.4L motor?

It appears so but I am looking for a 100% confirmation. Is it true the 09's will in fact have a 6.4L motor?

It is not yet a FACT.

It has yet to be "officially" announced
http://www.wkjeeps.com/wk_updates.htm

Ok I see that the MDS for the 08's is official. So my next question is there going to be a performance sacrifice? And once again can the MDS be disabled? I had it in my 06 Mag before I traded up to the SRT8 Mag and I hated it with a passion. I read that people couldn't tell when it was on 4cly. I say BS I ended up driving using the auotstick. Anyone with answers to my questions I've held off ordering the 08 because of the MDS and I really don't want to wait for a 09. But if it comes down to you guys with 06-07 being faster I'll have to wait.

i was goin to get my jeep this summer, but i guess ill just wait until 2009

from the look of the front, the headlights are convex at the bottom and the new bumper is shaped to fit them. you ll have to most likely switch both if you are going to do a transplant

from the look of the front, the headlights are convex at the bottom and the new bumper is shaped to fit them. you ll have to most likely switch both if you are going to do a transplant
The new fascia is not shaped to fit the lights, it is "flat" along the top as it is now.

http://www.cherokeesrt8.com/forums/attachment.php?attachmentid=1857&d=1183990079


top of the bumper certainly doesnt look flat to me. How will those light fit us with out a new bumper?

Ok I see that the MDS for the 08's is official...
NO MDS for 2008...

...top of the bumper certainly doesnt look flat to me. How will those light fit us with out a new bumper?
"Flat" as far as under the headlamps:

http://www.wkjeeps.com/srt8/SRT8_WK_Fascia_01.jpg

"Flat" as far as under the headlamps:

http://www.wkjeeps.com/srt8/SRT8_WK_Fascia_01.jpg
http://img.photobucket.com/albums/v320/DJRedBarron/GCSRT8-08-01-B.jpg
The area under the headlights doesn't look flat to me.

...The area under the headlights don't look flat to me.
The very bottom of the light housings are flat and not part of the fascia, like they are now.

the bumper definitly is not flat---the grille is diffrent as well--it looks a few inches longer

If you look at the far headlight in the picture you can clearly see the bumper flattens out just before the light making it possible that the rounded area is part of the headlight housing. But it certainly looks like the rounded area under the light is attached to the bumper, not the light. My guess, Resume is correct (because he usually is) and the picture is not an accurate representation of the production model.

The very bottom of the light housings are flat and not part of the fascia, like they are now.
So what is the body-colored curved plastic in the lower headlight area attached to? The headlight? That would be odd.

The pic (photo-shopped, granted) looks like the bumper is curved. Nothing is attached to the headlight. So the curved material has to be somewhere.

I am not saying you're wrong at all. I'm just trying to figure out what's up with the front end changes that may or may not be on my vehicle.

NO MDS for 2008...

Thank God,

I was at http://www.wkjeeps.com/future_jeeps.htm#08SRT8 not a hour ago and it showed the 2008 having the MDS engine now it doesn't. I am so happy that I can order my Jeep this week. :D :D :D

Thank God,

I was at http://www.wkjeeps.com/future_jeeps.htm#08SRT8 not a hour ago and it showed the 2008 having the MDS engine now it doesn't. I am so happy that I can order my Jeep this week. :D :D :D

Also see my reply (post # 2) here:
http://www.cherokeesrt8.com/forums/showthread.php?p=65801#post65801

Also see my reply (post # 2) here:
http://www.cherokeesrt8.com/forums/showthread.php?p=65801#post65801

Man there so much information available these days. The internet has really changed everything, good & bad. Don from Champion said he'll have pricing this week and I'm sure he'll have the final details on the 08's. So I'll be patient and order as soon as I know there's no MDS I'm pretty sure there won't be but you never know.

Man there so much information available these days. The internet has really changed everything, good & bad. Don from Champion said he'll have pricing this week and I'm sure he'll have the final details on the 08's. So I'll be patient and order as soon as I know there's no MDS I'm pretty sure there won't be but you never know.

A guy at work has a Charger SRT8 and hangs out on the charger forum... anyway, one of the guys there said his '07 build sheet for his Plum Crazy SRT8 also said "MDS"... which of course is incorrect... that further dispells this IMHO.

Mike

A guy at work has a Charger SRT8 and hangs out on the charger forum... anyway, one of the guys there said his '07 build sheet for his Plum Crazy SRT8 also said "MDS"... which of course is incorrect... that further dispells this IMHO.

Mike

I guess this is expected with a major company. The communication gets broken down with so many people involved.

...So I'll be patient and order as soon as I know there's no MDS I'm pretty sure there won't be but you never know.
No need to wait, the 2008 models WILL DEFINITELY NOT have MDS.

If you look at the far headlight in the picture you can clearly see the bumper flattens out just before the light making it possible that the rounded area is part of the headlight housing. But it certainly looks like the rounded area under the light is attached to the bumper, not the light. My guess, Resume is correct (because he usually is) and the picture is not an accurate representation of the production model.
Well I could certainly be wrong, we may not have a definitive answer until we actually see one in person. The problem is that DCX uses photoshop on some of their press images, and the fact that there are changes along the way. The 2008 parts book drawing does not show the "curves" for the headlamps. In some 2008 photos it looks like they are part of the fascia and some it looks like they are not. Then there is the part # change... sometimes figuring out the simplest things can be challenging!

is this a 2007 or 2008? It from the website and doesnt have a larger image. but the front facia is painted red above where the lower grill opening is?

http://www.wkjeeps.com/srt8/2008_wk_headlamps_01m.jpg

resumespeed any update on the new rims for the export models?

the 07 export models come with embarrasingly small and thin 245 front and back wheels and tires.

wk rumours section said that they might consider changing the tires and with the addition of newer rims...but only for export models.

has there been any confirmation??

thanks in advance
For The U.K. market, 2008 Jeep SRT8, I currently show:

255/45ZR20 and 285/40ZR20 ASP tires

20X9.0 and 20X10.0 aluminum wheels

I'll do some more checking and see if I can find out if the wheels have changed style-wise, so far part numbers have not been released.

For The U.K. market, 2008 Jeep SRT8, I currently show:

255/45ZR20 and 285/40ZR20 ASP tires

20X9.0 and 20X10.0 aluminum wheels

I'll do some more checking and see if I can find out if the wheels have changed style-wise, so far part numbers have not been released.

Thanks man!!:)

Finally we are going to the get the bigger tires and rims WOHOOO im booking an 08!:cool:

I just hope the new rims wont look too bad, the 07 ones are horrible, they are too small and they are not even chromed.:rolleyes:

this is great news for us ...thanks.

http://www.cherokeesrt8.com/forums/attachment.php?attachmentid=1937&stc=1&d=1184874185

http://www.cherokeesrt8.com/forums/attachment.php?attachmentid=1938&stc=1&d=1184874196

http://www.cherokeesrt8.com/forums/attachment.php?attachmentid=1939&stc=1&d=1184874247

http://www.cherokeesrt8.com/forums/attachment.php?attachmentid=1940&stc=1&d=1184874273