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nice find. i called and spoke to nick for about 20 mins. i've used ar headers before and they make a great product.

for this system he said it uses the stock tips, is 3", and has a x pipe. he said one owner that has it installed briefly had a cel most likely due to elimination of the exhaust flaps. he said the cel went out and hasn't come back though.

he said 1325 + shipping, but was willing to do a little better for some of the first guys in line. i requested pics and sound clips and he said he'll send them over when he gets a chance.
 

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Discussion Starter · #4 ·
nice find. i called and spoke to nick for about 20 mins. i've used ar headers before and they make a great product.

for this system he said it uses the stock tips, is 3", and has a x pipe. he said one owner that has it installed briefly had a cel most likely due to elimination of the exhaust flaps. he said the cel went out and hasn't come back though.

he said 1325 + shipping, but was willing to do a little better for some of the first guys in line. i requested pics and sound clips and he said he'll send them over when he gets a chance.
What a price tag.
And no exhaust valves on their cat-back.
That's a lot of money to spend.
Not to mention how much more you'll spend on future $4 - $5+ a gallon Gas.
Finding out the major functions of the AEV (Active Exhaust Valve) system and what it does for fuel economy is what the exhaust manufacturers need to figure out FIRST.
Sounds like they rushed it without knowing anything about this vehicle.

See.... that is what is scaring me away.
I am starting to email Borla, Corsa and asking them to better research the 12'+ Jeep SRT8's. I already emailed ARH asking for pics and stating my questions, concerns.

What these aftermarket exhaust manufacturers should be doing is driving the Jeep on the road first before modifying it. Yes.. on the road for real world testing.
Checking when the MDS ..ECO mode comes on ... what engine LOD/Throttle position percentages, etc it turns on at, shuts off at. Not to mention... the need for monitoring the back-pressure on the Stock OEM system first. Seeing how changes of the exhaust system upsets the MDS system. Whether it turns on at all ....or not at all.
Then using new valve/spring pressures when going larger exhaust pipe diameters should be done so they can maintain the ECO mode when cruising the highway.

We already know what happens when there are no exhaust valves.
http://www.cherokeesrt8.com/forums/showthread.php?t=59892
 

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I don't think I would swap my exhaust out without having the valves in the aftermarket. I still want good highway mileage. My best is 433 miles to a tank.


Sent from my iPhone 4S
 

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Is it that hard to simply re-install the valves in an aftermarket set-up? But seriously, if the damned things don't rob any power, why not put 'em back in and have the best of both worlds?
 

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Discussion Starter · #8 ·
Is it that hard to simply re-install the valves in an aftermarket set-up? But seriously, if the damned things don't rob any power, why not put 'em back in and have the best of both worlds?
Aftermarket companies only need to do their research as to why they are there in the first place. TheMAIN reason they're there is to help with the back-pressure/scavenging effects when the 6.4L is in MDS/ECO mode so the exhaust system at this time is the equivalent as an actual 4 cylinder. All in order to keep this over-sized 5100+ lb vehicle moving

Allpar/Chrysler statements given out detailed they are there so that this Heavy Pig of a vehicle enters ECO mode more often and it continues to as much and often as possible. Their purpose achieves 13% more fuel economy when cruising the highway. That's huge savings when you have a vehicle getting 12/18 fuel economy. Chrysler engineered it the way they did for a reason.

I already linked a thread where one member found out the hard way of eliminating the valves and the costs. Huge power losses and really crappy mileage on top of that.

And headers.... that's a good way to completely VOID the Chrysler Powertrain Warranty.
 

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And headers.... that's a good way to completely VOID the Chrysler Powertrain Warranty.
Only if they can prove that the headers themselves caused an issue with something in the powertrain that you are trying to get covered under the warranty.
 

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That is my truck, a couple of days after the install I had a cel come on. I brought it to the dealer and they said it was an o2 reading, they reset it and it never came back on. I haven't had any power loss whatsoever after the aev were removed. It sounds a lot better in person. As far as mpg, I'm getting 12.2 around town and 17.4 highway. The owner wants someone with a wk2 for two weeks to fabricate headers for it and he would give them a next to nothing cost, that's too much time for me to have it tied up for, lol
 

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Just my opinion, but the flaps are doing nothing for fuel mileage. Its to control the change in exhaust tone once in 4 cylinder mode. Looking at the advertised fuel economy on the 6.4 vs the 6.1 and the only increase I see is from the MDS alone. If you really want to increase your fuel economy, draft with a semi or go 5mph slower than normal.
 

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Discussion Starter · #13 ·
Just my opinion, but the flaps are doing nothing for fuel mileage. Its to control the change in exhaust tone once in 4 cylinder mode. Looking at the advertised fuel economy on the 6.4 vs the 6.1 and the only increase I see is from the MDS alone. If you really want to increase your fuel economy, draft with a semi or go 5mph slower than normal.
The AEV's are there for mileage. Simple as that. And for the 4 cylinder MDS/ECO function.
The valve flaps are semi-closing when the exhaust gases cannot force them open. Thus when the Engine is entering ECO mode while cruising.
This is making the exhaust system on the OEM 2.5" system at this time the equivalent back-pressure/scavenging effect that of a 4 cylinder! ...Restriction when its needed.

At the highway rated 18mpg minus the 13% ( which Chrysler is claiming it achieves ) , you're gonna lose 2+ mpg. And be just like the WK1 in mileage.
Currently I can easily achieve 19-20 mpg without even trying cruising the highway at between 60-65 mph. 17.5-18.0 mpg is attained easily at 70-75 mph.

I'm not gonna be drafting behind semis I see throwing rocks and chipping windshields (which every time I'm near I hear rocks hitting my windshield)

Manufacturers need to do some research on why the AEV is there in the first-place.
Not just eliminating it.
 

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So what you are saying is that when you remove the flaps, you get the same mileage as a WK1? So the MDS cutting fuel to 4 cylinders isnt helping at all in your opinion?

Do me a favor, go on a 5 mile stretch and measure mpg. Do the exact same stretch but do it in auto-stick and 5th gear which will shut-off MDS and see if it changes at all.

I absolutely refuse to believe these flaps will allow you to increase fuel mileage by 2mpg. If that was the case, why hasnt an aftermarket company developed them for other vehicles? A muffler company could easily incorporate that into their mufflers. I will ask an SRT engineer that I know and report back. I can see it "helping", but not 2mpgs.
 

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This is a quote

"I dont think they are there for mileage. I think they are mostly for sound attenuation, especially in mds mode. It really cuts down on the mds drone. The factory exhaust flows really well"

I asked him to confirm tomorrow, I will post up what he finds out tomorrow as long as he doesnt care. Maybe he will want to post himself but I doubt it.
 

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Discussion Starter · #16 · (Edited)
So what you are saying is that when you remove the flaps, you get the same mileage as a WK1? So the MDS cutting fuel to 4 cylinders isnt helping at all in your opinion?

Do me a favor, go on a 5 mile stretch and measure mpg. Do the exact same stretch but do it in auto-stick and 5th gear which will shut-off MDS and see if it changes at all.

I absolutely refuse to believe these flaps will allow you to increase fuel mileage by 2mpg. If that was the case, why hasnt an aftermarket company developed them for other vehicles? A muffler company could easily incorporate that into their mufflers. I will ask an SRT engineer that I know and report back.

Where??? ...Where did I say the MDS isn't helping mileage. What I'm saying is it will get worse mileage the less often the MDS system comes on. Which is based on ....Throttle position, Engine Load, And Incline << (Which Throttle position goes up at this time). That's all playing a huge factor of how often or not it comes on and stays on. At any time the exhaust gases overcome the valve/spring pressure and the valve opens... ECO mode goes... OFF. I've been driving this vehicle long enough now. Open up the exhaust system all the way and good by to 19-20 Miles Per Gallon on that particular gallon you choose to milk it for all its worth.

Others are reporting their own mileage on the highway in other threads. All get what they get based on how they choose to drive. A good amount of low mile-age reporters state why. High mile-age reporters seem to state the same reason... Lots of ECO mode.

I've already drove with the MDS system off for 100 miles before as I didn't like hearing the droning. All miles cruising the highway, 5th gear/Auto-Stick Mode it gets 15.5-16mpg with the 3.70 rear gearing without the MDS coming on at all. Cruising the highway at 60-65mph Using the Estimated Fuel mileage at the time. Used Odometer mileage: 1105 when resetting the fuel economy on the Jeep. Check. Check it 14 miles down the highway. Still fluctuating around "15.5-16" on the Fuel economy. Check another 2 miles later. 1121 miles on the odometer. Check the Fuel economy... reading 16. Pretty much says it. Reset fuel economy. And try all over. Another gallon to burn. Another gallon to test over many more miles burning it up ever so faster while in Auto-Stick.

It gets even worse when flooring it. Its a 6.4L with low gearing.
I crank up the volume/listen to music more often now. Don't have to hear the droning anymore while in ECO mode.

The 2010+ Camaro is using the exhaust flaps BTW...... Since you asked.
It has no shut-down 4 cylinder modes. But ....they're there.

I don't know about GM and their 4 cylinder shut system and it using exhaust valves or not. And on what vehicles. They have heavy pigs of vehicles as well. So its a possibility. I do know a co-worker that has a GM truck and he was raving about the mileage and asking about the 4 cylinder shutdown on the Jeep/Chrysler line-up. I'll be looking under his truck next time I see it when its in the parking lot.


Looking forward to hearing what an SRT engineer says.
 

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At the highway rated 18mpg minus the 13% ( which Chrysler is claiming it achieves ) , you're gonna lose 2+ mpg. And be just like the WK1 in mileage.
Where??? ...Where did I say the MDS isn't helping mileage. What I'm saying is it will get worse mileage the less often the MDS system comes on. Which is based on ....Throttle position, Engine Load, And Incline << (Which Throttle position goes up at this time). That's all playing a huge factor of how often or not it comes on and stays on.

You didnt say MDS specifically. You were defending the flaps and stated that chrysler claims a 13% gain in fuel mileage without ever clarifying that you were in fact referring to the MDS system.

Your claiming that with the flap system removed, that the vehicle will not enter MDS mode. This is incorrect. The flaps only function once MDS is already activated. Their sole purpose is to eliminate the drone.

I actually received a second text from the srt guy that stated this "I will ask XXXX tomorrow. He will be at the proving grounds. I doubt it has anything to do with mileage though. None of the other apps I know of use them for fuel economy (crotch rockets)"

Now obviously he isnt staking his life on it, but even he is pretty confident that they have nothing to do with mileage but I guess we will find out tomorrow.
 

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Discussion Starter · #18 ·
This is a quote

"I dont think they are there for mileage. I think they are mostly for sound attenuation, especially in mds mode. It really cuts down on the mds drone. The factory exhaust flows really well"

I asked him to confirm tomorrow, I will post up what he finds out tomorrow as long as he doesnt care. Maybe he will want to post himself but I doubt it.
Well. That's not what has been reported to the reporters/journalists.
So who are these reporters getting their information from and where are the increased mileages coming from ??

There are mileage improvements since the Active Exhaust Valves showing up on the exhaust system. And they clearly state why. It keeps the MDS system on longer.

http://www.allpar.com/cars/dodge/charger-SRT8.html <<< Charger SRT8 Link. Improvement of 25 % miles per gallon on the highway by the AEV. 15% more mpg's in the city. Larger motors. And more Mileage. What's improving everything ? .. The AEV and its ability they're reporting it has on keeping the MDS system on over a wider RPM range

http://www.allpar.com/trucks/jeep/SRT8.html <<< 3rd Paragraph. Last Sentence. Statement about the AEV Improvement. And the 13%
 

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Discussion Starter · #19 ·
You didnt say MDS specifically. You were defending the flaps and stated that chrysler claims a 13% gain in fuel mileage without ever clarifying that you were in fact referring to the MDS system.

Your claiming that with the flap system removed, that the vehicle will not enter MDS mode. This is incorrect. The flaps only function once MDS is already activated. Their sole purpose is to eliminate the drone.

I actually received a second text from the srt guy that stated this "I will ask XXXX tomorrow. He will be at the proving grounds. I doubt it has anything to do with mileage though. None of the other apps I know of use them for fuel economy (crotch rockets)"

Now obviously he isnt staking his life on it, but even he is pretty confident that they have nothing to do with mileage but I guess we will find out tomorrow.
I've been clearly stating what the valves are there for about 3 different times.
And when the MDS kicks on/off. And why.

And showing the Thread (My Post #4) so others know what eliminating them does.
Even articles from journalist/reporters (Info from Chrysler reps??) stating the AEV's existence so others know the Facts.
Simple as that.

Since about Post #8 ...I've been getting specific enough.
Specific enough even before you started posting
Break it down how you like.
I know how I stated it and its not like you're putting it.
 

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If you're buying a 60k+ truck, are you really concerned about that extra 2mpg? If you want to eliminate the valves, its your choice. I think you will hear more of exhaust noise when the MDS kicks in. As for the valves and the gas mileage and MDS....they do help the 6.4 enter MDS more often, but not 2mpg more often. I think they are there to help keep the SRT sounding like an SRT in 4 cylinder mode instead of the civic cruising next to you.
 
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