Does my '16 R/T A8 have MDS exhaust valves? - Dodge Challenger Forum: Challenger & SRT8 Forums
Intake & Exhaust This area is for the discussion of everything related to intake and exhaust, from the air intake/CAI to the tail pipe.

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 19 (permalink) Old 04-16-2019, 07:30 PM Thread Starter
Junior Member
 
Join Date: Apr 2016
Posts: 14
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
(Thread Starter)
Does my '16 R/T A8 have MDS exhaust valves?

Hello,

I'm ordering a Borla S exhaust system for my 2016 R/T Challenger with the automatic tranny. The Borla website has 3 different S-type models to choose from. It was always my understanding that an automatic transmission Challenger with 5.7L V8 had MDS. Is this assumption correct? If it is, do all MDS cars come with MDS valves? If not, how do I tell whether I have MDS valves? My car is in winter storage right now so it's not easy for me to just go and look. Does anyone have a picture of what the stock exhaust system MDS valve looks like? Also, where are the MDS valves located under the car? When I called Borla to ask the questions above they said, "No, you cannot actually assume anything on this vehicle. We cannot understand the metrics on how Mopar decides to equip these vehicles." Why is this so complicated?


2016-2018 Challenger 5.7L with Cylinder Deactivation (MDS) valves, Automatic/ Manual Trans., Rear Wheel Drive, 2 door.
This system is designed for vehicles equipped with MDS (Multi-Displacement System) valves. It includes replacement valves.
https://www.borla.com/products/chall...t__140713.html

2016-2018 Challenger 5.7L with Cylinder Deactivation (MDS) valves, Automatic/ Manual Trans., Rear Wheel Drive, 2 door.
This system is designed for vehicles equipped with MDS (Multi-Displacement System) valves. It features valve simulators rather than valves.
https://www.borla.com/products/chall...t__140715.html

2015-2018 Challenger R/T 5.7L W/O MDS (Cyl. Deactivation) Valves Automatic/Manual Trans. Rear Wheel Drive 2 Door.
https://www.borla.com/products/chall...t__140627.html
Lbftpsec is offline  
Sponsored Links
Advertisement
 
post #2 of 19 (permalink) Old 04-17-2019, 12:59 AM
Super Moderator
 
A Guy's Avatar
 
Join Date: May 2016
Location: Bay Area
Posts: 10,721
Thanks: 2,265
Thanked 3,577 Times in 2,715 Posts
Garage
Feedback Score: 0 reviews
Still very surprised Borla has never corrected this. MDS is part of the engine, cylinder deactivation, there are no MDS valves on the exhaust. They are talking about Active Exhaust Valves (AEV). The 2016 RT did not have AEV (RTs do now though, starting with 2017). Their 3 choices are system for cars without AEV (yours), system that has valves from Borla, for cars that had valves stock, and system that has valve simulators (tells the engine that your valves are working, even though they are not, eliminates valves), for cars that had valves stock.

https://www.borla.com/products/chall...t__140627.html

A Guy


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


2016 SXT Plus Pitch Black Blacktop Package. Eibach Pro lowering springs. Solo cat back exhaust. Paint and wheels coated w/ CQuartz Finest. DLux on all plastic.
A Guy is offline  
post #3 of 19 (permalink) Old 04-17-2019, 05:48 AM Thread Starter
Junior Member
 
Join Date: Apr 2016
Posts: 14
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
(Thread Starter)
Quote:
Originally Posted by A Guy View Post
Still very surprised Borla has never corrected this. MDS is part of the engine, cylinder deactivation, there are no MDS valves on the exhaust. They are talking about Active Exhaust Valves (AEV). The 2016 RT did not have AEV (RTs do now though, starting with 2017). Their 3 choices are system for cars without AEV (yours), system that has valves from Borla, for cars that had valves stock, and system that has valve simulators (tells the engine that your valves are working, even though they are not, eliminates valves), for cars that had valves stock.

https://www.borla.com/products/chall...t__140627.html

A Guy
Thank you for your reply. So you're saying the only choice for my order is 140627 because I do NOT have these valves in my exhaust system?


Just to ensure that we're on the same page here, are you sure there isn't a difference between an MDS valve and an AEV valve? I have a 2017 Silverado that has valves which open and close so that you don't notice the sound change over from V8 to V4 mode. I would have assume that in my case, this is an "MDS" valve.
Lbftpsec is offline  
Sponsored Links
Advertisement
 
post #4 of 19 (permalink) Old 04-17-2019, 02:31 PM
Senior Member
 
Jazz Blue Scat's Avatar
 
Join Date: Jul 2016
Location: Connecticut
Posts: 427
Thanks: 63
Thanked 82 Times in 68 Posts
Feedback Score: 0 reviews
You do not have the active exhaust but your car does come with MDS. You are talking about two different things.

2017 Challenger T/A 392 Redline Tri-Coat
Leather Interior Group
Driver Convenience Group
Sound Group II
TorqueFlite Eight-Speed Automatic Transmission
Power Sunroof
Black Hood Pins
Uconnect 8.4 Navigation

Jazz Blue Scat is offline  
post #5 of 19 (permalink) Old 04-17-2019, 02:37 PM
Senior Member
 
ChallyTatum's Avatar
 
Join Date: Dec 2016
Location: The state where 4 out of 7 former Governors went to jail
Posts: 4,030
Thanks: 378
Thanked 888 Times in 746 Posts
Feedback Score: 0 reviews
Active exhaust for the RT 5.7 was only added to the +2017 models and that was the year they started using 2.75" exhaust. If you zoom in on the others you can see the active exhaust valves and active exhaust valve simulator. 140627 does not have this which is what you want. Although, you might able to get away with 140715 (not sure if the mid pipes will bolt up to 2.75" pipe) as they just have the AE simulators (bracket that allows AE solenoids to be mounted but does not control an actual valve).
Attached Thumbnails
Click image for larger version

Name:	no active exhaust.JPG
Views:	23
Size:	26.9 KB
ID:	943759  


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

2015 Challenger RT+ (non-STP)
8lb Magnuson w/ Innovate PSB-1 wideband/boost/shift light gauge
Corsa extreme (2.5")
4" Aluminum one-piece driveshaft
Hellcat bottom airbox
Stainless Works LT headers (2" primaries)
Barton shifter assembly w/ Lou's short shaft and Speed Dawg knob
Comp Cam 7929 & 7748 push rods (gives slightly more lifter preload)
A2speed aluminum coil and valve covers (built in catchcan)

Last edited by ChallyTatum; 04-17-2019 at 02:45 PM.
ChallyTatum is offline  
post #6 of 19 (permalink) Old 04-17-2019, 02:59 PM Thread Starter
Junior Member
 
Join Date: Apr 2016
Posts: 14
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
(Thread Starter)
I just heard back from borla tech support. They said, “AEV and MDS are the same thing. If you want to be sure, just go look at your exhaust system.”

At this point I’m a little confused. Why does Borla themselves say that these are the same thing!? I know for a fact that MDS valves and AEV valves are different and that their terms cannot be used interchangeably. Am I missing something here? I’m going to go and check my car in storage to see what I have, but fundamentally I don’t really get why this purchasing process has been so difficult!?

Now, would the system with AEV valves sound different than the system without valves? I’m used to AEV exhaust on GM cars which gets louder above something like 3000 rpm. Is this the same thing? Could I wire the valve on the 140713 system into a simple switch in the cab to make the exhaust quieter or louder on demand?
Lbftpsec is offline  
post #7 of 19 (permalink) Old 04-17-2019, 03:04 PM
Senior Member
 
ChallyTatum's Avatar
 
Join Date: Dec 2016
Location: The state where 4 out of 7 former Governors went to jail
Posts: 4,030
Thanks: 378
Thanked 888 Times in 746 Posts
Feedback Score: 0 reviews
Quote:
Originally Posted by Lbftpsec View Post
I just heard back from borla tech support. They said, “AEV and MDS are the same thing. If you want to be sure, just go look at your exhaust system.”
It is not the same thing. MDS is Multi-Displacement System (it deactivates cylinders by collapsing the lifters on 4 of the 8 cylinders) which has been on the 5.7 since it came into production. AEV Active Exhaust Valve (controls a valve between the mid muffler and resonators) was only available on the Challenger 5.7 starting from +2017.

I think Borla is confused, my 2013 JGC 5.7 actually has valves (they are not controlled by the PCM, just has a torsion bi-metal spring) in the exhaust to help with MDS operation. The challenger 5.7 never had this.

As for adding AEV to a non-AEV challenger...not sure if it is possible. For starters you would need a new wiring harness and enable AEV in the tune. More of a headache than it is worth. Besides, everyone seems to go the opposite direction in that they want to disable AEV.

Funny that Borla did not mention anything about the difference in pipe size?
Attached Thumbnails
Click image for larger version

Name:	exhaust.JPG
Views:	121
Size:	57.7 KB
ID:	943761  

Last edited by ChallyTatum; 04-17-2019 at 03:26 PM.
ChallyTatum is offline  
post #8 of 19 (permalink) Old 04-17-2019, 06:14 PM Thread Starter
Junior Member
 
Join Date: Apr 2016
Posts: 14
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
(Thread Starter)
Great response Chally Tatum. I agree with everything you’ve said. I have the MDS valves with the torsional springs in the exhaust system of my Silverado.

As for the AEV valves on the Borla exhaust, can you clarify what these are for? Are they for allowing a greater exhaust note when you’re heavy on the throttle, and for reducing the noise when you’re highway driving, or is it for something else. My suggestion earlier about wiring in a switch to these valves should be taken literally. I don’t want to tie these into my PCM as my 2016 had no provisions in the harness for it. What I would like to do is have manual control over the valves, similar to how you can control them on the OEM C7 Corvette exhaust system. You can open them up for the track, or you can leave them closed in “stealth mode” when you don’t want to wake everyone up in your neighbourhood at 5am or to reduce highway drone. If this is what the AEV valves are meant for I may buy them anyway and then just mount a simple toggle switch in the cab which opens and closes then like cutouts. Thoughts?
Lbftpsec is offline  
post #9 of 19 (permalink) Old 04-17-2019, 06:36 PM
Senior Member
 
Tshane72's Avatar
 
Join Date: Jun 2013
Posts: 1,802
Thanks: 130
Thanked 251 Times in 230 Posts
Feedback Score: 0 reviews
There was another post somewhere here on the forum with a link to a website for a company that either makes the active exhaust valves you can install into a system like yours that came without active exhaust...or it was a complete cat-back system with active exhaust somehow...maybe someone else can chime in here about that. But I know there are a couple aftermarket systems out there supposedly that you can add active exhaust to older Challengers. Anyhow, hope you get it all figured out soon. I have a Borla s-type system on my car and love it...but I'm surprised Borla tech-Support is that confused about your question.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Living my life....one quarter mile at a time
Tshane72 is offline  
post #10 of 19 (permalink) Old 04-17-2019, 06:53 PM
Senior Member
 
ChallyTatum's Avatar
 
Join Date: Dec 2016
Location: The state where 4 out of 7 former Governors went to jail
Posts: 4,030
Thanks: 378
Thanked 888 Times in 746 Posts
Feedback Score: 0 reviews
The active exhaust is all about controlling sound. I for one am glad my 2015 does not have it...one less thing to fail. Like I said a lot of folks that have it try to delete it.

https://www.torquenews.com/106/all-2...l-mode-exhaust
ChallyTatum is offline  
Sponsored Links
Advertisement
 
Reply

  Dodge Challenger Forum: Challenger & SRT8 Forums > General, Performance, and Technical > Performance Modifications > Intake & Exhaust

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Dodge Challenger Forum: Challenger & SRT8 Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Challenger SRT 392 Scat Pack Borla Exhaust Touring #140676 @ PFYC-PartsForYourCar PFYC Vendor Deals 6 03-28-2019 11:06 AM
2015 Challenger information thread ResumeSpeed General Challenger Discussion 12822 06-29-2018 11:02 AM
Solo Performance 2015+ Challenger 5.7L R/T Mach XV-CH-RT Catback Exhaust GOINGSOLO2 Solo Performance 10 05-26-2017 08:13 PM
Recommendation needed for exhaust for '15 R/T with MDS! 6SpeedR/T Intake & Exhaust 26 01-18-2015 12:45 PM
'09 Challenger R/T Gathered Specs / Equipment & Info Related SIX-PAK Dodge Challenger R/T Specific 150 10-19-2014 02:38 AM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome