Updated 3/27/2021 & 5/5/2022 - A look at the 2020 GT500 and exhaust system valves

[Epiphany]

SEE NEWLY ATTACHED PDF. Ford finally made this a TSB!

UPDATED AGAIN (May 2022) - See newly released PDF at the bottom of this post.

At some point, some of you may see a message on the dash that looks something like this...

The dreaded "exhaust mode selection not available" message isn't new as GT350 owners get hit with it every now and then too. There are a number of reasons why the message can come up from melted harnesses, blown fuses, sticking butterfly valves, failed actuators, etc. Since I've spent a lot of time getting to know this exhaust system I figured I'd share what I've seen to date with this system.

I originally added a Lethal Performance resonator delete to my car not long after receiving it. It is a cut and clamp affair and while I was very happy with the sound I wanted to pull the section from the x-pipe back and tig weld it back up. Once reinstalled I wanted to tweak the mufflers so that the quad tips were more in line horizontally. You can tweak here and there a small amount. I wanted more freedom so I cut the mufflers at the fore end, aligned them to my satisfaction, and tack welded everything so I could pull the system again and weld it back up on the ground.

Pulling the system isn't that complicated, it just takes a little time. I removed the rear undertray, disconnected the actuator harnesses, loosened the exhaust clamps/hangers, lowered the system down, and got to work. I just figured this would also be an opportunity to show what you don't normally see regarding the actuators and their butterfly valves below. So with the system out this is what you see...

The actuators are perched up above the tips just aft of the mufflers. They are difficult to access from underneath the car. The shaft and plate (or butterfly valve) that they rotate when called upon resides beneath them.

So if you are this week's winner of the "exhaust mode selection not available" message you can either look yourself and/or drop the car off at your dealer for repair and enter the "that fucking dent wasn't there when I dropped the car off" contest.

I put this quick video together to help illustrate.



The above video should put the next few photos into context.

I'm not 100% sure this gets lubricant where I want but it shows that you could get something to the upper shaft "area" without pulling the actuator off...

I reassembled after cleaning/lubricating and reinstalled the system. It gets easier each time you do it.

Most importantly, inspect your harnesses in the area of the valves, ensuring they are not in contact with the mufflers or the tips as they exit the mufflers. Some have had issues with melted harness and blown fuses. When this happens you'll likely get a message regarding mode issues. One of my harnesses was sitting on the exhaust system as it's pushpin to hold it up and away was never put into place. I rerouted it giving it more clearance and zip tied it.

You can also have a valve that simply froze up or an actuator that died. But you should be in a better position now to try to identify for yourself what may happened.

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[kilobravo]

Tob: I gotta tell ya, I look forward to your write ups like this one, they're SO informative.

"I like to disassemble things." <smile>

Yep, a truer statement was never uttered. :-)

My only question is about WD-40. As I understand the history, it wasn't designed as a lubricant but rather, an anti-corrosion treatment for the outer skin of ICBM's. Just curious.

Top-notch clip. Another surprise was your voice which was not what was in my head. :-)

 

[Tomster]

Tob: I gotta tell ya, I look forward to your write ups like this one, they're SO informative.

"I like to disassemble things." <smile>

Yep, a truer statement was never uttered. :-)

My only question is about WD-40. As I understand the history, it wasn't designed as a lubricant but rather, an anti-corrosion treatment for the outer skin of ICBM's. Just curious.

Top-notch clip. Another surprise was your voice which was not what was in my head. :-)

WD40....... Water Displacement formula #40.

 

[MaskedRacerX]

https://en.wikipedia.org/wiki/WD-40

The spray, composed of various hydrocarbons, was originally designed to be used by Convair to protect the outer skin of the Atlas missile from rust and corrosion.

 

[biminiLX]

Learning is fun.
Great vid buddy.
-J

 

[2020GT500]

Thanks @Epiphany

By far my favorite tech tip write up and video!

 

[Epiphany]

I went back and looked at a gallery I had from my old GT350 when I added a Borla cat back. I had to pull the actuators from the stock system and swap them onto the Borla. Very similar to what Ford is using on the GT500.

Actuator motors are different. Note that this GT350 actuator design uses a plastic clip to retain the spring while the one for the GT500 uses a stainless shaft retain it.

GT350 spring worked the same way and if you look close you can see the spring indexing with the "mushroom head" that is attached to the butterfly shaft.

Something else. As much as the tips are different, I wanna say the two cars are using the same mufflers and pipes all the way forward to the "X" section. The GT500 muffler uses a heat shield that the GT350 muffler didn't have but other than that they are pretty much identical. Also, note that the GT350 pipes are tied together at the hangers where the axle gear case would be but the GT500 system is not tied together there. A quick side by side of the two systems.

 

[kilobravo]

I guess it's not surprising but I think that perhaps only you would have photos of each complete set, Tob. :-) VERY cool info.

 

[gfcobra04]

I went back and looked at a gallery I had from my old GT350 when I added a Borla cat back. I had to pull the actuators from the stock system and swap them onto the Borla. Very similar to what Ford is using on the GT500.

Actuator motors are different. Note that this GT350 actuator design uses a plastic clip to retain the spring while the one for the GT500 uses a stainless shaft retain it.

GT350 spring worked the same way and if you look close you can see the spring indexing with the "mushroom head" that is attached to the butterfly shaft.

Something else. As much as the tips are different, I wanna say the two cars are using the same mufflers and pipes all the way forward to the "X" section. The GT500 muffler uses a heat shield that the GT350 muffler didn't have but other than that they are pretty much identical. Also, note that the GT350 pipes are tied together at the hangers where the axle gear case would be but the GT500 system is not tied together there. A quick side by side of the two systems.

Do you have any comparison of the inlet and outlets? Wondering if the two different cars exhaust have the same diameters inlet and outlets for the mufflers?

 

[Hi-PO Stang]

I remember talking to Bob Glidden after he just finished racing in a race at Pomona in 1981 with his Pro Stock , I believe , and observed him liberally spaying WD-40 down his carburetor and also into each combustion chamber before he loaded his race car into the hauler for his trip home.

 

[NoXiDe]

WD40....... Water Displacement formula #40.

Another member who participated the Track Attack just recently was told to use Liquid Wrench. This was an tech with Ford Performance@ track attack. I thought one would prefer WD-40 tho.

 

[Tomster]

Another member who participated the Track Attack just recently was told to use Liquid Wrench. This was an tech with Ford Performance@ track attack. I thought one would prefer WD-40 tho.

I'm not a big fan of WD40. Its good for an overall thin lubricant, but it is not persistent enough for me. I was just expanding on what KB was saying. It isn't a well known fact.

 

[kilobravo]

I'm with you, Tom, never for lubrication but all the time for corrosion prevention down here. I always figured the "W" was "water" but never knew the "D" word, t'anks. :-)

 

[V00D00]

I went back and looked at a gallery I had from my old GT350 when I added a Borla cat back. I had to pull the actuators from the stock system and swap them onto the Borla. Very similar to what Ford is using on the GT500.

Actuator motors are different. Note that this GT350 actuator design uses a plastic clip to retain the spring while the one for the GT500 uses a stainless shaft retain it.

GT350 spring worked the same way and if you look close you can see the spring indexing with the "mushroom head" that is attached to the butterfly shaft.

Something else. As much as the tips are different, I wanna say the two cars are using the same mufflers and pipes all the way forward to the "X" section. The GT500 muffler uses a heat shield that the GT350 muffler didn't have but other than that they are pretty much identical. Also, note that the GT350 pipes are tied together at the hangers where the axle gear case would be but the GT500 system is not tied together there. A quick side by side of the two systems.

So you took actuators off oem mufflers, attached to aftermarket (borla), and still had oem-like control?

 

[Epiphany]

Oh yeah, the Borla system was designed for it. In fact, I'd say the butterfly hardware and the cast body that surrounds it was prepped and better toleranced than Ford's. I stacked the Borla system atop the factory GT350 for comparison...

Bends were more gradual (hence the funky path) with gentler radii, stainless was 304 instead of 409, and the system fit well. The butterflies operated with more precision and would snap shut perfectly. You can see how the mufflers were ready for the factory actuators and the stamping to receive them looked identical to Ford's.

Borla system was expensive but absolutely top-notch quality.

Ford Performance has really slacked off in terms of performance offerings for the GT350 and I sense a lackluster showing with the GT500 from them as well. I can see them carrying a GT500 Borla system again though.

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