Hellhorse Performance, Terrible Customer Service

[tdstuart]

Hmmm no. It definitely changes the runners length.

No offense but have you physically looked at the manifold and played with the imrc? When I ported my friends 2018 manifold I was able to move the flaps manually. It’s literally just a flap in the runner. The runner length does not change. When the flap is open is sits flush with the wall of the runner, as it closes it starts to stick out into the path of the air creating turbulence right before the air meets the fuel.

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[WildHorse]

No offense but have you physically looked at the manifold and played with the imrc?

None taken.
As far as the intake runner is concerned, it ends where the flap opens.
Under it would just be an extension of the cylinder head port.

 

[tdstuart]

None taken.
As far as the intake runner is concerned, it ends where the flap opens.
Under it would just be an extension of the cylinder head port.

What is the reason for redefining the rest of the runner as an extension of the cylinder head port?

 

[Pistol_91]

I took 2 pieces of small scrap metal I had laying around. Grinded them to uniform and drilled a couple holes. Did it in about 15 minutes. Zip ties work too, I guess. I just don't trust them after a few years of getting hot as balls. They get hard and break eventually. Not something I feel like dicking around with ever again so metal it was.

 

[Pistol_91]

IMRC changes the length of the port. Shorter (open) more low end power, longer (closed) more top end power.

You could be right you could be wrong. All I know is under normal driving conditions they're closed, under part power and WOT conditions they're open. That would contradict what you're saying here.

 

[WildHorse]

Not really a contradiction. You're adding volume.
Kinda the same way the gen3 intake manifold makes
more power than the gen2 intake manifold.

 

[MD18EcoStang]

Sooooo I've searched google and the forum and can't find a definition of what an IMRC is. Anyone mind enlightening me, apologies if it's a stupid ask and somewhere else, but I quit after two pages of searching.

Intake Manifold Runner Control
Absolutely drives me crazy when people use acronyms, but don't/can't define them.

 

[Skye]

can't find a definition of what an IMRC is

https://oztuning.com/imrc-knowledge/

Intake Manifold Runner Control. A detailed article above, with a brief explanation from an legacy post, another forum, below.

"The IMRCs are installed between the intake manifold. Their purpose is to provide the cylinders with a high velocity intake charge at rpm levels below 3250. This is accomlished [sic] by blocking the secondary intake port with a butterfly valve that is opened and closed by the IMRC controll [sic] which is mounted to the bottom of the intake manifold."

(sic) (with square-brackets usually) is an abbreviation of 'sic erat scriptum' which is Latin for 'thus it had been written', meaning that the quote prior was transcribed as it was found in the original source, complete with errors, coloquialisms etc.

 

[K4fxd]

Ford's system is really CMCV (Charge Motion Control Valve).
It is as Tristan says. It is a flap that makes the intake runner smaller thus raising velocity and creating turbulence. This makes it easier for the lean air fuel mixture to burn easier. Without them Ford would use 13 to 1 A/F instead of 14 to 1. I know when I lock mine out it likes a richer cruise mixture. About 13.5 Idles better too even with CMCV.

IMRC is used on some motorcycles and actually does make the intake runner longer and shorter.

Easiest way to "lock them out" is to keep the cans and let the spring hold them. Bernoulli will only open them with 10 + psi of boost.

 

[DrZed]

Zip ties work fine.

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[K4fxd]

Hey Freiburger, where is the Zip tie on your brand new Corvette?

 

[WildHorse]

WELL he asked about IMRC, so I told him what IMRC is.

 

[bankyf]

IMRC changes the length of the port. Shorter (open) more low end power, longer (closed) more top end power.

Some of the older manifolds (SHO comes to mind) actually had dual runners (short and long) and would switch between them. The later implementations are just a restriction that theoretically changes the length.

 

[Corporate_Rebel]

Thanks for the lesson guys!

 

[Jaymar]

Wasn't the point of 3D printed parts supposed to be print-to-order, no stock, last minute production? The ultimate dream of all those lean just-in-time philosophies? Either their production line is on fire or their management struggles with minute rice.

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