vacuum operated IRMC

[chris 96cobra]

hey yall wanted to let you guys no if you are having problems with your factory IRMC controller and want it to operate ,I built some vacuum operated IRMC .
i got the vacuum actuators from a Lincoln mark 8 and fabed some brackets out of angle iron with a torch a vise a hammer and die grinder .had to modify the the IRMC actuator arms .put the built bracket under the stock cable actuator so it would have the stops for the plates .and i grind the set screw down and one of the stops so the actuator arm would clear.:banana:
they work great on my cobra .i had the IRMC zipped tied open before,now i got tons of bottom end power now gets in to boost faster and now makes 3-4 psi more pulls a lot harder now

 

[goats]

It's easyer just to delete them

 

[chris 96cobra]

It's easyer just to delete them

but would that hurt your bottom end power? would that be the same as when i had my zip tied the runners open ?

 

[ksigatmsu7f02]

Mine are deleted with stock gears on a custom tune and I have more than enough bottom end....I'm sure a dyno would show some drop but I couldn't feel it so it is enough for me.

 

[1989Gt.]

but would that hurt your bottom end power? would that be the same as when i had my zip tied the runners open ?

Nothing gears cant make up no point in keeping the imrc plates lol,

 

[whtcobra1998]

if your super charged and making more boost than you have a restriction as nothing else was changed, you went backwards. as flow through your motor gets efficient like adding headers or intercooler-boost will lower even though your making more power. you are only making more boost because of a restriction, make sure they are opening and not over rotating

 

[CzchMex]

hey yall wanted to let you guys no if you are having problems with your factory IRMC controller and want it to operate ,I built some vacuum operated IRMC .
i got the vacuum actuators from a Lincoln mark 8 and fabed some brackets out of angle iron with a torch a vise a hammer and die grinder .had to modify the the IRMC actuator arms .put the built bracket under the stock cable actuator so it would have the stops for the plates .and i grind the set screw down and one of the stops so the actuator arm would clear.:banana:
they work great on my cobra .i had the IRMC zipped tied open before,now i got tons of bottom end power now gets in to boost faster and now makes 3-4 psi more pulls a lot harder now

Awesome dude! Sounds like you went through a lot of trouble to get them to work. Honestly zip ties in the engine make me worried :rollseyes

This application would be perfect for the person who city drives a lot and doesn't want to give a lot of gas to get the car moving quickly. Like me. But my IMRCs are going to get a make over soon. Don't want to remove them just yet. Just need to clean them.

 

[1989Gt.]

Awesome dude! Sounds like you went through a lot of trouble to get them to work. Honestly zip ties in the engine make me worried :rollseyes

This application would be perfect for the person who city drives a lot and doesn't want to give a lot of gas to get the car moving quickly. Like me. But my IMRCs are going to get a make over soon. Don't want to remove them just yet. Just need to clean them.

First off zip ties aren't IN the engine lol

 

[CJK440]

How do you control the actuation? Are they normally open with vacuum to close?

 

[SpittingCobra]

wow a lot of confusion in this thread!

You didn't "get more boost"!!!! You got more manifold pressure from blocking off the extra runners AKA a huge restriction! I'm worried if you're telling me you have 3-4psi more at peak then you're butterfly valves may be sticking closed or at least partially closed because you shouldn't have seen any increase in peak psi because the IRMC valves should be wide open (just as they were previously all the time when zip tied).

Your "boost" gauge reads the pressure inside the intake manifold, not the cylinder. With the same CFM of air traveling into your engine as previously, only at a higher manifold pressure means you are getting less air flow, not more. Your dynamic compression did not increase, you're likely getting less air into the cylinder now.

 

[CzchMex]

First off zip ties aren't IN the engine lol

Oh...ooops. Ok guess I have NO clue how the IMRCs work. Will find out more when I take it apart. Lol. Thanks for the clear up

 

[na svt]

i had the IRMC zipped tied open before,now i got tons of bottom end power now gets in to boost faster and now makes 3-4 psi more pulls a lot harder now

Hmmm, more boost? I have a feeling your IMRCs aren't opening. Also, with a tune will lose no low end power with deletes.

The problem with vacuum operated IMRCs is that they open as soon as you go full throttle, so basically it's just like deletes. With mechanically actuated IMRCs you can control when they open.

 

[crazycarlo]

First off I deff commend you for trying something diff man. The thing I see is that why yes the electrical/mechanical actuator's from the stock system get stuck and dont work often the main thing Ive seen causing problems with the IMRC system is the actual butterflies themselves. fact is they are still going to get dirty and crudded up, just a fact of the dual port head design.

 

[chris 96cobra]

i have the factory stops so it is not rotating to far.i have a lot more low end power and make more boost the car fells a good bit faster now.i believe that having more low end power im building boost faster an by that making more max boost .before i was making 5.5psi now 9psi i have a vortech v-3 sci-trim:burnout:

if your super charged and making more boost than you have a restriction as nothing else was changed, you went backwards. as flow through your motor gets efficient like adding headers or intercooler-boost will lower even though your making more power. you are only making more boost because of a restriction, make sure they are opening and not over rotating

 

[chris 96cobra]

How do you control the actuation? Are they normally open with vacuum to close?

they are open with no vacuum ,applied vacuum they are closed

 

[chris 96cobra]

Awesome dude! Sounds like you went through a lot of trouble to get them to work. Honestly zip ties in the engine make me worried :rollseyes
This application would be perfect for the person who city drives a lot and doesn't want to give a lot of gas to get the car moving quickly. Like me. But my IMRCs are going to get a make over soon. Don't want to remove them just yet. Just need to clean them.

o no ,no zip ties in the engine they where in back of the intake where the stock irmc cables operate the runners. lol :beer:

 

[chris 96cobra]

what your saying makes sense about them having a restriction but they are working properly .and also if i have a restriction why would the car be so much faster now :dancenana:.less air flow means rich,we all know richer is not quicker .a little lean is mean but to much is a melt down:burn:

 

[goat-ee]

what your saying makes sense about them having a restriction but they are working properly .and also if i have a restriction why would the car be so much faster now :dancenana:.less air flow means rich,we all know richer is not quicker .a little lean is mean but to much is a melt down:burn:

I can't see any way the car would make more boost with the mod you did, if the IMRC's are working right. I think common sense is telling you something pretty important. Your making more boost because you have more restriction in your intake path (IMRC's are closed). And your analysis of lean and rich from above...your right your seeing less total air, but it's being pressurized more, you may be too lean? Only a wideband could say for sure?

I could possibly see where the car might actually see a net gain in HP in the low to medium rpm range, because you are essentially doubling the boost. Of course its going to feel good in the low range. I can't however see that you would make more upper RPM hp, due to the flow limitation of unopened IMRC's? Probably the NEVER to be relied upon butt-o-meter lying to you?

If it were me I would just go back to electric actuator or delete them entirely. Get a smaller pulley to get your boost back up to your false high psi you are seeing now and tune for it.

 

[PSUCOBRA96]

are you sure they are opening up?

 

[SpittingCobra]

i have the factory stops so it is not rotating to far.i have a lot more low end power and make more boost the car fells a good bit faster now.i believe that having more low end power im building boost faster an by that making more max boost .before i was making 5.5psi now 9psi i have a vortech v-3 sci-trim:burnout:

what your saying makes sense about them having a restriction but they are working properly .and also if i have a restriction why would the car be so much faster now :dancenana:.less air flow means rich,we all know richer is not quicker .a little lean is mean but to much is a melt down:burn:

Buddy. First off let me commend you on your efforts to build this vacuum operated IMRC. Also let me thank you for taking the time to write about it and offer it here on the SN-95 Tech section.

However, it seems even though myself and a few other members tried to help you understand why your BOOST GAUGE is reading a higher figure, you still don't get it. You're simply providing misinformation here. Are you running a turbo? No you said you're running a Vortech supercharger. This unit does not "build boost" or "make max boost faster." The PRESSURE measured in PSI that you're reading on the gauge is irrelevant. The CFM (cubic ft per min) volume of air that your blower is puting out at any given rpm is dictated by the size of the pulley driving your compressor, and the rpm of the engine. :bored: If you do ANYTHING to get more air into your cylinder then you will a LOWER psi reading on you gauge.

Your explanation of air/fuel ratio is an indication that you're not really grasping the fuel injection system on this car all together, nor the fundamentals of supercharging all together.. Some reading over in this section would do you good: The Blower Bistro - SVTPerformance