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Discussion Starter #1
I really hate the idea of hooking my IMRC's up.

This is why,

1 I can't seem to get them open by hand so how is this little box going to?

2 I could spend the extra money for the controller on something useful.

3 I guess I don't truly understand them, and just like all people who don't understand something I hate them and want them gone! haha

4 My programmer is saying he can get more power out of the tune if I leave them off...

Any Ideas???

Motor 1997 Mark8 DOHC Car 1997 Cougar Sport Swap Soon...
 

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i would also advise you against doing an IMRC delete....you will lose precious aircharge velocity at low RPMs which helps fill the cylinder and promote swirl....this high aircharge velocity is crucial for better torque production at low RPMs, and we all know how the early 4V motors aren't exactly torque monsters with those two huge intake ports.....my verdict for your application: dont do it
with regards to your tuner being able to get more power, i thought you didnt care about top end power, since it wont be a race car?........besides, the intake ports on those 4V B-heads are HUGE......i doubt the IMRCs are holding anything back, and if they are, it would be above 5000 RPMs.....how often will you be over 5000 RPMs on the streets??
 

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Would removing the IMRC's give more flow per cylinder across the whole RPM range? At least, a little bit?
 

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I ran around for a month without them hooked after my swap. Even with 3.73 gears it was terrible down low. Once the motor was spinning about 3 grand the car took off like a switch was flipped. The imrcs improved the low end more than you'd think. For the summer I'm also pulling the 3.73s in favor of 4.30s, that should tell you something about 4v low end torque.
 

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Would removing the IMRC's give more flow per cylinder across the whole RPM range? At least, a little bit?
you're missing half the picture...you cannot talk about mass airflow rate (#/min are the units), without talking about the cross-cross sectional velocity....even if it could gain a little in mass airflow rate, the huge drop in cross-sectional velocity will hamper torque production, because the air wont swirl to disperse the fuel within itself for even-combustion......this is because the engine is simply not turning fast enough for the air to come rushing in fast enough through the intake ports into the cylinder
 

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If you can't open them by hand I would bet you are not going to get them to open with the controllers.
Seafoam soak might be needed to free them up.
 

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Discussion Starter #9
If you can't open them by hand I would bet you are not going to get them to open with the controllers.
Seafoam soak might be needed to free them up.
I'll need to try something since both of them are stuck. I tried opening both by hand and all they did was start to bend a little so I did not try harder in hopes of not braking them.

Next question, for all. If I can get them un stuck could I get the IMRC vacuum setup off a Gen1 and just use the vacuum controllers?

I understand the shape of the spacers is not the same so I could not use them however could I not just remove the vacuum controllers
 

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I'm a little confused, are you trying to put a Mark motor in something else? Why wouldn't you just leave it with the stock setup?

As for the IMRCs, definitely don't get rid of them. You will lose low-end torque for little to no gain on the top end. That is a bad idea on a street car. Keep the IMRCs there, and make them work properly. If you don't, it will make your car noticably slower.
 

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Discussion Starter #12
Well I am going to clean the IMRC's back up and get them moving after that I want to buy an MSD Window Switch since it looks like a fun toy to play with!

What RPM's do they open and close from the factory?
 

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Discussion Starter #13
I'm a little confused, are you trying to put a Mark motor in something else? Why wouldn't you just leave it with the stock setup?

As for the IMRCs, definitely don't get rid of them. You will lose low-end torque for little to no gain on the top end. That is a bad idea on a street car. Keep the IMRCs there, and make them work properly. If you don't, it will make your car noticably slower.
I was wanting to use the GEN 1 style IMRC's since they are controlled by vacuum rather than electronics but I think I'm going to use the Gen2 style since I got looking around and found a cool MSD Rpm Window switch.

I would however like to move the IMRC controller since I plan to do the Driver Side head cooler mod I'll need to move it.
 

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The IMRCs on my 97 engine were stuck open; bet that ran good... :)

They should rotate on the springs, unless crud is holding them closed.

They can be disassembled and cleaned, but it's a drag.

The motor drive pulls against the springs to open the imrcs; the springs pull them closed.

Be careful with metal scrapers, it's plastic.
 

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The factory setting was to open them at 3000 rpm.

I am aware that a couple tuners use 2400 rpm as the new point when doing a custom tune.
 
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