IMRC question

[Chris_Murder]

Is there anyone running around with a tune and an IMRC delete on a N/A first gen? I've heard this two ways....but I'm looking for the truth

Here what I've been told from 3 different forums
1: If you delete the IMRC's on an N/A gen 1 or gen 2 it will be a complete dog off the line unless you have a high stall tc and 4.10, 4.30, 4.56, 5.11's in the rear.

2: If you delete the IMRC's on a gen 1 or gen 2 and have it tuned you will expierence no bottom end power loss and will increase power most at the top.

I assumed that the truth is with the first one but I'd like to know if anyone has a side by side dyno graph available to compare, stock vs fabricated deletes, or stock vs mmr/ford racing deletes, or even fabricated deletes vs mmr/ford racing deletes.

I've also heard that if you switch from a gen 1 intake to a 96-98 cobra intake with deletes you'll still notice a power gain even down low....again it seems too good to be true so I assume it's not but I just wanted some feedback from other members. Hopefully to clear this up for me with some real world feedback.

I like to drive my cars daily so any low end power loss or driveability problems with them removed are a major concern for me.

Thanks,
Chris_Murder

 

[Rich88LSC]

I have seen graphs on Cobras. You pretty much lose down low what you gain up top after a tune. The factory tune pulls timing with the IMRCs closed that will affect power with deletes also. Sean had run deletes on a Mark with a higher stall TC and 3.73s and still did not think it's worth it.

I can't see the Cobra intake helping at all as it has a larger plenum and shorter runners.

 

[DLF]

1 is true.

2 is partially true. You can tune away some of the loss, not all, but you will gain up top.

I have deletes on my '98 Cobra, with dyno charts (the baseline was with the stock intake and deletes). I also have 4.56's in it.

+1 on the Cobra intake hurting at low RPM's, but it'll help up top.

I don't have any drivability issues with my Cobra, and drove it daily for quite a few years.

FWIW, I'm going to leave the IMRC's alone when I put a Cobra intake on my '98 LSC.

 

[Rich88LSC]

2 is partially true. You can tune away some of the loss, not all, but you will gain up top.

FWIW, I'm going to leave the IMRC's alone when I put a Cobra intake on my '98 LSC.

I didn't meant to sound like a tune will eliminate the low rpm loses but will make the most of the deletes. Still when I finally get the cams/PSR Cobra intake on the Mark I plan on leaving the IMRCs as well.

 

[DLF]

I didn't meant to sound like a tune will eliminate the low rpm loses but will make the most of the deletes. Still when I finally get the cams/PSR Cobra intake on the Mark I plan on leaving the IMRCs as well.

Rich, I wasn't commenting on your post, in fact, the +1 was me agreeing with you.

I was referring to the 1: and 2: statements of the OP.

 

[ripped camel]

So what should one do if they keep throwing a code that says the IMRC is stuck open?

I was under the impression that we don't have the part available anymore to fix that so I would be forced to get deletes.

 

[DLF]

So what should one do if they keep throwing a code that says the IMRC is stuck open?

I was under the impression that we don't have the part available anymore to fix that so I would be forced to get deletes.

What part?

Are you sure that it's not just a matter of cleaning them?

 

[ripped camel]

What part?

Are you sure that it's not just a matter of cleaning them?

It could be a matter of cleaning them. I'm not very knowledgeable about internals. Is it a matter of using like seafoam, or are you referring to disassembling and cleaning by hand?

The part I was referring to is some electronic controller that opens and closes the IMRC's. I have zero clue what that is but I swore I read that.

Are we able to get all parts needed for an IMRC rebuild?

 

[DLF]

It could be a matter of cleaning them. I'm not very knowledgeable about internals. Is it a matter of using like seafoam, or are you referring to disassembling and cleaning by hand?

The part I was referring to is some electronic controller that opens and closes the IMRC's. I have zero clue what that is but I swore I read that.

Are we able to get all parts needed for an IMRC rebuild?

Most often, you have to take the intake off and clean them by hand.

I don't know about the availability of the controller.

To check whether they need to be cleaned, or whether the controller is the issue, try to rotate the IMRC's by hand (engine off, of course!).

If you can easily, then it's either a controller, wiring, or cable issue.

If you can't or they are hard to turn, then they need to be cleaned.

 

[DLF]

To the OP.

Chris, Sorry that your thread has turned, but I hope I was able to answer your orginal questions.

 

[Rich88LSC]

The part I was referring to is some electronic controller that opens and closes the IMRC's. I have zero clue what that is but I swore I read that.

93-95, 96 and 97-98 are all different IMRCs 96 being the one year only and hard to find. 97-98 can use Cobra IMRCs.

 

[Chris_Murder]

Lol don't appologize for things beyond your control. This thread was informative. I went ahead and hand cleaned mine, along with a complete disassembly and reassembly. I tested their operation with a brake bleeder pump with a vacuum gauge before and after since mine are gen 1 and are vac operated. Before I cleaned them it took 15-17psi of vacuum to get them to operate. Now it takes 3-5psi. I'm very pleased. I also took the time to port match them to my intake. I've decided to keep them but I'll be adding an oil seperator in line with the pcv valve on this motor just like I did with my 2v to keep oil from entering the intake manifold. Hopefully that will help keep them clean.

 

[DLF]

I'll be adding an oil seperator in line with the pcv valve on this motor just ike I did with my 2v to keep oil from entering the intake manifold. Hopefully that will help keep them clean.

That will help a lot.