Change IRMC opening RPM?

[workmangc]

I'm running custom tune on my 98 via a handheld tuner. It looks from the dyno as though some more power/tq may be left on the table down low in the RPM band.

Does anyone know if there is a way to have the opening RPM adjusted?

 

[Napp E Roots]

o dam there has to be a way and that would be awesome

 

[STAMPEDE3]

I had it done on my SCT chip but not sure about with a handheld.

 

[Chris98vobra]

It is very easy to do with most tuning software. As said above, not sure if your hand held can though.

 

[TDUB003]

I would guess that you would have to have it done with a custom tune.

 

[na svt]

I'm running custom tune on my 98 via a handheld tuner. It looks from the dyno as though some more power/tq may be left on the table down low in the RPM band.

Does anyone know if there is a way to have the opening RPM adjusted?

A custom tune will can chagne the IMRC opening rpm. They are set to open at 3250 so opening the, later won't change performance below 3250.

The only way to know where to open them is to do a dyno run with the IMRCs closed till about 6k and another with them opening at the stock setting. Note where the powerbands cross and make that the opening point.

 

[mwolson]

A custom tune will can chagne the IMRC opening rpm. They are set to open at 3250 so opening the, later won't change performance below 3250.

The only way to know where to open them is to do a dyno run with the IMRCs closed till about 6k and another with them opening at the stock setting. Note where the powerbands cross and make that the opening point.

This is what we did for a local mutual friend of mine and na svt's. Turned out the optimum point to open the IMRCs was just a touch over 3K RPM. It smoothed and straightened the torque curve nicely.

 

[na svt]

This is what we did for a local mutual friend of mine and na svt's. Turned out the optimum point to open the IMRCs was just a touch over 3K RPM. It smoothed and straightened the torque curve nicely.

oh ya, forgot about that.

 

[workmangc]

Emailed my tuner. I'm going to send him the tune file and he will mod it for me. I have a stroker motor and on the dyno graph it seems to have a pretty obvious increase in tq/hp. I'm wondering if I open them a tad bit earlier if I can take advantage of this.

 

[Stephen4036]

offtopic but since i have the 98 4v in 00 GT i dont have IMRC's and we just left them open for now... is that going to hurt me in the LOW Rpms?

 

[MLS]

Yes. You need to do a delete and custom tune.

 

[na svt]

offtopic but since i have the 98 4v in 00 GT i dont have IMRC's and we just left them open for now... is that going to hurt me in the LOW Rpms?

You can use some zip ties and tie them open. The low end power will suffer until you have it tuned.

 

[Stephen4036]

You can use some zip ties and tie them open. The low end power will suffer until you have it tuned.

they are zip tied open. and i have a tune from VMP? do i need to tell him they are open?

 

[na svt]

they are zip tied open. and i have a tune from VMP? do i need to tell him they are open?

yes

 

[9804SNAKES]

Disregard...... found my answer. As you were.

 

[workmangc]

Got my tune modified. Received 2 separate tunes for 2 different opening RPM's. Don't know when I'll have a chance to get to a dyno for checking them out....

 

[96mystic_915]

well let us know how they do