Contour Enthusiasts Group Archives Forums Modifications Duratec Performance IMRC Opening Point

One more thing...since the programmer was actually at the dyno, he used his computer to change the opening point before each run...you know that thing that Diablo has trouble finding, he found it in 10 seconds and changed it before each run. I did about 16 total dyno runs to test out some intake mods and optimize my setup. I will try to get the graphs up soon, but work, school, and trips have taken up most of my time. I have some data that shows gains from the PCM reflash, MAFS & KKM, and an electric supercharger. Stay tuned.

This sounds very interesting!

I am very surprised you would throw away all this valuable collected data though...

Hi Demon, Please keep in mind that I saw the graphs and knew what the best point would be. Since there were no gains associated with this, I did not print it out. Don't worry, I went and got the graph today. All three scenarios are on one graph. I'll scan them so you can see the difference when I get the chance. I kept the graphs that showed gains, but again I'm just trying to find some time to do everything.

Thanks for the effort... I am interested in seeing any info you have...

Actually, dynos do lie. A dyno is nowhere near what the real world is -- ie, no airflow, etc. I've heard of many instances where a car or motorcycle was tuned to the best curve on the dyno and ran like crap on the track. A dyno should be used as a baseline, not gospel.

-Lance

I understand you point, but the dyno does not lie. It may not give track performance, but it is the only accurate way of determining exactly what power and torque you are putting down on the street. So what is the best way to measure a car's performance? On the track? What about the human error, track conditions, tire selection, etc? If you read my post, I was referring to the difference between 3 graphs with different opening points. I think it's safe to say that the dyno is gospel for that type of comparative analysis.

i think you took that out of context lance.

NYKnicksSVT - how much did it cost to do 16 pulls and several pcm flashes/reprograms?

i get a really good rate and something like that would run me well over $500. seems like alot of money to waste on imrc activation point.

Demon, do you have any Dyno graphs that show moving the IMRC open point does help?

Also, where did hear that the point was chosen just for emissions? I'm curious to hear. Because I just got done talking to the guy who calibrated the SVT, and his story was a bit different than yours. Wow, I'm so confused, I don't know who to believe, DemonSVT or the calibrator from SVT Engineering.

It seems that on my SVT, my Secondaries don't open until 3800rpms? Is this normal?

I loosened my screw (That adjusts the secondaries) and it seems to have made my car alot more fun to drive and alot more powerfull above 3200. I did seem to loose a bit more low end but I actually like it. I might try pinning them next. And the transition when the secondaries open up seems alot smoother.

Since I did this though, I seem to be running a little rich. My exhaust has been smothered in black soot.

Any clue???

Thanks and sorry for rambling!

The IMRC's open according to a curve that is a function of throttle position and rpm. the range (roughly, from memory) is between 3250 and 3800. And in general, the higher the throttle position, the sooner it opens.