Hello all,
Kinda in a pickle here, but would anybody care to share the timing & fueling compensation tables when going IMRC delete ? This is for a 2017 Mustang GT w/ 2020 intake manifold with matching air box. Many thanks !
IMRC delete - timing & fueling
Hello all,
Kinda in a pickle here, but would anybody care to share the timing & fueling compensation tables when going IMRC delete ? This is for a 2017 Mustang GT w/ 2020 intake manifold with matching air box. Many thanks !
huh? not sure what you are asking for.
Ford introduced mapped points 15-26 when IMRC was added to the gen 2 coyote. Mapped points 0-13 became the ones used for the IMRC closed. Cam angles are nearly identical for all these points and the only difference being IMRC opened or closed.
Deleting the IMRC is just basically deleting all this extra calibration and using 14-26 as gen 1 coyotes used 0-14. OR turning 0-13 back into calibrated IMRC open points. What you are asking, depends a lot on the strategy taken for IMRC delete. Some one could even have come up with a completely different set of mapped points for doing it, like something crazy like 9-22.
Mapped points for:
speed density compensates for any fuel differences closed vs open (think pressure multiplier in injector data, inferred rail pressure vs inferred MAP, yeah you are getting deep in the math)
borderline/ MBT compensate for any spark differences closed vs open
torque model compensates for any torque differences closed vs open
All just by using 0-14 or 15-26 mapped points depending on IMRC position.
Blending occurs when IMRC plates are in transition/motion, mostly 6,7,8,9 transitioning to 18,19,20,21,22. This is hard to catch and see in a log. 3,4,5 transitions to 16,17, but in, even less likely scenarios. Even with its limited applied time, Ford calibrated this, for the best drivability. You can get an idea of the changes needed comparing these points.
15-17 might be slightly different from 18+, but you should see the pattern.
Heres an example of removing that transition.
Stock SD mapped points compared
IMRC differences.jpg
SD mapped point fixed for no IMRC.
IMRC differences fixed.jpg
Then with some smoothing done to RPM column 3225, calculate new coefficients, load transitions even better for no IMRC.
IMRC differences smoothed more.jpg
When working on this you have to keep in mind where the most restriction in the intake is, throttle blade vs IMRC plate. Very similar to tuning PD blower bypass valves.
Last edited by murfie; 11-05-2021 at 04:51 AM.
Thank you for the detailed explanation !!
Murphy is very technical. In super layman terms... You dont have to make any fueling or timing changes. Just turn off mapped points 0-13 which use imrc runner control.
Technical doesn't bother me. It just takes longer for me to figure out. Thanks for the short answer !Originally Posted by ishyne22
It’s more then just disabling mapped points 0-13 you need to make adjustments in the imrc tab as well
not really "have to"...
v-performance.pl/
facebook.com/veee.performance/
https://www.instagram.com/v.performance.pl/
Remote tuning:
[email protected]
+48 697276579
I did this a few months ago on a gen2 and it was more difficult than the imrc tab might have you believe. Everything intuitive I tried resulted in disabled knock advance. Yes, if it detects an imrc error, it will disable knock advance.
I’ve never really found a quick easy way to disabled imrc and just have it drive like stock I guess it don’t exist lol
Majority of the tables following specifically the mapped points will need to be adjusted. Borderline, MBT, Torque/Inverse. Simply put, every day normal driving is mapped points 0 - 9, Optimum Power is 14-25, or the IMRC Open mapped points. You have to tune spark and the torque/inverse tables to run better, less aggresive in the IMRC Open tables, primarily in 14-19. You can have VCT and spark running 99% stock using 14+ without changing any of the mapped point cam angles.
Your main adjustment would be the Fuel Economy and Fuel Economy Mapped Point tabs. This is where you'll set VCT to run the correct cam angles if stock-like cam angles is what you desire, this is the table you'll adjust. Rather wanting stock-like angles or not these two tables must be changed as well as Optiumum Stabililty and Emission Reduction. If your strategy has Manual Launch distance, that will also need adjusted.
Your Torque/Inverse tables will have slightly higher torque in the lower loads in the IMRC Open mapped points. The numbers may seem minimal but are enough to cause drivability problems.
Borderline and MBT will be too advanced and the calculated torque produced will be too high or low in certain areas. You can correct a good amount of your drivability issues by correcting your Borderline and MBT Tables correctly.
Extra attention must be given to the IVO and EVC mapped point angles.
Stock 0, 1, 2 cam angles are now only ran in 0 and 15.
3, 4, 5 are ran in 16 and 17.
3, 4, 5 have EVC angles 20, 35, 50.
16, 17 have EVC angle of 20 and 50. You must use the distance tables to achieve mapped point 4's EVC angle of 35.
Excel is one of the best tools .
Last edited by Thatwhite5.0; 11-30-2021 at 05:52 AM.
This was a huge help, and solved all the issues I was having ! Many thanks and a virtual beer to you !!
Do you guys have a guideline for me and my 2018 gen3 5.0? I had to delete IMRC (clearance to firewall of kit car) and the flaps are permanently open.
I'd really appreciate it.
I have a 15 GT with the 18 manifold, IMRC lockout, Longtube headers, No cats, straight pipe, JLT Intake,
I did this tune but at low rpm it is very unstable, I really don't know how to fix it, could you help me
tune file Mustang Itasha 2015 IMRC LOCKOUT TUNED JLT NOCATS VERSION Manifold 2018.hpt
Give this a try. Should put you in the ballpark.
Reply With Quote