A couple of questions about procharger and knock

[ugstang17]

Load on my current setup (11-12psi) is 1.72 at WOT at 7500 RPM on the dyno. Thats a 2300 TVS PD setup with a twin 67mm TB and JLT 125mm air intake tube. Elevation is around 480 FT above SL.

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[markmurfie]

Load is how much air pressure made it into the cylinder. 1.0 would mean when the valve closed you had 1 atmosphere of pressure in the cylinder.

If you have 10 PSI of boost over atmosphere in you manifold and are only getting 1.3 load, the cylinder is not filling all that well.

I dont think your load is really even getting that high. Usually load is MAF(lb/min) divided by RPM, divided by 4, divided by .00167. .00167 is the air mass in one cylinder when it is full to 1 atmosphere of pressure.

You can not trust your MAF lb/min. if you look at the MAF hertz compared to it, they rise with the same slope, and fuel trims are happy. then at ~6250 the Lb/min rise sharply but the MAF hertz does not indicate airflow doing this, you see the fuel trims go rich.
If fuel trims stayed near 1.0, your lb/min would not have been much higher than a NA car. Meaning you are not making any boost, or none of it is getting into the cylinder.

 

[kstarnes72]

Load is how much air pressure made it into the cylinder. 1.0 would mean when the valve closed you had 1 atmosphere of pressure in the cylinder.

If you have 10 PSI of boost over atmosphere in you manifold and are only getting 1.3 load, the cylinder is not filling all that well.

I dont think your load is really even getting that high. Usually load is MAF(lb/min) divided by RPM, divided by 4, divided by .00167. .00167 is the air mass in one cylinder when it is full to 1 atmosphere of pressure.

You can not trust your MAF lb/min. if you look at the MAF hertz compared to it, they rise with the same slope, and fuel trims are happy. then at ~6250 the Lb/min rise sharply but the MAF hertz does not indicate airflow doing this, you see the fuel trims go rich.
If fuel trims stayed near 1.0, your lb/min would not have been much higher than a NA car. Meaning you are not making any boost, or none of it is getting into the cylinder.

Does this indicate boost leak?

 

[markmurfie]

From your first log, and this latest one, I thought your BOV was not closing.

The MAF signal in this latest one looks a bit better. smoother, less choppy. Still pretty bad relatively.

 

[sloride]

From your first log, and this latest one, I thought your BOV was not closing.

The MAF signal in this latest one looks a bit better. smoother, less choppy. Still pretty bad relatively.

Good idea to also verify the BOV is closing properly

 

[kstarnes72]

Good idea to also verify the BOV is closing properly

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[kstarnes72]

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So I added a manual boost gauge and I am getting 10-11 pounds of boost but load is still low. I have my irmc like this picture attached. If bypass valve was not working I would not build 10-11 pounds of boost at gauge correct.
https://datazap.me/u/kstarnes72/log-1580685807?log=0&data=12
Latest data log

 

[markmurfie]

Have you tried removing that small cap, and just have the top ports of the solenoid go to atmosphere?

If it's holding a vacuum that got built up, and not letting the diaphragms outgas, they will remain closed.

 

[ugstang17]

Have you sent the logs to Lund?? I am a PD person. I have never had to deal with IMRC devices. No sooner than a car with those has them, the intake is yanked and a blower sits in its place. The next thing you should probably do as mentioned above is verify your IMRC devices are actuating smoothly and that they are in fact opening when they should. I am not certain if they are motor or vacuum actuated on the S550. As I recall they were motor driven and PCM controlled on the 2005 I had but here again they weren't on long before the Saleen twin screw went on.

Sorry I can't help you more. I only have schematics and tech manuals for 2005 and 2011.

 

[ugstang17]

I pulled uot my advanced tuning book this morning. Calculation of theoretical fill is not that difficult. M= (Vengine)x(P air)x(RPM/2)

Density air standard is 0.00004671 (P air)
Engine Displacement is 302 CID (Vengine)
RPM - the RPM you seek to target. In this case I have used the peak RPM in the OP's recent log of 7569.

Remember that Ford calls the Coyote a 5.0L it is really 302 CID rounded up to 5.0L in the conversion. 5.0 Liters is actually 304.818 cid. This is why CID is used rather than Liters in the equation.

The theoretical fill (100%) of a 302 CID Coyote operating at 7569 RPM = 53.3857 lb per minute flow. At a load of 1.39 this equates to 74.206 lb per min seen by the MAF. The actual being seen by the MAF in the datalog is 71.95 which is well within tolerance. AFR is not going lean or being over corrected by STFT or LTFT. In fact I am jealous of how stable the STFT's are on this tune. So there are two things here you may wish to consider. 1.) It may be that Lund is scaling the values down that you are seeing in the tune in this case for some reason. Asking them about this would be the first thing to do so that you clear up the unknown. 2.) If they are not scaling then as mentioned by another contributor the IMRC plates may be restricting flow. Why your vac/boost gauge reads 10-11 (I assume that is constant and not just a peak and then settling lower on the pull) it may be tied in to a place in the vacuum system that may not exhibit actual boost being seen in the intake IDK. Again I deal with PD setups and vac/boost is picked up right on the intake.

Hope this helps you out.

 

[kstarnes72]

I pulled uot my advanced tuning book this morning. Calculation of theoretical fill is not that difficult. M= (Vengine)x(P air)x(RPM/2)

Density air standard is 0.00004671 (P air)
Engine Displacement is 302 CID (Vengine)
RPM - the RPM you seek to target. In this case I have used the peak RPM in the OP's recent log of 7569.

Remember that Ford calls the Coyote a 5.0L it is really 302 CID rounded up to 5.0L in the conversion. 5.0 Liters is actually 304.818 cid. This is why CID is used rather than Liters in the equation.

The theoretical fill (100%) of a 302 CID Coyote operating at 7569 RPM = 53.3857 lb per minute flow. At a load of 1.39 this equates to 74.206 lb per min seen by the MAF. The actual being seen by the MAF in the datalog is 71.95 which is well within tolerance. AFR is not going lean or being over corrected by STFT or LTFT. In fact I am jealous of how stable the STFT's are on this tune. So there are two things here you may wish to consider. 1.) It may be that Lund is scaling the values down that you are seeing in the tune in this case for some reason. Asking them about this would be the first thing to do so that you clear up the unknown. 2.) If they are not scaling then as mentioned by another contributor the IMRC plates may be restricting flow. Why your vac/boost gauge reads 10-11 (I assume that is constant and not just a peak and then settling lower on the pull) it may be tied in to a place in the vacuum system that may not exhibit actual boost being seen in the intake IDK. Again I deal with PD setups and vac/boost is picked up right on the intake.

Hope this helps you out.

Thanks for all the input guys, pulled that cap off irmc and behold load is way up in the logs.


https://datazap.me/u/kstarnes72/log-1580825718?log=0&data=12

Let me know but look much better to me.

 

[markmurfie]

That looks great! You could leave it and be fine.
I would not.

Contact Lund with what changes you made and new logs.

 

[ugstang17]

Send that log back to Lund and have them review them. Your load now indicates that the MAF should be seeing 104.89 lb of air at 7362. The datalog shows that your MAF actual is at 86.68 lb. There will be a little variation as my calculations are at sea level but IMHO a difference of almost 20 lb is a lot. Your AFR also now reflects a richer level. In previous logs as I recall you were right at .78 Lambda. Now you are at .70 - .71 Lambda which is much richer. The load is calling for more fuel than there is actual air in the charge. STFT's are trying to correct for that as well as they are down to .82 or so at the top end. STFT is correcting for 18%. The difference between my calculated MAF value at 7362 and the actual is 18%. This needs to be corrected IMHO by the tuner now that you have resolved your problem. Send the log to Lund. Let them know what you have found when you send them the logs. Then have them revisit the tune. It's too fat on fuel at this point IMHO. 0.78 - 0.82 is the happy spot for most FI setups.

Thanks for updating your findings. Helps others as well.

 

[markmurfie]

The maf Lb/min channel doesn't go higher than 86.68. So using it at this point can not be accurate. The actually calibration values most likely does.

It dropping from .78-.8 down to .72-.73 is catalytic protection. Fuel could be improved above 6k rpm a small bit, but it's with in 10% everywhere you had the pedal at 100%. Some times moving your seat forward a little helps you keep it at 100%.

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