TDStuart Tuning Adventure

[engineermike]

Here’s my causal logic:

aftermarket cams and gen3 manifold -> inaccurate SD model -> inaccurate manifold pressure -> inaccurate throttle body dP -> maf flow vs tb angle vs TB dP relationship mismatch -> incorrect calculated baro -> incorrect load at high throttle angles.

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[WildHorse]

How many OEM MAF sensors have you seen placed in a vertical duct riser vs. horizontally ducted ?

zero.

 

[tdstuart]

Me too. I think the MAF placement is less than ideal. Way to far from the TB.
At this point, I'd seriously consider putting the MAF closer to the TB if you wanna
keep the fender mount.

But I'm no engineer, and I'm sure James knows what he's doing.

The dude who does the PMAS stuff seems really knowlegeable and flow tests his stuff against competitors and the stock ones to make sure his is actually an improvement. He has a pretty cool setup

 

[K4fxd]

Tristan, is there any decrease in airflow with the stock CAI? I don't remember seeing any but I have not looked at all the logs.

 

[GregO]

inaccurate throttle body dP

Define this please, (dP)

 

[tdstuart]

Tristan, is there any decrease in airflow with the stock CAI? I don't remember seeing any but I have not looked at all the logs.

Hard to say because we didn’t have the PMAS dialed in. I would say we will probably see a 2 lb/min decrease with the stock.

 

[K4fxd]

Here’s my causal logic:

Which makes 100% sense. Although I have played with SD settings to find they do nothing. Gt350 IM also the Gen 3 truck manifold neither seem to respond to any SD changes I have made.

I'll admit I haven't gone down that rabbit hole far enough to draw any real conclusions. Just a trend.

 

[K4fxd]

Hard to say because we didn’t have the PMAS dialed in. I would say we will probably see a 2 lb/min decrease with the stock.

I'm using the Gen3 CAI, larger tube, and also have used the GT350 hot air intake and found no increase in airflow. I also have a fender well CAI that also shows no increase. This with all dialed in.

Unless you just want the looks I'd stick with a closed box.

 

[engineermike]

Define this please, (dP)

delta pressure, in other words barometric pressure minus manifold pressure. This pressure drop is what causes air to flow through the throttle body. Ford uses it to determine how far to open the TB to achieve a desired airflow, and apparently to determine what barometric pressure is.

 

[GregO]

delta pressure, in other words barometric pressure minus manifold pressure. This pressure drop is what causes air to flow through the throttle body. Ford uses it to determine how far to open the TB to achieve a desired airflow, and apparently to determine what barometric pressure is.

I would’ve kept up if written as Delta P
Thanks for the answer.

 

[markmurfie]

Sure you want to go down the road of adding a MAP sensor to the manifold and figuring out how to log its voltage?
This is looking pretty decent at WOT, and you can get in to the fine tuning of spark/ cam timing with out worry about your fueling being off.....

I like tuning SD, but its very math heavy and most people really cant fathom why its so complex.
Im more than happy to regress some coeffecients for you if you get me the logs with all the right data. Spot tuning the Ford SD is just not really possible.

 

[tdstuart]

Here’s my causal logic:

aftermarket cams and gen3 manifold -> inaccurate SD model -> inaccurate manifold pressure -> inaccurate throttle body dP -> maf flow vs tb angle vs TB dP relationship mismatch -> incorrect calculated baro -> incorrect load at high throttle angles.

But why is the baro affecting torque and why does setting the baro min fix this without actually making the baro stuck to 30?

 

[K4fxd]

Im more than happy to regress some coeffecients for you if you get me the logs with all the right data.

What parameters would you need logged? I'm at the point where I want to understand this aspect of tuning.

 

[markmurfie]

What parameters would you need logged? I'm at the point where I want to understand this aspect of tuning.

I need to know cylindar air mass. Perferrably with a MAF transfer no butchered by fuel trim corrections. Then using the air load PID is a must if the flow rate is above 86.68lb/min.
Locking the cams at their mapped points is the best way to do it. Thinks can be filtered by logging the MP weights, but its a ton of data management and never really comes out right.

Oh and of course a accurate MAP sensor, to get the correct MAP pressure, not just the calculated one. I can put in higher or lower pressures from what I see calculated, but I hate just guessing like that. Although Ive gotten fairly good at it using plausible VE numbers.

But why is the baro affecting torque and why does setting the baro min fix this without actually making the baro stuck to 30?

Barometric pressure is the driving pressure of any NA engine. Your engine has more torque at sea level than it does in Denver a mile above sea level.
You didnt add barometric pressure to the logs I looked at. Im sure if you set max and min the same, it was fixed at that pressure. dont confuse the MAP or TP MAP for the barometric pressure. Those pressures are on the other side of the throttle blade.

 

[tdstuart]

Sure you want to go down the road of adding a MAP sensor to the manifold and figuring out how to log its voltage?
This is looking pretty decent at WOT, and you can get in to the fine tuning of spark/ cam timing with out worry about your fueling being off.....

I like tuning SD, but its very math heavy and most people really cant fathom why its so complex.
Im more than happy to regress some coeffecients for you if you get me the logs with all the right data. Spot tuning the Ford SD is just not really possible.

Is the barometric pressure patch going to cause issues?

If it really won’t affect anything too negatively I don’t really care. As long as it won’t make drivability super bad or mess up my fuel trims / safety of the car I guess I don’t care too much.

How much work is it to add a map sensor and is it possible to get it hooked up to the pcm?

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