Coyote L&M aftermarket cam tuning questions`

[kjlindgr]

Hey all,

I have a set of upgraded intake cams from L&M (LINK HERE). They come with some initial tuning suggestions. The image of these are below. My issues is that I'm not exactly sure where to apply these changes.


cam_tuning.png

My hunch is that I could rescale and interpolate the suggested values to the tables below, but looking for a confirmation there. The other area I'm not sure how to apply are the suggested centerline values. The tuning suggestions seem to indicate that they are important. I don't see any location for "centerline" changes.

settings.png


If anyone has some suggestions on how I can get started, I would appreciate it!

[engineermike]

Centerline is just the traditional way to describe cam timing. Ivo/evc is how Ford controls it. You might notice in their chart that centerline is always IVO plus 120. The relationship is determined by the cam lobe profile. To make matters more complicated, the parked position and how 0 is defined changed some years.

[b00sty]

maybe have a chat with Shawn Perry @AED i know he's done a few.

[SultanHassanMasTuning]

what L&M sent you is probably for Gen 1 coyote

[kjlindgr]

The image from L&M was just a snippet. The top does say it's for a +2015 Mustang with their "intake only" cam package. What gives you the indication that this is for a Gen-1 mustang? I'm not pretending I know, just trying to learn.

[kjlindgr]

Centerline is just the traditional way to describe cam timing. Ivo/evc is how Ford controls it. You might notice in their chart that centerline is always IVO plus 120. The relationship is determined by the cam lobe profile. To make matters more complicated, the parked position and how 0 is defined changed some years.

The vehicle I'm trying to adjust this for has a FRPP. Where is "parked" position defined? I had assumed that this was the 1000RPM value in the IVO/EVC table, but I suspect that's not correct?

[engineermike]

Parked position is the cam position with no oil pressure or control being active. It is 0,0. However, this shouldn’t be confused with the actual cam event occurring at 0,0. If I understand correctly, look under airflow->variable camshaft->intake camshaft->intake valve open is 340. I believe this means that at an intake cam position of 0, the intake valve actually opens at (360-340=) 20 deg btdc on the exhaust stroke. So if you command -20, the intake valve actually opens at 40 btdc.

That said, the numbers from L&M look weird to me because they aren’t retarding the cam nearly as much as stock up top.

[kjlindgr]

The L&M cams have different/less breakpoints than the ECU has options for. Would you guys recommend that I populate and interpolate between the breakpoints or use a "stepped" approach between breakpoints?

[engineermike]

I’m pretty sure the stock algorithm automatically interpolates, probably linearly but possibly quadratically.

[kjlindgr]

Linear vs quadratic will make a pretty big difference I would guess.

But, to make the changes as per the tuning suggestions, would I make changes such as this? There are many more breakpoints in the OS than there are suggested points so I'm not sure what to do about that.

cam_modified.png

[engineermike]

That’s probably what I would do but I would be way more concerned about the maximum of -6 at high rpm vs stock going to +15. That’s a huge difference.

[murfie]

Its linear interpolation between cells. Quadratic you would have coefficients to work out. The ECU doesn't do regression.

Just populate the cells they give you(example 1 and graph). Then Interpolate between them if you want the resolution back(example 2 and graph). put the resolution where you are wanting more precise control of the cams to smooth the cam movements(example 3 and graph).

EXAMPLE 1

example 1.PNG

example 1 graph.PNG

EXAMPLE 2

example 2.PNG

example 2 graph.PNG

EXAMPLE 3

example 3.PNG

example 3 graph.PNG

[murfie]

That’s probably what I would do but I would be way more concerned about the maximum of -6 at high rpm vs stock going to +15. That’s a huge difference.

That's the increased duration making up for the need to retard the cams to move IVC. The bigger the duration, the less they need to move, the more they work at high RPM.

[engineermike]

That's the increased duration making up for the need to retard the cams to move IVC. The bigger the duration, the less they need to move, the more they work at high RPM.

You might be right but they are recommending to run IVO 21 deg more advanced than stock up top. In order to achieve the same IVC as stock, they would need to have 21 deg more duration but the description says “a few more degrees than stock”. Since IVC is usually much more influential than IVO, I would tend to believe IVC is already optimized in the stock tune for the stock cam, and that the “few degrees” larger L&M cam would add mostly on the IVC side. However, if you add “a few degrees” duration but advance IVO by 21 degrees then IVC would advance 15-18 deg, which is the part that doesn’t make sense to me. That said, I suppose L&M could have ground it on a different centerline, which would offset the whole IVO curve.

Another thing that seems odd is that the stock gen2 moves the intake cam a total of 35 deg at wot. Gen3 moves the intake cam 44 deg IIRC. But, L&M is only moving it 14.

[Plimmer]

I’ve dyno’d cam timing twice now, once as NA and once as turbo, so the only way you can get close to optimum is with a dyno. Here are a couple things I’ve learned that might help you:
The dyno won’t give you a precise answer, because no two runs are identical from a temp and time of day perspective, so you will need to log other parameters like MAF airflow, timing and lambda, then comparing hp to MAF flow to timing to lambda gives you a clue which setting makes most power.
In the tune hold the exhaust cam at close to stock timing, then make several runs starting with intake cam advanced to retarded. I would move it 5deg each time. Anything less will mean more runs and more confusing data to review
My experience shows that optimum is usually intake advanced 20 to 15 until about 5000rpm, then switching to retarded thereafter.
I’ve never been able to find anything significant from moving the exhaust around.
That’s my experience with a gen2 stock cams GT350 intake.

[kjlindgr]

Below is an update. The items that were changed on the car are the intake cams as discussed earlier and changed over to a 2018 intake manifold.

Some observations.
* EVC changes from the stock values to the suggested values made virtually no difference
* Keeping the IVO and EVC values stock made a fairly drastic decrease in power over the band
* Torque and power are down across the curve. Looking at the HP charts, they may have intersected somewhere around 6500RPM

Below are the settings I stopped at. Stock EVC values and suggested IVO values:

2021-04-06_2144.png


Below is the dyno chart. Blue is the stock cam, stock 2015 intake. Red is the L&M cams and 2018 intake. The original chart was not revved out all the way due to a fuel pump capacity issue at the time of the original tune.

DYNO.png


I guess I'm looking for some suggestions on where to go from here. I could just start swinging IVO values +/- 5 degrees to see what happens, but that just seems like a guess-and-check approach. Looking for some in put on targeted changes to make from those much more experienced than I am.

Thanks for the continued help everyone!

[engineermike]

Looks like the low end and mid torque went to crap. So the cam added “a few degrees” but advancing it 21 deg vs stock and it made more top end? It doesn’t add up. It almost acts like it has a bunch of retard ground into it.

I’m a little confused because you said the stock settings worked better but stopped at the recommended aftermarket settings. What was it set at for the dyno pull you posted?

[kjlindgr]

Sorry I wasn't very clear. The settings in the dyno were the ones I posted in #16, which were the "L&M Suggested IVO" settings and the stock 2015 Mustang EVC settings. In a couple runs, I flipped EVC settings from stock to "suggested" and it made no difference (IVO remained constant at suggested settings), so I just left it back to stock.

[engineermike]

So have you played with ivc at all?

[kjlindgr]

I did not, no. Those are still at factory settings