How to tune Ghost Cam (Solved+WriteUp, PCMTec)

[tdstuart]

What would really be cool is to use PCMTec multi-tune to have one slot be a ghost cam tune. In that way, you could switch it on and off easily just using the cruise-off button.

I would prefer not to use the multitune as it’s quite a bit more money. I also want the thread to be applied to people using hptuners if they are

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[mejohn50]

I would prefer not to use the multitune as it’s quite a bit more money. I also want the thread to be applied to people using hptuners if they are

HPT does not have the exhaust cam rate limit table defined in any of the OSes I have checked. It's not needed, as shown by people using HPT to do this and it works fine, but I have found both intake and exhaust rate limit tables to be helpful in not just tune switching but return to idle situations. It smooths out the transition from diving cam timing to ghost cam timing.

Either way, do like @engineermike said. The concept is the same on HPT and PCMTEC. Command a high overlap mapped point (or combination of mapped points to get the valve timing you want) at idle through the disatance tables then tweak torque values and MBT spark from there to get the sound and stability you want. There may be some other idle-specific settings that will help with drivability and idle stability as well, but you will have to play with it to see what works for you. You may also need to mess with max cam phasing limits in the idle areas as well, but my experience has been hit or miss on if this is needed and your cams may be a wild card for those values. The last thing I would do is slow the intake (and exhaust) cam rates in the idle areas so when it transitions back to ghost cam timing it isn't sudden.

If you set your distance tables up properly, it will only use the ghost cam timing values at idle and below whatever RPM you want (I use 1000rpm) then as soon as you step on the gas and/or go above your chosen RPM value it goes to normal cam timing.

If I were you, again like Mike said, I would make sure I had a good command of the mapped points controls before going down this path. I would also make sure I know the exact phasing limits those aftermarket cams need before doing any of this. Maybe the stock limits are fine, but I would make absoltely sure first.

 

[WildHorse]

I would imagine locking the cams at full advance, kill the idle timing, add a little more idle fuel.

 

[tdstuart]

I would imagine locking the cams at full advance, kill the idle timing, add a little more idle fuel.

Ya I understand the idea is the get the cams to overlap. I just have seen several different approaches. Saw some people setting by the car to be in optimal power mode at idle and depending on load it would exist optimal power

 

[engineermike]

I would imagine locking the cams at full advance, kill the idle timing, add a little more idle fuel.

Have you done this before?

 

[WildHorse]

Right at idle, aggressive valve timing lead to uneven pressure pulses within the intake and exhaust systems, creating a distinctive "lope" or choppiness in the sound of the engine.

Difficult to do well with a coyote.

A combo of LSA & Overlap will get you that chop.
Here's the stock cam (red) specs:

 

[engineermike]

I'll take that as a "no". Overlap is what causes the lope. Exhaust gas is drawn back into the cylinder during the beginning of the intake stroke because exhaust pressure>intake pressure and the overlap means both are open to the cylinder. The exhaust dilutes the air charge and causes a weak or mis-fire. Every so-many cycles, enough exhaust finally gets purged out and you get a clean fire. This mis-fire/clean firing alternating is what causes the lope.

And all the "instructions" in post #18 are incorrect.

 

[GregO]

Another rabbit hole thread by you know who !

 

[shogun32]

This mis-fire/clean firing alternating is what causes the lope.

Gah! We want this why?

 

[engineermike]

Gah! We want this why?

I hear ya. I did it. There's something visceral about it. Then 2 days later I put it back to stock idle specs and went on about my business. Things like this, pops-n-bangs, "fart shifts", etc are what I call novelty-tuning. They're fun to figure out and you learn something about the logic and controls along the way, but ultimately useless.

 

[steathv]

Shrader tuning in North Carolina, best ghost cam tune. Effective at idle only, ceases once you increase rpm. Lowers vacuum at idle just as a high lift cam would do. Use it on special occasions, prefer a performance tune for normal driving.

 

[tdstuart]

Another rabbit hole thread by you know who !

I thought that’s what forums are for

 

[tdstuart]

Gah! We want this why?

Same reason we modify the exhaust. Because it’s cool af and I’m jealous of all the Chevy boys

 

[WildHorse]

Because it’s cool af and I’m jealous of all the Chevy boys

Get custom cams & phase lockouts and you can be a cool kid too.

 

[tdstuart]

Get custom cams & phase lockouts and you can be a cool kid too.

I want to do a turbo setup with locked out cams. I’ve heard some cars with the setup and it sounded sick af

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