VVT Cam phaser tuning

[akalshaikh]

Hi,

So a good friend of mine and I are bulding his 2015 Charger R/T 5.7
The car will have forged pistons and rods (Manley) Stock bore, stroke and crank (will be booster at later stages)
Compression calculated will be around 10.7:1
with the following cam specs:

BTR 2009+ 5.7 HEMI VVT CAMSHAFT KIT (Stage 2).
Intake Duration @ .050? Lift: 216
Exhaust Duration @ .050? Lift: 23X
Lobe Separation Angle: 112
Intake Valve Lift: .587
Exhaust Valve Lift: .586
Intake Lobe Lift: .356
Exhaust Lobe Lift: .355
Intake Lobe Lift @ TDC 0.053
.650 lift spring kit with tip saver.
BTR Gen lll hemi VVT phaser.

My concern and inquiry, With the VVT phase limiter which tables do I change (if required).
Is it as simple as pulling degree out of the normal table under airflow / variable camshaft or is there anything specific to do as a solid start?

I will be uploading his stock file as the car is currently stock. I've done many cammed hemi's before but all have been pre-eagle engines 2004-2008.
I've searched the forums as well for a solid tune upload of anyone who has dialed is a phase limiter on hemi's but couldn't find one.

[james1595]

Go to engine>airflow>variable camshaft. From there you can adjust the exhaust cam phaser tables, intake does nothing. For simplicity, you can make all the tables the same, but dont have to. But to start, id start with advancing youre cam all the way to max of 125 till around peak torque (4k-5k) then retard the cam to your shift point. So id say 125 till 4k, then about a degree every 500 rpm(ish) till 120 at 6500 rpm

[LilSick]

I've done many cammed hemi's before but

do you check the ex centerline (degree the cam) and check v2p (valve to piston) clearance?

[akalshaikh]

Go to engine>airflow>variable camshaft. From there you can adjust the exhaust cam phaser tables, intake does nothing. For simplicity, you can make all the tables the same, but dont have to. But to start, id start with advancing youre cam all the way to max of 125 till around peak torque (4k-5k) then retard the cam to your shift point. So id say 125 till 4k, then about a degree every 500 rpm(ish) till 120 at 6500 rpm

I'll give that a shot and I'll upload the file here just to confirm if my changes correct.

do you check the ex centerline (degree the cam) and check v2p (valve to piston) clearance?

The engine builders does!

[akalshaikh]

So attached is the stock file and the file I made just to get it started properly.

Am new to VVT things so I this might be a stupid question,

What affect does advancing or retarding the VVT angle does to the car?

the stock figures were around 100 +/- at WOT and now i've set it to 120? so what is actually happening mechanically and electronically?

Since we will be installing the cam phaser what does 120 - 125 degree of angle does to the system and why specifically those figures?

I am just trying to get an idea of what is going while changing these parameters.

[Hemituna]

The numbers in your Cam File 1 tune should work pretty well.
Your tune has the cam at full advance (125) till 4k and then retards a total of 5 degs (120) after that.
BTR's cam card says similar, full advance till 4k and 8 degs retard at 7k.
So BTR would be using 125 till 4k then down to 117 at 7k.
Easy peasy.

[james1595]

So attached is the stock file and the file I made just to get it started properly.

Am new to VVT things so I this might be a stupid question,

What affect does advancing or retarding the VVT angle does to the car?

the stock figures were around 100 +/- at WOT and now i've set it to 120? so what is actually happening mechanically and electronically?

Since we will be installing the cam phaser what does 120 - 125 degree of angle does to the system and why specifically those figures?

I am just trying to get an idea of what is going while changing these parameters.

There is a really good thread on here about the vvt cam tuning. I cant remember what its called, but its on the forum here. Short story is, the cam faser moves the cam, either advancing or retarding. Advancing the cam alows for more low end torque, while retarding alows more top end horsepower. Aftermarket cams are to big for the full vvt range, so you limit it. The computer still thinks the factory cam is installed, so you sont have to try and over complicate it, trust me, took me awhile to figure it out.

[akalshaikh]

The numbers in your Cam File 1 tune should work pretty well.
Your tune has the cam at full advance (125) till 4k and then retards a total of 5 degs (120) after that.
BTR's cam card says similar, full advance till 4k and 8 degs retard at 7k.
So BTR would be using 125 till 4k then down to 117 at 7k.
Easy peasy.

Here comes my concerns here
1) There is no 7000 rpm range on the table as they max out at around 6000 rpms.
2) To me knowledge and based on what i've read, Advancing the exhaust cam degree is actually retarding it, so should I go 125 or -125 to actually advance it?

There is a really good thread on here about the vvt cam tuning. I cant remember what its called, but its on the forum here. Short story is, the cam faser moves the cam, either advancing or retarding. Advancing the cam alows for more low end torque, while retarding alows more top end horsepower. Aftermarket cams are to big for the full vvt range, so you limit it. The computer still thinks the factory cam is installed, so you sont have to try and over complicate it, trust me, took me awhile to figure it out.

Great, but as I mentioned above with regards to retarding or advancing the cam. i've read that intake and exhaust figures are inversely proportional as they rotate in opposite directions.

Advancing the exhaust cam angle (from 100 to 125) will actuall retard the cam angle by 25 degree and vise versa with the intake Unless i got it wrong.

thankfully Hemi's run only on exhaust tables so i will not worry about intake tables at all.

[james1595]

Like i said, it took me awhile to figure it out. But you are correct and incorrect. You are correct in that it is opposite, meaning that as the cam advances, the exhaust retards, but most people speak from the exhaust side when revering to cam tuning on the hemi. As for the rpm, you cam adjust your tables axis to what ever you want. Also 125 is max advance, you can not go negative, but the phaser stops that from happening. I can psot an example file later of your tune to deminstate what i mean

[akalshaikh]

Like i said, it took me awhile to figure it out. But you are correct and incorrect. You are correct in that it is opposite, meaning that as the cam advances, the exhaust retards, but most people speak from the exhaust side when revering to cam tuning on the hemi. As for the rpm, you cam adjust your tables axis to what ever you want. Also 125 is max advance, you can not go negative, but the phaser stops that from happening. I can psot an example file later of your tune to deminstate what i mean

That will be very helpful.

The cam just got delivered, I noticed that BTR recommends a total of 8 degree retard from 5500 RPM and higher for this cam.

But it seems weird that they want 8 degrees of retard while they recommend a 4 degree phase limiter for this cam (which they already included in the kit).

I'll keep it as is at 5 degrees for now and will see if retarding it more will have significant gains in the dyno

Find the attached image

[james1595]

That will be very helpful.

The cam just got delivered, I noticed that BTR recommends a total of 8 degree retard from 5500 RPM and higher for this cam.

But it seems weird that they want 8 degrees of retard while they recommend a 4 degree phase limiter for this cam (which they already included in the kit).

I'll keep it as is at 5 degrees for now and will see if retarding it more will have significant gains in the dyno

Find the attached image

Cam File 1 cam tuning.hpt here is a file of a tune changing only the cam phasing. should work pretty well, but adjustments can be made sense im not sure where your peak torque is

[akalshaikh]

Thanks for the file, I was about to use the hellcat scaling as they go all the way up to 6500.

once the car is done we'll flash the file and get it dialed in further. I'll keep this post updated and have the dialed in VVT figures posted here for anyone who will be looking for a starting point.

[akalshaikh]

So, Car runs but not great. Throttle response is amazing, idles rough a bit I am thinking its because of the cam

AFR at idle shows 14.5-15.0 using a wide band

My main concern now is it takes very long to start up. Lots of cranking

attached is a log file with the actual file it self.

I went through several YouTube videos but nothing helped the cranking TBH.

[JohnnyFW]

you need to dail in your VE tables when the car is warm after that you will have to play with startup airflow or startup injector pulse

[akalshaikh]

you need to dail in your VE tables when the car is warm after that you will have to play with startup airflow or startup injector pulse

Will do, thanks for the input..

Fir cammed hemi i usual take 10-15% off of start up fuel and it always works, so correct me if am wrong

[JohnnyFW]

that should be close in most cases

[edcmat-l1]

VE tables aren't correct I can tell that at a quick glance.

Looks like there is probably a lot more wrong than just that though from looking at the data log. The timing is steady in the negatives. Shouldn't be that way. MAP Kpa is too high numerically which means vacuum is really low even for an aftermarket cam.

[akalshaikh]

The wideband says my AFR are dialed in almost at 14.7 more or less
LTFT and STFT are in range for during idle.
LTFT is around -3 and STFT is zero.d

Car has higher compression ratio its around 10.72

Everything is running fine now except the long cranking

[akalshaikh]

Update:

Car starts perfect now, idles great

The change was in Start up injectors PW Scalar.

[akalshaikh]

Soo,,,

I am not sure if there is anything wrong or not.

Car currently has 60 lb/hr injectors & fixed the injector data.
Also, it has 6.1 intake manifold.

Why: it will be boosted within two or three months..

Now, for some reason as mentioned above the car is idling and drives in the higher side of the maps as you can see in the logs. I am not sure if the reading is correct or not or if its caused by higher compression ratio from 10.5 to 10.72

Another annoying issue is cylinder 1 and 7 misfire after high rpm.

I've altered the minimum spark to bring the idle spark a bit up, the car still needs work on tuning side which I am learning as going further with it.

Can someone shed some light with the tune file which is attached.

Edit: I've noticed that misfire goes away once o reset the adaptation.
When i do another high rpm pull >4000 rpm the misfire comes back. Amd only foes away after i reset the adaptations.