TiVCT timing on Coyote for most power

[tramotorsports]

Ideally you would dial in the fuel and ignition timing along with all off the attempted VCT breakpoints. This would obviously take an extremely long time to do properly but will give the best results. As cam timing changes so will cylinder pressure, So where changed cam angle shows less power it may have optimally put you in a better spot if the ignition and fueling were also dialed in.

[txcharlie]

I had my suspicions about spark. I had tried some different VCT combos and noticed on some of the runs I had picked up some knock and nothing was changed but the VCT.

[kris5597]

Ideally you would dial in the fuel and ignition timing along with all off the attempted VCT breakpoints. This would obviously take an extremely long time to do properly but will give the best results. As cam timing changes so will cylinder pressure, So where changed cam angle shows less power it may have optimally put you in a better spot if the ignition and fueling were also dialed in.

Very true. This would take a lot of time, but would definitely be worth it. During the process of dialing in each VCT breakpoint you setup, fueling and ignition should be dialed in to get the best results of each cam angle. Once its done, overlay each dyno pull with each VCT bracket and pick your VCT advance for each rpm breakpoint for both intake and exhaust and build your final VCT map. I have had such good results doing this on previous engines I've tuned, this one would obviously take longer and be more of a pain to do, but would definitely be worth it.

Kris

[LSxpwrdZ]

It can be done by monitoring the MAF at a certain rpm on a WOT pull. If it pulls in more air at a certain RPM with xx cam events then it is making more power. Thats for you guys that do not have a dyno at your disposal...

[kris5597]

Ah, good tip. Anyone have any experience tuning a 2015 VCT?

Kris

[MikeOD]

It can be done by monitoring the MAF at a certain rpm on a WOT pull. If it pulls in more air at a certain RPM with xx cam events then it is making more power. Thats for you guys that do not have a dyno at your disposal...

That's how I got actual numbers to compare on the tune I mentioned above.

[tramotorsports]

It can be done by monitoring the MAF at a certain rpm on a WOT pull. If it pulls in more air at a certain RPM with xx cam events then it is making more power. Thats for you guys that do not have a dyno at your disposal...

Good call. I'm getting spoiled with this dyno. haha

[tramotorsports]

Ah, good tip. Anyone have any experience tuning a 2015 VCT?

Kris

That's what I'm referring to. It the same concept.

[kris5597]

Yea, I wouldn't think it would be any different of concept however, since the 15 had different cams, valves, and heads, there are differences in the tune. I glanced at a 15 stock map and the intake cam actually goes into retard passed 4000 or so, the 12-14, always stays in advance. Just wondering if anyone on here is seeing similar results.

[txcharlie]

Is the efficiency of VCT timing directly related to engine itself or is it effected by Forced Induction? If I go through the process of finding best cam timing setting for my TVS, will it need to be repeated when I go turbo?

[SultanHassanMasTuning]

look into overlap and boost, usually you dont need must timing advance

[kris5597]

Is the efficiency of VCT timing directly related to engine itself or is it effected by Forced Induction? If I go through the process of finding best cam timing setting for my TVS, will it need to be repeated when I go turbo?

VE is found tuning VCT on the setup at hand. Ideally a turbo setup and supercharger setup SHOULD have similar VCT tables to an n/a car. The VCT curve should look a little like the torque curve, at least that's what I've seen in the past.

[txcharlie]

VE is found tuning VCT on the setup at hand. Ideally a turbo setup and supercharger setup SHOULD have similar VCT tables to an n/a car. The VCT curve should look a little like the torque curve, at least that's what I've seen in the past.

So it is most effected by cam profiles, engine compression and head design vs. boost?

[AKDMB]

One thing I forgot to mention, you will want to work on the VCT tables after fueling and ignition is dialed in. From there, depending on how the VCT adjustmen's go, you may be able to add more timing, and your fuel trims may need to be adjusted for as well.

Dialing in the MAF voltage first could be a way to see if VCT adjustments are increasing or decreasing airflow based on large fluctuations in fuel trims. Probably not the most ideal, but could aid for street tuning.

Kris

Catching up here, even if you have your MAF curve dialed in, you have to make adjustments to it after VCT tuning? How far off will it be? Also, say you get your ignition timing dialed in and you are right at the knock border, should you think about dialing in VCT? If you are going to create more cylinder pressure and in turn knock? The thing I don't get is what role the VCT plays in building cylinder pressure when ignition timing can give you all the cylinder you want (I think). Real noob here, just trying to understand.

[kris5597]

So it is most effected by cam profiles, engine compression and head design vs. boost?

Exactly, think about it this way. If you tune the car N/a, you are finding the most efficient way for air to flow through the engine at all rpm breakpoints. If you add boost to the mix, it should be very similar. Spool up for a turbo will be different but once in boost, it should be identical VE curve, just a lot more power.

[kris5597]

Catching up here, even if you have your MAF curve dialed in, you have to make adjustments to it after VCT tuning? How far off will it be? Also, say you get your ignition timing dialed in and you are right at the knock border, should you think about dialing in VCT? If you are going to create more cylinder pressure and in turn knock? The thing I don't get is what role the VCT plays in building cylinder pressure when ignition timing can give you all the cylinder you want (I think). Real noob here, just trying to understand.

Tune the MAF first, then target lambda and ignition at WOT. Once these are done, then you work on VCT. If you increase/ decrease overlap, and the engine theoretically makes more torque/ power, fuel trims should add fuel and MAF airflow should increase. If it does not like the increase in overlap or decrease in overlap. You should see MAF airflow and trims fall off. Tuning a 11-14 cams will be a lot simpler than 2015. When tuning VCT, lock cams at a set advance/ retard, do a pull, record results. If the fueling or ignition needs to be adjusted on the pull, do so and repeat pull. Do this for ever 10 degrees of cam adjustment, 10, 20, 30, 40, 50. After all pulls are done, look at all logs at each rpm breakpoint to choose where cam advance was most efficient, then build VCT map based on this information.

Hope that wasn't too complicated.

Kris

[AKDMB]

Thanks! I think I have a pretty good strategy now as to how to approach the tune.

[txcharlie]

Exactly, think about it this way. If you tune the car N/a, you are finding the most efficient way for air to flow through the engine at all rpm breakpoints. If you add boost to the mix, it should be very similar. Spool up for a turbo will be different but once in boost, it should be identical VE curve, just a lot more power.

Thanks Kris!

[kris5597]

Wherever you see VCT start to drop, that's where VE is starting to drop as well as the torque curve.

How's the car running Txcharlie? I've gotten into my 2015, and I must admit, it's been very fun and a definitely learning experience so far. SO MANY torque limiting tables.

[txcharlie]

Wherever you see VCT start to drop, that's where VE is starting to drop as well as the torque curve.

How's the car running Txcharlie? I've gotten into my 2015, and I must admit, it's been very fun and a definitely learning experience so far. SO MANY torque limiting tables.

I have solved my MAF tuning issues. It was related to my fuel system setup. I'm slowly fine tuning spark now. Must be on the right track as I caused a P061b a couple days ago.