2015 GT Valve Overlap Tuning

[murfie]

At wot for peak ve you want the most overlap. Not only that but the more this can happen on the intake side the better. This means we are not missing anything. -20 is our IVO limit. You can increase overlap on the exhaust side but it won't help blow through just egr.

I'm not sure if our phasers have a physical limit of -20 or if you raise the limits they will actually go further. This is especially unsafe with out checking the engine clearance.
There's three things we can do. Be stupid and brave, tear apart an engine, or accept there is nothing more there with out aggressive cams and focus on partial throttle improvements. These new phasers claim 100* of range we are only using 60*. If mid lock truely means the middle then we should have at least 20* more over lap on the intake side. And a total range of 80*.So do you choose A B or C?

[rhinogt]

Go ahead murfie, try it out for us! #NOBALLS! Lol, JK

[murfie]

I've been looking at other tuners customers logs. None have more than -20 ivo. Physical limits are not something I usually mess with. I'm looking into exactly how different the 15 is from earlier engines. I may have to go and make friends with my dealerships service department to get the the information about specs and sizes I need. My plan was to stop by tomorrow for this.

[Higgs Boson]

The phasers video is not a Ford video, it's a vendor video. Ford set the limits according to their cams, valves, and pistons. Leave it at -20 for the max advance and if you want more overlap, get longer duration cams with faster ramp rates.

[murfie]

It is the only reason we can't get more from the vct. The 11-14, boss, and cobra jet have more than 40* advance. Not much more but maybe enough more for an actual difference. The only thing limiting could be the valve pockets in the pistons. They must have changed these in order to accommodate the new diameter and lift. Looking at the lift of aftermarket intake cams compared to stock the ramp rates are just steeper and lift is the safe on the after market cams as in same height on all cams(13mm). duration starts the same then expands to 275(using advertised to compare to what the 15 was advertised as) They don't require phase limiter modification to any of these cams. That to me would suggest the clearance of p to v should be ok for the stock cams to go more than -20. Since the stock cam opens the valve slower it wouldn't come as close to the piston with the same duration and less lift rate.

I'm not even sure if you can get the phaser to move more than -20. Mid lock to me would suggest that you can. I just want to obtain the stock specs just to be absolutely certain.

[Higgs Boson]

What specs do you have?

[murfie]

http://www.compcams.com/Base/pdf/COM...0Camshafts.pdf

for the stock cams I saw 263 intake and 263 exhaust with 13mm lift on both as well.

[Higgs Boson]

http://www.compcams.com/Base/pdf/COM...0Camshafts.pdf

for the stock cams I saw 263 intake and 263 exhaust with 13mm lift on both as well.

I thought you had stock specs for the 2015. Actual grind numbers rather than just advertised duration.

[kris5597]

It is the only reason we can't get more from the vct. The 11-14, boss, and cobra jet have more than 40* advance. Not much more but maybe enough more for an actual difference. The only thing limiting could be the valve pockets in the pistons. They must have changed these in order to accommodate the new diameter and lift. Looking at the lift of aftermarket intake cams compared to stock the ramp rates are just steeper and lift is the safe on the after market cams as in same height on all cams(13mm). duration starts the same then expands to 275(using advertised to compare to what the 15 was advertised as) They don't require phase limiter modification to any of these cams. That to me would suggest the clearance of p to v should be ok for the stock cams to go more than -20. Since the stock cam opens the valve slower it wouldn't come as close to the piston with the same duration and less lift rate.

I'm not even sure if you can get the phaser to move more than -20. Mid lock to me would suggest that you can. I just want to obtain the stock specs just to be absolutely certain.

10 degrees more of advance is only going to help us in the midrange, where peak VE is. I'm not worried about midrange peak torque, I'm more worried about holding torque better from 4500+rpm.

I did notice that as well. All aftermarket cams have around .016" or less of lift more than our stock cams, just more duration. That would leave me to believe there is more room to advance the intake cam on the stock cams to take advantage of the extra 10 degrees without V to P contact, but as you stated, perhaps the phaser is maxed at -20*

So far, there is only one spot I have noticed VCT tuning on the 2015 coyote actually made a difference, and that was below 3500 rpm. With more advance on the intake cam, the car picked up a little torque.

Kris

[murfie]

I thought you had stock specs for the 2015. Actual grind numbers rather than just advertised duration.

Thats what I plan to try to get today from my dealership.

They are going to have the foreman get them. Then have him call me back.

comp cams did not have them.

[Dolsvt00]

don't be defensive, this isn't that kind of forum. save it for yellow bullet.

I hope you find the gains you are looking for, have a nice day.

Who's defensive? I'm just sharing experiences.

I just come here for the discussion, you and a few others are really the only ones I see trying to have some open discussion about this anyway.

I guess I could say the same to you, this isn't mustang 6g don't try and start a war. Although, that would limit my daily entertainment....

So far, there is only one spot I have noticed VCT tuning on the 2015 coyote actually made a difference, and that was below 3500 rpm. With more advance on the intake cam, the car picked up a little torque.

Kris

About what Ive seen so far also.

[Higgs Boson]

Who's defensive? I'm just sharing experiences.

I just come here for the discussion, you and a few others are really the only ones I see trying to have some open discussion about this anyway.

I guess I could say the same to you, this isn't mustang 6g don't try and start a war. Although, that would limit my daily entertainment....

hmm, maybe I misread your post.

anyways, join in on 6G anytime, it's pretty funny.

[kris5597]

Alrighty, find found time off work to do this comparison. Pulls are back to back literally within 5 min, only to swap maps. Stock VCT and rpm breakpoints vs bracketed VCT and new breakpoints. Peak hp is possibly an anomaly and proving no difference in power there, VCT is not that different at peak hp anyways. Also, the car holds power a tiny bit better with a little more retard on the intake cam all the way to 7k. Car runs pretty solid for only E73 fuel, Steeda intake, Stainlesspower catless long tubes, factory connect delete with 2.5" exhaust. Tuned file is attached, only thing different is the intake and exhaust OP VCT.

[rhinogt]

What gear did you do the pulls in Kris? Same stretch of road for both pulls in assuming? That kinda confirms that there's not much to be gained at this time from vct tuning.

[kris5597]

3rd gear, sane exact road in the same exact spot. 5 min in between pulls. Thus confirms VCT tuning on the 2015 with factory intake manifold results in not a whole lot.

[esacteksab]

3rd gear, sane exact road in the same exact spot. 5 min in between pulls. Thus confirms VCT tuning on the 2015 with factory intake manifold results in not a whole lot.

Based on that will you do 11-14 w/o IMRC and/or BOSS, GT350, CJ intake? I'd be down to help fund these intakes if you can do the testing share your findings.

[kris5597]

Next will be boss manifold then the GT350. The IMRCs are important for 2015 fuel economy, and the car being my daily, that's not a bad thing to get the best fuel economy I can. However if the power is there, it's worth the trade off for the boss or CJ.

[caniggia]

Next will be boss manifold then the GT350. The IMRCs are important for 2015 fuel economy, and the car being my daily, that's not a bad thing to get the best fuel economy I can. However if the power is there, it's worth the trade off for the boss or CJ.

Sorry, but 2015 is not getting any better fuel economy vs 11-14, i tested both on same piece of road, same conditions, after installing supercharger, so removed IMRC 2015 is getting exactly same fuel economy as before, of course all tables were set to IMRC open, so using this same timing etc. So if you want to change manifold, do it.

[kris5597]

Not better than the 11-14. absolutely, but it's not any worse considering the 2015 has more aggressive cams in it. I would say that the IMRC's have a little something to do with that.

I remember @caniggia, you posted before that when doing the IMRC delete, you changed the VCT tables at partial throttle mapped points to be the same as the 11-14 but with the new base positions taking into account the IVO and EVC positions and you had good luck with engine operation, is that correct?

Kris

[caniggia]

Finally I made it different, I disabled imrc and directed pcm to use tables for open, 2015 has this possibility. Customer is getting same fuel economy with Roush supercharger as before installation assuming he's not getting into boost