Advancing the intake cam increases overlap. You normally have the most overlap at peak VE and then it tapers from there depending on how well the engine/ setup flows. I would not advise using these cam angles for partial throttle driving too. You would more than likely loose torque. Partial throttle would use less overlap, how much? I'm not sure. It's very hard to tune partial throttle torque with VCT, IMO.Originally Posted by David Borden
Kris
Kris those cam timings you posted up was that on 2015gt or 2012gt? And what where the mods on it, thanks
On my GM tunes I keep low and medium loads fully advanced BUT that is overall cam timing advance/retard and I would have to look at the cam specs vs ford stuff to compare "how much" advanced or retarded that actually is for intake/exhaust.
Typically we only retard the cam at part throttle for emissions purposes, but I normally eliminate that in favor of more torque....
My next experiment is keeping the ford out of Emissions and fine tuning where the Fuel Economy VCT profile comes into play (like during light cruise only). Then use Best Driveability everywhere else and OP of course when heavy load.
The only thing really keeping me from finishing this is understanding Distance along Mapped Points tables.
Kris, what kind of power and torque did the 2012 that you tuned make and what kind of dyno? BTW, thanks for all the information you are sharing. Personally Im learning allot from it.
David
I would run these VCT tables on any 11-14 with stock cams with intake and cat delete x pipe setup as that is the setup the car was dialed in for.
I used the virtual dyno to calibrate the 2012 and my 2015. 2012 made a little over 400whp, but I wasn't after numbers. Just gains during the tuning process. This is a 2012 premium with intske and cat delete x pipe, after the tune it was door to door with a base model auto with the same mods and Lund tune. With a little faster shifter, this stick car would have pulled away.
Cool thanks! How would you guess the cam timing would change if you added long tubes to that combo? I experimented with the cam timing numbers you posted and I could really feel a difference 3000-5000 rpm.
I would assume more overlap from 5000-7000.
Kris
Has anyone tried the Cam Timing on the 15GTs manual?
I have a 2015 GT manual. I have also tuned the VCT for it, however, my setup is only an intake and catback, so VCT isn't much different than stock. But it looks nothing like the 11-14 engine VCT because of the mid-lock phasers, but the overlap is similar.
Kris
For anyone interested in what the new mid-lock phasers do:
"BorgWarner's CTA phasers use the existing torsional energy in the valve train to actuate more quickly, use less engine oil and operate under a wider range of engine speeds and temperatures than conventional VCT systems. For added calibration opportunities, BorgWarner's patented mid-position lock technology allows an increased range of camshaft positioning with a default stop at an intermediate position within the expanded range of travel. The unique passive mid-lock technology ensures failsafe return to the middle position for reliable engine starts in any operating condition."
http://www.prnewswire.com/news-relea...300070795.html
Video:
Product Sheet and Whitepaper:
http://www.borgwarner.com/en/MorseSy...0PR%207-15.pdf
https://s3.amazonaws.com/automotivew...alibration.pdf
So the 11-14 cars never "locked" cam timing, the system constantly worked to hold a specific cam timing value? The video said the phaser could "lock" at any point in its operating range, is this beneficial from a safety standpoint for the people running aftermarket cams that worry about using lockouts? For instance, on 2011-2014 cars, some tuners wouldn't tune comp stage 3's unless the motor had lockouts, this limited the cam phasing range though. I guess this was due to them not trusting the system to hold the cam timing at a safe value.
Last edited by AKDMB; 12-06-2015 at 03:26 PM.
What I gathered is that the new system is a huge help, not a problem to work around....
It also explains why the base calculation is not based off TDC with 0 values in the tune, but 340 and 369.....
My only remaining question is......why no negative values for the exhaust cam? No advancing of the exhaust past 369?
Yep, exhaust cam can go no more advanced than 9* ATDC. Unless you change the baseline position. But I don't think is a reason too. Most cars ive seen won't like any less retard on the exhaust than 10 degrees.
are the midlock phasers only on the intake cams? maybe i missed it.
Also, let's say we install aftermarket cams that are 20 degrees larger than stock. If we install them straight up like stock, will that move the open and close values degrees wider than stock on either side? Would it install with the same open value but an extended close value? Would we need to adjust the baseline values in the tune to accommodate or just work off the adjustment tables?
The midlock phasers are on both the intake and the exhaust cam on the 2015 GT. That is what gives the GT a base IVO position at 20* BTDC and the EVC position 9* ATDC.
Theoretically speaking, if you install aftermarket camshafts, and they are installed just as the stock cams (designed like stock cams) then the ECU will stay have the base IVO and EVC positions. If the new cam requires less advance/ retard, then the tune configuration will need to be adjusted to accommodate. But also take into account, that's partial throttle mapped point VCT configuration as well as WOT. It will more than likely be a headache without a good base VCT calibration to start with.
Yes, if the new camshafts had more duration, you would then result in a different IVC position and a different EVO position. I believe you can adjust the base value for the IVO and IVC positions, those base values will need to be adjusted for the new cam. Which if you know the duration, then you can populate that information, possibly starting with the same 340* IVO position, depending on how the new cam is designed to achieve maximum torque.
After looking at the 2015 gt tune compared to the gt350 tune I may have to say I was wrong about how the negative and positive numbers move the cams. I will say the reason for this was my lack of understanding about IMRC. Calculating overlap on the gt350 how I described would yeild 98.5* of overlap at 3500 rpms. This is absurd. Realizing that the IMRC being closed increases the intake charge velocity at the lower rpm (less than 4000rpm on the GT and 3500rpm on the GT350) I can see why the IVO was being moved toward TDC. This would cause the air/fuel mixture to get into the cylinder quicker and because the intake valve opens to a vacuum on the manifold side the shorter the amount of time it is open while the piston is moving up the better. you can also see the exhaust valve stays open further and further past TDC as the charge velocity increases. You can see this best in the Gt tune. In the GT tune after the IMRC opens at 4k RPM the intake quickly moves further BTDC all the way to red line. In base GT dyno graphs you can see dips in HP and torque right after 4K. In the GT350 tune there's not much resolution below 3500 rpm but it seems to go slightly toward TDC as it approachs 3500rpm. After the IMRC opens at 3500rpm the IVO moves to TDC and slowly increases BTDC as RPMs increase. Dyno graphs of the GT350 show a massive Spike in torque and HP at 3500RPMs. What makes it all make sense is thinking about the charge velocity in relation to the IMRC position and RPM. I think the GT needs to have its EVC pushed further ATDC around 4000RPMs (can't go near as far as the 350 flat plane crank)or I was right before and the GT350 spike is caused by the overlap going from 44* to 98.5*. Seeing as neither the Gt or GT350 use OP mode or mapped points from the factory I'm going with EVC needs to be pushed further ATDC. With that comparing the GT distance points, arrays, and IMRC positions to the GT350 I think gives you a better picture of how it all fits together.
Last edited by murfie; 12-28-2015 at 03:01 AM.
Can you post gt350 tune?
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