VTC cam angle limited to 20

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Hany
Posts: 28
Joined: Sat Oct 07, 2017 2:56 am

VTC cam angle limited to 20

Post by Hany »

I've noticed today that cam command and cam angle are limited to 20 degrees even if I put 25 for both low and high cam tables, I was expecting to be able to advance to the vtc gear limit of 25 degrees, this is a bummer as I was planning on swapping a 50 degree gear or modifying mine to benefit from the improved engine response.
Hoping this is fixable with an update.
KTuner
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Re: VTC cam angle limited to 20

Post by KTuner »

Those are factory limits.
Hany
Posts: 28
Joined: Sat Oct 07, 2017 2:56 am

Re: VTC cam angle limited to 20

Post by Hany »

That 20 degree VTC limit is a big limiting factor for n/a tuning, I'm surprised ktuner left that limit!!

I've also noticed that AFR CMD will not go any richer (Lower) than 12.06 in any log at WOT, I have WOT enrichment table set to (11.5-11) and it won't command that no matter what.
injector m/s seems to max out at about 12.4ms (around 33%) and no matter how much I skew the AFM Flow table to force a richer condition it won't follow! mg/stk keeps rising so does MAF reading but injector duty cycle and AFR CMD stays at those limits causing a lean condition.

I don't think that is a factory limit as the factory tune has WOT enrichment set as low as 10.8 at a few points.
KTuner
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Re: VTC cam angle limited to 20

Post by KTuner »

Make sure you're altering all of the WOT Enrichment tables. It sure does target what it's set to.

Sounds like you're doing it wrong. AFM.Fuel is the injection time based on mg/stk
Hany
Posts: 28
Joined: Sat Oct 07, 2017 2:56 am

Re: VTC cam angle limited to 20

Post by Hany »

I have altered both low and high cam WOT tables and low and high cam WOT cat heating tables just in case. when you alter any one it applies the same to all other cam angle tables, its behaving like there is only one table for all low cam angles and another for all high cam angles, and even then AFR CMD will not follow the tables and will stay at 12.06 in WOT while I have 11 in the tables at that RPM point.

I have also scaled AFM.Fuel for RDX injectors, and added a higher mg/stk value to the last cell of the table that skews the (ms) to around 25% more(no longer a linear relation between mg/stk and ms) to provide for additional fuel during WOT enrichment and still the Fuel Cyl 1 would max out at 12ms starting when MAFv reaches about 3.3 volts, MAFv will continue rising to 4 volts along with mg/stk but the duty cycle remains stuck which leads to going lean.
KTuner
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Re: VTC cam angle limited to 20

Post by KTuner »

Correct. There's only low and high cam WOT Enrichment tables.

The factory AFM.Fuel scale goes to 16ms, so it's in your scaling. Consult a professional if you need additional assistance with tuning. We don't offer tuning advice.
Hany
Posts: 28
Joined: Sat Oct 07, 2017 2:56 am

Re: VTC cam angle limited to 20

Post by Hany »

so we do have another limit on injector pulse at 16ms? Y or N?

can you explain how a professional tuner will correct a lean condition when the commands are not following the map values?

MAF readings are increasing, AFM flow was scaled with a dozen data logs and fuel trims are in check( no more than +/- 2% long term), AFM Fuel scaled to my RDX injectors and table has higher values for additional fuel, WOT tables commanding 11 AFR

Is there anything else I am missing that would cause the ECU to stick to 12 AFR.CMD and 12ms inj pulse?
KTuner
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Re: VTC cam angle limited to 20

Post by KTuner »

The factory AFM.Fuel table goes to 16. That's not a limit. Open a new file to see for yourself.

We make software. We don't teach tuning practices.

I don't know what you're missing. I just know it's not limited to either of those things. Consult a professional if it's beyond your abilities.
jona10silva
Posts: 1
Joined: Fri Jan 12, 2024 8:40 pm

Re: VTC cam angle limited to 20

Post by jona10silva »

Hi Friends,
Is this still a limit?
I have a 2007 Element with a 2006 TSX motor RSX oil Pump, 50* cam gear, RBC Intake manifold 3" exhaust and I'd love to use all the degrees i can.

Can i go past 20* now?
KTuner
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Re: VTC cam angle limited to 20

Post by KTuner »

If limit settings exist as an adjustable option you'd see them as a parameter in the software when you open a tune.
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