Vtc Turn Off Point?

[Badgaz]

a question for the been there done that tuner types.

i'm wondering what the best VTC switch off point for my mods would be?... the setting is currently 4700 i and i was thinking of turning it off earlier? its quite a confusing topic after the searching and reading...i don't understand why all the dyno graphs i look at seem to peak up when its turned off...and then i've had other advise to say keep it on longer....

can anybody help me understand this? i'm trying to learn to tune

relivant mod list

z32 afm

upgraded factory turbo running 16-17psi (1.15bar)

powerfc

fcdatalogit

intercooler

custom tune

[89CAL]

Your tuner is the best one to ask because he can physically check and adjust it to suit. Mine is 4500rpm from memory

[GTSBoy]

Yuh, One run with it switched off early, one run with it switched off late. See where the lines cross and set it more or less to there and see how it goes after that. Not quite rocket science.

[Kinkstaah]

This really needs to be tested on a dyno.

Do one run with it fully off.

Another run with it on.

Switch it when they bisect, basically. Seems to vary a little with every setup.

[Badgaz]

cool thanks.

[Dose Pipe Sutututu]

Yuh, One run with it switched off early, one run with it switched off late. See where the lines cross and set it more or less to there and see how it goes after that. Not quite rocket science.

Yes that's a method, however with it switched off I find from my personal, limited & road only tuning abilities you can dial in more timing with it switched off so then when you over lay it again the intersection point will shift again.

I would say that it would be best switched off at maximum VE to reduce the need to pull out timing (this will be dependant on turbo too of course)

[Lithium]

Yuh, One run with it switched off early, one run with it switched off late. See where the lines cross and set it more or less to there and see how it goes after that. Not quite rocket science.

I am pedantic, and at least for full power runs tune the whole timing/fuel map with it off - then do the same with it on, then you get to see the maximum potential of both (MBT and the torque number produced tends to change a bit) - *THEN* you can see when to turn it off, and then if/when to turn it back on again No one size fits all on this one, I don't think.