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Vvt tuning

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newbee I have a 1jz gte vvti with bc 264 cams my question is

1. do u do your fuel and ignition tuning with cam angle set too 0 degrees then you start adding cam angle and make changes too your fuel and ignition table and repeat process till u find best power and see where the lines join on graph and then set your tables? Is the main aim too see it go lean so u add more fuel (WOT)

2 adjustable exhaust cam would u play about with this after the main map is complete ?

Hi Andrew,

The way I do it is, roughly set mixture to your target, get ignition timing within a couple degrees of optimum, do a power run at 0 degrees, then add say 5 degrees and do another run, then another 5, another run, another 5, another run etc while doing this you will find you will need to start adding fuel as you optimse the advance. Maybe around 2 % each 5 degrees. Once you have an overlay of all the runs you will be able to optimise the advance and fine tune. Finding you will have plenty of advance in the mid range under power, tapering back to 0.

After this I then start moving the adjustable cam gear, after each adjustment of the exhaust, I will move the whole intake advance table up and down to see if there is any gains. While always ensuring the fuel mixture is close to target. Being within a few percent of your target won't massively influence the power so you don't need to be super accurate until you have set you timing.

Once you think you have it all about right, I then optimise the fuel and ignition timing then once again go back and move the intake map up and down around 5 degrees to see if there is any gains. By this stage there usually isn't and the advance is bang on.

You will find the intake will have a far bigger influence than the exhaust cam, mostly in the mid range under power and exhaust will influence more top end, although not as much.

I have attached a few webinars for you to watch which might help.

Thank you appreciate it lad