My sick 3.5efi

[up2nogood]

Bloody thing double posted!

[fridgefreezer]

Well strangely enough it connects to the O2 sensor input wire!

(That's the light blue wire, BTW )

[up2nogood]

Thanks for that

But is it necessary for a conversion where all a bloke wants to do is get the tuning close to perfect and the timing to suit, or is this one more for the enthusiast?

[RaginRover]

Thanks for that

But is it necessary for a conversion where all a bloke wants to do is get the tuning close to perfect and the timing to suit, or is this one more for the enthusiast?

A wide band O2 sensor isn't necessary, a standard one will work fine
as far as I have read. VN/VR/VT commodore

Tom

[fridgefreezer]

No, wideband isn't necessary to get a decent tune, in fact if you're used to carbs then you can go without and tune it by feel / guesswork as per usual

Don't know what it is in $, but I paid £10 for a 3-wire lambda sensor off a crashed Vitara. Doesn't matter what you use - 1, 3 or 4 wire, but the 3-wire is easiest to connect and being heated it makes tuning posible over a wider range.

To tune your mixture at high loads / RPM using a normal lambda, just take the value that MSTWeak suggests, for example 50, then to get a mixture of 12.5:1 (rich for high load) just do 50 * (14.7 / 12.5) = 59. This is because the lambda sensor only tells you when the mixture is at 14.7:1, see?