whats the correct air fuel mixture ratio

[s5frontmount]

does anyone know what the ideal air fuel mixture ratio is on rotary turbo (rx7 turbo2)
many thanks

[grinder]

isnt it 13.2 ??

dont quote me on that - but it sounds right ??

[BlitzBoy]

not on boost, on 8 psi it should be around 11s to 12s
14s on cruise

[kev-yorks]

As Mark said there is no one ideal A/F tick over wants to be as lean as you can get away with cruise 14\'s. Under load it alters with revs and boost. The higher the boost the richer you want to run likewise with the revs upto peak torque after peak torque then you can lean it out a tad.
Regards Kevin

[grinder]

i was close then !!

so the lower the number the leaner it is and the higher the more rich ??

[20B_boy]

i was close then !!

Close as in the difference between a running motor and a dead motor...

so the lower the number the leaner it is and the higher the more rich ??

No, the opposite! 10:1 = rich, 14:1 = lean.

[grinder]

still learning matey

so i take it that the figures are

10 air to 1 petrol - 10:1 - rich
14 air to 1 petrol - 14:1 - lean

[rx7veilside]

14 to one isnt actual lean but the correct mix for efficient burning of air and fuel i blve they call it stoich and i havnt a clue what it means but the idea is off boost to get as close to 14 to 1 as poss and only richen it up for on boost areas of the map

[Prof]

A \'Stoich\' reaction is one where the reactants are all used up to make the end product - so it\'s kind of like the perfect ratio.  The AFR for normal fuel is around 14.7 : 1, but is affected by the RON figure. 14:1 is a safer value to work to.  On Turbo cars the mixture is often rich so as to reduce the combustion temp and thus prevent knock occuring, but it\'s not quite so simple as that.  Run too rich and you get carbon build up which is also bad, as it could lead to preignition if the carbon heats to incadenscense and ignites the charge before it\'s time.