Info On Air To Ratio

[stef205 92 1 Cars]

My charger is due to come back with a smaller pulley fitted and since it will be creating more boost i want to check the fueling is in the right area. If someone could recommend fiqures for off boost and on boost, should be around 8psi. thanks

[Tom Fenton 1,542]

With boost you should be aiming for around 12.5:1 or so.

[stef205 92 1 Cars]

thanks tom, what would you say for cruising off boost?

[Tom Fenton 1,542]

If its a positive displacement charger it won't ever really be off boost, unless you have a clever part throttle bleed off/recirc arrangement?

[stef205 92 1 Cars]

yes im using dump valves, same set up really as allens tb after the charger.

[peter 20]

what CR?? 12.5 MAY be too lean if its a high CR and the ignition isnt retarded enough

[petert 586]

11.5:1 unless you're at the dyno with an experienced operator. Above 12:1 there's milliseconds between a hot piston and molten piston.