gear change ignition cut with ORB

[anasyakoub]

hello,

can I do both gear change ignition cut with ORB to keep the turbo spooling between the shifts ?
if yes then should I do it with gear change cut level and gear change Retard, or I have to setup the gear change ignition cut and boost enhancement together ?

thanks

[Stephen Dean]

Hi,

GCIC and ORB are used at opposite ends of the rev range, and shouldn't be overlapping. Typically with GCIC you will be at 100% throttle (or very close) when it is activated, and that throttle opening should remain constant through the shift. This retains mass flow through the engine, and due to the retarded timing used, retains the heat energy in the exhaust mass to keep the turbo spinning.

ORB is used to maintain boost when you are off the throttle (usually under braking) and is working against a almost closed throttle plate, using excess fuel and retarded timing to generate mass flow through the turbo.

[anasyakoub]

thanks a lot for your reply, I will use it for Drag Racing,
so I will go with GCIC, and as per the Motec help I should go below 100% cut level to enable the retard ignition right ?
what is the best numbers for cut level and retard ignition to start with ?

[Stephen Dean]

Can't help you with the numbers, as each engine will want different values, you would be best to talk to people who have tuned these engines for a similar usage and that you can trust to provide correct information and go from there, otherwise start with really conservative values and work up from there.

[anasyakoub]

got you,

thanks a lot