Originally Posted by senna555
Ok couple questions:
Now I understand as I move from say a #7 to a #8 plug I am increasing run time as I am able to run engine on leaner setting
However am I at same time decreasing peak engine output by running the colder #8 plug?
Seem some mixed info on this looking for some feedback.
Where is Roelof! Ha!
there is a danger with using too cold plugs.
if you running a very cold plug you have to lean the engine so it makes power at low-mid range
and you might end up with a too lean mixture which may damage the engine.
It needs some experience to mess with shims and compression but Roelof is right.
I would start with a mid plug and make a hard run. Then, inspect the
plug wire. If it is still shine and motor works well i would stay with it. If plug
wire is not so good and engine seems to maintain rpms at the end of the
straight when throttle is off or maintain high rpms at idle while your needles
are not set too lean, it is good to try moving up a #plug.
When weather is hot we may end up with a colder plug or if the track has a very long straight.
It is always recommended to use a colder plug when moving to higher %nitro.
Also, a hot plug will give you definetely more bottom-mid power while a cold plug will give you more top end.
i am not sure that a colder plug will help you with runtime because if the engine
doesnt produce enough power exiting corners you may end up using more throttle
and this definetily affects runtime.
I think that you have to run the plug that runs better with the engine and search
other factors affecting runtime such as gear ratio or pipe model.
just my experience.