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22zxla
06-24-2006, 07:33 AM
quick question, i see people talk about rev limits, is this the same as wot? If my wot is 4600rpm will that be my rev limit as well? If the rev limit is higher than wot than is it safe to run wot for as long as you want with no real harm?

MOP
06-24-2006, 08:08 AM
The rev limiter is incorporated in the ignition, it can be built in or added as an after market item. It limits how high the engine can rev by cutting the ignition, the ones on factory engines are preset most the after market ones can be adjusted. Running an engine at WOT for long periods within its designed max operating range really depends on the engines condition, If it in decent shape it should not hurt. It will make it wear out a bit faster and burn a lot more fuel, most people do short blasts but cruise a lower RPM's.

Phil

pmreed
06-24-2006, 08:09 AM
A rev limiter is an electronic device that stops the motor from revving past a certain number of revolutions per minute. This is done generally to keep the motor from turning too fast and causing damage to itself or attached components.

Ideal propping for top speed allows you to just approach or touch that maximum allowed rev limit at WOT. If you're over propped i.e.. too much pitch, you'll run out of power before you reach the design rev limit of the motor. If you're under propped i.e.. not enough pitch, you'll run into the rev limiter which will protect you motor from overrevving and possible damage. You may run a low pitch prop for pulling skiers or water toys, because it will have a better holeshot and get you up on a plane more rapidly. The rev limiter should keep you from damaging the motor if you get carried away. Propping is a combination of science and practical experience and one of the most talked about subjects here on the Donzi.net

I see your handle contains 22ZX. Do you have one? Depending on how you're powered, your max safe RPM could range from 4800 up to about 5100.
Other's can chime in here with more exact limits for your motor if you'll post your specs.

Welcome aboard,

Phil

22zxla
06-24-2006, 08:38 AM
Thanks for the quick and informative responses. Yea got a 22 with 7.4 mpi at 330 hp. My wot is 4600 which im hitting exactly with a mirage plus 23p. How do i know what my rev limit is? Is it safe to squeeze out some more rpm,s?

cigarette30
06-24-2006, 08:59 AM
Quick question: Last weekend, I was on the rev limiter with the 496 in the 22', quesss just the right current and load conditions, right at 5150 the alarm will go off, and the smart/craft indicated "over rev", but no "shut down" per say. Does anyone know how to tell if a 500 efi is into the limiter? I am sure it does not alarm, but does it just hold there? I had a 502 in my last Donzi, and it would "break up" when proped to small, thus you knew.