It's all for show. They don't need near that HP to run them, they don't
need nitrous oxide. More than likely the crank broke from the
acceleration and extra power from the nitrous oxide. Figure the
monstrous SWR from a mobile antenna being fed 75000 watts. It'd look
like a lightning generator. But it's unlikely they can do better than
50% efficient with the setups. So given 150 KW input they need 201 hp
plus change. Given the generators are not 100% efficient AND the output
frequency will change with RPM who knows what they get out of them.
Carl wrote:
>
>> At 11:09 PM 4/5/2010 -0400, donroden@hiwaay.net wrote:
>>
>>> peanut compared to some of the 11 METER MOBILE amps I have seen
>>>
>>> How bout a 4CX15,000 powered by four 200 amp alternators in a Suburba
>>> with a big block 454.
>>>
That sounds like they are actually using 48 volt alternators. Figuring
60% efficiency gives 37,500 watts input. going conservative means
37,500/800 amps = 46.8 volts which is close enough to guess at the 48
volt alternators, which means over all a very inefficient system. OTOH
even a 37KW, 240 generator would only take 49 HP plus change, neglecting
losses so maybe 55 HP would be needed. They might have a problem
fitting that relatively small generator under the hood though. The
setup described would have power loss in the alternators, loss in the
inverters,
>> I should be able to drive that amplifier with my VW Beetle engine.
>> It should only take about 80 HP
80?
>> where is all that power going from
>> the 454 bigblock with nitrous oxide injection? A hundred hp would be
>> a little less than 75kW.
>>
or about 45 KW output at 60% efficient.
Just remember these are for show, or they'd be coming from the shallow
end of the gene pool.
If they have to stick with 48V alternators of less the systems are going
to be very inefficient which means a lot of lost HP so far more than
what we figure would be needed. OTOH it still doesn't come to any where
near the amount they are using.
>> Sounds stupid to me.
>>
>> 73
>> Bill wa4lav
>>
>>
> A cranks snout is its weakest link and its not designed to be pulled on by a
> bank of monster alternators. I dont know if the CBers are using forged or
> cast cranks either but they do break.
>
My guess is, that although the monster alternators don't present a
tremendous load, what they do present along with the sudden acceleration
does and would probably be the reason for breaking cranks.
> Nitrous is stupid but probably the only viable option fo a 10 second run. If
> done right it wont destroy the pistons. A supercharger would be safer in the
> long run but thats in operation all the time.
>
A super charger or turbo can be hooked up with a bypass or pressure
relief (waste gate) like they do with aircraft so over boost isn't a
problem. With a manual waste gate they can be left in stand by except
for the run.
73
Roger (K8RI)
> Carl
> KM1H
>
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