Big inverters with power tools etc.

I had a Inverter built into my Toyota Tacoma, with a 110 volt power connection in the bed of the truck. "STOCK" Piece of Sh** It had two settings Bright and Brighter. If you connected a 60 watt light bulb to it, it did O.K. But if hooked a grinder or Sawzall to it, bamm....trips the breaker and you dead. Hoonatic is right you have to keep the RPM's up really high to get any results.

F250 will make the amps to run 1 inverter with some help from the go pedel. I think it would be more cost effective to buy an electric winch with a boon to lift the generator into the truck.

actually, i just remembered i have a winch for just that aplication. Got it about 4 years ago and i've never used it.

Get the generator and rig up a handle and some wheels like the smaller generators have.  Wheeling it instead of lifting it will save your back a ton.

You have to remember that batteries and inverters aren't electric pumps that will cram more electricity through your charger. They're like lakes of electricity and the charger is the dam that allows enough current to pass into the battery of you phone/camera/radio battery.

A smaller inverter would be much more efficient at charging small stuff and can be had for about $20. Just be sure that your wife doesn't leave it on all night unless you've packed a second battery in your truck. The 6kw would probably be okay for a small 110v welder. 6000 watts divided by 110 volts equals 54.54 amps. Check your welder's max draw to make sure it doesn't exceed 50 amps and you'll be okay. If you're over 50 amps, don't try it or you'll wear out the circuit breaker on the inverter in short order..

if you're going to get one of those inverters i recommend you trade your current tow vehicle in for an ambulance with the multiple altenators.

Since you have the diesel engine it will work fine if you don't use it too long. Making a quick repair - oK. Installing a cage from scratch trackside - not ok.

Modified sine wave is no problem for most things. The compressor certainly won't care. The welder shouldn't care either. I wouldn't use and inverter on our automated orbital welder at work but not because the inverter would hurt it.

You will be drawing about 230a on the DC side depending on the efficiency of the inverter. If you connect it to the truck batteries don't draw them down too much without letting them recharge. Starting batteries REALLY don't like deep discharges. If you run an arc for 3-5 min then let the batteries recover for about 10-15 min with the revs up on the engine to minimize battery wear. Not exactly a convenient duty cycle but one that the batteries will survive.

If you happen to have the diesel with the Ambulance prep package (dual alts) you are golden. Their combined alts will make over 300a Not likely though as they are very rare. 

You don't have to use a brick on the accelerator to keep the revs up. Just look up "Aux idle controller". It plugs in under the dash and lets you set the revs to anything you like within reason. It is particularly nice in cold climates in the winter for a quicker warmup while you wait patiently inside.

If you don't mind spending a bit more buy a couple of the Honda EU2000i generators and wire them in parallel. They are small and light. They would be perfect for this and have the advantage of doing other jobs away from the track. Two of them wired together have more than enough power to do what you want. The power is super clean too. Not the cheapest option though. It might make you want to sell your big heavy generator. 

Have fun. We will be out at the Lemons race at CMP in February if we can get the car back together in time.

I'm not familiar with Honda generators, but does the EU2000i have sophisticated electronics to match frequencies? You can't wire AC generators in parallel without matching the frequencies.

Or you could just slide a zip-tie between the throttle cable and throttle cam. Just be sure to remove it afterwards.

Using the Honda route wouldn't be too bad since we already own one. It just seems a shame to take along another internal combustion engine to make electricity when, ya know, there's already a nice big one in the truck.

The costs to safely add a second battery (and possibly alternator) for the inverter add up quickly, so I have a feeling we'll have a second eu2000i within 6 months.

The zip tie trick doesn't work on those trucks. Drive by wire.