I don't know if the SPX Stock Spec has the internal booster or not (I don't think it does, the V2 does), but in all ESC's going back to the dinosaur days of brushed motors the main heavy MOS-FET circuit which passes energy to the windings of the motor is completely independent of the internal computer. To do what your saying, just leave the switch for the ESC in the OFF position and then it will be powered running on the booster when the booster is plugged in, feeding energy to the ESC through the receiver into its signal harness as opposed to in 2s mode when power is fed from the ESC to its internal computer and then to the receiver. That will power on the ESC internal computer from the booster (6v). The ESC's main power connection doesn't even need to be plugged into the battery for it to power on its computer, only the signal harness. Still, the heavy-duty MOS-FET will continue to use just the 1s battery voltage and that is what will be passed to the motor.

Okay, I also looked at the Novak's Smart Boost manual. So this is what I understand:

1. Originally the Esc switch brings in power from the battery to power the board then puts it out through its signal wire to the BEC.
   
2. The Smart Boost draws power directly from the battery terminals routes the BEC through the receiver and powers the Esc board eventhough the Esc switch is off. Question: Does this work for all Esc's? Will the switches on other Esc's block power from coming through the signal wire?
   
3. The Esc with power to its board at 6v coming from the BEC through the Smart Boost is operational and routes the 3.7v battery power to the motor through its FETs. Question: Do the FETs have a minimum voltage? Are the FETs still functional with only 3.7v?

Save yourself the headache, get an 1S lipo ESC, like the Hobbywing 120A/1S, yes it's a bit big, but you will soon forget about that after you see the speed it gives your car.....

Every esc I've ever used works with reciever pack or booster. There is no way for the esc to "block" voltage from the booster if it is connected as instructed. There is no mimimum voltage for the fets and all esc's will work on a 3.7v battery, at least on all the ones I have used, and that would be most of the available brands

Okay, thanks for assuring me on that.

Do yourself a favor and dig out the instructions to your ESC just to double check. If you are using an LRP SPX plug the booster into the receiver, plug the ESC into the receiver, turn on the booster, DO NOT turn on the ESC. It should now operate your system.

to get my spx to work I had to remove the red wire from the speed control plug into the receiver only using the black and white wire. then turn the speed control on and the booster on. this is if the above doesn't work.

A size would be helpfull. I will be using pre cut CRC tyres.

dont you have the tyres yet Josh. CRC brand new are around 48mm i think so 51mm may be. i had very little rear tyre wear at ACT but the fronts had massive wear.

I know this is not the sale thread, but have a NIB Flexi I need to get rid of. PM me, thanks.

I just built my first 1/12 and would like to know how to accurately set toe?

I've set aside a host of links to setup 12th scale cars.
Check it out HERE

How about a base set-up for mod at TQ?

Working on getting the 10.5 to run with the SPX.

Here you go sir.

Thanks.

How do you check droop with a pan car?