i have two questions:

what is the difference between a regular clutch adnn a slipper clutch??

where can i get info on te Mach .15 that comes in teh XXX-NT?? between a HPI NitroStar 15 FE and the Dynamite Mach .15 which is more powerful? i think its definatly the mach but i want to make sure.

slipper clutch do you mean for the main clutch???

I'm sure you know the info below , but here it goes.

All nitro cars/trucks have a standard clutch. usually it is two plastics levers that push out using centrifugal force and make contact with the clutch bell. the clutch bell the spins the spur gear.
during idle the clutch retracts and the clutch bell is then disengaged.

The slipper clutch is a disc that uses friction to allow the spur gear to "slip" a bit so you don't chew up the gears.

You will see this mostly on stadium truck.

The slipper clutch is used so that so can control power mainly for 2wd cars is slippery tracks (like mud)
If you hit the trottle you will get the car spinning like crazy thus uncontrollable. By using the slipper you let only a part of the power reach the wheels reducing spin. It is a crude antispin system.

which is the better engine

dynamite .15 is better. I read somewhere that the mach .15 has good horsepower, but the hpi .15fe is one of the worst engines you could have. it only has a high speed needle and idle.

ok, how much would this be worth:

an fe engine that runs absolutey great, and another fe engine with no pull start and a stripped needle valve.

do any of the fe's have purple heads or 2 needle carbs with idle
the 2 can sell for $50-$70
$50's for no purple head a single needle carbs
and it's worth more with purple heads and 2 needle carbs with idle

both have purple heads single needle carbs

i'd say u could sell them for $60-$65 for both
check your pm