i have ofna hyper 7 nitro car and now i want make it to brushless.
can i use this motor and esc system and 4cell life battery.
are motor and esc too smal?

I am guessing that you do not have enough posts to be able to post a link... or you just forgot it put it in. What system are you trying to use?

hobbyking 100a esc
Scanner RC PowerSquare 2600kv Racing 550 Motor
ZIPPY Flightmax 4200mAh 4S2P 30C LiFePo4 Pack

I would say you need more of a lower kv rated maybe like a 1900 or 2200.

why. someones uses 2800kv motors but is thisd scanner rc 550 motor too smal on 1/8 car or need it be something XL motor

The ESC is for planes and I am not sure if it will work for a car. It will need a separate BEC or receiver pack since it does not have one built in. You would want something more like the following. I haven't owned either one, but they are built for cars.

http://www.hobbyking.com/hobbyking/s...dproduct=14635

http://www.hobbyking.com/hobbyking/s...dProduct=10370

The motor might work, but it is a little on the small side for 1/8th. The following might be a better idea.

http://www.hobbyking.com/hobbyking/s...dProduct=14632

The battery you are looking at appears to be a good match for your application. The rpm ratings on the motors should work on a 4S LiFe battery.

2800 would run very hot in a 1/8th buggy on a 4S LiFe. Since you are looking at a LiFe battery instead of a Lipo, you can get away with a slightly faster motor. Just doing the math, a 2250 on a 4S LiFe would be like a 2000 on a 4S lipo. The motors you are looking at are faster than that, but you might be able to make them work.

i mean hobbyking 100a brushless car esc with reverse. i want cheap motor and esc.
why i cant put url link's here?

This site restricts new users. I think you need to have at least 15 posts or something like that before you can post links.

what is good and cheap brushless set for inferno st us sports.
whic is better car inferno st or hyper 7

get the turnigy trackstar

and I would go hyper 7 cause its cheaper kyoshos are great but their parts can get spendy some times