Originally Posted by defcon13

hi,
i need some advice about these go engines. its to put in a truggy (losi 8ight-t) i have a hard time choosing between the pro .25 6ports or the pro 21 5 ports turbo. i need good bottom and good top. just to give guidelines, i was running stock engine (mach 427) in my 8ight-t. bottom was perfect for our track (not a lot of room before jumps) but top end was lacking. i need good top end because our straight is 180 ft long with banked curves at each end. the mach was totally out of breath before the end of it.
also witch one has the best runtime?
thanks!