Originally Posted by
kgombe
i tried jp3, 9901, 2013, bullit 1005(oh yeah i got 1 of those)... on the track i was running on i prefered the 9901 with the jp 3 running a close second... the 9901 allowed me not to have to much wheel spin and all the top end in the world and then some... i'll tell you what this engine screams... oh yeah and the 2013 would come in 3rd.. 1005 was ok.. but it lacked something.. i only noticed it when i tried the other pipes.... seeing that was the first pipe i tried...

Hi KG
Old post, I know.
Yep, the 9901 are VERY good on my HPI/Force stock engine. So much better than Hong Nor 2047! Had to lean the HSN 1/3 and gained more than 1 minute extra runtime
Addition: Stock shim, OD77T plug, 20% nitro, 5 liter through her.