Frostmann

I've had my Rs4-2 for about 3 years . The 15Fe just screams with power.I have a mips racing clutch,ported Cen header ,tune pipe. I'm wondering would I get anymore speed out of this If i put a 6mm slide carb on? 4mm rotory on it now.If so what carb do you recommend? or would it be wasted fuel?Thanks

rodrigo1508

A screaming power .15fe thats new to me

NCC

The oscv slide works nicely. And yes you will see a difference in power.

corvettecrazy

exactly my thought, even leaned out my .15fe couldn't beat my bike(not motor, the one with 2 pedals and 18 gears)

j240z

Go with the OS like ncc said. I bought the upgraded HPI 5.5mm carb and it broke within a couple months without even being wrecked. they don't seem to like hard driving. The OS should be pretty tough, plus it's a slide card. You will have to modify your throttle linkage. I think HPI sells a kit to convert to a slide carb.

Frostmann

I've ported and pollished the sleeve and intake on the crank and with the cen header ported and pollished.I milled down the heatsink head slightly for more compression also. I figured it's getting starved for fuel now.It's funny, at the track people come up and ask what I running for a engine and I laugh and say just a crappy old 15fe. I might still just bore out the original carb,there's still room but I thought the low idle adjustment would be nice too

Solara

iTrader: (17)

By your theory....4mm bore vs 6mm, you will see the improvment of the power....just like the SIRIO 15, someone dropped a slide Nova Rossi carb (5mm instead) and can tell the power was reduced compared to the rotary SIRIO oem carb that has a 6mm bore.

But, like others....I have a difficult time to imagine the "SCREAM" effect from a 15FE.....does that make about 1.3HP....? Not making fun of you, just wondering after all the mod and would like to know how much HP increase