Originally Posted by
fyrstormer
Thinking about putting it into one of my HPI Bullets, but I'm currently house-hunting so I have no time for anything. The housing market where I live never calms-down; houses sell within a week, sometimes within a day. Nothing like needing to impulse-buy something that costs a third of a million dollars to keep you up at night. But that's off-topic.
You still have a Bullet, right? Just tonight I did something to one of my Bullets that might be of use to you:
https://www.rctech.net/forum/showpos...5&postcount=11
Btw, what is the "uniflow mod"? I've never heard of it before, but I've also never had any problems with any of my other my nitro RCs leaning-out badly enough to make me care about improving the fuel feed. Anyway, no exhaust-pressure mod will be able to overcome the simple effect of a gravity-siphon from a raised tank downwards into the fuel inlet.
I still have my original drive cups, the drive shafts have worn a groove nearly halfway around the inside of them. I have spares in case it becomes a problem one day. Good idea though on the mod!
Anywho, uniflow is taking the muffler pressure inlet, and extending it down into the fuel, to the bottom of the tank. This causes the muffler pressure to equal carb inlet pressure, regardless of fuel head. Until you try it, you won't think it works. I was the same way. It's not specifically fixing a siphon effect, it's fixing fuel pressure variance due to fuel level. Any remaining "siphon" effect is not noticeable to me.
The Savage was notorious for half tank leaning. So much so, that it makes the truck almost undrivable. Set it for a normal tune near empty, and once you fill up the tank it richens to the point you can't get it to shift gears. Set it for a normal tune at full, and it leans so bad near empty that the RPMs hang, you can't get the clutch to disengage. Overheats, Etc..