ORIGINAL: Steve Campbell
Personally, I am FIRMLY convinced that the great majority of all this fuel hype is controversy created by marketers and fuel-mongers. I realize that this is probably throwing a grenade into the hen house, but, at least in the US, the pricing structure of fuel tells the story. Specialized "car fuel" costs up to twice as much per gallon as "airplane fuel"; yet it has LESS oil and equal or less nitromethane.
All I know is this; when I got my first r/c car a bit over three years ago, I bought a gallon of "car fuel" and was quite surprised to see that a gallon of 10% nitro Blue Thunder cost $6 more than a gallon of 15% Cool Power. The engine was obviously running hot, and that's when I discovered that the 'car fuel' only had 14% oil content. I began running that "awful" airplane fuel in it, with 18% oil, and haven't looked back. You read it all the time in fuel ads, magazines etc.; "Running airplane fuel in your car/truck will ruin the engine." That statement, Tex, is pure and absolute BS.
"Bleeding" shocks refers to getting all the air bubbles out before you close it up. Basically, you leave the plunger all the way down while filling the body almost to the top. Now, slowly move the plunger up and down a few times, "pumping" it so any air bubbles will be moved to the surface of the shock oil. Then top off the oil and screw the top on. Depress the plunger as far as it will go; you want to get a quarter-inch of rebound at least. This is for off-road stadium trucks, which is the limit of my land vehicle experience. I'm sure track cars, etc., are different.
Thanks for the reply Steve, your anecdote re: aircraft fuel in car motors is interesting. I might bring that up with the guys at the LHS next time I'm in there. As it happens, I got my wires crossed, and the fuel I bought the other day was in fact 20% nitro, so it looks like I'll be running her in on the full strength I intend to run. It seems logical to me that regardless of nitro content, the proper running in of the motor relies on throttle control, not what fuel you're running. Fingers crossed I'm right, but the guys at the LHS didn't seem too fazed when I told them that the manual simply recommended 20% nitro and made no fuel recommendations specfically relating to running in.
As for bleeding shocks, sounds like the exact method we employed when constructing my mate's electric RS4 MT - just wondered if there was a special way I didn't know about which yields extra-special results.
I guess HPI have had to build the MT2 to a budget - it seems to be a pretty good price for what you get, so I'm sure there are some areas that they are forced to compromise on to keep the price down. Obviously the benefit of doing so is debatable when it only seems to result in downtime anyway, I'd imagine most would rather pay a bit more up front, but then everyone doesn't think that way, I guess. I WILL be bashing mine off-road a bit at BMX tracks and the like, so it will be taking some beatings. I think I might spend a bit of time bullet-proofing the MT2 before I even fire her up for run-in. Replace the salad oil, shim the diffs (assuming the mesh isn't ideal), and put some shock socks on it. The time spent now will no doubt equate to longer-lasting fun down the track.
Has anyone had any experience with diff locking grease? I was looking on badhorsie.com at their shock socks and saw said grease, and am tempted to try it in the rear...