TNX 5.2R + fuel tank mod

[overdosed]

hey all,
i did this mod at around 12am while my parents were sleeping using a clanky old drill, lol!

pretty much its just turnin gth tank 180 degrees which helps keep the fuel line away from any dangerous flywheels or burning hot engine heads. also its more neat and tidy and some other stuff. took me like 10min to do. just better since no fuel line going around up and down to get to the carb or pipe. also shorter fuel line now.

pics:
http://img214.imageshack.us/img214/7826/p2130006oi0.jpg
http://img145.imageshack.us/img145/8981/p2130007iv8.jpg
http://img214.imageshack.us/img214/5723/p2130009to9.jpg

just works better for me

[Thai]

I personally think you need more fuel line....

http://www.rchobbies.org/engine-tuning.htm

The Dreaded Full Tank Lean Bog
If you've done much gas racing, you've probably encountered the dreaded lean bog that occurs right after a pit stop with a full tank of fuel. Right after the tank is filled, for about the next 3 or 4 laps the engine sags (lean bogs) when accelerating off of tight right-hand corners. On most tracks this happens when accelerating onto the straight. Seemingly, the lean bog magically goes away after a few laps but sure enough, after the next pit stop, it frustratingly returns-slowing lap times for several laps once again.

To solve this frustrating issue, it's important to understand what's causing it.
Here's the scoop. As the throttle is released entering a turn, the pressure in the tank is now greater that the reduced pressure in the pipe. When the tank is full, some of the fuel sloshes up into the pressure line. The centrifugal forces encountered in a right hand turn further pulls the fuel into the pressure line, causing reduced pressure in the tank. When the throttle is cracked open to accelerate, the engine goes lean because of this reduced tank pressure and hence the dreaded lean bog occurs. The reason it only lasts for a couple of laps is first, as the fuel level goes down in the tank it's less likely to slosh as much into the pressure line and second, as the fuel level goes down there is a larger open space in the tank that's pressurized, maintaining adequate pressure long enough to prevent the low pressure lean bog problem. (If your exhaust system is mounted on the left side, as with some of the latest monster trucks, then this phenomenon will occur in left hand turns.)


And also, once your truck is upside down, it'll lean out and stall quite quickly. And that'll increase the chances of excessively wearing out your engine.

[ericem]

Yes i suggest long fuel line, and just so you know, these fuel lines are heat resistant up to 500000billion C as far as i know :D

[avablast]

The pressure line is a good leingth, but yea definatly a longer fuel line, dont go crazy with leingth maybe another 2" will be sweet. If those are the standard lines than i bet that fuel filter was a bit of a bitch to put on.

Personally i never really liked the standard tank and ditched it altogether before i even ran my truck. I just didnt like the small nipples that had a small hole for the fuel flow and had nothing to retain the fuel line on, and when I got larger diameter fuel line, they would just slip off way to easily.

[overdosed]

i dont see whats wrong with shortening my fuel line a bit. i have always run it with that short fuel line and i roll over heaps. i can roll over 30m away, run to it and flip it back and its good.

its a slighty larger fuel line size and i got it to melt but hardly. funny story with the fuel filter with original tubing. i put it on and then when i pulled the tubing off the filter the tubing just ripped with a bit still attatched to the filter! thats why i changed and i never had that fuel bog woteva problem before. and on that website it says for racing and they use a pressure resovir (???) which my lhs dont has and i dont need

[ericem]

Ya, overdosed is right though, when u flip, there is very little fuel being used at idle, and u ususally have enough time to run up to the truck. mine was like 1 in :D and it flipped over for like 1 min, and didn't die. But its still good to have longer fuel line :D

[overdosed]

for racing log fuel line is great, but for bashing i want tidy as possible so nothing comes undo or dislodges itself during a bash

by the way, check out my new RC mods blog, mostly tnx mods. http://maddog-george.blogspot.com/ just been updated, hope u like it!

[fezzy]

Rotating the tank is not the most clever idea I've ever seen, if you note that the pick up is at the front of the tank rather than the rear, where do you think the fuel goes when under power? Yes it goes to the back. While this might not proove to be a problem with a good quantity of fuel in the tank, when you start to run low you may start to run your engine too lean without you realising it. Now the fuel tank does have baffles to help increase the fuel supply, but regardless of this your still putting the pickup at the wrong end of the truck, and you will run your engine leaner during the last 1/4 tank of fuel or so compared to running the truck with the tank in the standard config.

[mordraid]

Rotating the tank is not the most clever idea I've ever seen, if you note that the pick up is at the front of the tank rather than the rear, where do you think the fuel goes when under power? Yes it goes to the back. While this might not proove to be a problem with a good quantity of fuel in the tank, when you start to run low you may start to run your engine too lean without you realising it. Now the fuel tank does have baffles to help increase the fuel supply, but regardless of this your still putting the pickup at the wrong end of the truck, and you will run your engine leaner during the last 1/4 tank of fuel or so compared to running the truck with the tank in the standard config.

+1, no more to say. :teacher:

[mordraid]

Trow the stock tank away and get a new one.

I'm actually converting my old TNX30. to the new chassis. here's what it looks like so far.

http://img107.imageshack.us/img107/930/tnxchassis002no9.jpg

[overdosed]

why are there 2 pressure line nipples on that fuel tank? theres the pressure nipple ontop of the lid, but also look like one underneath it. that can be the fuel line can it? its too high to take in fuel.

[overdosed]

how can it be the fuel line nipple? arent they supposed to be at the bottom of the tank? otherwise how can it suck the fuel out if it is above fuel level point?

[mordraid]

Yes it is the fuel line. Have no problem at all with this tank.

[ericem]

why are there 2 pressure line nipples on that fuel tank? theres the pressure nipple ontop of the lid, but also look like one underneath it. that can be the fuel line can it? its too high to take in fuel.

well, there is a tube that runs to the bottom, its like the hyper 7 tank.

[zakerid]

overdosed,
another problem is that your fuel pick-up is now facing the front of the truck. under acceleration fuel will be forced to the back of the tank and starve your engine of fuel.

[overdosed]

i already know that, what about tanks with like a tube that like hangs inside the tank and takes in the fuel; can i have those types of tanks facing anyway?

[zakerid]

depends on where the clunk is hanging...