I have a Losi XXX-NT RTR does it matter how long the pressure line is? If so how long should it be?
My pressure line comes from the top of the fuel lid. Thanks in Advance

the average length should be anywhere from 8-14 inches. but it's not a huge deal. it's only suppoes to matter once you get your car extremely, and i mean extremely, dialed in. it's better to just let it be and not to risk leaning ur car out too much...

make it twice the length it takes to get from the tank to the pipe...thats what I do anyways.

Just roll it up, zip tie it, and you are good.

12 inches... maybe 11.

I have mine just long enough so I can have just a little slack so I can get the tank lid open and closed. Mines probably only about 4 to 5 inches long. I dont really think that it even matters as I have changed the length of the pressure line and havent really noticed a difference. As long as it there I dont think it even matters.


My thinking is the shorter it is the cleaner the truck is in apperance.

The length of the pressure line doesn't really matter because the pressure is going to stay the same no matter the length.

There is no set amount of length for .12 engines. Mine is around 5 inches. The longer the tubing, the longer till the fuel runs to the to the pipe, that's if your not blipping the throttle....lol

it does matter, too short & it will pulse & make the engine very hard to tune at low end. usually 8-10 inches it about right. any shorter & the pulse out of the engine will cause a pulse of fuel to squirt into the carb at the wrong time & your engine will seem really lumpy down low & stall easier at low revs. learnt from experience.

No it doesn't. The only difference is if you run a pressure line or not. There is no noticeable difference between an 5 inch to an 8 inch length. I've checked it with a Dwyer Magnehelic and measured it. The pressure line it self has very low pressure to begin with, enough to make it noticeable if you run a pressure line or not, but with any kind of length of 12 inches and under is undetectable to make any noticeable difference. Of course if you extend the length more than 12 inches you may find less and less pressure with every increase in length. I didn’t test any thing over 12 inches as it isn’t needed.

I have never had a problem with my pressure lines at all. I have use any where from 10 inches to now about 4 or 5 inches. I have not experienced any pulsing at all that would kill the engine at idle or anything that makes the idle rough. I have never heard any buddy ever say that a pressure line should be a certain length. And that anything shorter then 8 inches affects the engines performance at all. I do agree that anything above 12 inches is getting long and will prolly cause the pressure to drop because of all the extra volume it will need to make up for.


That pulse from the exhaust would have to move all the fuel already in the fuel line much faster then it is already moving. Im sure that the pulse will be very much minamized at the carb end of the works. For one thing the pressure line will not carry all that great of a pulse anyways and any and all pulse will be in the end basically nothing but the typical preesure that usually comes from a line that is longer.


I can see where your coming from but it doesnt really work that way. On paper it may seem true that this pulse would affect it. But remember on paper bumbles bees arent supposed to be able to fly either. And we all know that bumbles bee's are more then capable of flying.

I have to agree, as I do not see where the length makes a difference. On my MT the line is only about 4 inches long and my truck idles just fine. Some times getting ready to race it will be several minuets sitting and no problem idling or taking off.