stingerg64

Have just aquired an HPI 5B and have a question about the performance of the motor and what to expect out of it. I own serveral 1/4 scale aircraft with serveral different sizes of motors all but one are zenoahs. Have been a racer and mechanic for over 30 years so I am familiar with all the tuning techniques all the way to high performance with that said just wanted to know if it is common for this combination 23cc stock fuelie to break up in the high side of the midrange or can I expect for it to wind on up until the gear runs out? I have adjusted the carb both external and internal with the expected results from the changes. All I have been able to accomplish is to move the break up further out in the rpm range but not eliminate it. It almost acts like it is getting fat but I have good plug readings or I do I need more timing. Is this one of the reasons most of you are changing carbs and porting? I can do all this but don't want to if I don't have to. None of my aircraft engines run in this manner but they are always loaded with the prop and turn anywhere from 6800 rpm to 8900 rpm smooth as silk two stroke all the way thru the range. perfect plug readings 8 to 9 gallons of fuel thru them. Is some of this caused by the unloading of the mass as you get up in speed because the bottom is perfect and pulls hard all the way to the high side of the midrange were it just kinda gets flat and won,t finish going thru the rpm range. Any help would be appreciated.

Selfdestruct

My Feedback: (2)

what pipe are you running? If its the stock can, you might want to switch to the SS pipe, or check out the Jetpro pipes as they have the reputation for letting the engine wind out.

Lars from Norway

Scroll down to the Victory RC Pro Pipes on [link=http://www.oneillbrothers.com/rccar/pipes.htm]this site[/link], without having tried them i know from many others here in Norway that this gives most bang for the buck. It is even developed here in Norway by Jan-Erik at [link=http://www.rc-racing.no/]RC Racing[/link] together with ONB. Next time i am going to buy a pipe this will be it.

Sherv

My Feedback: (1)

I think you cant go wrong with a JetPro, DDM, or Victory pipe. They offer great value and lots of options between the three. JetPro tends to have more silenced or add-on silencers pipes.
All 3 are excellent. I did experience similar bogging with my old CY engine and stock box can. Almost sounds like its struggling/choking. A new pipe will definitely spring some extra life into that engine.

stingerg64

I really appreciate everyones quick responses, Yes I have the stock can style muffler on it at the present time and I agree that a tuned exaust will improve the performance is this the norm for performance charicteristics for an out of the box stock car with stock components? Is this simmular to how your cars ran before you made the pipe changes? I understand why that would be in that the tuned pipe will hold the fuel charge in the chamber longer and according to design change the power curve. With your pipe changes do they run out to the top of the rpm range in a two stroke or are we just pushing the flat spot out further? I don't expect the motor to wind up indefinetly but it should have some pull after the gear runs out. Is that close to what you are getting for performance with your pipe. I apologize for all the questions and thank you again for all your answers and guidance just trying to make an informed purchase the first time. Jetpro looks like a good choice are finding the baffeling for the pipes chaging the power band any? and if so which direction low end or high end? Thanks Jack

bbuzzard

My Feedback: (5)

Any tuned pipe will exceed the performance of the stock cans...period! Depending on your needs....speed vs. torque...there are different pipes to specify. All you need to do is tell us how much you want to spend, your environment (race vs. bash), and what will be the most durable.

stingerg64

Racing will be the environment, would like to keep the price to a 150.00 or less and clean up the high side. Thanks Jack

Selfdestruct

My Feedback: (2)

apparently the 5T stock can is a big improvement on the 5b can. Only difference being that the baffles are removed, not that ive ever tried it. my first pipe was the dom v1, never bothered with the cans.

TIGER76

swopped out a ss tuned pipe to a dom v2 [X(] night and day difference for the price m8 only wish i would of done it sooner those mod pipes let your engine breath alot better too

stingerg64

OK gentalmen after several days of research I finally have a pipe on the way. Went with the DDM Dominator side mount. Does anyone have any first hand experiance with this set up? Pipe should be here in a few days and I will report back when I get to run it. Thanks again for your input. Jack