ES composite pipes

[Flyingjon]

I've only run one can, and it was a proflow on a dle 35. It sure sounded nice but wasn't worth the weight.

So from what I'm hearing, the pipes won't be of much help with low to mid range power....?

 

[Alky6]

I've only run one can, and it was a proflow on a dle 35. It sure sounded nice but wasn't worth the weight.

So from what I'm hearing, the pipes won't be of much help with low to mid range power....?

This response will be in generalities:

It depends. Most expansion chambers have a usable RPM band in which they increase power. How wide that band is depends on the design of the pipe and how it works with the geometry and design of the engine. Because an expansion chamber is tuned on exhaust pulses (without getting into the details - it effectively supercharges the engine so it will make more power over stock) you can move that band to where it is useful in the rpm range. Moving it further back moves the band lower in the rpm range. Same goes for moving it closer to the engine. So if you want a lot of torque at the lower end move the pipe back (longer header). Just know that the top end RPM will suffer.

Finding the right prop that matches up to the power and where the pipe is situated is always best and you may accomplish the best of both worlds. An example - if the pipe makes power more toward the upper end of the RPM range, use a smaller prop to keep the engine in that range. Consequently, if the power range is lower, then use a larger prop to take advantage of the power there. Again, this is a very simplistic approach. Hope that makes sense.

 

[Flyingjon]

Now we're talking! I'm starting to get the theory of operation of these pipes. So we need a telescoping header that's mixed to the throttle servo to keep it in the power band all the time, huh?[emoji1]

 

[Alky6]

Ha! You are right on target! Here it is being used today on a 350cc outboard racing engine! LOL

These expansion chambers have VERY Narrow power bands that require sliding. Pipes back = 10,000 RPM

Pipes up = 14,000 RPM.

 

[dhal22]

Damn, I never thought of that. Very cool idea.

 

[Snoopy1]

From all the info I have and following Trever hoe does a lot of testing it seems that all the motors that I have played with and the last testing Trevor did with 35cc engines the ideal length is 8 1/2 header length. Hope that helps. The only unfortunate thing is that all the pipes and headers are tuned at full throttle. I am no expert but played with and built 50cc racing bikes in thr late sixties and early seventies and built our own e axpansion pipes for the motors. If you new the rpm you run while you were hovering you could tune the pipe into that location.

 

[Bbcorvette18]

I loved my carbon pipe on my dle55 in a 88 edge. Quiet sounds good plenty of power anywhere in the rpm range and the damn pipe only weighs 4.7oz. Not nearly enough weight to bitch about compared to pro flows or even regular cans.

Anyone really botching about weight hasn't held a carbon tuned pipe.

 

[Flyingjon]

I like what I hear! I'm going on Saturday to pick up my plane with a DA 70 and ES pipes. Looking forward to it!

 

[Bbcorvette18]

Fun fact the carbon pipe weighed like a tenth of an ounce more the my stock muffler. Granted I didn't add the header weight to see what the overall extra weight was. But the sound and it being quiet far outweighed the weight concern.

 

[Snoopy1]

How long have you had the carbon pipe. Never see one or held one in my hands. Do they last and does the heat get to them in time. Nice to see a picture and how they are mounted. Thanks. Interested in them.