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Speed,Combat,Scale,Racing => Speed Talk => Topic started by: david smith on August 07, 2009, 10:50:45 PM

Title: tuned pipes
Post by: david smith on August 07, 2009, 10:50:45 PM

I was watching you guys fly speed at the nats and I was wondering what makes the engines speed up so suddenly?  Is it just the tuned pipe or is there something else? If it is the pipe what makes the pipe do that? Basically how does it work? Thanks for your help.
David 

Title: Re: tuned pipes
Post by: Joey Mathison 9806 on August 08, 2009, 10:12:14 AM

the reason the piped speed planes seem the come alive all of a sudden is that on the ground the rpm is to low for the pipe to work as the plane gets airborne the prop unloads and the pipe starts working. ofcourse you need many other things to be set up correctly for this to happen.

Title: Re: tuned pipes
Post by: john e. holliday on August 08, 2009, 10:14:31 AM

David, you should have talked to some of the speed guys during their quiet period.  As Joey says there are other things like tank placement, propellor and engine setting.  Hope you had fun,  missed being there.  DOC Holliday

Title: Re: tuned pipes
Post by: W.D. Roland on August 14, 2009, 11:17:03 PM

David
The pipe comes in when Rpm and the reflected shock waves atart a sucking on opening and over suck drawing fresh charge into the pipe through the exaust then another wave on its way back stuffs the mix back in.
Different waves are involved, gas pressure pulse ,speed of sound pulse,(pulse down the material of pipe?)

That is why the pipe shape,header length and stinger length are all critical--to RPM.

That all I remember at the moment.

oh yea--fuel demand goes way up when on the pipe.

Hope pilot is in pylon when it comes on.
When they miss it can get scary--speed ships are fat even with 1/2 the prop gone!


Tuned pipes are why I never flew speed, its enough work to make this silly stuff work already.

David
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