ESE's works engine tuner

[Flettner]

My pipes are a compromise, one I like at the moment for the mid and low range power, top end is great but shorter pipes with steeper cones would be better, for top end.

[F5 Dave]

What if it's rainy season? Some sort of creek crossing scoop mechanism?

[katinas]

My pipes are a compromise, one I like at the moment for the mid and low range power, top end is great but shorter pipes with steeper cones would be better, for top end.

One of Honda's solutions, but of course not the same as sliding header.

[Peljhan]

The second reason: sealing. The circumferential gap that has to be sealed, is three times shorter for the trombone system. That means three times less leakage and three times less friction.

Video courtesy of Rimar Motors:
http://www.youtube.com/watch?v=0odVz...ature=youtu.be

Frits, you forgot about downside of sealing on the header compared to sealing on the belly, the temperature! Header heats up three times more than belly.
Do you know how sealing was done on this rimar engine trobone pipe? I am thinking about some kind of piston rings in combination with fiberglass rope?

[wobbly]

I tested the ATAC system on the BSL500. With a volume close to the cylinder displacement ( bigger or smaller wasnt better ) and a very short tube right at the header start with a solenoid operated
butterfly valve in line with the flow, it made 28% more power below the pipe.
It used a solenoid as the valve had to snapped open at a specific rpm, ramping open or closed lost power big time.

The only time it was useful was in testing a Pukekohe, where if the bike was geared to pull over 300Km/H we did not have a low enough 1st gear to get off the hairpin - a scenario not seen at any GP track.

[Flettner]

I tested the ATAC system on the BSL500. With a volume close to the cylinder displacement ( bigger or smaller wasnt better ) and a very short tube right at the header start with a solenoid operated
butterfly valve in line with the flow, it made 28% more power below the pipe.
It used a solenoid as the valve had to snapped open at a specific rpm, ramping open or closed lost power big time.

The only time it was useful was in testing a Pukekohe, where if the bike was geared to pull over 300Km/H we did not have a low enough 1st gear to get off the hairpin - a scenario not seen at any GP track.

In vinduro I have to get out of the 'hairpin' every second corner.

[Flettner]

What's the deal with two angle reverse cones? Why are they used?

[wobbly]

Two , or even better three angle, rear cones are used to manipulate the power curve by changing the amplitude and duration of the return plugging wave fronts shape.
If you start with a single rear cone , this can be changed to a progressively increasing angle three cones, starting very shallow, and ending in a steeper angle than before.
This gives more power everywhere - and the amount of overev generated is set by the length/angle of the final steeper cone.

If you have a PV that closes a T port, or all the ports in a 3 port, you can divide the rear length into three equal cones, starting steep, and getting progressively shallower.
This geometry looses front side, but the PV eliminates that issue, and this setup gives a huge increase in upper front side and peak, but the shallow last cone allows plenty of overev.
Dead perfect for road racing, or in an end use such as 500cc oval dirt track mini sprint cars, where they use one gear and rev it to the moon.
In that case I used semi steps ( 1/2 moon, top and bottom ) on the manifold face to pump up the bottom end, and the rear cone to generate the peak and overev needed.

A very powerful tool to tailor the power curve to the end use.
In your case Flett, an ATAC would give you more bottom end than you could wave a stick at - and easy to operate with a solenoid connected to any rpm switched supply.