Trex 600N Turbo

[Tom Burgess]

Anyone seen this before?

[ame=http://www.youtube.com/watch?v=_CbL9vYAoG0]YouTube - Trex 600N Turbo[/ame]

Amazing, whether it works or not!

[trillian]

That's quite strange.

If it is supposed to be going into the intake like a conventional turbocharger, I didn't know you could turbocharge a 2 stroke.

The other thing you could do is have it just blow into the cooling shroud, which may help with the cooling and allow a leaner mix, 'just taking a guesses.

....Just had a look on youtube, so now I can see it is indeed going into the intake.

There is another vid here; [ame]http://www.youtube.com/watch?v=i_EbWY0nIKw[/ame]

[Tom Burgess]

I was thinking the same, also, the exhaust gas blows through the turbine in a starnge way doesn't it? i thought the intake would of gone front to back?

[J-S-Q]

Yeah I saw that a while back on Helifreak but I don't think the guy gave any details of how he did the mod or whether it was actually successful.

[trillian]

Yeah I saw that a while back on Helifreak but I don't think the guy gave any details of how he did the mod or whether it was actually successful.

I think to have any real gain you would need to really co-ordinate the pipe end as well so the backpressure is right or you could lose power right from the beginning but I guess if you get all that dailed in it could be interesting.

The thing is you can always wring the maximum power out of a 2 stroke engine with a tuned pipe but then your powerband gets very narrow.

[Mart61]

I'm not sure it'd get any real gain from doing that, not without beefing up the engine internals and the head.

Also it sounded awful. Or is it my sound card?

[Kwickkwack]

The layout looks normal for a turbo so no problems there, but as has been pointed out you can loose as much as you gain by a badly balanced exhaust. My guess is this was a project just to prove it could be done.

[Ade_Law]

i was under the impression that 2 strokes dont benefit from turbo charging any pressure you produce in the inlet from the turbo will just go straight through the motor as both inlet and exhaust are open at the same time its the clever shaped porting and the pressure waves in the exhaust that make a 2 stroke work.

it works on 4 strokes because they have an inlet and exhaust valve whilst the exhaust and inlet valves are open at the same time (called overlap) for a short period its a very short period and engines designed specifically for turbo charging generally have less overlap than their normally aspirated brothers.

Ade

[400blade]

Ade_Law is wright a turbo will not work on a 2 stroke engine for the given reseaon both ports are open at the same time

[Tom Burgess]

Ade_Law is wright a turbo will not work on a 2 stroke engine for the given reseaon both ports are open at the same time

Not trying to say it would work but that is not right. If they were both open at the same time there would be no compression. The position of the piston in the cycle determines wether or not the port is available.

[MrKev]

Two videos of a 600N 'turbocharged'. My heli's better though - I've seen mine actually fly.

[trillian]

Not trying to say it would work but that is not right. If they were both open at the same time there would be no compression. The position of the piston in the cycle determines wether or not the port is available.

The exhaust port is higher than the transfer ports so the burning fuel starts to exit before the unburned mixture comes in but at a certain point both parts are open.

The way to squeeze maximum power is the tuning of the pipe to where as much burned gas exists and the bit of unburned mixture that makes its way out the exhaust port gets blown back in by the tuning of the pipe.

The problem is that with a fixed height exhaust port you end up with a very narrow power band where everything hits the 'sweet spot'.

The tricks that 2 stroke racing engines started using is reed or rotary valves on the intake to keep some back pressure in the case and exit more exhaust and then the really modern high performance engines have all sorts of inovations to squeeze out the power on the top end and still have power in the low and mid ranges. (but not turbochargers)

[unwind-protect]

The way to squeeze maximum power is the tuning of the pipe to where as much burned gas exists and the bit of unburned mixture that makes its way out the exhaust port gets blown back in by the tuning of the pipe.

Exactly; see one of the Interweb's more useful animated gifs:

Tuned pipe - Wikipedia, the free encyclopedia

[maderdog_1024]

2 Stroke = Suck,Squeeze + Bang, Blow

4 Stroke = Suck + Squeeze + Bang + Blow

[Ade_Law]

now imagine that same animated gif but with higher inlet pressure from a turbo or super charger.

it would just blow straight through and counter the effect of the pipe. Another thing with his setup is the turbo is on the end of the exhaust. it should be as close to the engine as possible as the exhaust gasses will cool down and thus loose some of their volume.

this was discussed at length a few years back as there was a tuning company that did belt driven super chargers for nitro cars. those didnt work either.

most of the mufflers we run today are mildly tuned pipes to some extent. Enough to increase the power without making them excessively picky.

Ade