It appears that they work best on small displacement engines. How long till manufactures start using these for their tiny eco cars? The little 1.0l or 1.5l cars?
Yes, I'll take 4 of these for my miata... (Need one per cylinder.)
Depending on how cheap they actually end up being they could be pretty interesting.
I'm skeptical. Reads like a piece written for cash. No independent dyno runs yet?
Early in the article it boasts psi claims for single and dual drums, then later in the article says there needs to be one per cylinder...
Interesting idea though, if it is not ridiculously dependent on length of header and intake tubes I'd be shocked.
I don't see it happening. All it does it take a little of the exhaust mechanical energy to make a little amount of boost.
And seeing how it works, it would be REALLY interesting to hear it, as I expect it would be quite loud.
alfadriver wrote: I don't see it happening. All it does it take a little of the exhaust mechanical energy to make a little amount of boost. And seeing how it works, it would be REALLY interesting to hear it, as I expect it would be quite loud.
I was thinking it should make the vehicle very quiet since it's turning the exhaust pulses into boost pressure.
For so many reasons, this is just cheap-electric-superchargers all over again...
It would be HILARIOUS to see a car at SEMA with these mounted where the sound system would be all over the car.
Gripe: they said "no computer tuning required" well that's bologna cause we all know you can't stuff air into something and not change fuel and spark timing.
Trackmouse wrote: It would be HILARIOUS to see a car at SEMA with these mounted where the sound system would be all over the car. Gripe: they said "no computer tuning required" well that's bologna cause we all know you can't stuff air into something and not change fuel and spark timing.
Yes you can when it doesn't make any difference. Like those ebay electric "superchargers". Which I'm fairly sure this is an equivalent. I would have to see proper independant testing before believing otherwise.
The problem with the eBay electric superchargers was that the motor was too weak to produce any meaningful boost (or even supply the engine with air at sufficient speed). You could in fact make a good working electric supercharger, but you'd be replacing a belt and two pulleys with a bulky motor-generator system. Volvo did it. F1 TERS is almost the same thing.
Other than that, the only thing they have in common is that they haven't been proved to work through independent testing. It could be the case that the boost from these units is so minimal that they get away with running with stock fuel and spark settings and manage to produce more power without damaging the engine.
Its an interesting concept. I'm curious how the exhaust side pulse valving works and what kind of back pressure it puts on the exhaust circuit which could ultimately rob power. I would also like to know what kind of mechanical butterfly valving system and spring they are using. With bikes routinely running 6K to 10K rpm, each spring and valve set would have to cycle half that amount. Durability would be a concern to me. A little over 4lbs of boost would give a small power increase without having to do any tuning, but with the exhaust timing being so critical I only see this being effective if the manufacturers install at the factory.
How long would that even last? Where does the flex come from with the 'speaker cone'? Hopefully more than a foam surround.
Aside from the obvious fatigue-failure problems, I'm wondering how this thing would work. I don't see a reed valve in there, and this thing will pump air back out the inlet just as easily as it'll pump it to the cylinders. A reed-valve two-stroke with a broken reed doesn't run.
RossD wrote: How long would that even last? Where does the flex come from with the 'speaker cone'? Hopefully more than a foam surround.
I thought the same thing, but then I remembered mechanical fuel pumps.
chaparral wrote: Aside from the obvious fatigue-failure problems, I'm wondering how this thing would work. I don't see a reed valve in there, and this thing will pump air back out the inlet just as easily as it'll pump it to the cylinders. A reed-valve two-stroke with a broken reed doesn't run.
It seems that it works by taking advantage of the timing of the intake and exhaust pulses to inhibit reverse flow...kind of like the extraction effect in 2-stroke exhaust, but on both ends.
GameboyRMH wrote:RossD wrote: How long would that even last? Where does the flex come from with the 'speaker cone'? Hopefully more than a foam surround.I thought the same thing, but then I remembered mechanical fuel pumps.
Same thing, except for the 1500F exhaust temps. Sure.
GameboyRMH wrote: Other than that, the only thing they have in common is that they haven't been proved to work through independent testing. It could be the case that the boost from these units is so minimal that they get away with running with stock fuel and spark settings and manage to produce more power without damaging the engine.
You just described how a cheap electric supercharger 'works' too...So yes, while the physical mechanism is different, they seem to pretty much 'accomplish' the same thing and make similar types of claims.
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D2W wrote: A little over 4lbs of boost would give a ~30% increase...
FTFY...Of course I'd bet money that the 4.35psi they claim is a peak measurment on a closed volume.
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GameboyRMH wrote: It seems that it works by taking advantage of the timing of the intake and exhaust pulses to inhibit reverse flow...kind of like the extraction effect in 2-stroke exhaust, but on both ends.
As far as I can tell, it would be a lot like resonance tuning for exhaust and intake manifolds, where gains and losses throughout the rpm band are cyclic. For every resonance rpm there is a subsequent interference rpm.
alfadriver wrote:GameboyRMH wrote:Same thing, except for the 1500F exhaust temps. Sure.RossD wrote: How long would that even last? Where does the flex come from with the 'speaker cone'? Hopefully more than a foam surround.I thought the same thing, but then I remembered mechanical fuel pumps.
They say they've got a fancy composite material for the diaphragm...unless this is a blatant scam they must have a material that can survive those temperatures, or it would melt down on the first hard run.
I found a dyno plot here Link I don't think it's that unreasonable. It's creating a well timed strong first order induction pulse. Very similar in principle to the Comprex wave supercharger which does work in some narrow applications. I would like to know what they claim that membrane is made out of. I don't thin't it's designed to go in the exhaust flow path but T-ed off rather. That would keep the temps down and give some conventional materials a fighting chance.
"Pumper" carbs on chainsaws, weed-wackers, etc. are diaphragm pumps that operate off exhaust pulses. That said, using pressure differentials in the exhaust gas to generate boost, vs. exhaust flow doesn't sound encouraging.
RXBeetle wrote: I found a dyno plot here Link
More importantly than the dyno, that link has a computer animation. Note the illustrated 'reed' valves that move this from laughable, to skeptically plausible.
In reply to djsilver:
The ones I've seen run of the intake pulses....
Pumper carbs also work at such low pressures that they can't even self-prime or overcome the restriction of some fuel filters.
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