freetors said:¯\_(ツ)_/¯ said:In reply to Robbie :
I remember a guy building a gs500 a long time ago with the same thought. Use the second cylinder as a supercharger. He essentially turned the second cylinder into a "two stroke" by removing the valves and installing reed valves. He said it made a very unique engine sound.
Now I know what I am going to do to the v-twin when I build my replica morgan 3 wheeler.
How much psi can a stock miata take before the Ecu freaks? If this gave 1psi, and added ~10hp, could the factory fuel system and management even compete?
It would be funny to try... but not on my engine.
Heres some math for you boost nerds. http://superchargersunlimited.com/specs.html
_ said:How much psi can a stock miata take before the Ecu freaks? If this gave 1psi, and added ~10hp, could the factory fuel system and management even compete?
It would be funny to try... but not on my engine.
Heres some math for you boost nerds. http://superchargersunlimited.com/specs.html
Those tiny superchargers are way overpriced on that website, they can be found for ~$250 on ebay all day long. AMR500 blower
freetors said:¯\_(ツ)_/¯ said:In reply to Robbie :
I remember a guy building a gs500 a long time ago with the same thought. Use the second cylinder as a supercharger. He essentially turned the second cylinder into a "two stroke" by removing the valves and installing reed valves. He said it made a very unique engine sound.
To turn one cylinder of any engine into a compressor, you can do one of two things: a really funny camshaft with double the bumps for that cylinder. Or a camshaft that spins twice as fast on that cylinder. For a car, this would work best on a SOHC V6/V8.
In reply to maschinenbau :
You would also want to find a way to double the duration of the charger cam - since it is spinning 2x as fast it would now only be open for half of the intake stroke or half the exhaust stroke.
You could actually turn the intake side into a reed valve by simply replacing the valve spring with something really light and taking the cam out. Something just barely strong enough to hold the valve up against gravity. On the exhaust side you would need to take the valves out and invert them somehow, or make a reed valve flange that bolts between the head and the "exhaust" manifold.
This is starting to sound do-able.
where was that cheap jag v12 again?
oh god. can we do this to the front rotor on a cheap rx-8?
for the rx-8, we would just need to remove both spark plugs on one rotor. One spark plug would be an additional 'exhaust' for the charger rotor and the other would be an additional 'intake'.
I guess for a little more work it may also be possible to cut similar ports into the compression side of the housing.
It's simple people, all you need are reed valves and a way to attach them to the intake and exhaust ports. You don't even have to mess with the camshaft, just remove the valves and seal the holes. Or I suppose you could leave those valves in and modify the cam so they never open. This requires the least amount of screwing around with stuff. It's already been done here: https://www.customfighters.com/forums/showthread.php?t=39520#/topics/39520
Robbie said:oh god. can we do this to the front rotor on a cheap rx-8?
This will not work with an RX8 motor...it needs to make compression.
maybe add a third rotor to use as the compressor.
Guys have been trying that split cycle stuff for a long long time.
There are still guys with patents related to this trying to capitalize on them, but no auto manufacturer is willing to bite. That tells me that either A) they want too much $, or more likely B) its not so great
In reply to ProDarwin :
It's probably not very efficient and likely puts some weird stresses into the crank that might be a durability concern, but if you just want to go fast, it should be good for making some cheap power.
akylekoz said:Robbie said:oh god. can we do this to the front rotor on a cheap rx-8?
This will not work with an RX8 motor...it needs to make compression.
maybe add a third rotor to use as the compressor.
Yeah, but you don't actually want your charger rotor/piston to make much compression. Compression tests go to 130-170psi? That would mostly be wasting energy resisting the crank. You're looking for volume with a supercharger, and if the charger rotor/piston goes 2x the regular one you can make about 2x atmospheric pressure max.
check out my low budget smog pump supercharged little Honda's--I know --it cant be done--wont work--but here I am 25 years later as I did these in 1994---just depends on what its put on as to whether it has enough volume --or not
So here goes the jank math. Pitbikes make between 2-3hp (Let's say 2.5). On a 250hp engine, to break even or make a little bit more, it'll take 100 of em.
My point being---"wont work" is too broad of a statement---just depends on the application---yes it works on a very low volume small displacement application just fine
From my research the ct70 guys running these setups are making triple the stock power, 9hp at the tire. I've got one for my atc70 sitting in my shop.
For an auto engine you are better off using one to build crank vacuum and set the rings up for it.
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