20B renesis pics!!!!!!!
04-09-2008, 03:33 PM
#78
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It's compression ratio is also very high, and because it's boosted, the dynamic compression is even more impressive, which allows the use of smaller valves and ports on the exhaust side.
My point was, that you can still achieve reasonable performance even if flow was restricted.
Besides, increasing dynamic compression ratio, doesn't reduce flow.
And again, since the Renesis has no port overlap, any exhaust restriction is of less importance, as fresh gases do not have the opportunity to scavenge any remaining exhaust gases anyway.
04-10-2008, 06:15 AM
#80
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Not really a problem with a rotary as the intake ports don't get in the way of the exhaust ports, so it's not really relevant, besides, it's the shape of the ports that makes them restrictive, not the size.
Last edited by PhillipM; 04-10-2008 at 06:19 AM.
04-10-2008, 02:15 PM
#81
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Originally Posted by PhillipM
No, but it allows you to get away with smaller exhaust valves so that you can fit larger intakes for more power, there's a trade off between the two that bias toward the intake valve the more compression you have.
it's the shape of the ports that makes them restrictive, not the size.
Needless to say that an exhaust valve has a worse aerodynamic coefficient than a brick and the Renesis has none.
Last edited by globi; 04-10-2008 at 02:17 PM.
04-10-2008, 05:49 PM
#82
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Any opening with a constant cross section with no turns or twists that is, you seem to be forgetting that the rotary has two 90* bends one right after the other which creat a huge disruption and boundary area, especially the sharp SSRs.
Valve overlap helps with power, so that makes your point even less valid, especially given that the engine runs at a pressure ratio of 1.5+, it has a huge amount more pressure available to flow air through that port.
The exhaust ports and flow on the VW has basically no similarities to the Renesis, it's not a valid comparison at all.
Valve overlap helps with power, so that makes your point even less valid, especially given that the engine runs at a pressure ratio of 1.5+, it has a huge amount more pressure available to flow air through that port.
The exhaust ports and flow on the VW has basically no similarities to the Renesis, it's not a valid comparison at all.
Last edited by PhillipM; 04-10-2008 at 05:55 PM.
04-11-2008, 01:34 PM
#84
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Any opening with a constant cross section with no turns or twists that is, you seem to be forgetting that the rotary has two 90* bends one right after the other which creat a huge disruption and boundary area, especially the sharp SSRs.
2. Regardless: Size is still more important. If the cross-section area is 4 times larger the flow is also reduced by a factor of 4. And again the pressure loss is always proportional to the flow velocity squared - regardless of shapes and twists.
If the flow velocity is quadrupled one ends up with 16 times the pressure loss for a given shape.
http://www.engineersedge.com/fluid_f...ssure_drop.htm
Large flow restrictions one does indeed obtain if the opening of the exhaust pipe (header) is significantly larger than exhaust port facing it. But this does not seem to be the case.
Valve overlap helps with power, so that makes your point even less valid, especially given that the engine runs at a pressure ratio of 1.5+, it has a huge amount more pressure available to flow air through that port.
If there's no overlap as with the Renesis, scavenging is simply a no-option and pressure loss through the exhaust port is of less importance.
Because whatever you do to reduce that pressure loss: You can never scavenge the remaining exhaust gases from the exhaust chamber even with 30 psi of boost pressure.
04-12-2008, 03:52 AM
#85
just been talking with a guy here in NZ that has built 2 x3 rotor renesis motors already and is now building a 4 rotor renesis for a guy in the US to put into an RX8..........
oh - and no BS calls please - this is the guy that built the engine for the 6second RX8 from Pueto Rico .
oh - and no BS calls please - this is the guy that built the engine for the 6second RX8 from Pueto Rico .
Last edited by Brettus; 04-12-2008 at 04:10 AM.
04-13-2008, 08:17 AM
#87
just been talking with a guy here in NZ that has built 2 x3 rotor renesis motors already and is now building a 4 rotor renesis for a guy in the US to put into an RX8..........
oh - and no BS calls please - this is the guy that built the engine for the 6second RX8 from Pueto Rico .
oh - and no BS calls please - this is the guy that built the engine for the 6second RX8 from Pueto Rico .
Regards
Carl
05-09-2008, 05:21 PM
#92
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How much?
Here it is!!!!
Engine is running in a drift FD in the UK... thought a 3rotor with side exhaust ports wasn't possible!
The vechicle that's it all in.
Built by----> http://www.mazdarotary.co.uk/
Engine is running in a drift FD in the UK... thought a 3rotor with side exhaust ports wasn't possible!
The vechicle that's it all in.
Built by----> http://www.mazdarotary.co.uk/
Failing that, how about a step by step construction process mapped out with photographs? I have access to a machine shop, but don't really have the expertise in engines to go into this cold.
05-09-2008, 05:41 PM
#94
Power!!
I noticed that you are running single length intake runners. Any thought to a variable length setup like the OEM renny? I know this is a big improvement for N/A rotaries.
05-10-2008, 12:01 PM
#96
Power!!
I agree it's complex and I don't know much about optimizing for drifting but I do know it was a key component to the Lemans team win in 1991 with their 4 rotor car.
05-11-2008, 08:56 PM
#100
Power!!
