Rx-8 vs NSX volumetric efficiency
07-20-2011, 09:09 PM
#1
Rx-8 vs NSX volumetric efficiency
I thought you guys might find this interesting. Here is a comparison of volumetric efficiency vs rpm from a number of different engines. The graphs came from the manufacturer's papers released on the respective engines.
Black line is the 6 port Renesis, Gray line is the 4 port Renesis. The hashed pink line is presumably the 89-91 Rx-7 engine which is the logical benchmark for the Renesis. Note that the Rx-7 engine does have 6 ports and a VDI system. However it does not have a variable fresh air duct, and the secondary ports are mechanically staged by throttle position instead of by a computer controlled shutter valve. Now here is the volumetric efficiency curve of the original NSX with the C30A engine:
The thicker line is the production NSX engine. The other line is a prototype, basically an NSX engine without VTEC which was used as a benchmark. The production NSX engine has VTEC to increase lift and duration by a fixed amount at the switchover point. This can be compared to the auxiliary ports opening on the Renesis. The NSX also has a variable intake system roughly equivalent to the VDI system. The GS-R and Type R Integras also had both systems.
Black line is the 6 port Renesis, Gray line is the 4 port Renesis. The hashed pink line is presumably the 89-91 Rx-7 engine which is the logical benchmark for the Renesis. Note that the Rx-7 engine does have 6 ports and a VDI system. However it does not have a variable fresh air duct, and the secondary ports are mechanically staged by throttle position instead of by a computer controlled shutter valve. Now here is the volumetric efficiency curve of the original NSX with the C30A engine:
The thicker line is the production NSX engine. The other line is a prototype, basically an NSX engine without VTEC which was used as a benchmark. The production NSX engine has VTEC to increase lift and duration by a fixed amount at the switchover point. This can be compared to the auxiliary ports opening on the Renesis. The NSX also has a variable intake system roughly equivalent to the VDI system. The GS-R and Type R Integras also had both systems.
Last edited by arghx7; 07-20-2011 at 09:14 PM.
07-20-2011, 09:43 PM
#2
I find both of those charts to be highly optimistic and, being that they are manufacturer-provided, my pessimism is well founded.
I'm sure the line slopes are pretty accurate (though the Honda line is highly "optimized"), but I can tell you that from actual experience with both of these motors that neither ever actually achieves a functional Ve over 105%.
I'm sure the line slopes are pretty accurate (though the Honda line is highly "optimized"), but I can tell you that from actual experience with both of these motors that neither ever actually achieves a functional Ve over 105%.
07-20-2011, 11:26 PM
#4
They are using different methods and equipment than you.
07-21-2011, 11:49 AM
#11
I think we can all accept that you are incapable of providing the ideal resources to test the ideal engine under the ideal conditions with the ideal equipment
otherwise if your point is that most owners will never see those numbers from their production engine then we can accept that too
the question is, can you accept that a few elite builders have on occasion seen numbers exceeding the chart?
otherwise if your point is that most owners will never see those numbers from their production engine then we can accept that too
the question is, can you accept that a few elite builders have on occasion seen numbers exceeding the chart?
07-21-2011, 11:54 AM
#12
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