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:You noted that I am using a smaller turbine housing and wheel that offers improved spoolup response, both of which are increasing the rate of spoolup. But you also said that Overall VE is only as good as your worst bottleneck, which in your case is your turbine and housing. While this is true, it is a fine balancing act to get the compressor to offer its best performance, which is the #1 priority.
:VE isn't a single point value either - it is a dynamic that is referenced at different RPM intervals. Yep, I agree that VE is not a static number So one cannot say that "overall VE is only as good as your worst bottleneck". This response below is to illustrate that fact:
:Consider this for a moment:
:Dee's car made 666RWHP and 590RWTQ at its MAXIMUM boost of ~26psi. It simply would not produce any more boost, power, or torque. His maximum boost was being limited by the hot section of his turbocharger. How do you know that he wasn't exceeding the limits of his compressor? Wouldn't this support my position that higher VE will see lower max boost because the superior flow through the engine will exceed what is capable of the compressor? :It took 2psi more boost, but my car also made 666RWHP. It made even more torque as a result of getting the compressor spooled up to higher PR through the RPM band where the setup has the best volumetric efficiency. But, Dee can't make any more than he already is - that was the limit. Of what? his compressor or hot section? Even though I have a bigger bottleneck, per-se, in my turbine section than Dee's car, the performance of his compressor has been negatively impacted perhaps it was maxed out?as a result, thereby producing lower massflow (VE) through his engine as a whole. Don't confuse VE and mass flow...VE is a unitless measurement that is not dependent on mass, but rather volume. mass flow is what it is...kg/sec, or whatever units are appropriate
:My clutch was also slipping through peak torque and I suspect this altered the torque numbers at their peak by about 25Ft/lbs. My setup is probably making 35RWTQ more than Dee's.
:Granted, my car required higher boost levels (by ~2psi) to make the same power, but it did make the same power with more torque, and with notably better bottom end and midrange performance, while Dee's car was incapable of making mroe than 26psi.
:It even seems to me that the .64 housing and the 9-blade turbine wheel is actually offering less overall performance after everything is said and done.... which is one of the reasons I have stuck to my guns on this Stage2 turbo. :)
:Just offering something to think about here in terms of the "balancing act". :)
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