400HP Possible N/A?
09-01-2010, 05:57 PM
#31
Please explain that one to me. I'm not trying to be difficult or start an arguement, I just want to know how a tuner would do it differently than the factory would. I've been thinking about this a long time now and at first I thought it would be awesome if a tuner could change the settings. But lately I've been thinking, how would changing the intake valve operation effect the engine. I mean, the mechanical components are set, like intake valve size, exhaust valve size, exhaust valve lobe is set, the max each valve can go up is set, the exhaust valves operation doesn't change at all, the LSA is set, and the port sizes and construction are set. The only real thing that changes is the lift of the intake valve right? Or can the whole cam be retarded as well?
I can see there being advantages to playing with the lift of the intake valve if going from a n/a to a f/i setup, but what if you were just staying n/a? Would there be an optimal setting for the VVEL? And if there is, is that one setting the best for all engines (minus any that have had the heads, valves, cams modded)? If there is an optimal setting, let's say highest hp up high and most tq down low, how far off would the factory setting be? Because that was what they were after in the first place.
I'm starting to lean on the side that VVEL tuning won't do much good unless you have f/i or you've modified your heads/cams.
I can see there being advantages to playing with the lift of the intake valve if going from a n/a to a f/i setup, but what if you were just staying n/a? Would there be an optimal setting for the VVEL? And if there is, is that one setting the best for all engines (minus any that have had the heads, valves, cams modded)? If there is an optimal setting, let's say highest hp up high and most tq down low, how far off would the factory setting be? Because that was what they were after in the first place.
I'm starting to lean on the side that VVEL tuning won't do much good unless you have f/i or you've modified your heads/cams.
09-01-2010, 06:15 PM
#32
Please explain that one to me. I'm not trying to be difficult or start an arguement, I just want to know how a tuner would do it differently than the factory would. I've been thinking about this a long time now and at first I thought it would be awesome if a tuner could change the settings. But lately I've been thinking, how would changing the intake valve operation effect the engine. I mean, the mechanical components are set, like intake valve size, exhaust valve size, exhaust valve lobe is set, the max each valve can go up is set, the exhaust valves operation doesn't change at all, the LSA is set, and the port sizes and construction are set. The only real thing that changes is the lift of the intake valve right? Or can the whole cam be retarded as well?
I can see there being advantages to playing with the lift of the intake valve if going from a n/a to a f/i setup, but what if you were just staying n/a? Would there be an optimal setting for the VVEL? And if there is, is that one setting the best for all engines (minus any that have had the heads, valves, cams modded)? If there is an optimal setting, let's say highest hp up high and most tq down low, how far off would the factory setting be? Because that was what they were after in the first place.
I'm starting to lean on the side that VVEL tuning won't do much good unless you have f/i or you've modified your heads/cams.
I can see there being advantages to playing with the lift of the intake valve if going from a n/a to a f/i setup, but what if you were just staying n/a? Would there be an optimal setting for the VVEL? And if there is, is that one setting the best for all engines (minus any that have had the heads, valves, cams modded)? If there is an optimal setting, let's say highest hp up high and most tq down low, how far off would the factory setting be? Because that was what they were after in the first place.
I'm starting to lean on the side that VVEL tuning won't do much good unless you have f/i or you've modified your heads/cams.
Given that the system is, theoretically, infinitely variable, you could give it "high duration high lift" settings to emulate that of performance cams. If you were to go into ultra high RPMs, you could increase overlap.
For FI settings, you'd do high lift, but with less overlap and less duration to prevent leakage.
Instead of having "one set of cams", you could tweak the settings to each individual setup every time.
In reality, none of this can be done because nobody has cracked the system (or even really bothered trying, as everything can be cracked), and all the system really does is create excessive amounts of heat. Nissan obviously knows this, since they prevent RPMs before load when you hit limp.
09-01-2010, 07:57 PM
#36
Registered User
09-01-2010, 07:58 PM
#37
Registered User
VVEL also controls intake timing obviously. Exhaust cams however, I think they're the same as the HR.
09-01-2010, 09:09 PM
#39
Registered Member
09-02-2010, 05:57 AM
#41
Registered User
Thread Starter
09-02-2010, 03:34 PM
#42
Administrator
09-02-2010, 08:06 PM
#45
Administrator
Intake valve opening is controlled by throttle pedal.. interesting.
So the intake valve opening is a function of both TPS & RPM? Like some sort of 3D table
So the intake valve opening is a function of both TPS & RPM? Like some sort of 3D table