Nissan 370Z Forum - View Single Post

BGTV8 · 05-21-2014, 01:59 AM

Another internet optimist ..........

Power is torque times revs .... the NA VQ can make serious power at high revs, but the OEM bottome end fasterners will not cut the mustard with big revs (eg: >7500) nor will the OEM oil pump.

So, to get more power at 7500 Vmax engine speed you need more lift and greater duration. VVEL might give you 12mm - 13mm at best and that implies you tighten the piston to valve clearances beyond safety.

If this is purely a theortical exercise and engine logevity is simpy not a consideration, the get your tuner to plug max lift into the VVEL, ognore safety margins and rev the engine to 9000 rpm

You;ll get ~400whp. The engine will die shrtly thereafter as a consequence of:
1. Damage from oil-pump failure
2. Damage from piston to valve interference clearance issues becuase the OEM valve springs cannot sustain the rev or because exceeding the VVEL max lift eliminated valve clearance
3. Rod bolts let go

So yes, in theory, you might get 400wHp for long enough to register on the (Optimistic) dyno - but you;ll kill the engine.

Any other option calls for the engine to be opened up and the relevant parts replaced to help the engine live at the rpm required to let it live for more than a few second (or minutes) ....

It's not that I am not a believer, but that I am realist - I have funded the build of dozens of race engines and funded the research that delivers reliable race horsepower, so my comments are based on hard-earned knowledge.

You need good airflow and compression (or boost) to make good torque and you need rev's to make horsepower. The limits in the OEM VQ preclude 450-470 Hp at the crank which is what you need to 400rwHp.

If you still believe in the tooth fairy or a magic pudding - be my guest, but I'm done here.

05-21-2014, 01:59 AM	#38 (permalink)
BGTV8 A True Z Fanatic Join Date: Dec 2009 Location: 03350 Australia Posts: 1,514 Drives: 09 Nissan 370Z M6 Rep Power: 39973	Another internet optimist .......... Power is torque times revs .... the NA VQ can make serious power at high revs, but the OEM bottome end fasterners will not cut the mustard with big revs (eg: >7500) nor will the OEM oil pump. So, to get more power at 7500 Vmax engine speed you need more lift and greater duration. VVEL might give you 12mm - 13mm at best and that implies you tighten the piston to valve clearances beyond safety. If this is purely a theortical exercise and engine logevity is simpy not a consideration, the get your tuner to plug max lift into the VVEL, ognore safety margins and rev the engine to 9000 rpm You;ll get ~400whp. The engine will die shrtly thereafter as a consequence of: 1. Damage from oil-pump failure 2. Damage from piston to valve interference clearance issues becuase the OEM valve springs cannot sustain the rev or because exceeding the VVEL max lift eliminated valve clearance 3. Rod bolts let go So yes, in theory, you might get 400wHp for long enough to register on the (Optimistic) dyno - but you;ll kill the engine. Any other option calls for the engine to be opened up and the relevant parts replaced to help the engine live at the rpm required to let it live for more than a few second (or minutes) .... It's not that I am not a believer, but that I am realist - I have funded the build of dozens of race engines and funded the research that delivers reliable race horsepower, so my comments are based on hard-earned knowledge. You need good airflow and compression (or boost) to make good torque and you need rev's to make horsepower. The limits in the OEM VQ preclude 450-470 Hp at the crank which is what you need to 400rwHp. If you still believe in the tooth fairy or a magic pudding - be my guest, but I'm done here.