VVEL Only on Intake Valves?
 

I am going to pick up my 370Z in about 2 weeks and I've been researching the Nissan engine technology a lot. It seems like on the VQ37VHR the intake valves get all the nice technology (VVEL and C-VTC), but the exhaust valves are driven by just "regular old" camshafts. Can anyone confirm this?

Do the exhaust valves at least have C-VTC (variable timing) on them?


BTW...VVEL virtually eliminates the need for a throttle body, which is amazing I think.

So no ones knows about the exhaust valves???

I've searched all of the interent and can't find anything about it. I'm just REALLY curious now as to what the answer is!

Aside from adjusting back pressure, I can't see the benefit to this.

For all those interested, I found the answer:

370Z Engine (VQ37VHR) > 370z.com > 370z.com - Magazine

"The exhaust cams are conventionally fixed in place like the GT-R's VR38DETT. This is unlike the VQ35HR and the Rev Up motor that have adjustable on the fly advancing and retarding for the exhaust cam."

^ Very good read on that site. I recommend going back to page one and reading the whole thing. A lot of good info.

Good find!!

That's pretty neat. I skimmed over it for now, but I'll read the rest when I get home. That's weird how the throttle blades stay open all the way most of the time.

+rep added!;)

Very very nice find! thankx

Do u guys think Nissan will add adjustable advancing and retarding for the exhaust cam to the 370 like how they did when they introduced the Rev-up VQ??

"The 370Z's VQ37VHR engine also uses CVTC and EVTC, tried and true technology that advances and retards the intake and exhaust cams to control overlap."

OK... So basically, VVEL will be like adding lift which will allow for a LOT more power when it's properly tuned. If only they did that for the exhaust, though. (Unless the lift on the exhaust is already pretty high.)

IIRC, VVEL varies lift and duration, and it negates the need for a throttle butterfly. In other words, our gas pedal controls VVEL instead of the throttle butterfly. There's still a pair of throttle butterfly valves for emissions reasons, but it is almost always 100% open.

Just think of BMW Valvetronic.

GTM, come join this one !

I think either Sam at GTM or Forged Perf could add a lot here... they're the two that seem to have spent the most time inside this motor

So, in that case, removing the butterfly would allow MORE air to pass through, correct? If the VVEL controls the throttle 100%, then I assume there'd be no problem removing the butterflies at all.

i was thinking the same thing!

I think you'd run into issues removing them. I pulled this from the article quoted earlier.370Z Engine (VQ37VHR) > 370z.com > 370z.com - Magazine

The engine does have dual drive by wire throttle bodies but they are used only for idle control and quick acting modulation for traction control. Otherwise the throttles are wide open most of the time.

As far as I know there is no need to vary the exhuast lift/duration as is done with the intake, You regulate the intake so as to allow more or less fuel. In the old days hi revving chevy v8's used cams of long duration and hi lift with the exhaust have a shorter lift longer duration so to be able to rev without freaking out the cam geometry, todays electronically/computer controlled motors are able to vary the intake for power or economy, the exhuast is just there to take out the trash so there isn't the need to open it longer than to clear the cumbustion chamber... Hope this helps..