Is the HR worth it?
08-30-2013, 09:37 PM
#161
Not trying to be combative here and you are being helpful as I never heard of this issue prior. You mention the lag applies to WOT between 3 and 4K on the tach. Im 99.9% thats not accurate. The car is a rocket at those RPMS, pulls like a freight train. I THINK, my gut reaction was right to this. I think it might be the delay at idle and going WOT or say 60% WOT. There IS DEFINITELY a delay before it picks up and the power comes on. Ive looked at the VHR torque curves and its well, gutless at idle to like 2000 rpm. However, its not even remotely close to a 3 second lag time of power. Im thinking maybe a half second of lag? And half second is being extremely generous.
A delay is not a pause. TPS gradually rises. That's indicative of continuous throttle opening, just not at the rate the driver would expect based on the driver's intent. When the driver drops the hammer, the throttle bodies should snap open. Watch the video below. This is how quickly the throttles should snap open when the pedal is floored.
<object width="420" height="315"><param name="movie" value="//www.youtube.com/v/KyZn8Uzwy7A?hl=en_US&version=3"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="//www.youtube.com/v/KyZn8Uzwy7A?hl=en_US&version=3" type="application/x-shockwave-flash" width="420" height="315" allowscriptaccess="always" allowfullscreen="true"></embed></object>
Instead it opens more like an exhaust cutout, opening gradually.
<iframe width="560" height="315" src="//www.youtube.com/embed/3rCT5FfwBl0" frameborder="0" allowfullscreen></iframe>
It opening rate gets faster as RPM increases, and beyond 4000RPM it operates like in the first video. Below 4000RPM it operates more and more like the cutout show above. The lower the RPM that you go WOT, the more like the cutout it behaves.
UpRev for the 370Z comes with a throttle table that eliminates the low RPM delay. Above 4000RPM it behaves normallly. The higher the RPM that you apply WOT, the faster the ramp rate of the TB. The data log shown is a worst case scenario, and one you'd probably really only notice occasionally driving around town. If you're launching the car, by the time you go WOT, you'd already be past 3000RPM and TPS delay would be minimal. If you launched at 3.5k-4k RPM, it'd be virtually nonexistent, except the clutch pedal would probably sink.
09-03-2013, 08:05 PM
#163
09-04-2013, 03:47 AM
#165
Ok that pretty much clears it up, thank you for that info. Might look into a tune now. I promised myself I wouldnt mod this car...its just my daily fun car. Not that i can really feel this lag but knowing it really exists...sigh. Damnit it all to hell now!! LOL.
Thread
Thread Starter
Forum
Replies
Last Post
