More on HPV?
I have enjoyed the series "Building a Human Powered Vehicle" very much. I am wondering however, will there be a Part 7, or some form of summary?
Sorry for the delay in the series. We’ve been doing some interesting things with the machine, including data-logging suspension travel and measuring seat vertical accelerations. There will be at least two more parts to the series, with the next part scheduled to appear in about four weeks. To see a sneak preview of the machine in action, have a look at www.youtube.com and www.youtube.com .
Upsizing MAF Flow
Our airflow meter bypass was done on a Nissan – series starts at Airflow Meter Bypass, Part 1.
Auto Air Off
Driving Emotion. “I didn’t feel a
huge lack of power (although I did switch off the air when overtaking)........”
I am surprised that you haven’t fitted a ‘switch’ to turn off the AC in these
We intend covering such a system using the Voltage Switch kit.
Space for Speakers
I was just reading your Driving Emotion from December in regards to speaker size issues. I have experienced this issue in a few small cars. My solution would be to try Akai speakers. They have a very shallow mounting depth and are very lightweight; the only drawback I have found is that the quality is not as great as some of the better aftermarket speakers.
I consider AutoSpeed to be the most useful car mag that I have ever read in the past 45 years (back to when I was still wearing short trousers to school even in the middle of winter). I have been able to top up on my, somewhat, out of date degree in automotive engineering and visit areas of the theory and practise that I might never have even considered.
However, I find it quite time consuming trawling
the back issues to find articles for research to help me with my projects. Is it
at all possible that you have kept a database and could incorporate an A-Z index
of all previous content?
Thanks for the positives. We don’t have an index of articles so the easiest way of finding relevant material is to use the search function using a variety of terms.
Measuring Intake Systems
Firstly, good quantifiable research in the recent articles, as always!
It may be too late, however in the original intake
configuration, I note you tested at 5000 rpm in 2nd gear (high load). I
don't recall if you've had the vehicle run up on a dyno yet? Is 5000 rpm
the rpm for peak torque? I expect having driven an EF in the past that the
torque band is rather flat and wide, and across mid-range revs, trailing off
towards 5-6K rpm.
By definition, peak cylinder filling per intake stroke occurs at peak torque - that’s what makes it peak torque! However, peak airflow occurs at peak power, and that’s when the greatest flow losses in an intake system will be measured. A torque loss anywhere in the rev range results in a power loss at those same rpm, so dyno sheets will clearly show if this has occurred. Pressure drop measurement will not show the tuned behaviour of the intake system. So for all of these reasons, intake manifold pressure drop measurement should be done at peak power (or at revs near peak power).