Re New Car Tests
was reading Response this week and noted John Masson's feelings regarding the
latest Subaru WRX STi (Response
It got me thinking about something I've been wondering for quite a while...
Going through the list of new car tests on AutoSpeed, it would seem that the
frequency of new car tests where the car is provided by the manufacturer is
diminishing. Please do not take this as criticism. The way I see it, because you
guys write honest opinions - without sugar-coating anything – I would surmise
that you guys are not that popular with the new car manufacturers any more.
This, as I'm sure many readers would agree, is highly distressing. If it's
true, it is pretty unprofessional behaviour on the part of the manufacturers -
not to mention that, by their own reluctance to loan AutoSpeed any cars, could
be regarded as tacit admittance that their cars may be bad. Regardless, I'm glad
to see that you guys haven't gone down the path of kowtowing to the
manufacturers in order to get road tests. It's just sad to see manufacturers
behave this way. I'm sure others would agree - I think it doesn't do them any
Example - the Renault Megane 225. Many criticisms were made about this car's
handling and other issues in the media. Shortly thereafter, the updated model
released late in '05 had these issues addressed. If motoring journalists didn't
provide valid criticisms of motor engineering, how are manufacturers supposed to
receive feedback? The average customer test drive? Not much expertise there and
the drive is far too short. Sales figures? Never a true indicator of automotive
design. No, it's the humble motoring journalist with their honest opinions that
can - and must - make the difference. So come on car manufacturers. Don't be
chicken. Let AutoSpeed drive your cars.
reading your articles on making stuff - Making Things, Part 1
and Making Things, Part 2
I imagine a lot of readers are the 'DIY' or 'making' type of people - like you.
If you haven't already, check out www.makezine.com
for a whole heap of DIY
projects ranging from low-tech to high-tech and everything in between. It is now
my second favourite website...
Re Dual Pipe Induction #1
Just read Dual Pipe Induction - Part One
and Dual Pipe Induction - Part Two
and I'm interested to find out where you obtained the calculation for the
potential 200kW output requiring a cross sectional intake area of approximately
46cm2? How did this figure come about?
On another note, are you going to be road testing the RenaultSport Clio
series (172/182/Cup) at all? Seeing the positive opinions from the UK car
mags/shows, I just wanted to compare this with an unbiased Aussie
The 46cm2 figure is the same cross sectional area as a 3 inch pipe. Based on
previous manometer testing, we’ve seen that a 3 inch feed pipe into a vehicle’s
airbox causes almost zero restriction at outputs up to about 200kW. And, yes,
we’ll try for a hot Renault to test!
Re Dual Pipe Induction #2
have a question about the following passage from your article Dual Pipe Induction - Part Two
“With the Magnehelic gauge again hooked up to the intake we saw pre-airbox
restriction slashed from 17 inches of water to just 4 inches of water. This
represents a 52 percent drop in the overall intake restriction – we’re now down
to 12 inches of water from 25 inches of water!”
Now, I currently run a pod filter on my S13 with SR20DET and am thinking of
returning to a factory style airbox with a decent 'drop in' filter and a better
feed pipe. The question I have is about the 4 inches of water figure - this is
figure is PRE filter, yes? So I would lose some flow by going to an airbox over
the 'direct to atmosphere' pod filter element (since I'm assuming zero
pre-filter restriction due to there being nothing there). However, at my power
level (170rwkW target) this might not be noticeable due to the engine not
needing to suck a great volume of air. I'm also ignoring heat soak issue as my
other option is to box the pod up - as I have planned to all along.
Jarich van Horck
Yes, the 4 inches of water measurement was taken upstream of the air filter.
With an airbox, you will generally have more restriction than an
exposed pod air filter – but, in your scenario, we doubt whether the difference
in performance would be measurable. Oh, and be aware than enclosing a pod filter
(to prevent ingestion of hot under-bonnet air) is effectively the same as having
Re Dual Pipe Induction #3
I would like to congratulate you on your articles on the "Dual Pipe
Induction" - (Dual Pipe Induction - Part One
and Dual Pipe Induction - Part Two).
The articles show that the mod I have done to my Holden Monaro will have
produced similar benefits. Adding a second pipe from the cold air intake to the
air box has seemed to provide a much more responsive engine and a slight but
noticeable improvement in usable power.
been reading an old article - (Shooting the Overboost
- about using a needle valve to control turbo boost. I am trying to get hold of
one of these valves, but either no one has heard of them, or a minimum number
have to be custom made by hydraulics companies. There are lots of bleed
valves/ball bearing boost valves about but these aren't the same. Can you please
advise where you got the one you used?
An adjustable brass needle valve should be available from most pneumatics
supply stores. You can also use a Festo 6509 GRA -¼-B flow control valve, as
seen in Brilliant Boost
and Bumped Up Boost