BOV Testing
First, I want to say
that I love your magazine - especially the tech articles and
DIY stuff. I'm a regular
participant on different
internet forums and have
found a lot of
threads discussing the
effect of dump valves (aka BOV, bypass
valve, bla
bla). There are a lot of
theories out there,
like:
- a bypass valve is
more effective than an atmo dump valve, as the air
stream goes
back into the
compressor
- no blow-off valve at all will destroy your
turbo, as the pressure
wave will force its way
through the compressor
backwards
- OEM turbo cars come with bypass valves
only to get rid of the
farting noise from the intake...
I would like to see a
test of these theories. It might be
possible to attach some sort of trigger to the compressor housing that
would register (optically?) when the blades are spinning and get some sort of rpm reading through a drilled hole or something. If this works, one could datalog the rpm loss with different
configurations, such as:
- No dumpvalve
- Different dumpvalves
- Recirculating valve
- Different turbo size
Such a test would kill a couple of myths I think...I hope you guys find this interesting
and feasible (technically possible).Thanks for a great online mag.
Arild Hofstad
Norway
Yes, there is a lot of discussion on this topic. Unfortunately, a conclusive
test would require a large combination of turbo sizes and blow-off valve sizes/types
together with a huge amount of time and specialized equipment. As always, nothing beats on-road testing with your
particular car!
Rare R32 GTS-4
I was just reading up on your Nissan GTS-4 article - Unknown Warrior - Skyline GTS4... You guys said something about a
four-door version
of the GTS-4, but had not seen one in Australia. I recently bought
a 1989 R32
four-door with "front kg-m torque" written on one of
the gauges. Sure enough,I
got underneath the car
and it is four-wheel-drive!It
also has the HICAS (4 wheel
steer) system as well.
I have been wondering how
rare they are and what
they are worth, because
I have met quiet a few
people that have
R32 four doors
but no one I have spoken to has even heard of a
four-door manual turbo
4WD. If you guys could give me some info about it, it would be
great.
Glen
Australia
Lucky score! Can any readers provide further info?
Cool Air for Rodeo Turbo Diesel
I noticed a query in
Issue 257 regarding an
intercooler for a 2.8TD Holden Rodeo (Response) and you suggested contacting APS. I
also want to intercool my
similar Rodeo, however APS don't manufacture
their intercooler for this
vehicle anymore. But MTQ
do - check out www.mtqes.com.au Their intercooler retails for
about AUD$1550 + GST and
comes with bonnet scoop and fitting instructions.
Brenden Cooke
Australia
Enjoying the XR6T Series
I really enjoy the series you have on buying a Ford XR6T (starting at XR6 Turbo Guide - Part One). It is informative to read interesting insights into buying
that model – price,
performance and problems. I hope you
will extend this type of article to other
types/models of car.
It reminds me of the detailed articles that used to be provided
in 'print' magazines in
Australia before they
decided to focus on 'hot model'
articles for the teenyboppers or company car execs. These days, the magazines focus on racing the cars or telling us how great they are to drive 'flat out' on road X, but almost completely gloss
over the real-life aspects of car ownership (like repair costs, fuel consumption and longevity).People that
actually shell out the $$$ for a car find your type of article really very useful. Well
done.
Craig Dunn
Australia
We’ll certainly be considering a similar series off
articles for
other models.
Electric PS for ’68 Mustang
I am interested in a
column-mounted electric power steering unit.I have a ‘68
Ford Mustang rally car
which is using a rack and pinion set-up. Is such a system available in
Australia - and at what
cost? Any info would
be much
appreciated.
Rick Woskett
Australia
We haven’t seen any off-the-shelf electric
power steering kits but it would be worthwhile
visiting some Japanese import wreckers and investigating whether any of
their cars
have systems that might be adaptable.
What a Load...
I just read Julian Edgar's Driving Emotion - "I'll never see big, multiple exhausts in the same way
again"... What a load of
crap. The message I got
from the article was that there’s no need for large cars, with huge V8s, with quad exhausts. But, wait, whenever there's an article on
such a car there's always huge praise on how fast they accelerate, how much fun you can have, so on and so
on. This spells out one
word. Hypocrite. Especially as you own a V8
yourself.
You forgot to mention the FACT that under similar driving styles
(a mixture of full
throttle applications plus general driving), the VZ HSV Clubsport - with its ridiculously big 6L
V8 - gets better
fuel economy than both the
Mitsubishi Lancer Evo 8
and Subaru WRX. Hang on, but this doesn't make sense... A stupid, big V8, with *gasp*
pushrods(!) getting
better fuel economy than state of the art 2L turbo cars? On highway drives, mind you, the polluting V8 gets down to
as low as 7-8 litres/100km. And
if it's using less fuel doesn't that mean
it will be emitting less
greenhouse gases? By the way, all three cars are Euro 3 compliant. Yes, the HSV is a bigger, heavier car still, but that
means it will more comfortably house its occupants and offer more boot space...
As for the notion that a more free-flowing exhaust does nothing to improve economy and emissions... you've got to be joking, right? The
more restrictive an exhaust is, the less efficient the engine will be at
dispensing with the gases, the less efficiently it will burn them in the first
place, the more poisonous gases it will emit. If the exhaust is designed well, it will not
only free up power and economy, it will also decrease the emissions level.
Fact of the matter is, rice burners are no more economic than "stone- aged"
V8s, let alone the (apparently) so much better high-tech ones. I've still got more to say,
but this is long enough already.If you want to do your bit for the environment, stop
breathing - you're
stealing everyone else's oxygen.
Evan Smith
Australia
Re AutoSpeed Falc #1
It's interesting that you looked at an EF Ford in the Car Crazies articles Car Crazies, Part 1, Car Crazies, Part 2 and Car Crazies, Part 3). I was never a fan of these cars
until my Dad gave me a
1996 EL Falcon ex taxi. I put in new 30mm lower springs and shocks
and gave it to my wife to use a the daily shopping trolley.
I couldn't believe it, but we kept that car until it
reached
780,000km– yes, 780,000km. We then sold it for a reasonable price. This car had only had
regular servicing in
its life as a
cab - two cylinder heads and two transmissions. When we had it, other than regular oil changes and
replacing a temp sensor in
the transmission, we
had no problems with it. Just goes to show the longevity of some of these cars when
treated right.
Robert Williams
Australia
Re AutoSpeed Falc #2
Re Car Crazies, Part 3 - The EF Falcon - I’m glad you got the Falcon, but IMO
if you want to turbocharge it the BTR four-speed is heaps stronger and better (with a few simple shift
mods).Check out www.fordforums.com
Tony Goodlich
Australia
How to Boost a VNT
Re: Boosted VNT? Response...
Dealing with boost control on a VNT is somewhat of
a problem. The VNT’s variable
vanes are moved by vacuum actuators (together with a vacuum
pump), which are controlled by the engine
management. This is why a traditional boost controller is not applicable - there is simply nothing to
bleed. Bleeding the vacuum
in the hose on the actuator will only make the boost lower. If the boost controller could send MORE
vacuum into the actuator,
the boost will increase - but the original engine management system will most likely
throw codes if the boost
has increased or decreased
more/less than the map tells it to.
My opinion? Adding a boost controller to
a VNT isn't worth doing - the best way to increase boost is via the
original map in the engine
management system.
Anders Damkjær
Fiat Club Denmark
Overlooked Centura?
In your articles 'Small
cars with big cubes' Small Cars with Big Cubes - Part One and Small Cars with Big Cubes - Part Two you not only left out the Cortina and
Capri - as mentioned by
another writer - you left
out the Chrysler Centura.
Don Sutton
Australia
Yes, the mighty 4-litre Centura is certainly
a candidate - but not quite up with the monster
4.2 and 5-litre V8 Toranas of the
time.
|