I'd really appreciate a pointer if you can help
me. I am using a pressure relief valve to control boost in a 2JZGTE Supra, but I
am having exactly the same problem that you describe in your article "The
Audi's DIY Boost Control - Part 1" - my boost is dead steady, but it is higher
in 6th gear than in the lower gears. If you've ever resolved this issue,
please point me to an article or send me a reply, I'd really really appreciate
Part 2 of that series covers a design that gave better boost regulation - see The Audi's DIY Boost Control - Part 2.
In The Celica ST-185 Convertible you refer to the
convertible 5th gen Celica as being a ST185. ST185 in fact refers to GT-FOUR,
GT-FOUR A and GT-FOUR Group A models with the 3SGTE and 4wd system. The
convertibles are ST183. SX models are ST184s with the 5SFE and ST182's are
hard-top with a 3SGE.
Got the GTR Right
just read your article Grading the GT-R.
As an R32 GT-R owner I thought it was a fantastic review of what living with one
of these cars is like and just thought I would drop you guys a line to let you
know. It was a great way to spend 5 minutes of my day and I think I agreed with
every good and bad point; overall a great and extremely accurate review. Well
Keep up the good work on your technical articles. I have subscribed for a few
years now and will certainly renew. What I like is the practical objective
investigations into technical issues. Could you do article on tyre noise or
origins of cabin noise? Why I ask is that I recently drove a 2006 Nissan X-trail
up to Cairns and back. Once you got onto the rougher type asphalt north of
Gympie, the road noise completely overwhelmed any music except heavy metal. Do
you have the resources to investigate tyre noise or cabin noise and how to
minimise it? Maybe test some tyres that claim to be low noise? Also when you do
a new car test could you include a noise db reading when the car is at cruise on
non-smooth asphalt? By non-smooth asphalt I mean the non-freeway stuff that
makes your tyres roar. Anyway, I hope you can incorporate this into a future
tech article as all newer budget cars I have driven seem to be built without
appropriate levels of noise deadening.
We've done a story on fitting sound insulation - see Fitting Sound Insulation. However, a quiet car really needs to be designed from the ground up, so retro-fitting insulation is often fairly unsuccessful. A noise meter reading alone tells you very little - it's the range of frequencies that you can hear as well as their loudness which is irritating.
Try the Hi-Clone
Just read with interest the story on the
improvements with changing inlet tract length (see Pipe Dreams). It may have been an
interesting aside to also include a Hi Clone in the mix to see if they can
improve airflow and hence power. Just a thought.
I am starting to get quite annoyed with the repeat articles. I have
already paid for these in prior years and I am now paying again for the same
articles, with just a few word changes in some and the whole article repeated in
others. Long time subscriber.
As covered in AutoSpeed is Changing!, after 8
years of publication most of our readers are completely unaware of past good
articles. We have therefore made the decision to republish selected articles.
Reader feedback ratings shows that these articles are attracting ratings as high
- and in some cases, higher - than new material. All current subs were extended
to take into account the changed format.
I am very interested in your "Simple Voltage Switch." I was hoping you
could fill me in on a few things. I need to build a switch that will
trigger a "kill engine switch" to cut off the engine under certain
conditions. I have to 0-5V inputs, one for the MAP sensor and one for a
water pressure sensor in my methanol injection kit. Can the SVS be used to
trigger my kill switch if one input is over say 3V and the other input is below
4V? Also, how do you define at what voltage the switch is triggered?
You would need two voltage switches to achieve this. The trip point is adjusted
with a potentiometer.
Too Many Kilowatts
Just emailing you about a small correction that might be required in your
article Relocating the Battery. Near the end of
your article you talk about cable thickness, and if I read correctly you stated
that at 100 amps on a running car voltage (14.4V for argument's sake), that
there is a possible load of up to 14kW. I think you missed a decimal point
there. 14,000 watts is a lot! BTW: Just checked out Jaycar Electronics and they
have a 70 and 100amp circuit breakers for $23 now.
Thanks - article corrected.
Intake Pipe Lengths
Read Pipe Dreams a little while ago,
and happen to have owned a modified Daihatsu Charade myself. Mods were: 2 inch
mandrel exhaust, 230 degree camshaft and most importantly, a "tuned length
intake pipe". Now my Daihatsu expert mechanic (prepares many rally cars, and won
a GrpA rally in the ARC), said the length he tested was perfect for power and
torque. Funnily enough, it matches exactly what you found on the dyno.
Hesitating Turbo Diesels 1
Re Hyundai Santa Fe CRDi. Your concern about the odd behaviour of the throttle and transmission rang a distinct bell with me! My 2005 Toyota Kluger has a similar issue. My example - approaching the end of the street I work on, I turn left into a slightly busier road, and coast up the last 10-12 metres to see what's around the corner before committing myself (there's a building right on the corner which restricts vision from further back). When I see it's clear and go to 'tramp it' the vehicle hesitates and leaves me in limbo for maybe 0.5 to 1.0 second, then drops a gear or two and launches. Not scary in this instance, but I've had the same 'roundabout' drama you described on several occasions with oncoming traffic. I've put it down to poor calibration of the electronic throttle and auto trans, and have seen the issue come up on various discussion sites. Like - it seems - the Hyundai, it's an annoying black mark for an otherwise excellent (for purpose: actually superb) vehicle!
Hesitating Turbo Diesels 2
Loved the article about the Hyundai Santa Fe. I have exactly the same misgivings about small capacity turbo diesels and auto gearboxes. A mate has both auto and manual new Prado 3.0 turbo diesels (lucky man). Driving the manual, it's obvious as you say the turbo is doing a fair bit of work, as it really comes on strong at about 2000rpm. But you can account for that and drive accordingly. In the auto however, it’s very hard to keep on boost – as it keeps selecting higher gears unless you are really up it. As a result it feels really doughy and unsatisfying to drive. I agree the manufacturers need to make these autos far more intelligent – or otherwise make the engines bigger until they can.