Re: Airbox Mod

[Gerard <gerard@poboxes.com>]

> IMHO, it works somewhat in colder weather but makes things worse in
> hotter weather because while it allows the motor to draw in air more
> freely, that air is heated by the exhaust manifold nearby ... in this
> case, however, the car may *seem* quicker due to the increased intake
> noise but in fact is slower.  (BTW, if you're into that sort of thing,
> the intake "noise" sounds pretty neat!)

Hmmmmm...what's that word  most of our cars get saddled with? Ah yes,
stealth! :) Got a lot of guys here who reckons noise=speed and mag
wheels=speed. :) They'll pull up along side a executive looking
Turbo car and go "thumpa-thumpa-blip-thumpa-thumpa-blip" and reckon
they're pulling heavy power ('cos dems gotta drainpipe exhaust there,
Jed). They're pretty much pissed when the silent running Audi kisses
it goodbye from the line. :) Stealth, yes, that's the key. :)

> A better solution for basically stock engines (where the airbox is
> able to provide more than enough air) is to remove the hot-air
> thermostat and duct cold air from the front of the car ... this will
> make a difference that you may be able to notice and has few drawbacks
> save perhaps for some rough running in colder weather.  With a bit of
> work, you can also install the nozzle from an '84 or '85 non-turbo 5k
> as this splits into two ducts and makes it easier to attach a hose (VW
> Beetle heater tubes work great!) than the stub left when the
> thermostat's been removed.  It's not easy to fit all this stuff onto a
> turbo car but it CAN be done with some cleverness...

This thermostat fits between the 2 intake ducts and one from the engine
bay, right? What's the full purpose of this? I don't have this, BTW.
Never came with the South African models (or British, I think). I agree
fitting extra ducting onto a turbo car is a mission, all the piping will
need to pass by that hot little turbine thing. Putting on my other
idea of fitting a cone  filter to the intake  could also situate
the air intake close to the heat source, so that idea is falling away
as one lister informed of decreased performance due to the cone filter
just sucking in more air. The better idea I think is fit a replacement
box filter from K&N and figure out some sort of ducting scheme to
get the air into the box from a cooler source. The obvious place is
low down on the fender/grill, but then you have to worry about sucking
in water.

Another idea would be to cut out a square hole in the hood, positioned
before the airbox and between it and the light/washer-bottle area. Put
on some sort of vented grill intake and modify the airbox intake
to turn upwards and fan out to gain air from this intake. In this case
some moulded pieces would be preferable as you can then mount a K&N
filter of the flat kind on the end of this moulding so that is
covers the intake on the hood. I've seen this done to a Nissan Sabre
turbo car with amazing results, but these things have very different
airboxes as they EFI equipped. The mod would look nice, but will give
away the car quickly as a modified machine. The work is also a bit
much to do and would require some nifty moulding. Unless, ofcourse,
one simply cuts the hole in the hood, puts in the grill and turns the
intake ducts upwards towards the hood (as is standard on my 200t)
and let it suck in whatever  comes through the opening (incl. bugs
and birdy guano (sp?)).

Ooops...enough silly thoughts. All in all, the drilled airbox thing
doesn't seem to be getting great reviews, especially in turbo cars.
The induction kits also just provide more hot air and affect performance
when the motor gets hot. Clever ducting can be more beneficial in
getting cooler air to the airbox, increasing the bore of the ducting
into the airbox can also help. Ducting is more difficult on a turbo
car. Fitting a dual duct from a early 4000/5000 may help. Removing
the airbox thermostat from those cars that use it (mine doesn't) also
helps and allows fitting dual ducts. That's my summary as I see it.

Thanks for the help on this airbox mod I read about.

G.
-- 
"a thousand miles from here, there is another person smiling"
1990 Turbo (200T)
name   : gerard van vught
tel    : +27-57-912 2658 (w) / 082 923 9609 (cell)
url    : http://www.acenet.co.za/homepages/gerard/
e-mail : gerard@poboxes.com  / han.solo@galaxycorp.com
         gerard@acenet.co.za / van_vught@frg.issi.co.za