Re: Anyone using a aftermarket fuel boost valve?

[Gerard <gerard@poboxes.com>]

> Gerard,
> Please, don't think that I'm flaming you, treat it just like a piece of
> good advice.

I do this will all mail from the quattro list. I'm not automotive genius
so any help will...well...help. :) I used to be on the DIY-EFI list
until
some idiot did flame me after I asked a question, but he did it in a
very condescending manner and didn't give me any answers and then still
proceeded in further e-mail to tell me that I am useless if I didn't
listen to his answers he gave to so many people before, which (as far as
I can tell) he didn't do. Don't like those kinds of mail, but helpful
ones will be kept. :)

> It seems that you are just trying to put as much as possible "bells and
> whistles" into your car without even thinking how they work or if
> they're really needed. I'm also getting the impression that you believe
> in everything you read in ads. "to give more fuel pressure..." "It
> increases power and acceleration, cause it just feeds more fuel...".

Yes, I probably am. I probably do believe a lot of ads, but then again a
lot of them do have some merit. I do see a lot of stuff in ads, some
with a lot of promise, but I haven't bought a single thing from them
yet. If I did believe in everything I read in ads I wouldn't be on this
list sending "wasted bandwidth" trying to determine if there is merit
behind the products being sold. That's why I'm here on this list (well,
that's one reason, the other one is I've been told to attend all my
AA (Audi Anon) group meetings :-> ). I like to see what is actually
useful and what works. As I said, I'm no genius with regards to
vehicles, so I like to get help from the more knowledgable people.
I prefer asking the silly question here about add-ons to vehicles
(like the dump valve I've been going on about since yesterday) so
that I don't go out and buy something only to discover I don't have
a motor 2 days after fitment. Safe mods are good mods, yes?

> Bu***it. Supplying more fuel does not make you go faster. It makes your
> engine run rich, actually _hurting_ the performance. To make your engine
> run efficiently and at top of it's performance you need the fuel to air
> ratio to remain in a specified range. Ideal ratio is, if memory serves
> me correct, 14.7:1 and is called "stechiometric ratio". It is sometimes
> altered a little depending on engine's operating conditions. The
> injection map can be reprogrammed in the process of "tuning" the engine
> to make engine run a _little_bit_ richer at full throttle, you'll never
> get much power increase that way, though. And it's accomplished by
> simply reprogramming the stock ECU, no need for aftermarket controllers
> for that. As you see, the key to increasing the performance is to
> increase the _mass_ of _air_ entering the engine. It can be done by
> several methods, the ones that are most useful to you are: making the
> intake system less restrictive, increasing boost pressure (but remember
> - the fact that you are running higher boost _does_not_ necessarily mean
> that you are feeding more air) and increasing intercooler's efficiency
> (yes - colder air mean more air).

This makes sense. So, please correct me if I'm wrong (as I've said above
I am a bit backward and stupid, but willing to learn), if fuel:air ratio
is
above this then the motor runs rich, right? When does lean running
occur?

I know doing things like fuel boosting can negatively affect
performance. It's
like slapping on larger wheels. I guy in this town also has a Audi Turbo
in
the same candy apple red as mine, but he has put on 17 inch Antera mags,
so it looks mean, but obviously he has now affective his performance
'cos
the motor surely doesn't have the right torque and power curves to drive
those things. Right? He'd probably be better off running on the stock
15inch
wheels.

Aftermarket controllers are something I'll never do, thanks to help from
this list. I was planning to throw away US$500 for a Superchip mod, only
to discover that the same thing can be done by myself since I have all
the
reprogramming and electronic equipment right here where I work. As I've
discovered from this mailing list this tuning at WOT can be accomplished
by remapping the fuel pump cutoff tables in the Hitachi MACxx ECU found
on these vehicles. I've still got to get back to the person who is
helping
me with that topic, I'm just working on finding out what is useful and
helpful to fit to these vehicles (and, urh, boost valves are not :-> )
Also, there are some mods that can be done to the vacuum piping at the
wastegate (which seem a bit dangerous to me), and the boost pressure can
be set in the ECU.

On the note of on increasing the _mass_ of _air_ entering the engine and
cooling it, would there be any advantages in sealing all air pipes with
some sort of heat retardant/sealant? K&N air filters also help, but are
pricey in this country, but are reusable which is a good thing. K&N also
manufacture air induction kits. They claim to have an induction kit for
the K-Jetronic injection systems used on these Audis. Do you have an
opinion on fitting these good breathers? How about ducting the intake
pipe to somewhere on the front of the car, instead of it sucking in
hot air from the engine bay? The problem with the induction kits is
that they eliminate the box and expose this mass of area and filter
through
which the car can breath, but obviously it is now sucking a whole lot
more
air from the engine bay area. But I'd like to find out more about these
filter kits.

Again on the topic of the heat seals, they're supposed to reduce
temperature
so would wrapping the air pipes in the stuff cause let heat to be
transfered
to the piping (and air within) from the heat in the engine bay? No, I
didn't
see this in some ad, I just see some silver heat seals in my engine bay
near
the turbo and it is already sliding off.

> Still the stock injection system is
> good for 300HP or so. You'll never be able to use such power on a FWD
> car, though.

You're breaking my heart. :)

> 87 Audi 5000CS turbo (mine)
> 88 Renault Medallion wagon (mom's)
> 91 mountain bike (just in case both cars broke at the same time :-)

90 Audi Turbo (200T)
Size 9 (US) feet  (just in case the car brakes down)

Thanks for the help. I hope people are not getting pissed off with me on
this
list. I'm not a super-genius mechanic and need to ask questions about
things
that might seem like they could do interesting stuff.

Thanks again. :)

Cheers!

G.
-- 
"a thousand miles from here, there is another person smiling"
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