A question about fuel?

[JShadzi at aol.com]

--
[ Picked text/plain from multipart/alternative ]
Agree with Jim, a high compression low boost 2-valve Audi is a waste of time.
 Newer designed cars get away with it using highly optimized combustion
chambers and very advanced fuel and electrical systems, on an older Audi it
will result in nothing but pinging and headaches, and eventually you WILL
swap the motor after the pistons have been detonated to all hell.

Swapping in an MC bottom end is not too big of a job to ensure a good running
and powerful motor.  I'm all for the try what hasn't been done, push the
limits, etc, but this is one place where physics rules, it just won't be
worth the effort.

HTH,
Javad
80tq.com

In a message dated 8/2/2002 5:48:46 PM Pacific Daylight Time,
jeg1976 at yahoo.com writes:


> --- alan pritchard
> <alanthecelt at alanthecelt.screaming.net> wrote:
> > Hi guys, after reading loads of mail forwards and
> > backwards i thought id ask
> > the question, what kind of ron fuel do you guys get
> > in the states?
> > see i just read a post where the lister mentioned 91
> > ron, is that good for
> > the states? see the reason i ask is the conversation
> > regarding turbocharging
> > an ng/nf engine, and it has always been said the
> > compression is too high,
> > Whilst from what i had read 10:1 is suitable for low
> > boost applications, ie
> > 5-6 psi, which i believe is easily acheivable with
> > the 95/98 ron fuel we get
> > here?
> > So the question is am i speaking out of my butt? or
> > is that the major factor
> > in the states?
>
> It's a small factor.  Up here in Colorado, we only get
> 91.  I heard that because were at altitude, it has the
> same effect as 93 at sea level or something.  From my
> experience, I have to say, that getting the turbo bits
> in the car is the hard part, so you might as well do
> the easy part too, and put the whole damn motor in.
> You might be able to get 5-6 psi on high octane and a
> little timing retard, but believe me, it will leave
> something to be desired.  On my MC-2 motor that is in
> reality running close to 9:1 CR because of the shaved
> a couple of times head, nothing really happens until
> 10 psi. That's even with lot's of advance from the old
> Haltech.  Don't get me wrong, it's still faster than
> stock, but around 12+ psi it really gets fun.  If you
> put and MC motor in, then you have all kinds of
> options.  If you don't want to mess with the fuel
> system, drop an MC in and run 9 psi.  Then you can go
> from there when you feel like it, which shouldn't be long:)