Dan's showing off some!

[ansonivan at yahoo.com (Anson Clement)]

I'm sure Dan is better equipped to discuss this but
I'll throw it out there anyway.

There is a horrible tendancy in the FI world to equate
boost pressure with performance ie more pressure is
better. Of course the real aim is to move more air
through our engines by whatever means necesary,
someone pushing 15 lbs of boost on an un-ported head
or ill sized turbo may very well make less power than
someone pushing 10 lbs on a properly designed setup.

More boost can mean more heat in the intake charge as
well ... not good.

Just imagine two garden hoses, one is straight and
devoid of kinks, the other is all knotted up.

Apply the same water pressure to each hose and
obviously the straight hose will flow more, even when
we apply more pressure to the kinked hose we may very
well still flow more volume through the kinky-ass one.

An over simplification for sure but you get the idea.

Anson

PS. Dan rocks my sox with his kickass build skills ...
I need him around to make sure my goofy-ass projects
get done right plus recieve forced induction.

--- Dan Bubb <dan.bubb@gmail.com> wrote:

> Take a look here:
> http://www.pumaracing.co.uk/turbo.htm
> 
> All I personally know is that this engine is way
> better than the old
> engine. Very responsive and wants to build boost
> easily. But there
> were way too many changes; different turbo, 5% more
> displacement with
> higher CR, and conversion to electronic injection,
> plus the P & P, all
> at one time to apportion the improvement. Mostly, I
> think it's the
> different turbo, but I wouldn't have spent two weeks
> porting it if I
> didn't think it was going to net some gain. I didn't
> open out the port
> sizes that much. If you run your finger around
> inside a stock port you
> can find lots of edges and discontinuities. Mostly I
> took care of
> those and cleaned up the area right around the valve
> guide.
> 
> Also, on this thread posted by Neal, if you look
> down a ways, you'll
> see a list of HP made by various people with
> supercharged engines.
> 
> http://forums.vwvortex.com/zerothread?id=1476793
> 
> Seems to me that the guys with ported heads are
> making more power and
> generally with less boost.
> 
> Me? I just like to pinch out every couple of HP that
> I can ;^)
> Dan
> 
> On 9/21/05, Jeff Toomasson <area53@validpath.com>
> wrote:
> > Hey, Dan - this is purely out of curiousity - was
> the head P&P'd before you
> > undertook this particular build? The reason I ask
> is that I was told by a local
> > machine shop that a P&P won't really present a
> significant gain under FI
> > conditions. Has your experience been otherwise? At
> least to me, it seems to
> > make sense that at least a nice polish would help
> and then even a porting would
> > allow more airflow...but it's definitely a lot of
> work and/or $$ that I would
> > avoid if it doesn't help that much. I've been
> debating this very thing on my
> > turbo x-flow head ever since that guy told me
> that...your thoughts?
> >
> > Your workmanship is looking good as always!
> >
> > JT
> >
> 
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> 


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