[Shotimes] Interesting...porting the intake

[Mark Nunnally]

Is there room in the head/CC for 25% increase?

I dunno.  I'm not an expert engine builder, but from those I've talked to
who are a lot smarter than me, tend to think the intake (great for the
street, to help make a broad range of torque) is the ultimate cork for
making n/a power (if you are just shooting for peak high rpm hp numbers).

I've got too many other things to tinker with on the 89 first.  Once I get
it to where I can flat-foot the current 255-260 hp around the whole track,
then I'll build a stronger motor :)

The time trail event this past week I couldn't have run a lick faster with
100 more hp.  Cars with 150 more hp than me were 2 secs slower.  The cool
thing about that is, it's cheaper to tinker with other stuff than it is to
build a new motor for more power:)

mark "pretty happy with the factory stuff for now"


----- Original Message -----
From: "Paul Nimz" <niks@dlogue.net>
To: "Mark Nunnally" <manunnal@netheaven.com>; "`V6 SHOtimes"
<SHOtimes@autox.team.net>
Sent: Wednesday, August 06, 2003 1:54 AM
Subject: Re: [Shotimes] Interesting...porting the intake


> How about 20-25% bigger valve area?  What would this do?
>
> Paul Nimz
> '97 TR
> '93 EG mtx
>
>
> ----- Original Message -----
> From: "Mark Nunnally" <manunnal@netheaven.com>
> To: <shotimes@autox.team.net>
> Sent: Tuesday, August 05, 2003 6:14 AM
> Subject: Re: [Shotimes] Interesting...porting the intake
>
>
> > The more I read, and talk to folks a lot smarter than me, and tinker
with
> > these things, it's more apparent in an n/a motor, the cams/intake
runners
> > are a paired team.  Basically the stock SHO runners are designed
(through
> > shape/size/length) to create the best resonance (ram air effect) where
the
> > stock cams want to make the most torque.  When you shorten the length of
> the
> > runner, or enlarge the ID, you are changing the resonance rpm tune on
that
> > runner.  You'd be moving it up higher in the rpm range.  I also think
the
> > shape of the runner is important as well.
> >
> > I think EH is probably the best (yeah it's $$$) method to "cleaning up"
> the
> > runners.  What I would be interested in is having somebody measure up
some
> > EH runners and figure up the math to determine what rpm resonance that
> they
> > are "tuned" for.  Then build a cam profile to suit.  And of course
> > gasket/port match the runners to the heads.
> >
> > One of these days I'll get around to port matching the intake/head
runners
> > on the 3.2L (mine have a terrible mis-match, one of the worst I've ever
> > seen).  I borrowed an EH intake once and lost significant low end torque
> > (above 3k it would regain itself).  Never ran it at the track to see
what
> > top end gains might have been there, but it seemed to pull hard.
> >
> > Realize going much higher hp that what you can get out of a BOS 3.2L is
> > probably going to be maxing out the stock injectors.  I'm getting 90%
duty
> > cycle on my stockers on my 3.2L now (at 216 FWHP).  If you are shooting
> for
> > 300 hp some 30 or 36 lb'ers probably would be needed.
> >
> > I think for open track work the stock cams/runners do pretty decent, as
> they
> > make a lot of torque over a broad range of rpm.  Personally I'd rather
> build
> > power through more cubes (3.4L anyone? <g>) and compression.  Ie, things
> > that will pick up the whole torque curve, and not just from 6000 rpm on.
> >
> > I think if you EH'd a set of runners, had a cam profile built to match,
on
> a
> > John H. type 3.4L stroker motor using about 10.75:1 (or 11:1)
compression
> > (running on 94 pump gas) with a little more injector, I think you could
> make
> > an honest 300 hp with a GOOD torque curve.  Hmm, sounds like what I want
> to
> > build for the track 89 :)
> >
> > mark
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