[Shotimes] 89 sho dyno charts posted

[Robert Bruce]

I gained hp & tq, but it wasn't necessarily just the exhaust.  I've done
lots of changes to my motor package.  Some mods are un-published, so my dyno
results may not be a fair comparison to the results of other folks.
Besides, my motor is a 3.2 while Don's is a 3.0 and that alone is a pretty
large change.  Additionally it is hard to compare dyno runs from one source
vs. another.  Too many variable come into play.

Don's results show that peak hp moved up the rpm range and tq is now flat
over a much longer band.  Both are nice results.  Peak tq shows down, some
of which should be expected for those cams and the rest can be explained by
many variables.  Maybe he used different fuel, plugs & wires are aging, etc.
I am assuming his before & after runs were all done on the same machine.
If not, there is no way to reasonably compare runs.

Most notably to me is the secondary opening point.  In the first runs, hp &
tq both increased when the secondaries opened.  In the "after" runs, just
the opposite occurred, it dropped.  That tells me that  he could see gains
by moving the butterfly's opening point up by a few hundred rpm.  After that
I would expect tq & hp to both rise a bit in the 4500+ range.

His a/f results seem a bit erratic which make me wonder how the sample was
taken.  Guess I believe the trend from lean to rich as RPMs rise.  I just
wouldn't hold too much faith in the a/f ratio reported at any single spot on
the charts.

Overall I think Don's dyno results are fine.  I understand how he may be a
bit disappointed with the paper results.  My bet is that once he gets it on
the track and feels the extended tq range he will be quite pleased.

Of course this is all just my opinion.  That & a $1 may get you a cup of
coffee, but not much more.

Robert Bruce
92 w/3.2
http://www.cardomain.com/memberpage/810875


-----Original Message-----
From: shotimes-admin@autox.team.net
[mailto:shotimes-admin@autox.team.net]On Behalf Of Bill Murray
Sent: Tuesday, June 07, 2005 10:30 AM
To: shotimes
Subject: RE: Re: [Shotimes] 89 sho dyno charts posted


A properly done exhaust shouldn't lose tq.  As I remember Bob gained hp and
tq with his exhaust.  Terry Richards is running a 3" catback and he gained
both as well, he had something like a 30hp boost at the top end, just from
the catback upgrade, he aleady had other mods though.

Bill
-----Original Message-----
From: Donald Mallinson <dmall@mwonline.net>
Date: 06/07/05 09:41 AM
To: shotimes@autox.team.net
Subject: Re: [Shotimes] 89 sho dyno charts posted

Bill,

I doubt the Dynomax system is the problem.  it is bigger than stock and
most people continue to lose torque with bigger and bigger exhaust.

Don

Bill Murray wrote:

>I wonder if the dynomax is holding back power.  Bob Bruce gained a decent
amount of power when he went to the full 2.5 ich catback, and that was with
stock cams.  Isn't the dynomax only 2.25"?
>
>Bill Murray
>-----Original Message-----
>From: "Justin Schick" <jschick@aafp.org>
>Date: 06/06/05 11:06 PM
>To: <shotimes@autox.team.net>
>Subject: Re: [Shotimes] 89 sho dyno charts posted
>
>Don,
>
>I've seen a few dyno graphs in my day but am no means adept at deciphering
them, and am staring at a so-so laptop LCD. What happened to the performance
seems to be what I'd expect with what mods were made. The intake path was
opened up and the powerband moved up in the RPM range. The torque curve is
now flat as Kansas and great for a track car. This is what I see:
>
>old
>max HP = 205 @ 6200
>max TQ = 195 @ 4750
>
>new
>max HP = 220 @ 6750
>max TQ = 190 @ 3500 - 4000, 4750 - 6000
>red (the first run) was better and more rich.
>
>If you want off idle torque, give it about 6 psi or another half liter of
displacement! =)
>
>Justin
>parted 92 - need something (like an intake?)?
>
>
>
>>>>Donald Mallinson <dmall@mwonline.net> 6/6/2005 7:45 PM >>>
>>>>
>>>>
>I finally got the prints of my dyno test of the new .20 cam setup.  So I
>don't use up bandwidth, I have put the dyno charts up on the shoclub.com
>web site.  here is a short link:
>
>http://makeashorterlink.com/?A2625163B
>
>I could not get the new charts on disk so I had to scan all of them.
>
>to my way of thinking, this is a much weaker engine than before.
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