[Shotimes] What causes power loss?

[Steve Tatro]

I'm not sure all your "upgrades" are what they're cracked up to be!

What do you think you gained by removing the lower air box?  You still have
the same K&N panel filter that I do, so your maximum CFM is the same as
mine, but yours is sucking in hot engine air, right?  A lot of people don't
realize the SHO has a cold air intake in original form!  You may be better
off putting the air box back together.

I haven't ever driven a car with a Hypertech, so I'm not sure how good/bad
these are.  If your MAF requires the use of a chip, you may want to try a
MAF that does not.  There are various sizes that plug right in using the
stock electronics that don't require a chip at all.

I'd guess your 30k mile timing belt is fine.  It may have stretched a teeny
bit, but shouldn't be causing any power loss so soon.

I would get the valve lash adjustment done ASAP.  I always thought my SHO
was a strong runner, then I had the lash adjusted, and omigod.  It was night
and day.  Similar to you, I was able to spin the tires almost at will, which
I couldn't do before the maintenance.

Here's another one that people neglect: fuel pump.  Many people think fuel
pumps either work, or they don't.  I don't think that's exactly true.  I
believe that there will be a noticable difference in replacing a tired fuel
pump with a brand new one.  If getting the engine maintenance up-to-date
doesn't solve your problems, you may want to try this.

Good luck.  Don't assume the car's life is "waning".  There are many SHOs
with over 200k miles that still run very strong.  Yours can too!

Steve Tatro
Red/Black '93 with 169k miles
Cincinnati, Ohio


----- Original Message -----
From: "Christian Kesselring" <ckesselring@sisna.com>
To: <shotimes@autox.team.net>
Sent: Friday, August 15, 2003 5:44 PM
Subject: [Shotimes] What causes power loss?


> I have been meaning to ask a few questions to the list for a while now, so
> here is the first.  When I first got my SHO, back in 1997, it was a very
> strong runner.  I learned that if I dumped the clutch at anything over
> 2500rpm, the tires could spin and smoke for a while before hooking up, and
> it was just very fast overall.  Now, six years and 50K miles later (My
god,
> has it been that long?), it just doesn't seem as strong, despite the
> upgrades over time: deletion of the lower air box, addition of a K&N
panel,
> 73mm MAF, Hypertech chip and cat-back exhaust.  Last year, before the MAF
> upgrade, I had it dynoed and it hit stock wheel hp and tq only with the
chip
> installed, and had a very jagged curve.  What causes this type of
> degenerative power loss?  Can I ever hope to get it back?  I am thinking a
> shim adjustment and possibly timing belt replacement could be in order.
> Last time the valve lash was done is questionable, timing belt was 30K
miles
> ago.  Plugs and wires have about 40K miles on them.  When I checked vacuum
> at the intake, it looked good other than a minor high rpm wiggle that
could
> be weak valve springs (I think).  I hope there are some good suggestions
on
> this.  Otherwise, on a college student's budget I think I will just have
to
> prolong the car's waning life long enough until we can afford another car.
>
> Christian Kesselring
> '92 SHO 128k
> '02 PT Cruiser 28k
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