10-25-2006, 06:44 AM
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#1
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Registered User
Join Date: Jul 2004
Location: Houston, Texas
Posts: 7,243
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It would be germane to this thread to bring up two issues:
1. Every time you redline it, your Boxster's computer records it permanently. This gives Porsche the ammo they need when your engine blows out, forcing you to pay for it. My mechanic says that they don't even clear it out (or can't clear it out) after they replace a blown out engine... so you have to carry the sins of the previous owners and the way a previous engine was treated with the car for a lifetime.
2. Power does not increase to the redline and beyond it. In a 2.5 or a 2.7, by the time you hit 6300 RPM or so you've sqeezed all the HP and TQ out of the engine. Going beyond this simply wastes fuel and is unnecessarily hard on your engine.
I've written it here before, and I shall write it again just to remind myself of it...
If I am ever lucky enough to buy a brand new Porsche, I will not sign the papers and take possession of it until I see a PST tool's display myself to insure some idiot on a test drive hasn't repeatedly redlined the car before I bought it. If you ask me, those couple of hundred miles on the Porsches that sit on the lot are the hardest engine miles that car may ever see. Lord knows on a test drive I put my foot in it to see what a car can do, so the next guy is no different!
And yes, I know the factory takes the brand new cars out on a track for a test drive and they probably redline it at least once to see if it can handle it, and that may be on the computer... but if I see 20 or more redlines on a new car with 200 miles on it, I'm afraid I would have to drive away from the dealership in the car I drove there.
Last edited by RandallNeighbour; 10-25-2006 at 06:47 AM.
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10-25-2006, 07:27 AM
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#2
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Registered User
Join Date: Mar 2006
Location: Houston
Posts: 116
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May I add a few words here?
These engines, at least the 3.6 and the 2.7 Box that I drive have
redlines, meaning the rev limits, of 7,300. The reading I have done
tells me that the computer's black box history recorder thingy (that
is a technical term) records two types of over-rev conditions.
Forgive me if I don't recall what their names for them are, but
one is where you exceed the rev limit upon acceleration and invoke
the rev limiter function of the DME. You are not hurting the engine
by doing so, but it is indicative of your driving style. And it gets
recorded.
The other is a hard over-rev. This is where you are winding out
third, let's say, nearing 7,000 rpm and 100 mph, right?
As you grab for a fast shift into fourth (which, in my opinion,
you never need to make a really fast shift -- these are not
drag cars) as a result of over-enthusiasm, inexperience or
perhaps alcohol induced state of "I can out run that Mustang!"
-- whatever, but you instead select second gear.
As you let the clutch out (if it didn't already blow up first)
and if your engine doesn't grenade right there (which it likely
will), then Mr. Black Box will let Porsche know you revved it
to a zillion rpm. And you get to pay for your new engine. As
you should.
Even if you just downshift a tad early, but over-rev the engine
it would be recorded as a hard over-rev.
Anyway, those are the two types of conditions that I understand
are recorded.
But these engines are Porsches and are designed to run at any
speed less than the indicated "red line." I don't know about your
2.5, Randall, but the 2.7 runs to 7,300 and the resonance flap
(which yours does not have) does not even open until 5,500 rpm.
So the moral of my little story is this:
To enjoy your car a long time, change the oil often, use factory
stuff (filters, etc.), warm it up completely before any heavy
throttle or rpm use, rev it within reason -- meaning don't hit
the rev limiter -- and keep in mind that high rpm and open
throttle = high fuel consumption.
And shift reasonably slowly, which saves your synchronizers
in the trans, don't miss your shifts and enjoy a great car.
Have a Boxster day...
- Mark
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10-25-2006, 07:39 AM
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#3
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Registered User
Join Date: May 2006
Location: Northeast USA
Posts: 910
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Each time I push above 4k rpms with the top down it's like opening a "box of chocolates". I can't imagine the sound geting any better. I frequent the 4-5.5k area quite often (when solo) -- with rare 6k+ excursions -- but have never hit the red-line, not even on the track. Simply see no need for that.
Z.
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10-25-2006, 08:22 AM
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#4
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Registered User
Join Date: Jul 2004
Location: Houston, Texas
Posts: 7,243
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Mark, thanks for that great explanation!
Gee, I never missed having a resonance flap until you told me I didn't have one. I gotta get me one of them flappy thingies on my next Porsche.
I still think it's important to recognize that the power curve falls off well before one hits the redline and it's not necessary to redline the car to get all the power out of it... or am I wrong on this?
Z, I couldn't imagine a better sound either until I swapped my headers and exhaust for what Che provides. It's like getting a chocolate FACTORY thrown at your ears when you have the top down and you really open it up gear after gear. I no longer give a rat's ass about my stereo system unless I am on a long trip somewhere.
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10-25-2006, 08:27 AM
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#5
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Registered User
Join Date: Jul 2004
Location: Houston, Texas
Posts: 7,243
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Oh yeah, Mark I forgot to add something important...
It's time to contemplate your NEW screen name now that you are saying goodbye to the C4S and saying hello to the '07 987S.
How about "Houston 3.4/987" ?
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10-25-2006, 09:52 AM
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#6
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Registered User
Join Date: Mar 2006
Location: Houston
Posts: 116
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Randall,
And I apologize to the rest of you if this sort of hijacks this
thread a tad, but a couple of comments here.
One: None of the 2.5s had the dual chambered intake manifold
with the flappy thingies. And the way yours drives, it feels fine
without it. If you look in your manual, I think there is a graph
that shows the power/torque curves of your engine. Indeed,
at a point, the horespower actually lessens after a certain rpm.
That's simply a mathmatically calculated number based on torque
at a given rpm. As the torque falls off, so must the horsepower.
And that's a function of air inlets, filters, mainfolds, DME controls,
valves and cam timing/lift, headers, cats, etc. And flapper thingies,
too.
But to your question of if it is "useful" to redline the engine,
the answer is sort of a weasely one -- it depends.
On the street for everyday driving, no.
On the track, which is something I need to talk you into
doing for your own education and resultant safety (you can
quote that to your wife!), there are times where running it
to the rev limit will let you skip a shift. Ie, leaving it in third
rather than short shift to fourth and then right back down
to third again, which wears the synchros, clutch, upsets
the car, etc. At least as long as you don't bump up against
the rev limiter.
And again, it won't hurt anything to do that except
your chances of getting Porsche to help pay for your
new engine if it blows up someday.
I think that answers that.
Now on to Two:
Shhh! Don't tell anyone, I don't know how to change the name
thingy! Shoot, I don't even know how you get one of those
picture thingies next to your name.
I know I am a Mac guy and this stuff oughta be easy, but this
does not appear to be a Mac function, rather a forum thang.
So maybe you can show me? But don't let on to all these other
smart guys what a dummy I am.
Okay?
- Mark
PS: If all goes well (at least for the other guy) the 4S goes to
Dallas tomorrow. My last drive in it. Sniff, sniff!
Unless he doesn't like the color, or its condition, in which case
I bring it back. You may agree that's an unlikely scenario.
But the new Box is officially on order.
And hopefully no one will want this 2001 Boxster before around December
or maybe even January -- we have the best top down months of
the year coming up! A perfect ultra low mileage Box should sell
easily.
Otherwise I will be in a Porsche-free zone for a while.
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10-25-2006, 10:11 AM
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#7
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Registered User
Join Date: May 2006
Location: Northeast USA
Posts: 910
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"But the new Box is officially on order."
Congrats, Mark! Colors, options?
Z.
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10-25-2006, 09:39 AM
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#8
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Registered User
Join Date: Feb 2006
Location: College Station, TX
Posts: 54
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Quote:
Originally Posted by RandallNeighbour
I still think it's important to recognize that the power curve falls off well before one hits the redline and it's not necessary to redline the car to get all the power out of it... or am I wrong on this?
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It depends. If you accelerate and you are going to upshift, then you want to wind it out past the HP peak, because once you upshift you will land 800-1000 rpm lower than you were before. You'll want to hit somewhere close to the HP peak after your upshift for maximum continued acceleration.
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