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Does your 911 run out of steam near redline?

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Old 07-29-2008, 01:10 PM
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Tippy
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Originally Posted by Malakas
ok stupid question (since this is my first 911)... i like the sound, and i hope (think) its normal, but the engine gets really raspy near redline... is this typical?
When I did the MK I muffler mod, my car sounded very raspy right before it hit redline.
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Old 07-31-2008, 08:24 PM
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nope.... having the reflash ecu, headers, mufflers, ipd, hi flow cats, the engine just pulls to redline........
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Old 08-01-2008, 03:50 AM
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Originally Posted by Porsche_Smile
nope.... having the reflash ecu, headers, mufflers, ipd, hi flow cats, the engine just pulls to redline........
ditto, mine is strong past redline and reprogrammed ecu, it climbs too fast sometimes...........
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Old 08-08-2008, 06:32 AM
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Originally Posted by Tippy
But, I think the E46 M3's (if that's what you are referring to) fall on their face too before redline.
The S54 makes its peak power at 7,900RPM.
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Old 08-08-2008, 08:12 AM
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Max power is at 6800rpm, but the redline goes a bit beyond that so that when you upshift you are still at a high enough rpm to be making good power.
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Old 08-08-2008, 09:11 AM
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1999Porsche911
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Don't rule out your engine's oil viscosity when running an engine with hydaulic lifters. Too thin an oil can reduce lift at high rpm's.
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Old 08-13-2008, 12:21 PM
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My 2002 C4 has a distinct burst once I get close to the redline.
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Old 08-13-2008, 12:56 PM
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Originally Posted by Stuttgart951
The S54 makes its peak power at 7,900RPM.
Yes, but to me (being a drag racer), S54's feels like they stop pulling before that. I always shift a car the split-second I feel the engine plane out, puts the engine in a better torque range to carry the car quicker IMO.
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Old 08-13-2008, 01:00 PM
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Originally Posted by 1999Porsche911
Don't rule out your engine's oil viscosity when running an engine with hydaulic lifters. Too thin an oil can reduce lift at high rpm's.
That is an old school theory, don't you think? The weight of the valvetrain in the M96 is very light (no pushrods, lighter spring rates) compared to an old V-8. I mean, we are still talking 40 weight oil that I assume most are running.
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Old 08-13-2008, 01:29 PM
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a MAF in its early stages of decline can cause this issue (so can a dirty one!). turn off the car, unplug the MAF, and go for a drive. if the car pulls hard to redline, change your MAF.
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Old 08-13-2008, 01:35 PM
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Originally Posted by Tippy
That is an old school theory, don't you think? The weight of the valvetrain in the M96 is very light (no pushrods, lighter spring rates) compared to an old V-8. I mean, we are still talking 40 weight oil that I assume most are running.
A hydraulic lifter is still a hydraulic lifter. As the speed of the piston increases, improper oil often prevents the lifter from a full pump which in turn decreases valve lift. This was, in fact, a problem in the old days and continues to be a problem today.

Remember, there is a HUGE range in allowable viscosity in 40 weight oils. Not all 40 weight oils are alike.
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Old 08-13-2008, 02:59 PM
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Originally Posted by 1999Porsche911
A hydraulic lifter is still a hydraulic lifter. As the speed of the piston increases, improper oil often prevents the lifter from a full pump which in turn decreases valve lift. This was, in fact, a problem in the old days and continues to be a problem today.

Remember, there is a HUGE range in allowable viscosity in 40 weight oils. Not all 40 weight oils are alike.
You think high-revving, modern engines have float, especially Porsche engines? I would think not but I wasn't there when the valvetrain was designed.
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Old 08-13-2008, 03:05 PM
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Originally Posted by Tippy
You think high-revving, modern engines have float, especially Porsche engines? I would think not but I wasn't there when the valvetrain was designed.

Mobil 0W40 wasn't there when the vavletrain was designed either.
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Old 08-13-2008, 03:23 PM
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HA!

Originally Posted by 1999Porsche911
Mobil 0W40 wasn't there when the vavletrain was designed either.
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Old 08-13-2008, 03:47 PM
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Originally Posted by 1999Porsche911
Mobil 0W40 wasn't there when the vavletrain was designed either.
I ain't touchin' that with a 10-ft pole.
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