View Poll Results: Does your 964 have a power 'step'?
I don't push hard enough to know
1
2.56%
Yes
32
82.05%
No
6
15.38%
Voters: 39. You may not vote on this poll
Step in Power Delivery at High Revs
04-11-2005, 01:52 PM
#16
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Hmm...
I generally go over to Germany to do that. I MIGHT do that later this year.
Over here, well, we won't talk about that until after we've had our vacation in Scotland.
I generally go over to Germany to do that. I MIGHT do that later this year.
Over here, well, we won't talk about that until after we've had our vacation in Scotland.
04-11-2005, 01:58 PM
#18
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NO - IT STILL (oh, sorry, still shouting after an earlier thread!) seems to be the same. Certainly isn't affecting acceleration, mind you! 
04-11-2005, 03:02 PM
#19
Three Wheelin'
the top speed run will most likely not prove anything since the car is geared to top out at red line as opposed to being drag limited (see John's avatar above ) The car could be down 10-20 hp and not show if the good aerodynamics still allow for 162 top speed at redline. However, I would highly recommend doing a top speed test because : 1. to ensure there's not a major loss of power that doesn't allow specificed top speed to be hit- i.e. for the car to redline in 5th, since the speedo may be "optimistic" can't go strictly on that (doubt there is a major loss of power), and 2. because a top speed test looks like a hell of a lot of fun 
) The car could be down 10-20 hp and not show if the good aerodynamics still allow for 162 top speed at redline. However, I would highly recommend doing a top speed test because : 1. to ensure there's not a major loss of power that doesn't allow specificed top speed to be hit- i.e. for the car to redline in 5th, since the speedo may be "optimistic" can't go strictly on that (doubt there is a major loss of power), and 2. because a top speed test looks like a hell of a lot of fun
04-11-2005, 03:16 PM
#20
Originally Posted by John Boggiano
For almost as long as I can remember, my 964 has had a characteristic, small step in the power delivery. It only occurs at full throttle, beyond about 5250rpm. It is accompanied by a distinct change in engine note and I have always assumed it was due to the resonance flap operating.
Although I am sure I don't have a resonance flap..... 
04-11-2005, 04:54 PM
#21
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4000rpm = engine coming onto cam
5600rpm = resonance flap opening
Cannot speak for a standard car, but a 964RS on Motec makes 20bhp more with the res flap open above 5600rpm.
Christer, you definitely still have a working res flap and the engine makes more torque with it shut and more power with it open.
John, they do gum up but the easy way to tell if it is working involves one quick run on the dyno; give Johnny a shout to bring it over & I'll run it up for him.
5600rpm = resonance flap opening
Cannot speak for a standard car, but a 964RS on Motec makes 20bhp more with the res flap open above 5600rpm.
Christer, you definitely still have a working res flap and the engine makes more torque with it shut and more power with it open.
John, they do gum up but the easy way to tell if it is working involves one quick run on the dyno; give Johnny a shout to bring it over & I'll run it up for him.
04-11-2005, 04:59 PM
#22
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Thanks, Colin.
The car's back with me now and I'm tied in to working six days a week for a while, BUT I will be in touch when I get the chance.
The car's back with me now and I'm tied in to working six days a week for a while, BUT I will be in touch when I get the chance.