Dundon 991 GT3/RS Street Header (catted) Update
#1
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Dundon 991 GT3/RS Street Header (catted) Update
Hi Guys,
Thought I'd start a new thread to record the further development of the Dundon 991 GT3/RS Street System.
We learned in the last iteration that the car was down on power in the midrange and had a slight drone.
We redesigned the system and will update with Dyno Results and the transparency you've come to appreciate from us!
Running on the dyno today and at the track tomorrow on the Stock ECU, going to put it through it's paces and see how the car/ecu behaves!
Here's a iphone pic to get an idea.
Dundon 991 GT3/RS Street Header System v2 with valved side deletes.
Thought I'd start a new thread to record the further development of the Dundon 991 GT3/RS Street System.
We learned in the last iteration that the car was down on power in the midrange and had a slight drone.
We redesigned the system and will update with Dyno Results and the transparency you've come to appreciate from us!
Running on the dyno today and at the track tomorrow on the Stock ECU, going to put it through it's paces and see how the car/ecu behaves!
Here's a iphone pic to get an idea.
Dundon 991 GT3/RS Street Header System v2 with valved side deletes.
__________________
Dundon Motorsports
Gig Harbor, WA
253-200-4454
jamie@dundonmotorsports.com
www.dundonmotorsports.com
Facebook.com/dundonmotorsports
Instagram @dundon_motorsports
Dundon Motorsports
Gig Harbor, WA
253-200-4454
jamie@dundonmotorsports.com
www.dundonmotorsports.com
Facebook.com/dundonmotorsports
Instagram @dundon_motorsports
#5
Race Car
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#8
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Maybe do the db measurements like I did on my car way a log time ago when I just had a bypass. Instead of stock you could just do catted and race:
Here is the dB info I measured at 1 meter behind the car at a 45° angle.
Idle:
Stock 77 dB
SW 81 dB
3000 rpm:
Stock 87 dB
SW 96 dB
4000 rpm:
Stock 93 dB
SW 100 dB
5000 rpm:
Stock 99 dB
SW 106 dB
6000 rpm:
Stock 101 dB
SW 108 dB
Here is the dB info I measured at 1 meter behind the car at a 45° angle.
Idle:
Stock 77 dB
SW 81 dB
3000 rpm:
Stock 87 dB
SW 96 dB
4000 rpm:
Stock 93 dB
SW 100 dB
5000 rpm:
Stock 99 dB
SW 106 dB
6000 rpm:
Stock 101 dB
SW 108 dB
#9
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1. Drone elimination. The stock center muffler has two paths, a long one for when you want it quiet and a short fatter one when you need more flow.
2. More power and torque. This I won't explain throughly as a few shops are trying to copy our designs. Flattery and all that. Needless to say it helps and we have the data to show it if you're interested wil explain via PM...
#10
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Maybe do the db measurements like I did on my car way a log time ago when I just had a bypass. Instead of stock you could just do catted and race:
Here is the dB info I measured at 1 meter behind the car at a 45° angle.
Idle:
Stock 77 dB
SW 81 dB
3000 rpm:
Stock 87 dB
SW 96 dB
4000 rpm:
Stock 93 dB
SW 100 dB
5000 rpm:
Stock 99 dB
SW 106 dB
6000 rpm:
Stock 101 dB
SW 108 dB
Here is the dB info I measured at 1 meter behind the car at a 45° angle.
Idle:
Stock 77 dB
SW 81 dB
3000 rpm:
Stock 87 dB
SW 96 dB
4000 rpm:
Stock 93 dB
SW 100 dB
5000 rpm:
Stock 99 dB
SW 106 dB
6000 rpm:
Stock 101 dB
SW 108 dB
#11
Race Car
Hi again,
The Porsche Club Sweden measures sound like this:
Standing car
Behind at 45 degrees angle, at the height of the exhaust pipe
RPM: 4500
That would be interesting in my case
(This is done before a trackday to make sure that we don't upset the track owner too much, then there might be other sound measurements being done during the day which might lead to an too early ending of the session anyway.)
And as you mentioned: "Full throttle down the front straight" would be interesting too but it will be less scientific of course...
#13
Three Wheelin'
Originally Posted by Jamie@dundonmotorsports
For those looking for the power of the race with cats and lower decibels, I think we have a winner!
#14
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Were reluctant to do dB readings as they're very subjective to the way it's measured, the weather that day etc.
That being said we can get the 4500rpm differences between the two for everyone that Kobalt was looking for!
#15
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