Electric cutouts
Safety Car
Joined: Oct 2007
Posts: 4,222
Likes: 1,077
From: South Florida
Its my favorite thing about daily driver
The point of cutout is having silent stock exhaust to drive around with all the time for comfort and smell. Then, the opposite available whenever you want it, uncomfortable and smelly and noisy.
Things to be aware of:
1. It won't make the car much if any faster unless you are forced inducted and even then there is a caveat because of low flow rate fluid momentum
2. If its too close to your ears it can damage your hearing
3. Cutouts gradually carbon-stiffen up and the gear drives get worn and they need to be routinely maintained or replaced. I always keep a spare. The cheap cutouts $35~ seem to last about 12-15,000 miles.
4. It makes using a dynometer wideband more difficult - it will read false lean no matter where you put the wideband at the tail or cutout.
The main advantage is for turbocharging where a massive drop in exhaust gas backpressure can yield substantial torque onset and top end power output.
Heres a video of me driving around a bit with open cutout you can see how easy to rip the tires loose, the turbo becomes more like a switch.
E.g. you can control the rising rate of torque from the turbocharger via exhaust gas pressure controls.
0:05 get on highway cruise note 16's
3:38 note 15.8 to 16.0:1 still cleaning plugs @ 65mph in traffic
5:18 kick out of lockup and small boost in 4th to move up in traffic
6:29 step down lightly into lockup for some boost in 4th
7:18 get off highway
8:23 downshift rip the tires loose at 50mph
9:12 slowing down for stoplight
9:20 Showing A/F Stopped at stoplight note 14.7 to 15.0 open loop steady
10:51 leave light, turbine whistle
11:30 cruising 15.6 to 16.0 housekeeping plugs
12:18 rip tires loose at 50mph 'spool character'
13:05 stopping for traffic light
13:10 show a/f for traffic light stop 15.5 walking into 14.7 to 15.0 open loop
13:52 2nd gear chirp coming leave light
The point of cutout is having silent stock exhaust to drive around with all the time for comfort and smell. Then, the opposite available whenever you want it, uncomfortable and smelly and noisy.
Things to be aware of:
1. It won't make the car much if any faster unless you are forced inducted and even then there is a caveat because of low flow rate fluid momentum
2. If its too close to your ears it can damage your hearing
3. Cutouts gradually carbon-stiffen up and the gear drives get worn and they need to be routinely maintained or replaced. I always keep a spare. The cheap cutouts $35~ seem to last about 12-15,000 miles.
4. It makes using a dynometer wideband more difficult - it will read false lean no matter where you put the wideband at the tail or cutout.
The main advantage is for turbocharging where a massive drop in exhaust gas backpressure can yield substantial torque onset and top end power output.
Heres a video of me driving around a bit with open cutout you can see how easy to rip the tires loose, the turbo becomes more like a switch.
E.g. you can control the rising rate of torque from the turbocharger via exhaust gas pressure controls.
3:38 note 15.8 to 16.0:1 still cleaning plugs @ 65mph in traffic
5:18 kick out of lockup and small boost in 4th to move up in traffic
6:29 step down lightly into lockup for some boost in 4th
7:18 get off highway
8:23 downshift rip the tires loose at 50mph
9:12 slowing down for stoplight
9:20 Showing A/F Stopped at stoplight note 14.7 to 15.0 open loop steady
10:51 leave light, turbine whistle
11:30 cruising 15.6 to 16.0 housekeeping plugs
12:18 rip tires loose at 50mph 'spool character'
13:05 stopping for traffic light
13:10 show a/f for traffic light stop 15.5 walking into 14.7 to 15.0 open loop
13:52 2nd gear chirp coming leave light
Banned Scam/Spammer
Joined: Mar 2007
Posts: 3,684
Likes: 425
From: Indiana Cornfield
I talked myself out of getting these as I was going to cut up a perfectly great exhaust system full of Headers, x-pipe, and Corsa. But I still like the idea. I also lack a qualified shop to do this work in my area. NW Indiana.
