cutout
Senior Member
Joined: 10-14-06
Posts: 2,318
Likes: 2
From: New Bedford, MA
I have a non-elecrtic one on order, should be here this week.
There are 2 real problems with an electric cutout.
1- There is almost no room under the car for an electric cutout. Go on under there and look. Your gonna run over something like a dead racoon or bear and its gonna rip it off, especially if your lowerd.
2- I'm assuming you want the cutout off the downpipe cause that would be the conventional way. There would not be enough exhaust velocity (read : backpressure) for your car to really benifit from this. Go disconect you down pipe from you cat back and give you car some revs. Chances are it will stall.
I'm gonna put mine after the resonator and have it exit out the driver side right infront of the rear tire. If you take a look under there you will see a great place for one. Not an electric cutout, a wing nut one, there still isn't enought room for an electic cutout.
There are 2 real problems with an electric cutout.
1- There is almost no room under the car for an electric cutout. Go on under there and look. Your gonna run over something like a dead racoon or bear and its gonna rip it off, especially if your lowerd.
2- I'm assuming you want the cutout off the downpipe cause that would be the conventional way. There would not be enough exhaust velocity (read : backpressure) for your car to really benifit from this. Go disconect you down pipe from you cat back and give you car some revs. Chances are it will stall.
I'm gonna put mine after the resonator and have it exit out the driver side right infront of the rear tire. If you take a look under there you will see a great place for one. Not an electric cutout, a wing nut one, there still isn't enought room for an electic cutout.
Last edited by Maxim_X; Jan 30, 2007 at 06:45 PM.
Senior Member
Joined: 01-05-06
Posts: 10,877
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From: East Brunswick, NJ
Originally Posted by Maxim_X
2- I'm assuming you want the cutout off the downpipe cause that would be the conventional way. There would not be enough exhaust velocity (read : backpressure) for your car to really benifit from this. Go disconect you down pipe from you cat back and give you car some revs. Chances are it will stall.
There is no reason to have an exhaust cut out on an supercharged application like yours. It highly benefits on turbocharged cars because exhaust velocity isn't important, it's about releaving backpressure so the turbocharger can spool easier without the negative effect of backpressure.
On the exhaust side, velocity is still important to you as well as releaving back pressure. What you're basically doing is creating an exhaust leak. Even though you are supercharged, your exhaust side still acts in a way of an naturally aspirated vehicle.
Senior Member
Joined: 09-15-05
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From: OP, KS
Explain more please Adam. I am looking at custom welding up a downpipe and I want to put an electric cutout in it. That way at the track I can just open it up, but still maintain the stock catback (which I like the sound of) I was under the impression that any reduction in flow should result in a more efficent engine.
Senior Member
Joined: 01-05-06
Posts: 10,877
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From: East Brunswick, NJ
Explain more please Adam. I am looking at custom welding up a downpipe and I want to put an electric cutout in it. That way at the track I can just open it up, but still maintain the stock catback (which I like the sound of) I was under the impression that any reduction in flow should result in a more efficent engine.
While getting rid of backpressure is always a positive, there is a trade off in lack of backpressure and maintaining an proper exhaust velocity. This is why you don't see (or shouldn't see) guys who are naturally aspirated, stock engines running 3" or 4" diameter exhaust systems.
Granted you guys are boosted, you're still effected as well by how much exhaust (volume) is leaving your exhaust ports during the exhaust stroke...while an increase in cylinder pressure helps the exhaust leave quicker, the volume of exhaust still plays effect. If you're running stock ported head (relatively smaller), it's not suiting you well to do something like this or go with an extremely large exhaust system.
But also, RPMs still plays into it as well.
Talking it over though, my friend makes a good point. Like you wanted to use it for racing only, you are constantly staying at a higher RPM, it could be some use.
So I guess I'll put it like this, if you're looking to have it open constantly and in lower RPMs, it will be a negative playing effect on gas mileage, sound and performance (like above stated) but I understand more that would be more suitable for someone who is racing at higher RPM speeds and more on the modified side (example: Stage 2 guys).
Senior Member
Joined: 09-29-06
Posts: 1,043
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From: Marquette, MI
Adam is correct in his post. A cutout on a non turbo car does not really help performance. Where on a turbocharged car it is more beneficial. Also the electric cutouts have a high failure rate. If you are going to get one stick with a mechanical.
Senior Member
Joined: 09-15-05
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From: OP, KS
A cutout, while reducing backpressure will also disrupt your exhaust velocity. Even though you are boosted, you are still effected by exhaust velocity. For example: Look at the guys who have 3" exhaust systems who say that they have a loss of power on the bottom end of their powerband but they have a bit more power in the top end. It's a transfer of power because of the delay in velocity build up.
While getting rid of backpressure is always a positive, there is a trade off in lack of backpressure and maintaining an proper exhaust velocity. This is why you don't see (or shouldn't see) guys who are naturally aspirated, stock engines running 3" or 4" diameter exhaust systems.
Granted you guys are boosted, you're still effected as well by how much exhaust (volume) is leaving your exhaust ports during the exhaust stroke...while an increase in cylinder pressure helps the exhaust leave quicker, the volume of exhaust still plays effect. If you're running stock ported head (relatively smaller), it's not suiting you well to do something like this or go with an extremely large exhaust system.
But also, RPMs still plays into it as well.
Talking it over though, my friend makes a good point. Like you wanted to use it for racing only, you are constantly staying at a higher RPM, it could be some use.
So I guess I'll put it like this, if you're looking to have it open constantly and in lower RPMs, it will be a negative playing effect on gas mileage, sound and performance (like above stated) but I understand more that would be more suitable for someone who is racing at higher RPM speeds and more on the modified side (example: Stage 2 guys).
While getting rid of backpressure is always a positive, there is a trade off in lack of backpressure and maintaining an proper exhaust velocity. This is why you don't see (or shouldn't see) guys who are naturally aspirated, stock engines running 3" or 4" diameter exhaust systems.
Granted you guys are boosted, you're still effected as well by how much exhaust (volume) is leaving your exhaust ports during the exhaust stroke...while an increase in cylinder pressure helps the exhaust leave quicker, the volume of exhaust still plays effect. If you're running stock ported head (relatively smaller), it's not suiting you well to do something like this or go with an extremely large exhaust system.
But also, RPMs still plays into it as well.
Talking it over though, my friend makes a good point. Like you wanted to use it for racing only, you are constantly staying at a higher RPM, it could be some use.
So I guess I'll put it like this, if you're looking to have it open constantly and in lower RPMs, it will be a negative playing effect on gas mileage, sound and performance (like above stated) but I understand more that would be more suitable for someone who is racing at higher RPM speeds and more on the modified side (example: Stage 2 guys).
Ok, I totally agree with you now Adam. I guess I should prolly be looking at a mechanical one anyways to save the money and since I will be pulling it off at the track. I would love to loose some low end power
Maybe it would help with traction....
Senior Member
Joined: 01-05-06
Posts: 10,877
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From: East Brunswick, NJ
Yeah. Glad it helped you out some.
Senior Member
Joined: 10-14-06
Posts: 2,318
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From: New Bedford, MA
Yes and no. It's also good if its in the right place. I.E. not on the down pipe. One that just cuts out the muffler would probly give some horsepower and not take much if any low end torque away.
Well, atleast I hope so. I will tell you all by next week. Thats when mine will be in.
Well, atleast I hope so. I will tell you all by next week. Thats when mine will be in.
Senior Member
Joined: 01-05-06
Posts: 10,877
Likes: 2
From: East Brunswick, NJ
Yes and no. It's also good if its in the right place. I.E. not on the down pipe. One that just cuts out the muffler would probly give some horsepower and not take much if any low end torque away.
Well, atleast I hope so. I will tell you all by next week. Thats when mine will be in.
Well, atleast I hope so. I will tell you all by next week. Thats when mine will be in.
New Member
Joined: 11-12-06
Posts: 67
Likes: 0
From: Bradenton, FL
Dude. I posted a link for a google video for the Cobalt SS. a guy put an Electric cut out on the driver ide pre-resonator. it can be done. he mounted the switch central in the pen slot under the radio.
The video shows u everything. I think it sound like shat.
http://video.google.com/videoplay?do...45882802658000
The video shows u everything. I think it sound like shat.
http://video.google.com/videoplay?do...45882802658000
Senior Member
Joined: 10-14-06
Posts: 2,318
Likes: 2
From: New Bedford, MA
Thats excatly where mine is going, It's right after the resonator. Its pretty much the only place where you can put one. To bad I wont be able to put it in where it gets here. My PCM is being shipped to tag today, and well its gonna be pretty hard to get my car to the exhaust shop w/o a PCM lol.