Exhaust cut-outs
12-10-2013, 01:18 PM
#25
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Cutouts malfunction because people don't give them
the maintenance they need. They have gearboxes
that needs to stay lubed and so on, and all of them
will wear and eventually bind up. And by a few years
out, you'll lose your ability to service them because
every steel bolt will have corroded stuck.
There is significant backpressure in any muffled
exhaust. Your gain is in shedding that final restriction.
It will only be significant at higher RPM (where your
HP peak also lies). Significance on the street, that
comes down to how you use the powerband. You get
the noise full time (while open), of course.
the maintenance they need. They have gearboxes
that needs to stay lubed and so on, and all of them
will wear and eventually bind up. And by a few years
out, you'll lose your ability to service them because
every steel bolt will have corroded stuck.
There is significant backpressure in any muffled
exhaust. Your gain is in shedding that final restriction.
It will only be significant at higher RPM (where your
HP peak also lies). Significance on the street, that
comes down to how you use the powerband. You get
the noise full time (while open), of course.
12-10-2013, 04:27 PM
#26
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I got DMH low profile on my '01 WS6 I put two on at the bend of each side of the Y pipe, so i practically run open headers when they are open. the seal great and they sound awesome. i dont see much of a HP gain but i feel as if the car has better throttle response when open.
As far as not being able to get in contact with him. his site is messed up and is being repaired. so ull just have to call him, but the guy is very curtious given my experience with him. I told him exactly what i wanted and and what i was trying to do and he made mine work perfect, he even made it with a bit more angle on my turn down as i requested.
I had the QTP one on my old WS6 but i could only fit one under my rear seat on the passenger side, given the size of the motor. Thats why i chose the DMH low profile ones so i can fit two one there.
the only real benefit i see besides the awesome sound, is that my car is so loud at WOT that who ever im racing cant really hear their car, and it caused one guy to miss a shift and bounce the limiter, which of course gave me the edge to win haha
As far as not being able to get in contact with him. his site is messed up and is being repaired. so ull just have to call him, but the guy is very curtious given my experience with him. I told him exactly what i wanted and and what i was trying to do and he made mine work perfect, he even made it with a bit more angle on my turn down as i requested.
I had the QTP one on my old WS6 but i could only fit one under my rear seat on the passenger side, given the size of the motor. Thats why i chose the DMH low profile ones so i can fit two one there.
the only real benefit i see besides the awesome sound, is that my car is so loud at WOT that who ever im racing cant really hear their car, and it caused one guy to miss a shift and bounce the limiter, which of course gave me the edge to win haha
12-10-2013, 05:29 PM
#27
I had a FLP sliding style that was mounted over the axel on the stock over the axel pipe. when open it made 10 more hp then through the stock muffler. That said I choose that location so that I could run with it open without knocking out the fillings in my teeth. You need to maintain it. Spraying with brake cleaner worked pretty good with keeping the crap from building up. The other issue is the weight. The one I had was very heavy and it was always pulling the exhaust down on one side. I spoke with a Magnaflow rep and they were not happy with what I had built so I now have a 4" cutout about a foot from the merge. This should really help the motor flow but it could require a separate tune.
12-29-2013, 07:34 AM
#29
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I have electric cutouts on my 03 SS Silverado behind the short tube headers which when open bypasses the cats and mufflers. I have had them two years and the only problem I have incurred is the remote switch burned up and the plastic switch from Headman's cost almost $100.00
The truck has the F.A.S.T. LSXRT intake with the 92MM throttle body ported, a Comp Cams mid to high RPM cam, dual cone CAI kit and a HP tuneup. I run the truck in Landspeed time trials held on two mile airport runways where you speed is recorded from a standing start at the one mile traps with one mile to stop. I made four runs in Ohio at the end of Sept. at which there was a consistent 15 MPH headwind. My truck weighs almost 6100 Lbs. with me in it and is an aerodynamic brick. I have ran almost 136 MPH before with a wind and before the intake/cam change which was my Bright idea but with around 70 HP on paper my best speed was 131 MPH with the cutouts open and was consistent to less than 1/2 MPH. On the third run I ran with the cutouts closed in case I was loosing too much back pressure. Under the same conditions It ran almost 5 MPH less.
Now I am trying to figure out why I ran 5 MPH less with 60-70 more HP. It felt all the way through low gear like it was on the fastest pass I have ever made. I think it had something to do with too much line pressure or a torque converter problem. Any opinions please?
Thanks
The truck has the F.A.S.T. LSXRT intake with the 92MM throttle body ported, a Comp Cams mid to high RPM cam, dual cone CAI kit and a HP tuneup. I run the truck in Landspeed time trials held on two mile airport runways where you speed is recorded from a standing start at the one mile traps with one mile to stop. I made four runs in Ohio at the end of Sept. at which there was a consistent 15 MPH headwind. My truck weighs almost 6100 Lbs. with me in it and is an aerodynamic brick. I have ran almost 136 MPH before with a wind and before the intake/cam change which was my Bright idea but with around 70 HP on paper my best speed was 131 MPH with the cutouts open and was consistent to less than 1/2 MPH. On the third run I ran with the cutouts closed in case I was loosing too much back pressure. Under the same conditions It ran almost 5 MPH less.
Now I am trying to figure out why I ran 5 MPH less with 60-70 more HP. It felt all the way through low gear like it was on the fastest pass I have ever made. I think it had something to do with too much line pressure or a torque converter problem. Any opinions please?
Thanks
12-29-2013, 06:51 PM
#30
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Exhaust cutouts are awesome! I love my DMH cutout, have it installed right after the i pipe and under the rear passengers seat. Sounds amazing if the car is cammed and screams at WOT. No cats by the way
12-31-2013, 01:13 PM
#31
DMH cutout only yielded 3whp over my Magnaflow catback. That was on a heads/cam/LT's/ORY setup.
The sound was great and the motor did not burn out for the 2 years I had it.
The sound was great and the motor did not burn out for the 2 years I had it.
