Exhaust "Cut-out" valves ??
08-09-2003, 04:33 AM
#1
Exhaust "Cut-out" valves ??
hey guys, i dont know if you have seen those exhuast cut-out valves. they are these valves that you can install in the exhaust system before catalytic converter, after headers, that on request can open there by immediately escaping the exhaust route. So this essentially would be the same as running complete straight pipes.
This would seem like a great mod for those who want crazy power when racing but when you want to return to normal driving simply close the valve.
Some are manual but they even have Electric ones that you can adjust with just a simple touch of a button.
what do yall think?
This would seem like a great mod for those who want crazy power when racing but when you want to return to normal driving simply close the valve.
Some are manual but they even have Electric ones that you can adjust with just a simple touch of a button.
what do yall think?
08-09-2003, 05:13 AM
#2
08-09-2003, 02:20 PM
#4
well unfortunately with benz there aren't many options, benz tuning is as primative as the 1930's 
so its actually cutting edge for benz 
It just seems its alot cheaper alternative to some exhaust HP than paying $$$$$ for high flow exhaust and cat. just my 2 cents
so its actually cutting edge for benz It just seems its alot cheaper alternative to some exhaust HP than paying $$$$$ for high flow exhaust and cat. just my 2 cents
08-09-2003, 04:19 PM
#5
Member
Join Date: Jun 2003
Location: Phoenix
Posts: 231
Likes: 0
Received 0 Likes
on
0 Posts
I'm way ahead of ya. I bought 2 cut-out valves for my 500/560 SEC and they are being installed within a week or 2. They are the kind with the pulley cable. The pulls will be located just below my ashtray. I drag race the car a lot so I'll see if it makes a difference. I have done so much custom stuff to that car that I'll probably never end up selling it, which is fine. It was the first car I bought myself and I think the old coupes have timeless looks. I'll just keep changing the guts when needed. I'll let you know when its running. Probably won't do any 1/4-mile runs until October though... too hot here.
08-09-2003, 04:45 PM
#6
I plan to get the electric ones with the special high flow "flowtech" cut outs to get maximum power. they said on really restrictive cars (aka benz) you can get has much as 20-30HP depending. So hopefully it will work.
Trending Topics
08-10-2003, 03:23 AM
#9
Super Member
Join Date: Jul 2002
Location: Oregon
Posts: 757
Likes: 0
Received 0 Likes
on
0 Posts
C32AMG
I don't think that Lakes pipes will produce much more than just extra noise.Whatever melts your butter. Just stay the hell off my street...my neighbors like to throw rocks at obnoxiously loud cars or bikes.
Just stay the hell off my street...my neighbors like to throw rocks at obnoxiously loud cars or bikes.
08-24-2003, 11:37 PM
#10
Newbie
Join Date: Aug 2003
Location: Fort Worth
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
1989 560SEC
This was a factory option for mid sixties Pontiac GTO's.
There was a commercial on TV showing a guy and his girlfriend in his GTO. He had opened the pipes to impress her and then saw a police car in the rear view. He then closed the pipes and winked at his girl..........
Old idea. How much does back pressure relief really help if your already tuned for emissions?
There was a commercial on TV showing a guy and his girlfriend in his GTO. He had opened the pipes to impress her and then saw a police car in the rear view. He then closed the pipes and winked at his girl..........
Old idea. How much does back pressure relief really help if your already tuned for emissions?
09-02-2003, 02:25 PM
#12
Member
Join Date: Feb 2003
Posts: 99
Likes: 0
Received 0 Likes
on
0 Posts
I would not run cutouts before the cats. The length of the exhaust system actually improves scavenging up to the point where restriction occurs and this is virtually always above torque peak. It is better to engineer a better flowing full system from the cats back (or money no object starting with ported heads and tuned headers). It is best to use the SMALLEST size pipe that will not create a high RPM restriction. The small pipe maintains velocity which is key to low RPM power. Giving up low RPM power for a small increase in high RPM power will reduce the fun factor of the car and possibly/probably make it slower in a drag race. Power under the curve is much more important than peak power.
The best use of this type of valve would be to run it just before the last muffler. Choosing a very quiet but restrictive muffler is good for cruising conditions and the cut out for max power. This would leave the rest of the system for scavenging.
The best use of this type of valve would be to run it just before the last muffler. Choosing a very quiet but restrictive muffler is good for cruising conditions and the cut out for max power. This would leave the rest of the system for scavenging.
09-03-2003, 04:31 AM
#13
what about just keeping cats and taking out resonator and exhaust and using a remus universal exaust and connecting that to the catalytic conveter? sound like a good idea or not?
09-03-2003, 01:32 PM
#14
Member
Join Date: Feb 2003
Posts: 99
Likes: 0
Received 0 Likes
on
0 Posts
I am not familiar with the remus universal exhaust... but... you have the basic idea. Improve the flow after the catalyst. Now, when I say improve the flow I mean use the SMALLEST diameter pipe that will not create a flow restriction at max power. This pipe must use mandrel bends (the fewer the better) and it must NOT have any sharp edges sticking into the exhaust flow an must minimize any volume changes. By volume changes I mean steps up or down in the pipe diameter. All junctions, merges and splits need to be aerodynamicly optimized. The mufflers need to flow very well. Sound control is an individual choice and good flowing mufflers can be found from quiet to very loud.
In the case of a street car with a full exhaust... a long exhaust system that flows well will maximize low RPM scavenging and power as it creates a siphoning effect that lowers the pressure seen at the exhaust port.
Of course an optimized exhaust manifold is very desirable but very expensive.
In the case of a street car with a full exhaust... a long exhaust system that flows well will maximize low RPM scavenging and power as it creates a siphoning effect that lowers the pressure seen at the exhaust port.
Of course an optimized exhaust manifold is very desirable but very expensive.
09-04-2003, 03:48 AM
#15
im debating whether to take out resonator and muffler, or just the muffler and see which works better, another benefit is weight (which helps alot more than most people think). i guess the best route is to take out just the muffler first and then if i want more sound or performance i can always take out resonator, what yall think? sound like a good idea?
