Author Topic: Boost controlled exhaust cutout - not electronic (Read 15888 times)

kennysabarese · « **on:** April 28, 2009, 06:16:56 PM »

Is anyone familiar with something like this? It seems like an excellent way to mix low volume cruising, with high power catless performance.

http://www.atpturbo.com/root/releases/release091004.htm

lil goat · « **Reply #1 on:** April 29, 2009, 07:31:52 AM »

From the sample it does not bypass the cat on the VW and on our cars would have to up under the hood as that is where the cat is if it did, with a Solo Street Race you have the same thing this offers, an open exhaust, but it would work with a stock exhaust to open flow.

kennysabarese · « **Reply #2 on:** April 29, 2009, 07:49:26 AM »

I am more curious if this is a legit concept, I don't expect this exact part to fit on our cars. I figured you could build (or a vendor could build) something that could fit before the cat. I'm sure there isn't much room in there, but anything is possible right!

If I only used my car for racing I'd definitely have a straight exhaust, I figured this could be the best of both worlds and more reliable then an electronic exhaust cutout.

lil goat · « **Reply #3 on:** April 29, 2009, 08:44:35 AM »

Yes the concept is very valid and very old (Carolina moonshiners used to do this, you know the guys that started NASCAR), the new twist is that it is automatic and boost controlled. I know of several people with late model GTO's that use someting similar except it is manually controlled with a cable, this looks better except I wonder with all the heat and soot how long it would operate before gettiing clogged up. I don't see any way it could be used as a cat cut out on our car do to the cat location and you would have basically no exhaust system when it was open, hot exhaust under the hood would melt stuff fast, been there done that when I blew an exhaust gasket, it could be used as a muffler cut out like they did on the VW, and it is very illegal to cut out the cat, but there are SOME people who don't even have a cat.

kennysabarese · « **Reply #4 on:** April 29, 2009, 09:43:19 AM »

Hrm. ok good point on the heat.

I have a question though. Don't you need to retune to take advantage of going without a cat? in that case if the exhaust cutout was manual, would you have to switch tunes when you flip the switch?

shabby · « **Reply #5 on:** April 29, 2009, 09:45:49 AM »

I was thinking of picking up a boost actuated cutout but there's simply no place to put it. You want to put this before the cat since it robs the most power, but since our cat sits so close to the turbo there's simply no place to install it.
Another idea i had was to use a catless downpipe, weld one of these cutout at the bottom of it and then attach the rest of the exhaust and a cat before the cutout, but again space constrains limit this.

lil goat · « **Reply #6 on:** April 29, 2009, 02:03:34 PM »

You make a good point about the tune, I don't know anyone using a cutout with a turbo. With an NA car you would just tune the car a bit rich to compensate for the cutout.

kennysabarese · « **Reply #7 on:** May 20, 2009, 01:10:48 PM »

is it possible to get a catless dp then put a generic cat in a different spot on the car, with one of these exhaust cutouts before it? then you could route the cutout exhaust out the side, or just to the back with a mufflerless pipe. sorry if this sounds stupid, I am just thinking outloud here. (noob warning)

i wanna help mother earth when my pedal isn't to the floor

shabby · « **Reply #8 on:** May 20, 2009, 04:12:50 PM »

Sure you can, but if you crawl underneath the car you'll notice the only place where there's room for a cutout is basically under the tunnel brace. Then you have to add a cat/o2 sensor after the cutout and run an extension to there. If there was more room right where the cat/catback connect i'd do this, but there isn't.

kennysabarese · « **Reply #9 on:** May 20, 2009, 05:48:52 PM »

good point. i was looking at photos, but it's hard to tell without looking in person

kennysabarese · « **Reply #10 on:** May 29, 2009, 12:36:00 PM »

Quote from: shabby on May 20, 2009, 04:12:50 PM

Sure you can, but if you crawl underneath the car you'll notice the only place where there's room for a cutout is basically under the tunnel brace. Then you have to add a cat/o2 sensor after the cutout and run an extension to there. If there was more room right where the cat/catback connect i'd do this, but there isn't.

Sorry if I'm beating a dead horse, but I really am trying to learn something here...

So I saw this Mallet V8 Sol exhaust pic, looks like there is some room further down right at the end of the trans where the two pipes come together... if they can cram two pipes where we have one...

Kelu · « **Reply #11 on:** May 29, 2009, 01:52:12 PM »

I have a friend from the car club which was about to buy such a thing for his car, Golf GTI MKV, I know he was saying to be manually controlled, I will try to speak with him and let you know.

As about the tune, when you want full power, you open the valve if the case is being manually controlled, so your tune to be made for the case when you are open, in the case you are closed doesn't matter those 5-10 hp anyhow cause you are runing with cat.

elff · « **Reply #12 on:** May 29, 2009, 02:16:01 PM »

Buell 1200 CC engines have this in their muffler.

At low RPM's it blocks one side to maintain a level of back pressure which keeps the torque nice and high

shabby · « **Reply #13 on:** May 29, 2009, 06:21:09 PM »

Quote from: kennysabarese on May 29, 2009, 12:36:00 PM

So I saw this Mallet V8 Sol exhaust pic, looks like there is some room further down right at the end of the trans where the two pipes come together... if they can cram two pipes where we have one...

Here's a better pic, as you can see the only place where there's any room is where the tunnel brace starts. I guess if you'd take out that skid plate you'd have more room.

Kelu · « **Reply #14 on:** May 29, 2009, 08:51:55 PM »

elff don't compare NA engine of a Buell with our engines, we don't need back pressure not even at low rpm cause could ripoff our turbos, we need high flows. I hope I wasn't wrong

elff · « **Reply #15 on:** May 29, 2009, 10:04:56 PM »

Your not wrong, but the technology is similar.
I was just illustrating how someone has successfully implemented a system that controls the flow of the exhaust to help the engine depending on the type of driving.
To state it in a different way, I think the system Kenny was asking about, if implemented properly, could be a good system.

kennysabarese · « **Reply #16 on:** May 30, 2009, 03:56:55 PM »

Quote from: shabby on May 29, 2009, 06:21:09 PM

Here's a better pic, as you can see the only place where there's any room is where the tunnel brace starts. I guess if you'd take out that skid plate you'd have more room.

Ah I see! The Mallet car doesn't have the plate, probably since the tranny is larger. So maybe a quick hack of the plate would give you the room. If you did that, would you exhaust right under the center car or would you want to send the exhaust to the back? Right under would be easier of course

shabby · « **Reply #17 on:** July 27, 2009, 10:44:28 PM »

My cutout arrived today(yes it is purple... for some reason), gonna be taking it to solo performance soon and see if they can fab everything up. Gonna replace the cat with a race pipe, add a cat after the cutout and move the o2 sensor behind the cat.
The cutout has a 6lbs actuator and is fully open at 15psi.

snaponbob · « **Reply #18 on:** July 27, 2009, 11:26:06 PM »

In looking at the original post, this MIGHT work on a car set like mine. An LNF engine with a catless downpipe feeding a MagnaFlow exhaust could have the cut out mounted near the diff before the muffler. Pointed down, there shouldn't be an issue as you have to be moving to develop the boost needed trigger the butterfly.

Hmmmmmmmmmmmmmm ...................................... How much are these things?

stonebreaker · « **Reply #19 on:** July 28, 2009, 10:21:47 AM »

What about this? You could put the cutout on the end of the muffler...

Kelu · « **Reply #20 on:** July 28, 2009, 10:43:41 AM »

If it is at the muffler doesn't increase the performances too much. The cat is the main thing which limits the power of a turbo engine, if you don't bypass that there is nothing much to be gain. For more info see differences between stock cat-back and free larger aftermarket cat-back exhausts, nearly null improvement.
Especially with our stock exhaust which is 2" if I'm not wrong.

shabby · « **Reply #21 on:** July 28, 2009, 04:56:45 PM »

Quote from: snaponbob on July 27, 2009, 11:26:06 PM

How much are these things?

Usually around $300.

stonebreaker: you want to dump the exuast before the cat, not when it reaches the muffler.

DeepBlueGXP · « **Reply #22 on:** July 30, 2009, 11:45:33 AM »

I was in Buffalo this week and I spoke with the Solo Performance guys. they don't like exhaust cutouts because they chatter due to the compression hits on the butterfly and they don't seal completely making a whistling noise. Once they get dirty, they won't close all the way.

If you use a cut out and have it under the car, you will more than likely smell exhaust...

shabby · « **Reply #23 on:** July 30, 2009, 09:37:02 PM »

Im sure there will be a small leak, i can see some light passing through near the shaft on one side. But if it'll bother me that much during daily driving i can just take it off and add a block off plate, and put it on when i need it.

kennysabarese · « **Reply #24 on:** July 30, 2009, 09:42:13 PM »

are you planning on sending the "cut out" exhaust airflow through a pipe to keep it away from the car?

I was thinking just run a pipe out to the back of the car, one side would be going through the cat and muffler, the other for the cut out airflow and it will look stock from behind

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Author Topic: Boost controlled exhaust cutout - not electronic (Read 15888 times)

lil goat

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