Would like your opinion on a new exhaust cutout prototype.

[ExhaustFreak]

Hi, We are considering having this manufactured. We are not manufacturing this or have any for sale. We would like your opinions and thoughts on this prototype. Would it help your Turbo breath better? We are familiar with the pros and cons of the electric exhaust cutouts, as well as the npp style mufflers. Our design is the only true manual cutout that flows completely to the atmosphere. Again, please give us your thoughts and criticisms. We really want to hear from the performance enthusiasts. Thanks!

 

[deathraider6996]

Have you flow tested each to show differences?

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[dank GN]

Pretty slick I also would like to actually see some sort of data to back up your theory . I do see how the Y pipe could cause a turbulence but it would be nice to see the difference . If u had some Dyno data with a Y pipe and one with your design to show you get X amount of HP over the traditional Y pipe those things would be selling like hot cakes . Good luck bud wish u the best in your business venture

 

[ExhaustFreak]

Have you flow tested each to show differences?

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I know this is by far not the most scientific test, but it was what I had available to work with...

 

[ExhaustFreak]

I know this is by far not the most scientific test, but it was what I had available to work with...

This was demonstrating the old design. After much thought, we decided the design needed to be more compact.

 

[dank GN]

I love it bud you built it with what you had and it does show a difference under a controlled environment . I used to test parts for aerospace and the only thing that would be different is I had the tools to have a calibrated controlled flow and also a calibrated anemometer .

 

[Rich B]

I like it

 

[bison]

I could see big gains on an NA engine with a good set of headers but with a turbo engine there's about nothing there unless the mufflers and post cutout exhaust are complete crap. With turbos once the mufflers are a straight through design and the post turbo exhaust has adequate cross section the turbulence and flow restrictions that murder NA applications don't apply anywhere near to the extent they do on an NA engine. On a turbo regal the cutout is over 4' away from the turbo. The critical part is the exit of the turbo. You want to let the gas see as much pressure drop as possible and straighten the swirling gas as much as possible to increase flow across the turbine. Once the gasses are a few feet away from the turbo they have straightened out and cooled enough to make changes further down stream less noticeable. Reducing drive pressure relative to manifold pressure gives the biggest gains. Properly sized turbine and least restrictive Intercooler that still maintains good heat rejection is where the power is unless you want to start changing the mechanics of the engine. Once the turbo is all in its the limiting factor.


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[TURBOELKY]

Put it on a dyno and test it. If it works you're golden period. Pretty cool and well thought out part. I'm sure there is plenty Buick guys around you that would be willing to let you test that on their setup.

 

[ExhaustFreak]

I could see big gains on an NA engine with a good set of headers but with a turbo engine there's about nothing there unless the mufflers and post cutout exhaust are complete crap. With turbos once the mufflers are a straight through design and the post turbo exhaust has adequate cross section the turbulence and flow restrictions that murder NA applications don't apply anywhere near to the extent they do on an NA engine. On a turbo regal the cutout is over 4' away from the turbo. The critical part is the exit of the turbo. You want to let the gas see as much pressure drop as possible and straighten the swirling gas as much as possible to increase flow across the turbine. Once the gasses are a few feet away from the turbo they have straightened out and cooled enough to make changes further down stream less noticeable. Reducing drive pressure relative to manifold pressure gives the biggest gains. Properly sized turbine and least restrictive Intercooler that still maintains good heat rejection is where the power is unless you want to start changing the mechanics of the engine. Once the turbo is all in its the limiting factor.


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Interesting, Why is the cutout so far from the Turbo? Is that the only possible place to install a cutout on the G body cars? Also what if the DirectFlow cutout was installed in the down pipe and some short form of piping was attached to it and routed the exhaust to a safe place under the car (in case of flame, racing application only). Then the pipe could be detached from the DirectFlow cutout and recapped for street use. I've noticed that many of the all out turbo race cars route the exhaust right through the hood or front fender.

 

[John Larkin]

Years ago some guys used fender dumps through the wheelhouse. The pipe was about 2' long. But it required hacking the fender liner and nobody I've seen has done that recently.

 

[earlbrown]

So, your version that deflects the exhaust down 45 degrees doesn't have the same flow restriction (I cringe every time I here the word 'backpressure') as a dump with a 45 degree outlet? I'm gonna have to call BS on this one and look at it as a marketing gimmick.

 

[ExhaustFreak]

Well first off, it doesn't have the problem of filling the classic dump tube with exhaust when the dump tube is capped off. Second, the classic dump tube only expels part of the exhaust to the atmosphere when the cap is off. The rest has to go out the entire exhaust system. If this theory doesn't make sense then drag cars should run exhaust systems instead of open headers (with collector extensions of course). I have never seen a drag strip car run an exhaust system to breath better. They only run mufflers to pass decibel limited drag strips (bummer).

 

[NY Twin Turbo]

I like it. Low profile, non bulky. I had my exhaust and down pipes fabricated from scratch. Whether it works or not, I would have integrated this into the system if it was available. Why not? Maybe I would use them. Maybe I wouldn't. But nice to have.

I did not integrate Y-cut-outs because they are bulky and I didn't want to see them hanging under the car. Not even from 50 feet away. Especially because I may have never used them. Sometimes it's just a matter of how elegantly a design can accomplish a task.

 

[Chuck Leeper]

Last open vs closed, with the "Y" type dump, that we did on the stage car = 3+WHP. The system was a Grand Bending 2.75" dual w/ Dynomax muffs.The DP was a 3.5".
I would look at extending the cutout to a point at/near the rocker panel. May help w/ straightening the flow, and make use of what venturi effect it may gain...ALA, pipes and clay on cyl heads on the flow bench.

 

[bison]

Interesting, Why is the cutout so far from the Turbo? Is that the only possible place to install a cutout on the G body cars? Also what if the DirectFlow cutout was installed in the down pipe and some short form of piping was attached to it and routed the exhaust to a safe place under the car (in case of flame, racing application only). Then the pipe could be detached from the DirectFlow cutout and recapped for street use. I've noticed that many of the all out turbo race cars route the exhaust right through the hood or front fender.

Plenty of racers cut holes in their wheel wells in the 80's and 90's and ran a section of pipe through it. That is definitely the best scenario but it's not common these days


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[ExhaustFreak]

Thanks for all the replies. This is what we are seeking, input both positive and negative! It helps with our decisions. The venturi effect is interesting. It seems like a header collector extension would give that effect. We felt this could be done by positioning the cutout at the classic 18" ish point past the end of the header, to give the best torque. We just felt that the compactness of this design would be the best all around way to go.

If built, we want to keep the cost reasonable so folks can try them and experiment with them. We feel that there is a market for them with those who want to win the loud exhaust competition The peeps that want to run around for the day uncorked, The racers, both drag and road race, etc. Lastly I believe many rides that have cats, especially stock cats, can run the track insert open as the cats cut the sound down. I installed one right after the cat, on my wife's stock 2003, 4.7 litre Lexus suv (yes I know, shameful). With the track insert in driving around normally, it just sounded like an aggressive cat back. When you stomped it and got into the sweet spot it sounded really nice! Some people thought I had supercharged it.

 

[ExhaustFreak]

Another question, How nasty is the exhaust coming from the down pipe. In either stock, mild or extremely modded cars. Is there a real danger of flames damaging the vehicle? could you just route (point) the down pipe toward a metal suspension area for track time only? I have never ran a turbo except my stock Turbo T/A, so I am new to this.

 

[Pronto]

Those dumps into the wheel well cooked the tire. Houston used to make Jersey cut out. It had a 3 bolt plate in the last bend of the downpipe. It pointed down to the ground. I imagine it was effective and you didn't have to hack anything.

 

[ExhaustFreak]

Those dumps into the wheel well cooked the tire. Houston used to make Jersey cut out. It had a 3 bolt plate in the last bend of the downpipe. It pointed down to the ground. I imagine it was effective and you didn't have to hack anything.

I tried to look up the Jersey cutout, couldn't find anything on it. It sounds like what I was thinking of.