Does anyone build anything original anymore?

[simplife]

Did Prospeed come out with a new exhaust? The Prospeed I have that replaced my GTLW didn't look anything like the GTLW which has a single muffler canister vs two muffler canisters on the Prospeed. Any link to the new exhaust? The one I have weights 22lbs. How much lighter is the new one?

Maybe he was confused with the new GTLW/Enduralite replica recently introduced by Pride.
http://www.nsxprime.com/forum/showthread.php/174872-PRIDE-Light-Weight-Exhaust-19-5-lbs-(Stainless)

 

[TURBO2GO]

I've been wondering in general why I never see carbon mufflers on cars. A few years ago I was seeing them everywhere on bikes, until so many of those started going to the under-engine type. Now, I know that carbon is more prone to cracking than any of the standard metals used for car exhaust, but most people really don't drive so many miles with this type of car. Could save a lot of weight, I think. Especially if you were to make the muffler bodies with a carbon/kevlar weave, that could reduce the chances of cracks a bit.

It's expensive to do right, and the weight savings over titanium is minimal and the longevity far less. Even titanium isn't that popular because of cost.

 

[RYU]

That is true. A full exhaust rework from heads to outlet will work as a unit better than the old mix and match, but to get perfect gains throughout may not come so easily with just proper pipe routing and a good muffler. Even the Ferrari 458 has electronic controlled valves in the exhaust to aid in noise/power band production. Would be so easy to do with a proper standalone and activate it based on engine speed, throttle, and load All you need is a servo controlled exhaust valve and you have the ability to control your backpressure when the engine likes it best. I have already done that and it works well even on a 3 inch exhaust naturally aspirated. I have toyed with the thought of making the full package, but there needs to be significant interest from people who want to get rid of expensive pieces already purchased for their beloved Xs.

You and I will get along just fine. Have I mentioned I really like how you think? haha I was inspired by Mac Attack a few years ago to really think thru exhaust design properly and not just build something to be as big as possible. So I definitely want to give him credit for all his help.

After buying a welder and doing 2 "proof of concept" versions myself, for the final version I contracted a talented fabricator here locally (he's making Alum chassis braces for me now) and he built a proper exhaust of my design for my NSX. I wanted it quiet for cruising which means cats and 2" ID pipes, smog legal, but also free flowing bypassing the cats at WOT so I don't burn them out and get maximum flow via 2.5" ID pipes for each bank. I still wanted the sound unique so the low pressure side goes thru small pipes Cats, a helmholtz mixing chamber of sorts (my car doesn't drone at all) and thru perforated straight thru 3" mufflers. My high side bypasses everything but the 3" muffer section. The only way I could accomplish all this without electric bypass valves which were prone to fail at the time, and I didn't want to bother with making a control module yet, was to use vacuum bypass valves like the BMWs and Corvettes use. My current configuration now is for my valves to stay closed automatically below 4800rpm and maintain some backpressure like you said but to be open above that while under VTEC. I'm using the same OEM VViS intake air valve mechanism already on our cars but, in concept I put the valves on the exhaust side. OEM operation, OEM concept, OEM reliability. In effect I'd like to think i'm just maximizing what Honda already designed into the VViS system. My exhaust is one of my favorite things about my car. Best of both worlds and it helps my journey to making it a proper road car.

I'm also toying with the idea of running a "track tune" which will bypass the VViS control system and just run my valves off pure vacuum which as you know.. is wide open at boost. Should be perfect for a track setup and trim maps for Meth Injection - via a push of a button. Too many projects right now though so hopefully someone else tackles this idea and they can help a brother out - ME.

You can see one of the valves on top. The other is covered by the driver side cat.

Maybe someone else can be inspired with this thread and build their own unique stuff. There's still so much to do on the NSX. It's a great chassis.

 

[9doors]

someone in SD is on it:wink:. However, no Est. date and likely won't be CARBed. Another labor of love case.

Yup, and if all goes well, my car will be the 4th install. We're shooting to do mine next May.

 

[DreamPowered]

Ryu, that an great looking exhaust. The way you described it reminded me of the mugen twin loop that I had on my ek. Absolutely loved that exhaust. I have searched and was not able to find any proof that mugen had a twin loop for the NSX. If you don't mind, I will be pm'ing you with a few more questions.

 

[dmscrx]

You and I will get along just fine. Have I mentioned I really like how you think? haha I was inspired by Mac Attack a few years ago to really think thru exhaust design properly and not just build something to be as big as possible. So I definitely want to give him credit for all his help.

After buying a welder and doing 2 "proof of concept" versions myself, for the final version I contracted a talented fabricator here locally (he's making Alum chassis braces for me now) and he built a proper exhaust of my design for my NSX. I wanted it quiet for cruising which means cats and 2" ID pipes, smog legal, but also free flowing bypassing the cats at WOT so I don't burn them out and get maximum flow via 2.5" ID pipes for each bank. I still wanted the sound unique so the low pressure side goes thru small pipes Cats, a helmholtz mixing chamber of sorts (my car doesn't drone at all) and thru perforated straight thru 3" mufflers. My high side bypasses everything but the 3" muffer section. The only way I could accomplish all this without electric bypass valves which were prone to fail at the time, and I didn't want to bother with making a control module yet, was to use vacuum bypass valves like the BMWs and Corvettes use. My current configuration now is for my valves to stay closed automatically below 4800rpm and maintain some backpressure like you said but to be open above that while under VTEC. I'm using the same OEM VViS intake air valve mechanism already on our cars but, in concept I put the valves on the exhaust side. OEM operation, OEM concept, OEM reliability. In effect I'd like to think i'm just maximizing what Honda already designed into the VViS system. My exhaust is one of my favorite things about my car. Best of both worlds and it helps my journey to making it a proper road car.

I'm also toying with the idea of running a "track tune" which will bypass the VViS control system and just run my valves off pure vacuum which as you know.. is wide open at boost. Should be perfect for a track setup and trim maps for Meth Injection - via a push of a button. Too many projects right now though so hopefully someone else tackles this idea and they can help a brother out - ME.

You can see one of the valves on top. The other is covered by the driver side cat.

Maybe someone else can be inspired with this thread and build their own unique stuff. There's still so much to do on the NSX. It's a great chassis.

I like your ideas thus far as well and the exhaust is a nice implementation of that. Instead of vacuum assist, I have implemented exhaust servos with exhaust valves using electronic voltage control based on throttle position, load, and rpm. That way the valve will follow the power curve and open more depending on the engine's needs. To implement this based on track day VS street is a simple as a rotary switch (0-12V) or a toggle switch to make it full open which will override the former hope this helps.

 

[RYU]

Ryu, that an great looking exhaust. The way you described it reminded me of the mugen twin loop that I had on my ek. Absolutely loved that exhaust. I have searched and was not able to find any proof that mugen had a twin loop for the NSX. If you don't mind, I will be pm'ing you with a few more questions.

Thanks. Last I looked at the twin loop Mugen there really was nothing special right? It didn't have valves to control flow, did it?

Take a look at this thread. It'll probably answer most of your questions. http://www.nsxprime.com/forum/showthread.php/146644-NSX-Valvetronic-Exhaust-System-(first-ever-)

I like your ideas thus far as well and the exhaust is a nice implementation of that. Instead of vacuum assist, I have implemented exhaust servos with exhaust valves using electronic voltage control based on throttle position, load, and rpm. That way the valve will follow the power curve and open more depending on the engine's needs. To implement this based on track day VS street is a simple as a rotary switch (0-12V) or a toggle switch to make it full open which will override the former hope this helps.

With an EMS the sky's the limit. However, in my research 2-3yrs ago electric valves had a high failure rate due to the heat (have they improved?) and they were a bit slow. I also wanted to keep it simple. You should provide a solution like this for NSX owners. I'm sure there will be folks interested!

 

[dmscrx]

The electric servos I use drive cables, similar to a throttle cable that is attached to a mechanical valve in the exhaust system. That way it can be remote mounted and away from the heat; tucked away from visible view of course Similar situations exist on most high end street bikes. Coming up with a system wouldn't be too difficult but it would need to be for those who have the know-how to make use of it properly.

 

[RYU]

The electric servos I use drive cables, similar to a throttle cable that is attached to a mechanical valve in the exhaust system. That way it can be remote mounted and away from the heat; tucked away from visible view of course Similar situations exist on most high end street bikes. Coming up with a system wouldn't be too difficult but it would need to be for those who have the know-how to make use of it properly.

Ah, i'm familiar with that. I actually bought a surplus valve from a CBR1000rr but realized upon receiving it that it doesn't seal completely closed and the ID of the pipe was so small.

Very cool! I could see how a remote electric servo like that would work great.

 

[DreamPowered]

As far as I know the twin loop only uses backpressure to make its unique sound. I believe the exhaust gases flow through the twin loops during normal driving and as the back pressure builds some of the gases go through the loops while the others only go into one of the loops and then right out of the tip.
Your link was very informative and you have a very unique exhaust, I was unable to view the video's to fully hear your work.