Here is the STR prototype.

 

Unfortunately, it sounds like there is going to be a rule change that would violate my prototype...

 

So what is the drone like compared to a Berk Test Pipe or High Flow Cat? I have a Greddy SE Dual, for reference. If it reduces the resonance and drone at 3-4,000 rpm because you changed the location of the Cat, that is a very cool and great idea. Price is a little high. I would do it for 500. Which is about double the price of Berks HFC. I just have a hard time spending almost as much on a cat as a I did for my exhaust system, just my .2 cents. for out of the box thinking and trying to solve the drone issue.

 

Drone is caused by a mismatch in exhaust components. If you install an exhaust that is designed to be matched with an HFC or OEM cat with a TP, then it will drone. Similarly, if you install an exhaust that is designed to be matched with a TP with an HFC or OEM cat, then it will drone. What my mid-pipe does to fix that issue is to simply fix the mismatch issue.

I can see how that wouldn't be worth $1100 to someone. However, that is NOT all it does. It also provides much bigger gains than any other exhaust modification ever known to the S2000 community. If you think $1500 for a header that provides 5 HP is worth it, then you should be willing to pay $3000 for my midpipe.

BTW, the raw material that it takes to build my mid-pipe costs more than $500, but the raw material to build a bolt-on HFC is less than $150.

 

I should correct what I said about the "cause" of drone. Every exhaust is technically going to drone somewhere,. but all aftermareket exhausts are designed for minimal drone with EITHER a cat OR a test pipe.

 

I'm guessing most of that cost comes from the conical sections?

 

The megaphones are definitely expensive, but all of the material is expensive, just because I am not buying in large quantities. I'm paying retail prices for almost everything. Spend some time on Summiit Racing looking at prices for 304 stainless mandrel bends (in 4"), 304 stainless V-band flange assemblies, and HFC's, and you'll see what I'm talking about.

Labor is also expensive, since I'm paying full shop rate at the local performance place to have them TIG welded.

 

Um...who told you that?

The only rule changes for next year is added sentence: "Replacement converters must have a minimum catalyst density of 100 cells per inch and minimum substrate length of 3 inches". I can't imagine your design fails that. Unless they were saying that if you were to design this then they would react with a new rule against it?

 

I don't know when the rule change would take effect, and I don't think the committee has decided exactly what the rule change will be. However, the committee member I talked to said that they are going to change the rule to limit the length of the expansion or the location of the catalyst core. I asked him to post in this thread with more specifics, but haven't heard back from him yet.

 

Subscribed for future reference!