I can see replacing the exhaust with a high quality titanium system that will save some weight at least. Most of the systems don't really produce much more power than the already excellent Honda Factory system.

BUT why on earth would anyone take off an excellent factory system for some trash system or worse yet cobble together some pipes to make their own which is almost guaranteed to make less power than stock?

 

But why refusing the idea that it could get better???

 

Beig, why exactly are you so sure that it will lose power over stock? I understand what your trying to say, however its really not valid without some proof supporting your thoughts.

Everything is speculation, I make no claims of HP increase. It might it might not, its never been done with the S. It will save weight for sure, it will change exhaust note for sure, it will look different for sure. But how can you or I assume anything about power gains or losses without seeing an example or having any solid facts?

 

Companies like Mugen spend tons of money and go through multiple prototypes on the dyno and even they can't get a significant amount of HP improvement.

What are the chances that some guy on a budget of obviously under a grand will get something better by welding together bits of pipe in his garage? He will be lucky just to get it to fit right.

Believe in fairy tales?

 

Mugen in particular has a different goal for an exhaust than other people may want (although most will prefer the Mugen). They spend all of their time and money designing the exhaust for more than just power. If all Mugen wanted to do was gain hp, it would be completely different in design. The Mugen is a combination, of looks, sound and HP (with the S2000 application having the HP factor considered the least of the three).

For max HP, there is no need for a dual exhaust on a 4cyl motor. A single exit exhaust with minimal presilencers and a very straight path will yield the most hp. It will not look as pretty or be as quiet. Evidence of this is the Amuse exhaust which is known to give a 8ps increase in power. The Amuse design is not rocket science, its just a very straight design with a single outlet and optimal piping diameter. They didnt care about noise (hence so many complaints about it being loud), and looks were not a huge factor (single outlet vs dual), but it gives an 8ps gain, vs Mugen's 0ps gain.

All of this is meant to explain the point that this idea is not to create a better exhaust than the Mugen or HKS, or Neuspeed, etc. Its to create a DIFFERENT exhaust with different goals, being weight savings and power increase, not looks and quiet sound.

Please explain why this cant be done, using factual evidence proving your point.

Ben

 

It

 

The guy doesn't want (or is unable) to spend the money on a HKS or other reasonably priced system so we know the upper limit of his budget.

Dyno testing is not likely with what he wants to spend so anything he puts together or the local shop puts together will not be tested, proven and refined.

Even if you are able to make it fit and hang nice under the car (that's the realatively easy part) you still only have one shot (on his budget) to get it right. Odds are it will resonate horribly at certain RPMs and after all this trouble will not produce any more HP, look cobbled together and be a waste of time and money.

Spend the extra bucks and buy a refined design from the get go or leave it alone unless of course you are looking for a project and an expensive lesson.

Of course that is just my opinion.

 

Bieg, catback exhausts are the EZ part of the exhaust system. It is just not very hard to design them. MUCH, MUCH more forgiving than the upstream parts of the exhaust. If anything, most of the trial and error is oriented toward getting the subjectively best tone. A good fit is needed too. Neither are hard to achieve if a competent effort is made. The most "efficient" mufflers tend to have largish cans so that you can get a good combo of noise reduction and low back pressure. The thing that amazes me about S2000 exhausts is the frequently awesome price compared to comparable products for more expensive European cars.

Has anyone yanked the rear O2 sensor and inserted a pressure gage to get a clue about OEM muffler back pressure? It's very likely that the car comes with a very good exhaust already. So you can just go for reduced weight and a louder and nastier tone with comparable or perhaps VERY slightly more power. Hopefully no loss. You don't need dual exhaust on this car if someone really wanted to optimize weight and cost and power.

Again it really is not hard to do this sort of thing.

Stan

 

Maybe, maybe not. Designing an exhaust is not just a matter of fitting big diameter tubing to the headers. Anyone with any experience tuning a Harley knows that big diameter straight pipes do not increase the HP, just the noise. They have a big hole in the midrange and it is mostly because they don't provide enough back presure.

I remember seeing articles on how critical pipe length and even the type and shape of the exhaust tip was for extracting maximum power. You must remember that "tuning" the exhaust is just that, tuning. The length and volume of the exhaust system determines such things as the natural resonance frequency. Sound waves properly utilized helps scavenge the burned gasses from the cylinders. Improperly tuned systems can create "standing waves" that can interfere with this scavaging. The volume of any enclosed space has a resonant frequency, think of blowing over the mouth of a soda bottle. Rooms resonate and sound boomy at certain bass frequencies because of this. Any sound engineer knows that reflected sound waves can cancel out certain frequencies and double others. This same type of thing happens in poorly designed exhausts and can actually rob you of HP.

It is just not as simple as fitting big diameter pipes.

 

Bieg, the cat back part of the exhaust is the EZ part of the exhaust. The tuning is mostly (nearly all) taking place at the front of the system, mostly before the cat. Your point about dyno tuning is MUCH more applicable to things like headers as opposed to mufflers at the back of the car. Good cat backs are not difficult things to design and produce. Still there are likely stinkers out there. On many modern cars catbacks are essentially jewelry in the sense that appearnace and sound are primary considerations along with some worthwhile weight reduction. On high quality cars, mufflers don't help much unless you do thing like add nitrous or a supercharger since the exhasut flow would be increased so much.

Stan