Aftermarket Performance Exhaust for Prius v

That is last option to choose....you should try to see other types of getting more power....then you will need to adjust calibration for various things to adjust for new power....
This type of thing will be just wasting .....
Unless you have way and knowledge to Tune ....
Keep the cash for new HV battery some day on the road

Posted via the PriusChat mobile app.

 

If you want a performance car.......
You should jack up the Prius and slide a whole new car in under it.

Seriously.

Screwing with the exhaust/muffler is ILLEGAL in the US and may cause the computer to throw fault codes and run worse.
Of course it will cause it to be noisier; probably sounding like a lawn mower with no muffler.

 

Go big -- cat-back Ti quad-tip -- or go home... Stickers alone are worth +10 BRWHP!

 

Sam: If screwing with mufflers is illegal in the US, why are there so many made, advertised, installed, tested, and run here? Google "cat bypass pipes Boxster" for an example I'm familiar with. Many states have so little or no testing that they seem to pass.

OP: An Atkinson cycle engine is designed to run most efficiently in a very narrow power band. It is not a high reving motor where improved breathing might help your bragging rights figures.

Even on "normal" ICE engines the dollars per gained-HP expense will generally disappoint you biggly.

 

Because there generally is little to no actual enforcement in most places.
But that does not make it legal just because you can get away with it.

Nor does it make it a prudent or wise thing to do.
There still are places in the US where the air is BROWN part of the time.
If you had to live in one of those places maybe you would have a better appreciation for the problem.

In addition to my right to live in relative peace and quiet. Most places have excessive noise laws too......also which are seldom enforced.

 

There's a guy down our cul-de-sac, rolls by daily in his battered diesel pickup. Unburnt diesel just hangs in the air for the next 10 minutes. Maybe 10,000% more crap going into the air, comparing to our Prius?

 

The catalytic converter and O2 sensor feedback loop are the only EPA/CARB-regulated aspect of exhausts.

 

In an Otto cycle engine, the compression ratio and the expansion ratio are the same, so when the fuel burns a great deal of pressure is still unrealized and a great deal of expansion happens in the exhaust. The Atkinson cycle engine in the Prius has a compression ratio of about 8 to 1 and an expansion ratio of about 13 to 1. So significantly more expansion was captured in the cylinder and less is wasted in the exhaust.

If you are interested, you can make your exhaust noisier, it just won't improve performance or MPG.

 

No they aren't.
Absolutely and totally false.
It is specifically illegal to modify or tamper with any part of the stock exhaust system on a production street vehicle so that it emits more NOISE OR OTHER "POLLUTANTS" . Mufflers specifically must be tested and approved to be "legal".

As a matter of fact, I think I have seen that quoted in more than one recent owners manual.

 

Please quote chapter and verse. If you can.

Hint: An Owner's Manual is not a regulatory filing.

 

And the impact on you hearing over time. Hearing aids are expensive.

 

Sure. But it all adds up.
That truck might be equivalent to 1,000 tampered with Priui.
Both need some enforcement applied.

 

I spent a few minutes googleing. IANAL

You can change a pipe or muffler beyond the CATS and O2 sensors.

Most states have a noise pollution laws. I'd love to see them enforced along with trash from the car laws. Not in my state they aren't.

CA has an emission certification law for in-state vehicles. Product must have a sticker on it. The other 49 states seem to not have such a requirement though if you want to sell a system you have to certify its effectiveness with tests that you keep on file for the feds to check if they have the time/resources/money. Or until that regulation is repealed.

 

The noise issue even goes to the track and parking lot (autocross), where 100db (with some venues less) at 50 feet is the limit.

 

Look at this from the vendor's perspective: How many Honda Civic ricers are there to sell to? It makes sense to sell aftermarket exhausts that are louder so they will think they are faster.

A station wagon where the engine does not even run while 'cruising'? How many station wagon owners who want flatulent noises intermittently could there be? You are never going to make the tooling back in sales.

Buy a fart pipe for the end and call it good.

(as the conversation implies, what is legal in a modern 'first world' state like CA or NY, will not be the same as a 'third world' state like MS or AL. Since you do not list a location, no one can guess what is legal there)

 

I don't believe that is true.
I too did a little quick searching and found this in about 3 minutes.
https://www.epa.gov/sites/production/files/documents/exhsysrepair.pdf
See question and answer #7.

I'm sure there is a LOT more and I'm also sure that the regulations since then have become tighter and not looser.
Alas, the enforcement has stayed almost non-existent.

And no, I will not spend my time looking up additional references.
Those who wish to argue can spend their own time ........trying to find official documents to the contrary.
Good luck.

 

That might well be true for general noise regulations but vehicle emission regulations, including vehicle noise emissions I think, are Federal and apply to all 50 states. States have the option to be MORE strict but not less.

 

That's why I'm glad I live in Florida where there's no inspection or emissions tests on vehicles here

 

Thankfully, the ideal cat-back Ti quad-tip retains single exhaust, OEM cat and O2 sensors and overall length -- good to go!

Remember to apply stickers for an extra 10 BRWHP...

Given the magnitude of the aftermarket exhaust industry, I'll venture that 1991 typewritten EPA interpretation has been superseded.