k&n And magnaflow

Are you looking to increase mileage or power? Filter won't help mileage, even though they claim it will (see the study at the bottom of this page). Don't know about power. I do like the sound the intake makes when you remove the tube going into the airbox, maybe you could try that while you're at it.

 

It's all snake oil.

It will end up sounding like a sick lawn mower and the K&N might cause some trouble if it is the "oil" kind and you put too much oil on it.

Regardless of what you are trying to accomplish, except maybe just more noise, you are likely to be disappointed.

 

With all the work Toyota put into the Prius to get it as fuel efficient as they could make it. Do you not think that something as easy and cheap to change as an air filter or exhaust box to improve the efficiency they would not have done it.

John (Britprius)

 

replacing the muffler without redoing the whole exhaust isn't gonna do anything but sound bad. the exhaust pipe coming out of the cat is necked down too thin for a moped to breathe properly and it only gets worse from there. if you were to cut the pipe at the back of the cat and bend up a new system using 2 1/4" pipe all the way back it might help. justdidit also installed an aftermarket yaris header, and most likely did get a little extra power. all the naysayers are gonna say "but Toyota would have put on a better exhaust system if it would have helped". but Toyota has cost considerations and also figured that prius owners would prefer a very quiet exhaust over a free-flowing system. I like a little exhaust noise, but then engines with tiny little pistons mostly sound bad if you let em breathe.

on the other hand if its a stainless steel muffler and looks cool, there's nothing wrong with that either.

 

Going from a mix of quiet and silent to loud and silent sounds pretty silly to me.

Avi

 

Sure. Let's do keep it real.
Those components were purposely designed to work properly the way they ARE.
More is not automatically better.
Less restriction is not automatically better.
Sometimes things actually turn out worse.

 

You have to remember the Prius does not rev above 4500 rpm, and produces it's most efficient output at around 2000 rpm. Further it is not an Otto cycle engine, but an Atkinson cycle engine where part of the cylinder intake is returned to the inlet manifold. This is around 10% more fuel efficient than an Otto cycle.

John (Britprius)

 

they do work properly. but do you think Toyota spent time and $ trying to get every last bit of power at any expense, or came up with a good compromise for the market?
but sometimes more IS better.
less restriction probably won't hurt, might help, but got to try it to find out.
sometimes things actually turn out better. glass is 1/2 full here.

yeah we know that stuff. but its very possible less back pressure will help. it works on just about every other kind of ice, diesels, 2 strokes, who's to say it can't help an Atkinson?
I'm not claiming any advantage to the cai I made, although every now and then if the tires don't break loose, (integritys suck. I hope they don't sell this garbage in the EC) it seems like it accelerates pretty quickly for what it is.
as far as custom exhaust, its just cool looking. and if it isn't too raspy, it might not sound bad.

that ice is so small, by the time it gets through the cat and pipe, it ain't gonna be very loud. its not like its gonna have drag pipes. might get that nasty yo boy buzz though... that would be embarrassing...

 

Every now and again I miss the Flowmater 40 series with custom bent oversized tubing with reso delete from my since traded in Charger RT…

But Silently rolling from light to light has its benefits too!!

 

I like the sound of screaming 325/50r15 drag radials even better than the straight through borla dual exhaust on my chevelle. gonna have to drive it more since gas is down.
but one problem with hybrids is they're so quiet people and animals don't hear em coming, so I play the stereo kinda loud.

 

Ill tell you what I don't miss….

The Samsom street sweepers with no baffles on my 2009 Yamaha Warrior….

Those sons of bitches gave me a raging headache every ride, even with earplugs….

Borderline Ridiculous..

But "I ain't heard you coming" is not a valid excuse anymore with them...

 

I have better things to spend my time and money on.

 

that's why I still have stock exhaust.

nothing borderline about it. I had open drags on my chopper-- for a little while. made my whole head ring if I got on the highway. my friends were like "whats up with yer bike? its LAF". I bought some expensive baffles and had em in ever since. still sets off car alarms though.

 

I love how anyone asking about modding the intake or exhaust will bring comments out of the woodwork saying "don't do it! Toyota spent all this money researching... it's perfect the way it is... etc!) Yes Toyota did R&D on fuel efficiency to maximize MPG. But not everyone wants maximized fuel efficiency, because you will have to compromise somewhere else. You could get awesome low-rolling resistance by retro fitting the OEM wheels to super thin tires like 145/80/13 but that would compromise handling and safety. To maximize fuel efficiency Toyota limited the air intake and exhaust.

I've dropped in a K&N filter, and cutout the bottom of the intake resonator, to modify it from a resonator and turn in into an intake.

Before anyone freaks out and says you'll be hydrolocked etc. I've had this mod for over 2 years, and driven through plenty of rain storms with no adverse affects. I've even tested it by using a paper filter, driving through the rain storm, and then checked the filter. I found no water infiltration into the stock air-box and no water on the filter. Also keep in mind that any atomized water droplets would have to pass through the filter, go up through the secondary charcoal filter, across the top of the air-box and then back down to the throttle body into the engine.

I experienced minor MPG loss, but gained so much acceleration, I'm no longer afraid to merge into highway traffic. I compromised fuel efficiency for acceleration and safety.

Orangeeeyore, I'd say mod away. I'd start by adding the K&N, and then modifying the huge white air resonator into an intake. If you're worried about not being able to go back to stock by modifying the resonator, try driving with the resonator removed for awhile and see what a difference it makes to improve the air intake air-flow.

Orangeeeyore, I'd also add an Econoaid Throttle Body Spacer (PN: 1017). It mounts under the throttle body, and is an easy mod to do. Some will claim that it's snake oil, but you can find it on amazon for about $30. Which isn't too much to waste on the possibility of acceleration or fuel efficiency. I have no dyno proof, but I felt an acceleration improvement after installing it on my car.

Watch this video on removing the headlight, you'll need to do this on the passenger side and remove the headlight assembly.

and check out my previous discussion on air-intakes:
Cold air Intake? - Not a Joke or Noob question | PriusChat

My latest design is different that the pictures shown in those posts. I've since purchased another resonator, and cutout the bottom (as apposed to the cutouts on the sides as shown in that thread.)

 

OK well there are ALL kinds of people who own cars; not all of them are mechanics or even mechanically inclined.

It appears that YOU have the savy and skill necessary to do this kind of stuff.......but not everybody does.......and those who don't know which end of a wrench to use probably should NOT be tinkering with anything.

One size does NOT fit all.
Both sides of the discussion need to be presented and making snide remarks about "coming out of the woodwork" does nobody any good.

 

What can I say EasyRider2, I'm just a snarky kind of person. I don't mean to offend anyone. Happy modding Saturday to everybody!

 

I know where the extra horsepower and fuel mileage come from when installing K&N filters, etc. This recent study is similar.