Prius Exhaust Mods?

maybe some side pipes? or a big rig stack...
please take pix if you do this. toyotech claimed to have straight piped his, but never got back on what it did for the car.

 

I did some more research. The 2 above headers are for the xB, which won't fit the prius unless you were to 'trick' the ecu into thinking the o2 sensor was being used. Neither header uses a 02 sensor in the exact area that the Prius and Yaris do.

Here are the correct headers:
DC 4-1 Header


Cheap eBay Yaris Header vs Megan headers...

Almost exactly the same. Just eBay header looks more unfinished when compared closely... welding and clean-up wise. Almost like eBay headers are the QA rejects from Megan. See full write here: Pre Hack Revival: Megan Racing Header vs Ebay Header - Toyota Yaris Forums - Ultimate Yaris Enthusiast Site

Weapon R Header



Weapon R compared to Stock:


Most Yaris users are worried about losing torque from the DC headers so they like the WeaponR or Megan. However, for the Prii application with the assistance of the MG2, I'm not too worried about losing low end torque but more interested in gaining higher RPM HP. I haven't decided between the WeaponR 4-2-1 or the DC 4-1 Header setup. The Megan/eBay header is too close to OEM configuration for my liking.

 

i'd bet the oem config is pretty good; just the tubes might be a little small. but a 1.5 L engine really doesn't need huge primary pipes. the cheap ebay header would be my choice, cause its big enough and i'm a cheap mofo.

if you got a deal on a header w/ no o2 sensor bung, its not difficult to add the bung. i did it to my chevelle header to help w/ tuning.

well damn. i just looked at that ebay header. if it does fit, for about $60, that isn't too much money to be wasting on a header. i'm tempted to go for it, but i sure would hate it if it didn't fit...

 

Agreed, super cheap! I'd probably already ordered one of the headers, but i really want to figure out the CAI first w/o throwing a "MAF out of range or Running Lean" CEL... Then dyno.... Then move on to the exhaust. Def feel free to make the jump first. LOL, I was gonna b the 1st (that I know of) running headers on the G2Prii, but I won't hate u if u beat me to it.

 

don't worry. my cheap @$$ isn't buying any header until someone else does it and tells me it fits. (it could be you!!!)but unless you do the whole exhaust, its not gonna do much. the pipe after the second cat is way too thin for the ice to breathe. i am gonna look at my friends yaris exhaust the next time he needs an oil change. its going on my rack to see if the yaris cats and resonator will fit.

 

From what I can tell the sedan midpipe would fit and the HB would just need to be lengthened about 9"-13".. however swapping a yaris exhaust wouldnt net you much gains if any over doing your own choice of header...then just hacking off the rest of the stock Prii exhaust after the cats (bcuz of the restrictive resonator, smaller piping and own muffler) and creating you own custom 2" setup. I'll probably do as such like I suggested previously. New header (most likely the WeaponR) bolted to the stock cats with a new mendreal bent setup usining 2 of the Magnaflow 7" round straight thru muffler #14714 with the Magnaflow #35168 Tip to keep the dB down. One to replace the stock resonator and one to replace the muffler itself.

 

is the yaris exhaust thin too? i was hoping it would have a bigger diameter.
i'm thinking scrap the resonator and use a flowmaster in the back. hopefully the flowmaster would take out any nasty raspy noise like these damn kids seem to like.

 

Both the 2GPrii and Yaris use similar exhaust setup and configuration - headers connected to the cats is all 2" piping . Right after the midpipe section the diameter drops down to 1.5" or less as it makes its way to the muffler.

A few more comparison photos..

OEM vs DC


OEM vs WeaponR


Megan vs OEM


AMK Racing (eBay) vs OEM - AMK Racing Header - Toyota Yaris Forums - Ultimate Yaris Enthusiast Site

Looks like its already been done. SCCA Solo2 F Streep Prepared Prius (56k warning) - SCCA Solo2 FSP Prius was running the TRD Yaris header...



Part #17100-NP100 - Expensive lil bugger..

 

looks like they were trying to make them equal length.

 

Great thread on backpressure at the 24 HoL forums here: Back pressure question (Page 1) — LeMons Tech — The 24 Hours of LeMons Forums

I tell ya, take my advice... go check some hot rodding / drag racing forums and you'll get a head full of great ideas... none of this "throw spaghetti at the wall" stuff that gives you naught but CELs and headaches.

 

Ordered my DC header from thmotorsports.com with a coupon (dcsports | 5% Off All DC Sports Headers, Intakes, and Accessories) Can't wait for this to come in - WootWoot!



DC: THC4407

 

Personally I would not mess with the ICE intake, exhaust, etc... its a prius... You want performance gains get a second pack and start getting 90+mpg.

 

How is this supposed to help the OP?

How exactly does a 2nd pack double the efficiency?

With a second pack you're going to add a significant amount of weight to the Prius. And you're also going to double the amount of work the ICE has to do to maintain SOC. So where does the extra 45 MPG come from, "Expert"?

 

ditto.. unless your just sales pitching...and not actually serious.

I believe there is more of a miscommunication - you idea of 'performance' and mine are not on the same page - your looking at improving only the Prii MPG... I'm looking at improving the ICE performance and HP.

So I have been learning more and more about the Bonneville Landspeed Prius. If your thoughts of improving 'performance' is to add a 2nd pack... why would TRD not do such. Instead - they used DC Boost circuit to increase volts from 500 to 550, they modified the intake manifold from what i can tell was from the 2AZ-FE for better intake flow, they swapped the exhaust manifold with a Yaris TRD manifold...They did the Otto cycle from Atkinson cycle engine swap...modifed JDM ECU to increase RPM limit - among other things... None of which by design was used to increase MPG performance.

Houston.....we have a problem.

DC header bolts up to the block perfectly...connecting the rest of the exhaust - it doesn't match up. The support bracket doesn't match. The Prius donut is bigger than the Yaris - can't simply swap over. The spring bolts from the Prius mid-pipe don't match the Yaris.

Donut Gasket:
Prius: 17451-21060
Yaris: 17451-21070

Exhaust Manifold support Bracket:
Prius: 25591-21050
Yaris: 25591-21060

So.... pulled the DC header back off...put the OEM prius header back on...temporarily - and will buy the correct support bracket and donut gasket and have an exhaust shop help mate up the mid-pipe. Will report back. I WILL have SUCCESS!

 

bummer. good luck. i hope you figger it out soon!

 

With an angle grinder and a MIG welder, you'd have this problem fixed in all of 20 minutes. Grab yourself a Yaris exhaust from the junkyard and make your own header-back system.

You can only do so much to a car with just a wrench. Stop dickin' around with these bolt-on solutions and build something cool already!

 

Had I had those tools at my immediate disposal..I would have.... but i dont and didn't..

Exactly what I plan on doing... well at least that "dickin' around" comment could arguable... lol

 

I got both off of Craigslist for about $500. Practiced on a bunch of scrap steel, then used it to fabricate seat mounts and a roll cage for our race car. And, yeah, I ended up welding our exhaust system together too... took all of 15 minutes.

 

ANy update for Weapon R or other header for Prius?