Overall, i still need to get used to the louder note coz with WR it releases the true sound of your catback exhaust.. Its loud.. Definitely.. Without a doubt.. Well ofcourse it'll still depend if you're gonna used N1, chambered, spoon, j's, hks, dc sports tip, etc. i think as of now oem midpipe is fine because its possible that 50mm-60mm diameter (might) cause it to decrease in power since no other engine mods internal parts are being installed so stick with the oem 44mm( to be safe ). And dont remove resonator ofcourse to resonate the sound or replace a longer one to make it more quiet.

Btw, no buzziness/raspiness sound with aftermarket exhaust (well again it depends on what ur using) but mine doesnt have any annoying unnecessary sound may it be in the exhaust or underneath (vibration), no fitment issue etc..

Again, as of now no cel.. Smell of the exhaust is a little different already. And as of now i can still smell the silicon gel or whatever paste that we applied on the gasket and thinking it will disappear in time (the horrible smell of the silicon) lol

 

I have the Weapon R header. I yet to have it tuned, but my wide band is telling me a wot its close to 13:1 so there is no urgency.

Raspy. Louder. Popping. Vibration through 3k to 4k. I mean it's a "race header", what do you expect. The cat significantly quiets the exhaust. I have the HKS axle back and the OEM b-pipe. I wouldn't call it Really loud. But people know when you are coming and going. My other cars I would consider loud. The "popping" is when you lift, worse with higher octane. That cant be tuned out with what is available (unless you go stand alone).

Definite power increase.

 

Noticed any changes in fuel consumption? And lose of power in low end?

 

No, if anything better mpg. and No again there would be a torque gain.

 

Considering you are removing two cats and still maintaining reasonable piping size, Im surprised there isnt a larger performance then we all see on posted dynos and duringthe few online videos.

im excited to get one when taxes come!

 

Modern cats are design very efficiently these days. They are all "high flow" now for gas mileage, performance...

 

Indeed, most modern cats follow that guidance. But the Fit is ULEV, remember. Zero fucks were given for performance in those cats. They were designed from the ground up to contain as much emissions as possible without choking the engine out so bad it needed a high duration cam


This is why weaponR/T1R cat delete owners are so happy with the results.

 

I have the Weapon R header on my car, and I agree, I happy. It's probably the biggest gain from a bolt-on for the GE. Saying that Honda doesn't care about performance..... Performance= MPG. And they care about MPG.

Also to have a ULEV vehicle doesn't change the cat. It introduces heat-shields that help the cat warm up faster. Also secondary air to also get the cat to warm up. The CAN system plays a part in emissions being able to quickly control settings like AFR. Among other things, it doesnt the density of the cat material causing "blockage".

 

My understanding with the ULEV spec was that it was a pretty large increase in cell count inside the cat.

ULEV doesnt mean it got heatshields and such. All the cat converters Ive ever seen have had heatshields of some sort. double edged sword, to heat teh cat up faster, and prevent nearby parts from burning up too much

 

I know engineering stuff is boring, but here's a good article (and it's short lol):
The Achievement of ULEV Emission Standards for Large High Performance Vehicles

They (automobile engineers) found that having two cats (main and post cat with low cell count) is equivalent to a single "high-density" (high cell count) cat, but with a high velocity fluid flow. That's why the cat material are not as dense and there are two.

As for melting cats, the have a very high failure temp, something like 1500 F depending on the materials. They commonly fail because liquid gets into it, not from over heating. Usually from a leaking head gasket (oil/coolant) or a leaking injector. The main purpose of the heat shields and secondary air is to get the cat up to operating temps.

There are many thing that contribute to over all ULEV emissions, it doesn't rest solely on the cat. I feel like we had this discussion on another thread...

 

well just to sum up my own personal experience with WR headers, after a week of driving, I am happy and fully satisfied with the results it has given to my car.. sound and performance wise, it really did awesome..

 

I wonder how it would sound with the Weapon R "Header", T1R B-Pipe, and Tanabe Medalion Exhaust. Anybody running that combo?

 

I have the OEM B-pipe and mine is loud. So it has to be loud. The HP gain replacing the b pipe will be minimal with bolt on's. I thought I read somewhere the b pipe is a 1hp gain. Meaning the performance is in the weight savings.

I would suggest install the header and axle back... then decide to spend the money on the b pipe.

 

Man.. now I'm nervous. I currently have the b pipe and axle back set-up, just purchased the header off somebody here last night to complete it. I really hope its not obnoxious. I should have it installed by Friday, hopefully.

 

Well, i was told that oem midpipe is ok. But changing it to a way bigger pipe size may result in loss of power unless you got other aftermarket mods under the hood that can compensate the power it produces and will be requiring a bigger diameter pipe. Sound may be louder but it wil really depends on how long the resonator will be.

 

bigger midpipe is unnecessary unless you start making over 200hp or so. Even then, the minor gains are outweighed from the low/mid rpm losses

 

totally agree.. k20r, boosted/supercharged and/or heavily modded L15a7 (if possible) would be some of the examples.

 

So what would you guys recommend?

Completely remove the T1R B Pipe and just swap it back to the stock b pipe and then add the down pipe and keep my axle back?

 

What's the diameter of your b-pipe? 2.25? 2.5? I think stock midpipe is more or less 42-45mm. If your b-pipe is over 60mm and up you might want to consider replacing it with oem instead. If your engine is stock, its still safe to use 50mm or about 2inches in diameter. It might lose backpressure if u go over 60mm. Check the specs of ur bpipe online if possible.

 

you do NOT need back pressure in your exhaust! backpressure is wasted power!

Going too big of diameter reduces VELOCITY. It reduces the scavenging effect of exhaust pulses "pulling" on each other to exit the motor/exhaust system faster.

I recommend a maximum of 2 inches until you start going near 170whp/200 crank horsepower


My crx turbo ran just dandy with a 3 or 3.5 inch downpipe leading to a 2.25 or 2.5 inch catback. Was a very responsive 320whp, and never acted like it was being smothered