J'S RACING GK5 FIT C304 SUS exhaust system center pipe 50C
See Post #10



My bad translation --->
"Use SUS304 stainless steel tube of thickness 1.2mm to the main pipe. By making the flange portion and the stay part that was thin to the limit in a hollow structure, it was even finish to lightweight.
Exhaust efficiency is significantly improved the diameter of the pipe portion by a 50φ. We made ​​muffler, of course, you will be able to make big power up, even in combination with third-party and genuine muffler."

36720 Japenese Yen Approximately $310.65

**Updated 4-7-15 Video Added**
Purchased this with their resonator as well.

 

Wow...no response to this one. I've finally given in to ordering this. Was trying to decide between the Spoon Sports B pipe and the J's Racing one with the resonator. The Spoon Sports is 45mm while the J's racing is 50mm. Since I'm working on getting cams and Ktuner (hopefully they complete deciphering the ECU code), I went with the 50mm. Will show pics when it arrives. Currently it's a two month delay on it.

 

I think you made the right choice on this man both are great but that extra little bit could help, so it only set ya back $310

 

I hope I did! I've been wracking my brains on exhaust diameters for the last two months or so before giving in to this 2". Will see how it goes though. I'm actually leaning on thinking 2.25" is the perfect size for the 'B' pipe since it hits a double bend. I remember reading in another exhaust thread here that referenced a Neon site and their recommendations. It was something about an exhaust losing 8% of its flow every 90 degree bend it hits.

Either way, I will be testing it out at the dragstrip as usual. Man, I just want us to be able to hit high 14's N/A and run neck-n-neck with a stock late model Civic Si. For now! Can't hurt to try!

 

That would be awesome I ran a skunk2 b pipe on my gd3 and it was great, some good gains about 4 hp on the dyno it showed and that was wit I think 2.25" piping, but can't wait to see the results, that happen with you, I'm actually more curious to see your dyno numbers and see if ya can hit the 140 to the wheels mark, but befor I start on engine mods hoping ktuner will take me in soon. To get baseline numbers

 

Did u get it through your same guy again or did u try going through js racing directly

 

I never try to get through directly. I think you need to speak Japanese. I sent you a PM on this though.

 

**Update 4-3-15**

So much for 2 month wait. I'm expecting this piece by next week.

It should mate (HOPEFULLY) up quite nicely with the J's Racing Cat delete piece since they both have the exact same diameter (2"). Expecting gas mileage to go up slightly. Not sure what it will do power-wise. With the increase in exhaust velocity, hopefully it will not be more restrictive than the 2.25" pipe I have attached to my Midas 2" 'B' pipe. My current 2" Midas pipe has a nasty 2.5" bulge where it mates up to the J's Cat Delete pipe from my previous setup. Flow is not smooth at this section but it's doing ok.

I'm going to stay with the 2" theme the whole way out through the muffler. Was tempted to keep the muffler at 2.25" but have some concern about sound levels. Can't wait! So much to learn from this but the general consensus is that 2" is best from all the info online and here. If it comes in quick enough, I'll be able to test it at the track either Wednesday, Thursday or Friday next week. Weather forecast calls for rain during the week.

 

Nice man I'm excited to see how it will come out for ya

 

**Update 4-6-15**

The J's Racing B pipe arrived today (Only two weeks after ordering it on 3/23/15). It is the exhaust piping on the left while the stock is on the right. It was packaged really nicely and there did not appear to be any damage to it. Welds look fine, it was shiny (I don't care about this either way). Nothing else to add!


I laid the J's racing B pipe on top of the stock pipe to see if it looks like it would or would not fit on the car. It looks like it is a go.



I took measurements of the J's piping at different sections since I took measurements of the stock B pipe sections earlier today. Here's a pic of the differences. O.D. means 'Outside Diameter'. I.D. means 'Inside Diameter'.


In the case that the picture does not load up in the future, here is the piping diameter info of the J's Racing B Pipe from measuring with a digital caliper.
Feel free to take your own measurements. The stock piping measurements are in this thread --> 2015 Stock B-Pipe Diameter & Weight. Results may vary.

Outer Diameters
Inlet Piping diameter -- 46.6mm I.D. (1.83")
Pipe after 2nd cat -- 49.5mm (1.95")
90 degree bend
Pipe leading towards the resonator -- 49.86mm (1.96")
Bend towards resonator
Inlet piping to resonator -- 49mm (1.93")
Resonator
Resonator outlet pipe that has slight bend -- 50.66mm (1.99")
Piping after slight bend that goes to muffler -- 50.4mm (1.98")
Piping outlet to muffler -- 41.9mm I.D. (1.65")

The J's Racing B-Pipe weighed in at 12.2lbs. (5.53kg)
The stock B-pipe weighs 10.4lbs (4.72kg)
The J's Racing B-pipe weighs 1.8lbs (0.82kg) more than the stock pipe.



I will be re-installing a 2" Hi Flo-Pro Max muffler I had on the Fit previously. More information on it here -- 2" Hi Pro Flo Max Muffler.


This muffler has the stock piping attached to the inlet side of it. The exhaust side of the muffler tapers down. Here is what I measured today.
O.D. = Outer Diameter, I.D. = Inner Diameter
Piping to inlet of muffler -- 41.82mm (1.65") O.D. **Too Small**
Muffler Outlet pipe - 40.93mm (1.61") O.D., 39.82mm (1.57") I.D.,
May pick up a Dynomax Ultraflo SS Muffler (My favorite kind since it's quiet), if this setup doesn't prove quiet enough.
2" Dynomax Ultraflo SS Welded

The muffler ain't pretty. This ain't a fashion show. This is for testing for results. I can always 'upgrade' to a muffler that's {prettier} with cool welding later. This thread ain't about the muffler though. Hi Flo-Pro Max Muffler and stock pipe weight is 12.4lbs. I purposely purchased the biggest straight through muffler I could find knowing it'd have to do the work of the previous cats a resonator on quieting down the exhaust.

I'm happy with the purchase thusfar. Will have the B pipe installed tomorrow and remove the 2" to 2.5" monstrousity I have on it now. I may update with a pic or two as well.

I apologize for any wrong numbers I may have typed in and will correct it if necessary.

 

Awesome info man really looking foward to how it is going to react with wat you having going on but opening it up should help you, plus it's nice to see your gaining about 5-10mm around the diameter of the piping

 

Thanks! I had to look at all the numbers again because I had my numbers a little screwed up. The 2" High Flo Pro Max muffler's stock inlet piping isn't optimal. I'm being picky but the inlet is only 1.6". I want 2" minimal in and out. **Sigh** Arrrghhh! I'll see how it goes before considering investing in the type of muffler I want to get. Dang it! Need to read if I want to go with 2.25" or 2". Definitely not 2.5" though. I have a 2.1" in and 2.44" outlet Hi Flo-Pro Max on now which is cool but the piping goes directly to the Xlerator 'pre-muffler' I have installed before it. There's no flange in between.

 

**Update 4-7-15**

The J's Racing B-Pipe fits like a glove.


And the flange that attaches to the J's SUS Converter aka Cat delete is a match made in heaven.



I have all of this mated up to the 2" muffler I have in the pics above. I will changed that out eventually because the muffler has the stock 1.65" O.D. pipe connected to it. The muffler is 2" in/2" out O.D.. However, the car is absolutely quiet, whether I'm leisurely driving or on the gas. Unbelievable! I wonder what it'll be like when I get a proper 2" in/out muffler and piping soundwise. To be continued!


Oh yeah, here's the B-pipe I have been playing with for a bit. It's not pretty!
The B-Pipe itself weighs 18.2lbs (6lbs more than the J's) and the muffler 13lbs. The piping you see before the resonator was 2.5" but I changed it to 2" a couple weeks back to test the car for feel, sound and how it'd perform at the track. It goes from 2" to 2.5" Ultra Quiet Resonator to 2.5" Xlerator muffler to 2.5" Hi Pro Flo Max muffler. It it still had a good bit of sound to it. The transition from the cat delete pipe to the B-Pipe's inlet was very nasty. It went from the J's cat delete to 2.5" to 2". That just was a crappy job the muffler shop I went to did (My muffler shop guy was on vacation so I stopped by another shop on the other side of town). How crappy was it? Look at this --->


Now mind you, I just was running 15.6-15.7's at 88mph with this thingamajigga attached to the Fit. It'll be interesting to see what improvements the J's B-pipe will be and how much of a role this nasty transition impacted my 1/4 mile times. That's not to say that the 2.5" Xlerator muffler and resonators are bad. This is what I ran the low 15's in while trapping at 90-91mph. It's just that these things could be improved. I was checking the outer diameter at the crush bends and such and the whole setup just seem to suck....in theory. It'd taper down to 2" and back out to 2.5". Just horrible! But...It worked though. And that's what's important.

There's more work to be done. Learning a lot!


Oh yeah, I'll upload a video of how the exhaust look. No video of the sound. It's so quiet, there's nothing to .....hear.

 

The track is somehow open tonight. It's cool and humid (50's going up to the 60's). I'm looking forward to testing the weird setup I have in the video above. I have no idea what to expect. I wouldn't recommend it but it seems like it flows better than my previous 2" J's circuit converter to ghetto 2.5" setup. I'm not talking from butt dyno but from looking at maf sensor g/s readings. Its maxing out higher than before, maf sensor voltage is slightly higher and injector duty cycles are slightly higher. However hp/tq and 1/4 mile time seems to be the same (15.7-15.8 and 120-122whp range). I don't trust ANY of this stuff. Just sharing but that's why we test these things. Being though the exhaust is 2" J's circuit converter and 2" J's B-pipe, it has the stock exhaust's 1.65" inlet piping going into a 2" Hi Pro Flo Max muffler. The muffler is awesome and it's the biggest I could fit under there. The muffler with the skinny 1.65" skinny stock piping makes the car QUIET. No noise! No drone! You don't even notice the exhaust, even at wide open throttle. It's just subtle! It will be funny as hell if I can get below a 15.7 and above an 89mph in the 1/4 mile tonight. This would seem to be the ideal setup for someone on the very conservative side for sound. I like the stock exhaust piping for it's size because it looks like Honda did a very good job in not crushing the piping as the piping turns.

Either way, I find these things interesting. Will report however it turns out. Here goes nothing......

 

Very nice it looks so pretty haha, but man the way they mashed up your set up must have killed exhaust flow, can't wait to see what happens with ya tonight

 

Runs 9 days ago with the previous 2-2.5" Ghetto B-pipe and 2.5" Hi Pro Flo Max muffler at the same track were -->
15.704@88.45mph (Testing 2"to 3" Coupling Intake)
15.713@88.16mph (2 to 2.5" to 3" Coupling)
15.832@88.95mph (2 to 2.5"longer Pipe to 3")
15.675@88.92mph (Was testing Filter in a Cold air box)
42-44F temps

**Traps speeds are what I really compare to test for power**

Tonight, I did seven runs spread apart. Same intake I used as the 15.832 run above.
52-55F Temps
15.572@88.99mph
15.730@89.02mph
15.570@89.27mph
15.712@88.55mph
15.584@88.96mph
15.619@89.52mph
15.661@90.37mph

Conclusion!
Mph creeped up very slightly but isn't significant.
Lowend/Midrange seems to have picked up because the 1/4 mile time was quicker.

All this to say that you could probably get away with a Midas/Meineke or some similar ghetto crush bent piping and get away with similar performance than a mandrel bent 2" B-pipe. There still are too many variables as just the B-pipe was not the only thing changed out.

Waiting for muffler to arrive for more testing. This is all for now.

 

Man great info gathered again, but wish we saw more like 15.4 or so kinda dissapointing but really good to know, maybe though when you complete the piping in the axle back to a 2" the should get it an even flow, I remember when super street did a dyno on just the axle back it added about 3hp to the wheels up top, and I know on my gd it did the same, wonder if the gk will act the same way.

 

hey Kevin - where did you pick your J's racing midpipe up from and how much did you pay? i can't find it available anywhere. on the J's Japan site, it is listed for 124,200 JPY which converts to 998 USD. im hoping thats not what you paid..

 

I sent you a PM! I don't recall paying that much but I honestly can't remember.

Update!
Correction....this is the piece I purchased --> C304 SUS 50CT

It's 45,000JPY. That's around $361. You are looking at the more expensive version. Scared me...heh.

 

lol, ahhh, my fault. thanks!