B&B vs Custom midpipe
 

I want to get my cat replaced and i was thinking of getting a custom midpipe done for my car. The shop told me $150 to do it. A B&B pipe cost $240(?) so im saving a lot of money. Anyone know the disadvantages of this or if there is any?

What type of piping are they making it out of?

Im assuming that you are removing the cat from the system completely?

I'm opening up and crushing the stock cat with a 40,000 lb press and welding it back together =)

ROFL :D

Yes, you are saving money, but what are you going to do about the O2 sensor? Also, you'll need some good earplugs - it's going to be loud as hell without any resonators in the pipe.

Here is the link to some sound clips of the Rotary Performance (Bonez) midpipe, and it even has a resonator in it!

http://rx7.com/RPGReddyRX8exhaust/soundmovieclips.html

I guess the piping thats they originally use when making custom pipes. I think i need 2.5 inch diameter if im not mistaken ?

I'm serious

just go with a 4 inch..you'll be fine..haha

150 bucks is pretty damn cheap. Just be sure you get it made out of stainless. I looked into getting a custom one but I couldnt find anyone that would do it for under around 350 stainless with a resonator. Also, the triangular spring loaded flange on the front of the pipe was tough for shops to match up. B&B was pretty cheap and it comes stainless with a resonator so I went with that. The only thing with B&B is I had some trouble installing it and ended up having to dremel out the rear flange slightly.

Other than that, its just a damn pipe so you can't really go wrong and blow up your car by getting a cheap one.

StealthTL suggested for me just to beat the cat and use it as a midpipe. If someone showed me some pics if they did the same would be great, cuz then this mod would be free!

I wouldn't hoolw out the cat when it would be so much easier to just replace it with a pipe. You can buy the front flange from Racing Beat. Just make one long midpipe that attaches to the exhaust manifold and the other end as a slip fit at the muffler. This would be very easy and cheap to do. You can use a resonator if you want to. The cars I've heard without them sounded very raspy.

Slip on in the back sounds good, but i think ill get both flanges done. How much would a decent resonator cost? If it even matters, and would it effect performance ?

I'm going to hollow the cat and when smog time comes get a random high flow. I'm bored. and it's cheap =)

I made my custom mid pipe using the stock pipe and replacing everything between the flanges with 3" stainless pipe and it only costed about $80. It sounds very loud and raspy at times. On the other hand I can actually feel the power gain in the back tires. Plus it shoots flames alot.

Any CEL ?

there for a while it would go on and off. Now it's just off and I hope it stays that way. For some reason everything I put on this car produces a CEL but goes away after a little while. Kinda like it adapts or something.

Jamie

I really don't like B&B. I got a downpipe of theirs for my STi and it was nice. Bolted it up and noticed that the rear flange wasn't lining up with either my JIC cat back or the stock cat back. So I call up B&B to do a trade on a defective part. They instantly critisize me saying that it was installed wrong, that it was only designed to fit the B&B cat back, etc. Their site says that the DP fits any cat back. They then told me to pretty much "go fu*k off". I called up the vendor who sponsors me and B&B gave them sh*t too. Luckily the vendor was nice enough to trade dp's with me for no charge. Find a different co. for your test pipe and let B&B eat sh*t.

Nick

For those considering messing with their stock cats...
 

If you're considering hollowing out your stock cat, consider this... That part is $1400. I had mine replaced under warranty and, since I work for the dealer, I found out that it would've cost me $1400 for the part alone. You may want to think twice about destroying a part that expensive to avoid spending $200 or something on a midpipe.

There is no point to hoolowing out a stock cat when a straight pipe does the same thing and can be made for very little money and time. You would probably still get a CEL with a hollowed out cat just like a straight pipe and also the now hollow cat doesn't work as a muffling device. You just made a really expensive straight pipe. Take the thing off the car and replace it. Do it the easy way.

what about the back presure? i see some resonators have these gills inside that sticks out alot, some resonators look like an inside of an apexi muffler ( no gills sticking out ) which is better rotarygod?

Gills

http://i2.ebayimg.com/02/i/03/7e/2b/8d_1_b.JPG


No Gills

http://images.andale.com/f2/111/109/..._UV_CAT3_4.gif

?

The one in the top picture is called a louvered core. These are worse for flow in most cases than many stock mufflers yet many people still use them. If you must use them, you can get better flow by running them backwards so that the air bounces off of the louvers rather than gets grabbed by it. This will obviously be louder. These don't quiet very well anyways. The effective pipe size through them is only the area between the louvers. They are crap. Stay away from them. Leave them to the ricers.

The bottom picture is a perforated core. This is what should be used. They flow much better and do at least an equal job of silencing if not better compared to the louvered cores. The larger they are, the more they muffle.

i notice that the BB Mid Pipe doesnt have a resonator. is that the reason why my friends RX8 is flamin? and so much louder? if i used the bottom Rez it will sound the same as a straight pipe?

i notice that the BB Mid Pipe doesnt have a resonator. is that the reason why my friends RX8 is flamin? and so much louder? if i used the bottom Rez it will sound the same as a straight pipe?

http://store1.yimg.com/I/hopup1_1832_3698201