Exhaust Restriction

[iiiwildfireiii]

Well, I've searched and searched and, granted, I've probably just missed it, but its past 1 am and I'm beat, so here goes. The worst that can happen is that I get reamed and shown several posts where my answer is at. Like THAT's not happened before.

As it turns out, when I had Midas build me a cat-back, they didn't make a true cat-back. They cut an inch or so after the 2nd o2 sensor, leaving about 6 or 7 inches of 2 inch piping after my cat. Now, I've got a new purty 2 1/2 in. downpipe sitting here ready to be installed tomorrow and it eliminates the cat. Cool? My question is, will leaving that 6 inches or so of stock piping be a huge restriction in my system or does the gains warrent me having to clean up after Midas? I'm an AT so every bit of power is badly needed. On a side note: Power Pages @ Import Tuner dynoed a DP without a cat at around a 27-ish horsepower gain. Nice eh?

 

[billdo_83]

If you are going with a 2.5" setup I would have them replace the little section of 2". It shouldnt cost too much for a muffler shop to put in another section or better yet, have them cut off one of the flanges and weld in a peice of pipe inbetween the 2 sections so there is only one flange in your exhaust.

 

[esi-slowboy]

Ya get that evened out or else it will be a crazy bottleneck on your exhaust sys.

 

[evolvingGS-t]

Sure it's a restriction. It's like putting a kink in a hose.

 

[iiiwildfireiii]

Yeah, I've got some pics to show you guys, just for the heck of it. We ran into some major problems today. Problems that an impact hammer and an air saw couldn't repair (not for lack of 'entheuastic' trying WTF ) and I have to take it tomorrow to a shop to get fixed. the flange on the DP doesn't mate up exactly right to the o2 housing...and well...like my gf said, "if the holes dun line up..dun force it stupid." Yeah, we didn't listen. Not only that...but it was raining on and off too. *Sigh* Anyway, pics in my next post. Just have to go out and get them.

 

[iiiwildfireiii]

ah, here we go.

 

[dsm4life]

no no no .... like told before, your exhaust will flow as god as your smallest piping. So you just paid for a mod stock exhauts bad call. Get it fixed. Just my 02

 

[25psi]

Looks like they did it to keep the stock rear o2 sensor bung.

 

[iiiwildfireiii]

Yeah, that's exactly why they did it. Midas is big on following emission specs. I just want the dang thing out. On a side note, my car is now at the machine shop getting a new stud because, as my uncle said, "we buggered it up good." Now, I have to pay upwards of $50 an hour for a mechanic just to mount my downpipe flush with the o2 housing and get it tightened up. *gah!* The price I pay for getting in a hurry. Lesson learned.

 

[Snail Tuning]

my buddy had a civic turbo, and it wouldn;t boost over 6lbs with a 1.75" outer diameter pipe installed. we figured that the small pipe limited the hp to 145 or less. it would glow red hot when driving around and hitting boost for extended periods of time.

so that 2" section could limmit you to 200 or less whp. so id get it taken out soon. Anything that will restrict the flow will creat turbulance, and heat, causeing the air to hang up, and keep you from full boost and your fullest power potential.

to mitas for there jerry riging, but they do have to cover there asses.

good luck with the project.

 

[iiiwildfireiii]

You know, I never considered the heating aspect of the restriction, but I figured that simply removing the cat had to make SOME fair gains for me. At least until I can get that rusty eyesore out of there. Seems like I've gone about the entire thing backwards. I mean, getting a catback that isn't a true catback. Then trying to replace the downpipe. THEN having to go back and somehow get ANOTHER restriction out of there. Lets see...$410 for the midas job. $219 for the downpipe. And then whatever it costs to get that last bottleneck out. For that price I could have just gotten a nice turbo-back apexi. Live and learn.

As for the midas situation...don't get me wrong. They do good work, and you'll pay an arm and a leg for it, but they don't have to be so...uptight. On the other hand, I went back and asked for a 2 foot section of pipe to fix the stock section, and they liked my car so much, he gave me the piping for free! All I have to do is find someone to weld it. .

And for my 2" section limiting boost...well, before the downpipe I was hitting a constant 15 psi, so I'm not too worried about that. If anything I need to go ahead and get a boost controller to limit what boost I hit, incase having such a highflow exhaust causes me to start creeping or spiking. Any comments about the dual stage dejontool MBC?

 

[Snail Tuning]

to midas hooking you up with the pipe.

hopefully you get everything worked out good.

p.s. for the price you paid you should have looked around for a used turbo back.

i found my apexi N1 turbo back for $200 a steal of a deal!!!!!!