Odd cat-back question

[SallySpeed3]

Ok so I have the mod bug again. I want to get a pro-tune but I also want to make sure I'm done with everything else first. Which leads me to CNT's cat-back. It's only $310 bucks. Even if it doesn't give me any gains (which I think it will give me some) it's a great buy. But I cannot stand the way the tip comes out on an angle. If I were to take it to a shop is it plausible that they would be able to bend the pipes a bit to make the tip come out straight? if so how much do you think they'd charge? let me know what you think.

 

[ras]

It's possible to do this if it will fit on the bender and the other bends on the pipe are not in the way. It should not be much, a reptuable shop may do it for free.
Go talk to a couple of them, would be my advice.

 

[MSMS3]

Do not expect any gains from an aftermarket CBE on the MS3 unless you are modding to a flow rate greater than 300 whp, which is close to impossible without going big turbo. The stock CBE flows that well. Spend the CBE money on the one power mod I do not see in your sig that needs to be added to make you fully bolted before you go with the protune: A catless or catted downpipe. You already have the test pipe, but you've only addressed about 1/3 of the restriction. It's all upstream of the CBE and 2/3's of it are in the stock DP and its low flow cat. Fix that, then you are good as gold for the protune.

 

[Domino81]

Will a catted DP make the car as loud as non-catted one will? I ran into a guy here that had non-catted DP & RP with a STOCK exhaust and was as loud as aftermarket exhaust. I'm not trying to wake up the neighbors. Nor do I want that much extra attention. It'd defeat the purpose of me buying this car in the first place.

 

[blackdragon0731]

I'm running catless and an hks hi-power CBE and it gets pretty loud, loud enough to hear down the street but not loud enough to be ridiculously obnoxious. Even a high-flow cat will quiet the exhaust over a catless DP, i know that because i wanted the cobb piece due to quality and sound being a big priority but getting into an accident took $850 away from me and i had to settle for the catless ATP dp in order to get my tune as scheduled. *sigh* bottom line, catted will be quieter, idk how much though, but with the stock CBE you should be pretty well off with sound, should sound badass without being too loud.

btw, thats the exact question i had about my hks, it comes out at that angle not bent to come out straight and i might take it to a shop to get a quote sometime soon because i love the way it looks but the angle kinda bothers me too

 

[SallySpeed3]

Do not expect any gains from an aftermarket CBE on the MS3 unless you are modding to a flow rate greater than 300 whp, which is close to impossible without going big turbo. The stock CBE flows that well. Spend the CBE money on the one power mod I do not see in your sig that needs to be added to make you fully bolted before you go with the protune: A catless or catted downpipe. You already have the test pipe, but you've only addressed about 1/3 of the restriction. It's all upstream of the CBE and 2/3's of it are in the stock DP and its low flow cat. Fix that, then you are good as gold for the protune.

I completely agree with you. I'm just scared crapless of getting a downpipe. Wasn't really something I wanted to mess around with. I already have smoking, which I've taken care of with upping the idle rpms but I'm just worried that if I put on a downpipe that I'll cause even more problems. What do you think? I would love the power but there are also risks.

 

[MSMS3]

Every car seems different on the smoking issue. I'm over 45,000 miles now with no smoke. I use synthetic oil only at 5W30 weight, change it every 3K miles, and have had no problems with smoke. My downpipe has caused no problems other than that there were some very quick transient spikes in the 21 psi range when first coming up on boost. They instantaneously fell to target levels. My HT tune eliminated the spikes, so surely a good AP protune would take care of that. I do not have boost creep.

The one thing I did which may have given me a little protection against creep, and which also addresses a couple other concerns raised in this thread about noise, was to put a big 3 inch straight through reso welded into the middle of the race pipe section. That killed the big drone issue I was having at 2,500 rpm when decelerating and may have added just a tiny amount of restriction to keep me from getting any creep, which can happen as a result of flowing so much that the wastegate maxes out.

I can't answer how a downpipe would work on your car. I can say that it is a huge benefit on mine. Not only does it make nice power, but the power is all across the power band. If you are concerned about emissions, then by all means go catted. We don't test in my state, so I saved some money and increased flow a bit by eliminating both cats.

The biggest issue for you will be the install if you try to do it yourself. Those turbo studs are very hard to get to and there is risk of stripping one of them or stripping out the O2 sensors getting them out of the downpipe. Gotta take your time and use plenty of solvent like PB Blaster and let those mothers soak, soak, soak, and go slow, slow, slow. After reading some of the horror stories of failed install efforts, I farmed out that install to a local race car oriented performance exhaust shop, even though I have a lift and every hand and pneumatic tool you could imagine. Those guys do this all day, every day and I felt more confident turning it over to them. We have a business relationship with them, so I was in their shop observing their work. I was glad to have them doing it.

But replacing the stock dp is a significant benefit on this car at your mod level.

 

[SallySpeed3]

Hey guys, installed a magnaflow cat back last night. I think I might need to do some readjusting of the tailpipe cause I'm getting a rattling sound at idle sometimes, probably hitting part of the frame, but anyway, Question: Took it for its first drive and I noticed a weird smell when I pulled it into the garage. Kind of smells like burning, not quite as potent as a burnt clutch smell but pretty noticeable. Is it just cause of the new pipes getting hot?

 

[Ogcoda]

I had a the same thing happen to me when I put an exhaust on my duramax awhile back. Turned out it was just that the pipes were just getting hot for the first time and burning off some left over residue. Hope you get everything worked out.