Hey guys,

As some of you know after i installed my Berk HFCs I've been getting a weird rattle sound on acceleration and also a weird hiss sound on decceleration.
So while i was in STL this week I went down to Hi tuned Performance, to see if i could fix that problem.

Matt was really helpful, placed the car on the lift and tried to find the source of the sound, we concluded that it came from the Y pipe where the gasses meet. So we decided to get the magnaflow 11385 X pipe.

We talked about doing a full exhaust from the cats all the way back to the Tanabe mufflers. He said that he didn't need to weld or anything on to the tanabe's can can make an adapter so that it would be like stock. However, it would have taken him all day to do that, and he was pretty booked, and i couldn't stay. So in the end that we did was cut off a bit right before the Y in the Y pipe and at the resonators and installed the Muffler. The X pipe was 2.25 piping but because we were going to be attaching them back to the stock pipes he had to use 2 inch pipes to connect them back.

The part we cut off.



the new X welded in




The welds were really good in my opinion.


Well after all that, still took around 4 hours, the sound on acceleration was gone in it's place was a more throaty exhaust note, but i don't think it was louder, on the trip back there was no drone at all up to 80 mph.

I still have a weird sound when the Revs drop fast though at exactly 2.7-3k rpm as the needle drops you get a sound that sounds like "sweep" instead of the "psHisssshhh" that was before. We but the car back on the lift and tried to find where the noise was coming from. It sounded like it was possibly from most of the mid pipe hahaha. We couldn't pin point where the sound was coming from. It's softer than it was before, not sure where it was coming from. Maybe it was just the sound the engine makes when the revs drop, i mean we need someone to just disconnect the exhaust and try it and listen as the exhausts come straight out of the Cats. But this was already way past closing by then so we left it. You can't hear it while you're driving in D or with the windows up though. Only when you are in manual mode and you sit in a gear and let the revs drop, the faster the rev drops the louder the sound. Easiest and loudest way to hear it is to put it in park and jab the gas to rev past 3 k.

Oh, don't ask me if it made power, i'm sure it most likely did, but not sure my how much. I hope this helps people, or someone can help me fix this noise! Lol.

 

Looks good. Do you care to throw out a ballpark cost on this? I am curious how the cost of this and the Tanabe's compares to a full exhaust.

 

Looks great, Clement... Nice quality work... I'm curious to hear what it sounds like... please post some sound clips when you get a chance.

 

Get work csquared I was thinking of doing this in April on my Vacation.. Vid would be nice.. I'll take you word on how it looks I can't see the pics??

 

Looks good. I added the x pipe to my borla.

Question. Did you peer inside and actually verify that this unit had the X pipe inside?

 

Thanks guys, yep, I did it looks like the pipes were crossing inside, all i can say is at least i could see through it the Y on the Stock you stick it up the the sun and almost no sunlight lol.

 

Nice welding. The guy did a good job. I'm jealous.

 

Thanks guys, I have a question though is it bad the the pipes go from 2" to 2.25 to 2 back to 2.25 for like a really short bit then back to 2" again?>

 

Short answer, just a little bit in your case, but it's easy to understand why your shop did it the way it did. You have to consider what you had before which was a nasty choked down Y pipe which had lots of restriction so I think that even with the sudden size changes you are better off now than before.

In general, the transition "profile" also makes as much a difference as the diameter and typically in exhaust systems the transitions are made by simply welding different sized pipe together or at a flange. Either instance, the diameter change happens suddenly with a sharp edge which causes flow restriction. Gradual and smooth diameter changes work best (take a look at good quality exhaust collectors). The diameter change probably won't hurt you much since 90% of the stock exhaust is still 2" anyway. You could improve the flow by using gradual and smooth diameter changes but probably more hassle and expense than it's worth. They would have had to special order those transitions or try to expand the 2" to 2.25" which I am not sure is possible.

 

Thanks for clearing that up, so you dont' think i need to save up and just redo the whole thing? like the front with 2.25 or anything? That just like this if fine right?

I mean this is just like 2 - 2.25 - 2 lol in like 5 inches


Also right now i think my exhaust is like a frankin Fish or something it's SS and Aluminium and whatever stock is as well lol.

 

You could probably have found a Magnaflow X in a 2" but don't worry about it. If you ever upgrade your exhaust, you can go to 2.25" pipe and retain that X.

I'm glad that unit is a X. I kept hearing it was but Magnaflow's site didn't say it was. I just couldn't pull the trigger so I got the 14385 2.25" unit instead. Their site states it's an X and I got a drawing from magnaflow verifing it was. Just for your reference, here it is. (so you compare this to what you observed with your unit)

 

I guess but I figured 2.25 prob flows better I wanted to do the whole pipe 2.25 but time was a problem. yeah it was similar I 11385 and 14385 is the same thing it's just the 14385 is polished and 11385 is not. Well that was what i heard.

 

My opinion is that redoing just this magnaflow diameter mismatch can move to the very bottom of your to do list. However, if you are thinking of redoing the entire thing like a cat-back system then that might actually make some additional power, but if that was the case then why didn't you just get the cat-back from the beginning.

I believe that our OEM exhaust pipe is all stainless.

 

Well i wanted to but time was a problem I drove 6 hours down to the shop, lol. Yeah I guess it's the last to do thing, I don't think i'll get much more sound out of it anyways.

are you sure it's all stainless it looks like there are different colors on the pipes, there is some dark brown kind then bright silver hahaha. No idea.

 

The magnaflow is 304. Not sure about the oem. But it's welded up so why care? lol.

When I was doing mine, I was looking around for a 2.25" used Y pipe that someone was going to sell cheap. I was going to have the shop cut that one up to fit it to the X pipe. But I had the shop hack my Borla dual Y for the job. Don't worry about it now.