cbe, dp, up sound questions

I have a 07LGT and I have a question about how the exhaust notes sound in conjunction with different modifications. I ordered a borla cbe as a starting mod for my car because i really liked the sound in addition to the possible slight increase in performance. eventually, i would like to get to the point where I can install an uppipe and/or catted dp with a tune for a more noticable performance gain. My only problem is that i dont really want to lose the sleeper image that the legacy gives off. So does adding an uppipe and/or downpipe in addition to a cbe really make the car sound annoyingly loud? and if so, is chopping and welding in a 3rd muffler really the only way to fix this?

There's really no reason to swap out your UP. 07 and up LGT's have catless UP's from the factory. Once you swap out the DP, your car will get louder. Not sure how much louder with the borla system, but you'll definately notice a change in sound.

thanks, i wasn't aware that the 07 and up had catless uppipes. all of the forums i had read made a strong argument for upgrading the uppipe solely based on the possibility of the cat failing and causing serious damage to the turbo.

I didn't hear any noticeable difference with the addition of my cobb dp. You should be fine, and I would NOT put a 3rd muffler on the car, that sounds a bit crazy!

I run a full aftermarket exhaust system and the sound level of the car is very tolerable. Grimmspeed -> Cobb -> Bosal. Pretty quiet until you get on it.

If you wanted sleeper but with a moderate increase in power, you went about things the wrong way. You shouldn't have touched the CBE at all. You should have just swapped in a catted DP and left the stock CBE.

 

The combination of an aftermarket CBE and a DP makes a noticeable increase in noise. Liveable/tolerable, absolutely, but also definitely noticeable.

 

I'm not sure how loud it'll be though since you got a Borla exhaust. According to my research, Borla's exhaust is a 2.5" exhaust, not 3".

http://legacygt.com/forums/showthread.php/which-cbes-mate-up-invidia-dp-perfectlyi-115489.html?t=115489&highlight=mate

Thanks everyone for the inputs. (Rock 2534: are you running a Cobb catted dp->Borla cbe? If so how did you go about mating the two together?) I admittedly messed up in getting the cbe first because I didn't do enough research prior to planning a modification path for the leggy. but, it is too late to cry about that now and i was just trying to figure out a way to accomplish a noticeable hp/torque increase without ricing out the car or putting too much stress on the engine since it is going to be my daily driver for quite some time.... hopefully. That being said I am glad to hear that a performance catted dp->performance cbe apparently doesn't sound that much like a cheap tin can exhaust if quality parts are used.

If you haven't thrown away your stock CBE yet, hang onto it. Your next step is to put a catted DP in and get a stage 2 tune of some sort. Personally, I think you'll be able to deal with the noise okay. If not, throw the stock CBE back on. I have an SPT v2 full 3" with a catted DP. The car was definitely louder than I would've liked and droned at highway speeds so I had to have a 5" round Magnaflow muffler welded on to reduce/eliminate the droning.

 

But...your Borla is not the SPT, and it should be a smaller diameter too, thus quieter.

If you haven't thrown away your stock CBE yet, hang onto it. Your next step is to put a catted DP in and get a stage 2 tune of some sort. Personally, I think you'll be able to deal with the noise okay. If not, throw the stock CBE back on. I have an SPT v2 full 3" with a catted DP. The car was definitely louder than I would've liked and droned at highway speeds so I had to have a 5" round Magnaflow muffler welded on to reduce/eliminate the droning.

 

That's exactly what I plan on doing to my SPT until my power needs require a less restrictive CBE.

@ cwindle07... cobb catted dp fits directly w borla cbe, no adapters needed.

 

DP and Borla CBE is not loud @ all. I run a Cobb Catted DP w Borla, idle has a pronounced but refined boxer sound, take off a little louder, no drone on the highway, get on it and sure it wakes up, looks stock unless you look at the tips. Excellent sleeper look/sound choice!

 

Matter of fact, I would like it little louder so my question to you exhaust experts, if I get a custom 3 inch resonated mid pipe only, will that increase sound? I would mate it to the cobb dp and keep the Borla y and mufflers. As indicated above, Borla is a 2.5 cbe system. Ideally would like to get a Cobb cbe but $$$$