started that exhaust today
07-20-2016, 11:25 PM
#41
So if you wanna say I told you so, nows the chance. So the weird sound that the dynomax mufflers were creating, turns out to be a broken baffle in the passenger side one. I contacted rockauto, they are going to refund them both at roughly 75 bucks a piece. Decided to pickup two cherry bomb vortex mufflers 88101 on ebay from pepboys for 60 bucks for two. Over half the price of the dynomax direct fits. These are straight 2 1/4 in out instead of the weird 2 1/4 in and 2.5 out like the dynomax were, pretty sure they pulled some universals off the shelf and they were backwards.
Anyhow, these cherry bombs are muuuuuuuch much more well made over the dynomax, they weigh 15 POUNDS EACH! They are stuff to the brim with packing on the sides, and the case is very very thick, dont forsee these going bad for a good long while.
Anyhow, these cherry bombs are muuuuuuuch much more well made over the dynomax, they weigh 15 POUNDS EACH! They are stuff to the brim with packing on the sides, and the case is very very thick, dont forsee these going bad for a good long while.
07-21-2016, 09:18 PM
#44
Well the reason I always chose the super turbo over traditional turbo styles is because they are a little better at flowing over the traditional style with the patented flow director they advertise. However, on other cars they have always sounded good, they sounded like **** on the grand prix. I tried to get used to it, and just couldnt get used to it sounding like a v6 all the time. I still have to get the cat put on because the shop refused to install it, told me i would have to remove the headers first. They said it wouldnt be in the factory location which is bullshit but i didnt argue with the guy. Wasnt gonna force him to do something he wasnt comfortable with. Ill have to take some pics of the muffler work, kid who did the work was from the mid west, used to work at an LS performance shop, so he knew all about the car from the get go, and he did great work on the install. Couldnt have asked for a better job.
07-21-2016, 09:58 PM
#45
My whole exhaust is band clamped. In 3 pieces. They seal very well and no welding required and when I want to go ***** out I can drop it in 5minutes. Might be worth looking into. If your into that. I understand wanting the cat welded in though.
Remember most commercial auto shops won't touch something without a cat. Due to federal law and tampering with emissions. Find a mom and pop exhaust type of place and have em do it.
Remember most commercial auto shops won't touch something without a cat. Due to federal law and tampering with emissions. Find a mom and pop exhaust type of place and have em do it.
07-26-2016, 10:23 PM
#50
couple pictures of the full setup, ill be installing that wideband this weekend in the rear o2 bung (and before you get started about post cat AFR readings http://www.dtec.net.au/Lambda%20Test...0Converter.htm) cherry bombs sound real good with the cat now, but still ungodly ****** loud, its probably gonna wind up going back to OEM mufflers because I just cant ****** stand DD'ing this car with a loud exhaust. Regardless of horsepower or whatever else anyone wants to complain about, i have to be able to drive this thing year round without migraines. So im just gonna chop them off with the tips and whoever wants them can buy them.
07-27-2016, 12:34 AM
#53
If your gonna start with the size thing again, I wanna stop you right there. Forget my car for a minute. Show me an instance where someone has gained a ridiculous amount of power from a "cat-back" system on a NA car. I don't care what kinda car you compare it to, just show it to me. You seem to be under the impression that my reason that I am missing about 100hp compared to what the rest of you are producing is directly related to the exhaust system, yet there is not a single shred of evidence to show that there is any more then 10hp to be gained from going from a stock catback to a 3" system. Hell ill even quote overkill himself...
The common counter argument is this: A 2.5" exhaust supports XXX Horsepower. I hate this argument. I guess if you took a 600 horsepower engine that was running a 3" exhaust, then stuck a 2.5" exhaust on it and it made 565 horsepower, you could say that the 2.5" exhaust supports 565 horsepower, but why the hell would you give up horsepower over a simple exhaust system swap? The real question is how much is gained swapping to a 3" system. My answer to that at the moment is I don't have a solid figure to give you, the proper way to test would be to take a car with a 3" downpipe or header pipe, 3" cat, that has a 2.5" cat-back currently, dyno it, swap to 3" from the cat back, with identical rear mufflers, and re dyno. I haven't done that yet, noone to my knowledge has, but I've driven enough LS4s as part of my job to know there's a difference. With headers, I'm confident that the 3" gains would be around 10 wheel horsepower on a dyno.
And frankly i gotta tell you, making this car uncomfortable to drive every day, for the sake of adding 10, maybe even 15 at best, horsepower isnt worth the time, effort or even care for that matter to me. I havent found a single instance where someone has PROVEN that there are significant power numbers to be gained no matter how you slice this situation and I welcome evidence proving the contrary.
The common counter argument is this: A 2.5" exhaust supports XXX Horsepower. I hate this argument. I guess if you took a 600 horsepower engine that was running a 3" exhaust, then stuck a 2.5" exhaust on it and it made 565 horsepower, you could say that the 2.5" exhaust supports 565 horsepower, but why the hell would you give up horsepower over a simple exhaust system swap? The real question is how much is gained swapping to a 3" system. My answer to that at the moment is I don't have a solid figure to give you, the proper way to test would be to take a car with a 3" downpipe or header pipe, 3" cat, that has a 2.5" cat-back currently, dyno it, swap to 3" from the cat back, with identical rear mufflers, and re dyno. I haven't done that yet, noone to my knowledge has, but I've driven enough LS4s as part of my job to know there's a difference. With headers, I'm confident that the 3" gains would be around 10 wheel horsepower on a dyno.
And frankly i gotta tell you, making this car uncomfortable to drive every day, for the sake of adding 10, maybe even 15 at best, horsepower isnt worth the time, effort or even care for that matter to me. I havent found a single instance where someone has PROVEN that there are significant power numbers to be gained no matter how you slice this situation and I welcome evidence proving the contrary.
07-27-2016, 01:02 AM
#54
Chill, Rob so let's use this as a example, you seen trucks before with tiny 2inch pipes that are obnoxiously high pitched? Then have you heard for example a truck with a nice 3 inch system that just has a deep tone to it? .....all I'm saying perhaps the unintended effect of your choice of a smaller diameter and heavier breathing motor is a higher pitched frequency which maybe why you feel it's so much louder than it should be.
The other point is your choice of putting your wide band post cat. If your going to use a wideband for accurate tuning it should be pre cat as stated by the article...
The other point is your choice of putting your wide band post cat. If your going to use a wideband for accurate tuning it should be pre cat as stated by the article...
07-27-2016, 06:42 AM
#55
The problem i am having isnt related to high frequency sound, its exactly the opposite. The sound is so deep and so low frequency that you cant even hear it in the camera because it wont pick it up. Im talking low frequency window rattling rumble. And its LOUD too. So much so that the shop couldnt believe how deep the sound was. He started the car and all the windows in the shop started rattling. Like i said, it sounds good but the rumble is so much that it vibrates the car to death and everything around it.
As far as the sensor goes, not sure how to respond to that. You read the article and the difference between pre cat and post cat was negligible. And i knew that fact going into it because i asked the dyno shop i plan to go to if they ever had issues tuning with their tailpipe afr sensor on catted vehicles and the answer was no. Even more so with the high flow cats.
As far as the sensor goes, not sure how to respond to that. You read the article and the difference between pre cat and post cat was negligible. And i knew that fact going into it because i asked the dyno shop i plan to go to if they ever had issues tuning with their tailpipe afr sensor on catted vehicles and the answer was no. Even more so with the high flow cats.
07-27-2016, 07:42 AM
#56
Daily drivers have to be right, or its obnoxious. For modification sake the small mods I have made so far all took away from the refinement of the car. The factory exhaust sounds great in my opinion, but I will be going loud when I do mine because it wont be driven daily . These cars are finicky anyway, and were most likely not intended to be modified as witnessed by the lack of aftermarket support. Its a wonder there are so many great modified cars on this LS4 section, its a testament to the owners ingenuity really.Everyone has different tastes, and some are perfectionists. I always say if it isn't right it isn't worth doing , thats just my 2 cents.