We have recently been looking to replace the terrible exhaust that is on the TGP. We discovered the mufflers we had purchased have no chance of fitting so we have to figure out what mufflers to get. I want something that is quite but flows relatively well, this engine is far from stock and its pretty damn loud so I don't need that for a daily street car. The next thing the place we took it to said they wouldn't be able to get very big of pipe after the "Y" and if they did it would be very restricted. They said 2" max and maybe not even that. They also said from where the downpipe attaches to the cat there is that weird "S" shaped bend has that ever been a problem for anyone that has done the exhaust on their car?
So yeah, we are going to take it to another place and see what they said. Anyone have any specifics on what mufflers from different companies will actually fit considering GM's intelligent idea to make both mufflers different sizes, and what size pipe after the "Y" is the best or easiest to fit..
Do you have any pictures of the "s" bend in the exhaust Brian? My car came w/ a modified exhaust system and I don't recall ever seeing an "S" shape anywhere on it. Also, I'm not sure why they say they can only do around a 2'' bend for the y-pipe as I have 2.5'' on two of my 1st Gen GP's(my '90 TGP and 93 SE) w/ no problems. I suppose their bender can only accept piping that is right around that size? I'd definitely shop around and find someone better equipped if these guys are saying it would be a lot of trouble to do it the right way.
As far as mufflers go, I believe magnaflow makes some nice flowing mufflers that will easily fit in the stock location. I think most GP guys use the "4x9" or "5x8" mufflers(something like that). The site I'm posting a link to has dimensions of the magnaflow mufflers as well as some prices to give you an idea of what they run(they can probably be found cheaper elsewhere). I would also look into something like Dynomax Ultraflows, they're supposed to be fairly quiet and they outflow pretty much everything else out there according to their test results on flow rates.
http://shop.ivalueinternet.com/bigexhaust/index.cfm/action/shop_by_subcat/category_id/95.htm
BTW, the setup on my TGP consists of 2.5'' piping, a "high flow" cat(I believe it's a carsound/magnaflow cat..looks like those anyways) and a universal resonator. It does not have any mufflers on it at all and it's really surprisingly quiet. The only time it's really that audible is at idle(has a really deep idle, it's not "loud" though). When cruising or even giving the car full throttle, all you hear from the exhaust is a slight burble inside and outside the car. I listened to it outside once when I let him do a little 30-100mph romp on the car and the exhaust was whisper quiet outside(upon stomping the gas), only the turbo + motor sound was audible.
EDIT: I'll try to get a short video/exhaust clip of my car to post here this weekend if I can get my friend to bring his camcorder over.
EDIT again: The resonator on my car looks like the ones in this auction.
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&tc=photo&rd=1&item=7965888527&category=33630&sspagename=WDVW
I don't think that the inside/core looks like those though(I think that inside pic is actually from one of those "chambered ehxuaust mufflers/resonators" instead of the bullet shaped ones like those.
Yeah, I would stay clear of that shop. It sounds like they don't know what they are talking about. I have the Ultra Flo's on my car and they sound great. A bit louder then stock but still very quiet. On these cars the turbo buffers the exhaust tone considerably. That is why so many people are running straight pipe and are happy with it.
http://pictures.sprintpcs.com/i/87856894469_3300_1.jpg?ext=.jpg&border=2,255,255,255,1,0,0,0,0&outquality=90//
Here is a picture of the stock CAT for the TGP and you can clearly see the "S" bends. I just cut it off and put a strait pipe and high flow dynatech cat on it. Now my TGP sound extremely well with the stock exhaust at any RPM. :twisted:
I've got Flowmaster 40's and a highflow cat with 2.5" pipe the whole way. The part right in front of the cat the shop bent up that tapers up to the 2.5" I believe.... The mufflers sound good and throaty at low rpms but quiet out at driving speeds... just what I wanted. and they flow pretty well too :)