Mufflers finally came

downstream of the resonator, you are in 2 1/4. Aaron's y would work, but you probably won't be able to clamp it on.

As far as I know only the DP is double walled. By the diagram it looks like it changed in 98. Mine is a 97, and the exhaust guys showed me the double wall pipe he cut out.

Is there a concern that the y section is double wall or something?

I was concerned the long piece running from res to Y was double-wall. Would make matching up interesting if you wanted to use stock res and pipe back to the Y.

i've decided that I probably should have done more reasearch on this before I ordered these.. but i'm just going to order two of these



then 2.5 inch inlet to 2 inch outlet or so to a 2 inch inlet to a 1 7/8 inch outlet or something.. it's just way too loud straight piped, and I can always pick up the Y when I have more money/time.

oh.. and I went to a local muffler shop to see if they could fab up some reducers for me so I wouldn't have to order them, and the guy said he'd put them on for 150-200 big ones.. then banged on my cat. converter with his fist and told me that it was bad.. so I laughed and took my car elsewhere

If it were my car, I'd spring for the 3" DP and have the muffler shop make me a 3" all the way to the Y. There are few bends so it will be fairly cheap. The DP is maybe 80$.

I would not waste my time on the dual reducers. If you don't want to go 3" right away, install just one of the mufflers while you gather the required money. A single muffler will flow more than 2.25 straight pipe.

not sure about you bro, but i'm yet to come across a mechanic who's willing to do anything for "fairly cheap" that was the only muffler shop around here, and now the guy's telling me 150 to 200 bucks just to do that small of work? just imagine what he'd want for 3 inch piping to a 3 inch Y

I guess I am lucky then

seriously though, if you install the DP yourself and supply the Y, I don't know why it would cost you all that much. Most places are glad to charge you just labour if you pay cash. They probably put it in their pocket, but I don't care.

i could install a dp myself?

I think so.

Isn't the DP welded?
I would think you'd have leakes out the ass if you tried to clamp all that.

that's what I figured. pics/video to come this week.

the riv's DP is welded and not at all like the one pictured. is that from an Aurora or bonny? or is the 96' riv different?

that is the gm parts catalog illustration for the 98 riviera.

can you check your 98' to see if its like the 96's? my cat and DP are welded together, there is no square bolt flange/gasket as pictured #14. plus (and i guess you cant really check this) there is no flat gasket (#22), it is a doughnut style at the top of the DP. i ran into both of these problems when i got my 3" DP put on. but like i said maybe its just a year difference thing.

when mine was up on the lift, coming off the DP there was a square plate on the end of the DP with bolts, so I guess they're not welded together

It looks like there is one on Aaron's picture of the underside of the riviera. Check the FAQ section.

i guess i should have taken some pics of mine b4 the change :/
i never noticed that in the pic, maybe b/c its on the crease but you're right its deffinatly there on the 97+ rivs.

but do aftermarket DP's come with that same bracket?

sorry for steering from the original topic

no the GTP DP that zzp sells is different than your 4 (?) bolt design. you will need to buy the [zzp] off road shorty DP and weld it to the pipe/cat. at least thats the way i understood it, but there may be a DP for another car with the same upper and lower flange as the 97+ riv's.

could be :> I changed my mind about my exhaust.. I should have just done this in the first place.. i'm gonna take it to a local muffler shop and have them cut off the Y, and run either 2 1/4 or 2 1/2 pipe, (just one) 45 degrees, then another 45 degrees back maybe 3 1/2 feet total length and it'll put my muffler closer to the rear.. but i'm only gonna have them weld that pipe on, and i'll buy a 3 inch outlet to 2 1/2 inlet and hang the muffler myself.. shouldn't cost more then 100 bucks for that small of a job..

Hogan performance sells a 3" dp for the bonneville. Read about it at regalgs.org

I read the thread, but did the bonny dp end up being a bolt on fit?

I don't know if anyone tried it. Look under your car to see if you have a four bolt flange before the cat.

yeah it does, on each end