I'm looking at replacing my single stock muffler with duals.

[Toxicadam]

On a Grand Marquis 1999.

What FlowSound Muffler will fit my application?

http://stores.ebay.com/The-Race-Part...34Q2ec0Q2em322 These are flowmaster knockoffs. Flowmaster lost their patent to the 40 series. You can get some awesome deals on aftermarkets.

I'm asking because I don't know if there's a offset I need to look for.

[DriverSideImpact98]

Oh wow good prices on those. That was one things i didnt like about flowmasters, next to the fact that they flow like crap, is that they are like $85/ea. They even have the single chamber on there (I think its the 10 series).

What exactly are you looking to do with your exhaust? That will be a large factor in what fits and what doesnt.

Do you have duals? Do you want duals? Just swapping the stock muffler?

[Toxicadam]

Do you have duals?

No.

Do you want duals?

Yes.

Just swapping the stock muffler?

No.

What exactly are you looking to do with your exhaust?

I want to upgrade for better sound and performance. Not too loud.. Would the 40 series fit these requirements?

Do Grand Marquis 99 have any offsets? Like do the pipe inlet or outlet need to be centered on the muffler?

And for clarification, the stock pipes are 2"?

[SVT98t]

You need a h-pipe for starters. You can either get one from the junkyard or get a new one. I got a new one from Advance Auto for $74. The manufacturer was Walker.

It is 2" stock.

You will need to get 2 pieces of straight 2" pipe. I think they're around 12-18". You need these because the stock mufflers are so long, that when you replace it with aftermarket ones that are usually not as long, you have to make sure they are back far enough so that the over-axle pipes don't rub on the axle or other things.

You will also need a left over-axle non-resonataor pipe. Once again, j-yard or new. My Walker piece was only $27 brand new at Advance Auto. You will need a bracket for that side too. I got mine from a CVPI.

You may need to weld a bracket or hanger to help support the mufflers.

I just did all of this in November.

http://www.grandmarq.net/vb/showthread.php?t=18521&page=3

Hope this helps.

-ryan s.

[Toxicadam]

Thanks man! This helps a lot

[DriverSideImpact98]

Yeah what SVT98 said. As far as the 40 Series. They are pretty loud. probably some of the loudest mufflers you can get. (i think the flowmaster 10 series and SLP LM 2 are the loudest)

[Leafsrule16]

You could try and find a cop car exhaust as well .. I have dual exhaust on my car now, im running the h-pipe, using 2 inch piping. I bought 2.5 inch, offset inlet and centered outlet thrush welded and they have a nice growl to them.

[r2t]

This thread is relevant to my interest in dual exhaust.

Would I be able to replicate the appearance of the dual straight pipes of a Marauder on a GM?

[Merc3517]

Yes. And just some food for thought, the original exhaust systems on these cars were stainless so if you are looking for a direct fit with stock sound a J yard will be a good place to find a whole system with hangers and such. Other wise chances are if you just add a non stock pipe and H pipe to make the duals in a about a few years you will have single exhaust again but with a major leak. This also depends on where you live though.

[SVT98t]

You can buy the tips at www.innovativeinterceptors.com

Thats where i bought the 4" tips for the Marauder. I put the old Marauder tips on my 93. The whole set up sounds great. You can... never mind. I was going to tell you about everything you should get, but i just realized i did that in post #4. Any questions, ask!
You can see some of the pics in my Tank profile using the link in post #4.

Ask away!!

-ryan s.

[r2t]

Nice1 SVT. Yeah I want my GM to look just like this.



Is it me of does that rear bumper cover have a bit of a cut out/taper for the pipes?

[SVT98t]

It does. They all should have that cut out, regardless if it's dual or not. so....
Here's with the stock 3.5" resonators...


And here's with the 4" resonator-deletes (Res-deletes).....



Here's the stock 3.5" ones from my Marauder on my Tank...



Just remember, they are 26" long....


I like the way they look on that Merc in the pic. Hope this helps!!!
And good luck! There's nothing like the rumble that a freer-flowing exhaust creates!!!

-ryan s.