topdownTA

Hey everybody,
I've been researching exhaust setups for several weeks. What I am hoping to go with is a true dual 3" setup using Magnaflow 4x9s dumped before the axle (similar to BAIN's old setup, view pics of this on his cardomain site here http://www.cardomain.com/ride/360927/5)

There is plenty of information available on these setups, but little available about the type of floor pan modifications under the rear seats required to fit these mufflers and still have an acceptable amount of ground clearance. I continually find that people are having to beat the floor pans with a BFH to gain clearance. I really am not interested in taking a BFH to the underside of my car, I'm hoping for a little "cleaner" solution to this problem. I would like to "box" the floor pans beneath the rear seats with sheet metal to gain additional clearance to run these mufflers. I also want to keep my rear seats in place. I created this thread to hopefully identify some members who have done this, or may possibly know someone who has done this. Pics of anyone who has done this would be outstanding! I appreciate everyone's input on this.

I plan on doing this setup right the first time, so that I don't continually wind up changing exhaust setups in the future. I'm not afraid to be a pioneer, but if anyone has already been down this road before I can certainly use the suggestions. Please don't suggest that I go with the TSP true duals w/ bullets, as these setups are TOO DARN LOUD for me! Thanks in advance for everyone's input!

Xtnct00WS6

iTrader: (8)

If you do want to modify the floor pan, I think it's a good idea to do it right the first time. One thing to keep in mind is that true dual systems dumpted at the axel are LOUD. That's a very general statement, I know. But even with decent mufflers and cats, it'll be loud b/c the exhaust exit is closer to you than normal and the mufflers are closer to the front of the car making them less effective. The farther away you have the mufflers the more effective they are at canceling out the sound and the better it is for performance.

My suggestion would be to bring it all the way out back, esp with a T/A bumper. I currently have a medium size cam, cats, long tubes, x pipe, and Edelbrock SDT mufflers dumpted at the axel and it's too loud. I'm going to bring it all the way back to quiet it down a little. Hope this helps.

95 Z28

iTrader: (21)

I'm not sure if this helps you whatsoever but I had 3" duals with Magnaflow 4x9s dumped on my car which was lowered on a Pro-Kit. I just tucked them up close to the floor. The outlet of the mufflers was pretty much directly under the rear seat belt holes. My clearance was much better than you would think, I rarely scraped. Just figured I'd mention that before you go beating up your floorpan.

topdownTA

Excellent! I had been waiting on someone to tell me that I didn't have to go through all this. Do you have any pics you can post up that would show your setup, and ground clearance. Thanks!

topdownTA

How do you like the Edelbrock SDTs (besides that they're too loud)? This muffler is similar in size to the Magnaflow 4x9s, and I wouldn't be opposed to going with them either. Pics? Ground clearance?

teke184

iTrader: (5)

i didn't do any floor mods to get my 4x9s to hang well.

the mufflers really don't hang much lower than the front part of the duals.

the drivers side muffler hangs a bit lower, but that was a fabrication error...had to weld the system up pre-maturely due to an impending hurricane (wilma in 2005).

BigKap94z

iTrader: (47)

I like your setup. Any more pics or sound clips? I'm running a H pipe setup, because it was easier for me to fab up but I am at a standstill for my mufflers. Currently the 3 stuck in my head are Hooker AeroChambers, Magnaflow, and Dyno-Max ultraflows.

Xtnct00WS6

iTrader: (8)

The mufflers themselfes aren't too loud. They sound great. LS1sounds.com has a few great sound clips of the mufflers. It's on an exhaust system almost exactly like mine. Once I bring the exhaust all the way out back, it'll be perfect. The clearance is great. If you look at the demisions (height espicially) of the Edelbrock SDT muffler, it's the best you can find for a 3in inlet and 3in outlet muffler that's not a bullet. I did put a heat shield on the fuel lines and fuel filter though. I'll try and get pics soon.

By the way, the picture on jegs and summit of the Edelbrock mufflers is pretty decievingly restrictive. It show's a cutaway of the inside, but leads you to believe the whole muffler has sound deadening panels all throughout it. That isn't true. Check out this picture to see what the muffler looks like inside. It seriously sounds great!

topdownTA

I'd love to see some pics of your setup when you get a chance to post some. From the cut away pic you posted, I'm thinking that this muffler should be quite a bit quieter than the Magnaflows, since the Magnaflows are a straight through design and these are not.

Anyone know how the Edelbrocks flow?

I'm kind of in a position of wanting to have my cake and eat it too. I want true duals for the improved flow and sound over a Y-pipe & cat back. I want good ground clearance too though, and since I want it loud, but not too loud, I want to use a regular muffler as opposed to a bullet.

And I still wonder if anyone has ever cut the rear seat pans to improve ground clearance, and if so, I'd like to see. I was thinking that the concave rear seat pans could be cut out, and then I could fabricate a flat replacement panel and form a "brace" w/ a bead roller that would allow me the ability to tuck the mufflers up higher. Its kind of questionable whether or not I would be able to retain the rear seats though....

topdownTA

Are you stock height? I did not mention, but I would eventually like to lower the car slightly.

teke184

iTrader: (5)

i'm stock height...but i plan to lower it as well.

the sound is awesome on the MFs...they really do a GREAT job of toning down the exhaust.

i have a comparison video of straight pipes off the X, and then with the mufflers. car wasn't moved, camera wasn't moved...i just slipped the mufflers on and fired it up.

you almost can't hear it run...even when reved....i realize the camera is not great. but it is a great comparison....ear splitting loud (straight pipes) to nice and quiet (mufflers). even though the car is still loud.

pipes:


mufflers:

95 Z28

iTrader: (21)

Sorry I dont have any pics of that setup anymore but it honeslty didn't hang low at all, I could pull into gas stations and other big incline type entrances without scraping. Dump 'em right before the axle and hang them either from the rear seat belt holes (that's what I did, worked out real well) or bolt them up to the back rest area. With the mufflers close to the floorboard you will not have a clearance problem. Remember, I'm lowered on a prokit and had 3" duals too, it can be done, and it's not anywhere near as hard as some make it out to be to set it up nicely.

Xtnct00WS6

iTrader: (8)

I think there's a pic on this thread: https://ls1tech.com/forums/generation-iii-external-engine/531756-true-duals-questions-answered-here-post-your-information-pics-too.html

jrob56

iTrader: (39)

i have had three friends all with pacesetters, x pipe, and the magnaflow 4x9s dumped. they sound great at any speed but especially at WOT, any interior noise is tolerable by anyone i would say unless you get a big cam then it gets a little loud like one of the cars above. they tuck up better than you would think as others have said here. i have been in one of the cars on the couple of occasions it scraped and it was on ridiculous inclines at gas stations or something, but was rare and avoidable. this car also had the most poorly fabbed true duals of the bunch. i am wanting to do this same setup but with an h pipe instead next summer when i get some money. i hope this helps.

Assassin66

iTrader: (8)

Hey bro...95_Z28 and i traded exhausts so i'll post up pics of the TDs this week when i put it on...most likely tomorrow or wednesday since my headers arrive today so that you can see how low they hang...i will eventually run them to the back and relocate the mufflers so that it all fits into my cme valance but i need to save some money first!!

topdownTA

These are great responses I'm getting from everyone! Thanks! Based on what everyone is saying, there is no need to modify the floors, which is what I was hoping to hear!

Now for the other question raised. I need opinions on muffler selection, b/c until I started this thread, I was pretty much sold on the Magnaflows. I was under the impression that the Edelbrocks were out of my price range, but I didn't realize that they made them in mild steel. The mild steel Edelbrocks are about the same price as the stainless steel Magnaflows.

One one hand, I would kind of like the setup to be all stainless, but I can't afford the stainless Edelbrocks at $150 ea. +1 for the Magnaflows. On the other hand, the Edelbrocks are not quite as common (which is cool b/c I would like my setup to be somewhat different), and might possibly be a little quieter. +1 for Edelbrock.

What are everyone's thoughts? Any other suggestions on muffler selection to throw into the mix (Borlas are already out due to $$$)? Thanks!

topdownTA

Thanks man! I'll be looking forward to seeing it.

LTLRDSS

iTrader: (2)

did you think about single chamber flows. look up a guy named jmm98ls1 he has awsome sound clips in his sig and he is the reason i chose single flows

if i get my car back tomorrow ill post pics

topdownTA

I was thinking that the single chamber flowmasters might be somewhat louder than what I'm looking for. I know for fit they're great due to the small size. What do you think about the sound level? I'm trying to find a good compromise...if I make it as loud as I want it to be I'll have to put up with my wife's bitching about it indefinitely....

LTLRDSS

iTrader: (2)

well with sound level your going to have to figure that out, i thoght open header was going to be loud but it wasn't that bad but i only drove like that for 2 days then i got my td's on. and also with the mags, because they are filled with fiber glass they get louder over time.