Pro's and Con's of TD's
 

i know all the good things about TD's however what are the disadvatages if any. in my state we dont use the sniffer so i could pass but i have always wondered if by having no back pressure it could hurt anything. i have the set up in my sig now, what could i expect power wise to gain and what TD set up would you go with. also undecided in whether to get the turn downs or go over or under the axel, have heard the turndows blow dust everywhere. thanks for the help

if you have the visual, you will fail as they relocate the cats (if you use them) as MD doesn't even have the sniffer so I'm sure your fine there. power wise there mostly proven improve rwhp and definitely sound bad ass compared to any other setup. and yes turndowns will blow ass all over the back end of your car :(

how about back pressure?

I have 2 LS1/LS6 reference books that say GM did such an outstanding job researching, developing, and computer modeling the OEM exhaust flow characteristics, that the 2-into-1 "dual" set-up from the factory is actually pretty damn good. This isn't to say you will not pick up HP with true duals...you will....how much, I don't know. For the price of a GOOD, mandrel-bent, over-axle system, in my opinion the money would be better spent on other mods, first. But that's just me. Turndowns are a lower cost option. I've seen some pics on this site of some good-looking side-dumps. As long as they weren't turned straight at the ground, I don't think blowing dust around would be that big of a deal.

With your Kooks & induction kit, your flowing air in & out pretty good right now. There are so many other things you could do before installing a true dual system, you might want to consider your options; heads (aftermarket or ported stockers), cam, intake, gears, etc. And remember, unless you've already gone over it, your 4L60e is going to take just so much.

BTW, it's a good thing you have a catted y-pipe between those Kooks and that SLP Loudmouth. I've heard long-tube/Loudmouth/ORY set-ups.....they'll rattle windows, scare little children, and activate every automatic garage door-opener within a 2-block radius.

You will not hurt anything but you will grow tired of them. I would do dual 2.5" over the axles. It will sound good andhave real mufflers. JUst cost big money for it to be done right.

i love my true duals, cost me a $125 with me bringing the bullet mufflers.

back pressure isn't an issue. they are long enough to negate any issues with that. i like my TDs, however sometimes i do wish my car was quiter.

I think back pressure is a bad joke someone is playing on everyone.

TD's lose some ground clearance and with mine dumped at the axle it is a little louder in the car. But, I'm happy and wouldn't trade them for any single catback system.

I'd suggest a dual getup, over the axle through the stock routing, into a couple of (insert brand name here) mufflers before exiting in the stock location.

Unless you love rattling your teeth out... then dual 3" dumped with a couple of LM1 resonators. :P

:werd: Mine sound better than any catback i have heard. Wouldnt trade them for any catback.

You can go under the axle which is cheap, has decent clearence, and keeps the resonating sound out of the cabin.

GROUND CLEARANCE!!!oh wait there isnt any... but I love them just gotta work on the clearance.

if you have a skilled builder make the duals...theyll tuck up better than any other exhaust system.

i built a set of 3" duals for a friends car...lowered on eibachs...has yet to scrape..yet to bottom out...you cant even see them from the side.

With patience, a true dual setup can fit well. I have mine run under the axle and love it. Check the link in my sig for pics. (damn I say that alot..... :jest: )

They do blow up dust if dumped, it was a problem for me every now and then, but not too often with this pavement pounder. I'd expect maby 10rwhp and possibly a little less weight with a catless dumped true dual system.

Probably the biggest con of true duals is the attention the sound is going to bring (both the wanted and unwanted)
It's up to you to decide if the negative attention (cops, pissed off neighbors, and ricers) out weighs the positive

i talked to a guy from speed inc. and he told me the worst thing you can do is run them under the axel. he highly suggested running over because the axel moves up and down......i see he point..maybe...but i dont think it would be a prob. if i get the TSP dumped can i later fab. the rest of the piping out the back?

The axle does move up and down, he's correct. :gruffy:

The problem is, if you were to hit a big enough bump causing the rear suspension to unload (axle moves down), it could possibly hit the pipes running under it. I don't have very much clearance between my swaybar and my pipes (which run under the axle), and have NEVER had a problem with it. Even after hitting some pretty nasty railroad tracks late for school.

I HAD the TSP duals dumped, but got tired of how loud it was. I could live with it, but my poor neighbors couldn't. They never said anything to me personally, but I didn't want to upset them. I had cats installed to cut down on the noise outside, and had them run out the back to cut down on noise inside.

With stock gears, highway speeds in 6th was pretty quiet (1500rpms). After putting in the 4.11's, I now turn 2100rpms, which is right where the duals started to get loud.

how much did the cats quiet down ur dumped duals? i love how mine sounds, but itsa bit loud and the dead know when i come home at 4 in the mornin

Alot. When I first had them done, I thought it was "stockishly" quiet. Turns out it was just such a drastic change, that I thought it was. People still tell me it's freakin loud, but I like it alot more. I had the cats put on and the pipes run out the back at the same time, so I can't really comment on each by itself.