True duals or GMMG/Borla setup
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From: Vancouver,[KITSILANO].B.C. Canada *WestCoast*
Originally Posted by scrmnws6
I currently have a GMMG, but am thinking about going to TD's just for an increase in hp and tq.
Do the true duals over the axle with some chambered pipes or a bullet. Not loud in the car at all and sounds rediculous outside. My true duals over the axle with bullets is quiter than my buddies gmmg inside the car, but not outside and my true duals over the axle still cost less than just his catback 
Originally Posted by scrmnws6
I currently have a GMMG, but am thinking about going to TD's just for an increase in hp and tq.
you're really not going to get that much more power. thats a lot of money to spend for a few hp/tq (if that)
i felt a big difference in tha seat of my pants, especially in the 3-6k rpm range. car feels like it pulls a goot bit harder. also for some reason like stated above, duals ran out the back are much quieter inside the car than any catback ive hurd. i dunno y that would be tho.
Originally Posted by bolton98TA
also for some reason like stated above, duals ran out the back are much quieter inside the car than any catback ive hurd. i dunno y that would be tho.
not true.
i've ridden in a couple different cars, 1 stock manifolds and GMMG, another LTs + GMMG....they are MUCH quieter then my TDs. you can have a normal conversation in both of them, and you have to almost yell to talk in my car
and as far as feeling a difference, i guess it depends on what mufflers/cat back your running....but still, like stated above; i would say 3-5hp gain on average (if any). i think it's all in your head
Originally Posted by SweeTbone
I recommend the Longtube/Catted Y/GMMG setup. Great sounding setup with no fumes in the cars from dumped duals. My Kooks setup has GREAT clearance and is nearly better than stock.
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From: I-L-L-I-N-O-I-S
Well, this is all about personal preference (what YOU prefer in terms of tone, volume, appearance, power, etc.). I have a stock internal '02 Z28 and went from Kooks LT's, highflow catted-Y, and GMMG to Kooks LT's, no cats, 3" H-pipe, and two Flowmaster 1-chambers dumped before the axle. For me personally, I like my true dual set-up MUCH better than the previous GMMG one. Yeah, it's louder all the way around, but the sound quality is much better. Don't get me wrong, I liked the GMMG at WOT, but that exhaust doesn't compare to my Flowmaster race mufflers. 
Also, the H-pipe has given my car a noticeable increase in power under the curve as compared to the old Y-pipe. As far as the power differences between the two set-ups...I dynoed a best of 341rwhp & 353rwtq with the cat-back (GMMG) and a best of 346rwhp & 362rwtq with the true duals. But again, even though I didn't gain much peak, it does feel much more responsive down low and under the curve with my car.
As for Borla, yuck. Borla + LT headers/ORY =
Also, the H-pipe has given my car a noticeable increase in power under the curve as compared to the old Y-pipe. As far as the power differences between the two set-ups...I dynoed a best of 341rwhp & 353rwtq with the cat-back (GMMG) and a best of 346rwhp & 362rwtq with the true duals. But again, even though I didn't gain much peak, it does feel much more responsive down low and under the curve with my car.As for Borla, yuck. Borla + LT headers/ORY =
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Originally Posted by 2000LS1Z28
Well, this is all about personal preference (what YOU prefer in terms of tone, volume, appearance, power, etc.). I have a stock internal '02 Z28 and went from Kooks LT's, highflow catted-Y, and GMMG to Kooks LT's, no cats, 3" H-pipe, and two Flowmaster 1-chambers dumped before the axle. For me personally, I like my true dual set-up MUCH better than the previous GMMG one. Yeah, it's louder all the way around, but the sound quality is much better. Don't get me wrong, I liked the GMMG at WOT, but that exhaust doesn't compare to my Flowmaster race mufflers. Also, the H-pipe has given my car a noticeable increase in power under the curve as compared to the old Y-pipe. As far as the power differences between the two set-ups...I dynoed a best of 341rwhp & 353rwtq with the cat-back (GMMG) and a best of 346rwhp & 362rwtq with the true duals. But again, even though I didn't gain much peak, it does feel much more responsive down low and under the curve with my car.
As for Borla, yuck. Borla + LT headers/ORY =
Also, the H-pipe has given my car a noticeable increase in power under the curve as compared to the old Y-pipe. As far as the power differences between the two set-ups...I dynoed a best of 341rwhp & 353rwtq with the cat-back (GMMG) and a best of 346rwhp & 362rwtq with the true duals. But again, even though I didn't gain much peak, it does feel much more responsive down low and under the curve with my car.As for Borla, yuck. Borla + LT headers/ORY =
hey man are u a auto or m6 cause our number are right with one another
...A buddy of mine is running LTs and true duals dumped before the real axle, and at cruise and idle its quite inside the car, went with him out to irwindale and it was perfectly fine, no fumes not overly loud where I had to raise my voice just so he could hear me. WOT it sounds like cannons are going off but at idle and cruising its loud just not to the extent where you have to raise your voice or anything like that.
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From: lynchburg, VA
i have the borla adjustable system it nice but if i was doing it agen i would deffinetly go with the true duels! well worth it! UNLESS u are thinking of lowering the car then consider the clearence issue (this also depends alot on the installer) but my buddy has true duels and had no problems till a drop and now they scrape on his over every bump in the road!
Hmm.. true duals seem to be a very very popular choice around here. I am still debating on this, but you guys have about convinced me.
If I did run true duals, I would want it over the axle and out the back. That is just a preference of mine...
Also, sounds like I will get a little better sound and a little more power over the catback? Please correct me if I am wrong though.
If I did run true duals, I would want it over the axle and out the back. That is just a preference of mine...
Also, sounds like I will get a little better sound and a little more power over the catback? Please correct me if I am wrong though.
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From: I-L-L-I-N-O-I-S
Originally Posted by Brads LS1 02Z
hey man are u a auto or m6 cause our number are right with one another
well......... anyone wana here the gains i got from true duals.....?
going from pacesetter LT's, catted y, and TSP rumbler catback/ pacesetter lt's, no cats, TSP duals out the back...... i gained 1hp and 4ft lbs.
it might have been a little different but i was sucking oil from the pcv, time for a catch can!
on the other hand.......... damn did it sound mean on the dyno! lol
going from pacesetter LT's, catted y, and TSP rumbler catback/ pacesetter lt's, no cats, TSP duals out the back...... i gained 1hp and 4ft lbs.
it might have been a little different but i was sucking oil from the pcv, time for a catch can!
on the other hand.......... damn did it sound mean on the dyno! lol
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From: I-L-L-I-N-O-I-S
Originally Posted by bolton98TA
well......... anyone wana here the gains i got from true duals.....?
going from pacesetter LT's, catted y, and TSP rumbler catback/ pacesetter lt's, no cats, TSP duals out the back...... i gained 1hp and 4ft lbs.
it might have been a little different but i was sucking oil from the pcv, time for a catch can!
on the other hand.......... damn did it sound mean on the dyno! lol
going from pacesetter LT's, catted y, and TSP rumbler catback/ pacesetter lt's, no cats, TSP duals out the back...... i gained 1hp and 4ft lbs.
it might have been a little different but i was sucking oil from the pcv, time for a catch can!
on the other hand.......... damn did it sound mean on the dyno! lol
But I'm guessing as the motor is opened up for a cam or heads/cam, that is where the true duals might really shine up top.
Originally Posted by Almostryan3
...A buddy of mine is running LTs and true duals dumped before the real axle, and at cruise and idle its quite inside the car, went with him out to irwindale and it was perfectly fine, no fumes not overly loud where I had to raise my voice just so he could hear me. WOT it sounds like cannons are going off but at idle and cruising its loud just not to the extent where you have to raise your voice or anything like that.
you speakin of BayAreaSS? his setup is similar to mine (mine goes over axle) and his is a lot quieter then mine is too....kinda strange i thought..
Originally Posted by 2000LS1Z28
On a full bolt-on car with a good flowing 3" cat-back system running some some highflow cats or ORY, you're not going to gain much peak (if any at all in some situations) by switching to an X or H true dual set-up. I gained a best of 5rwhp & 9rwtq peak by going from a highflow catted Y and cat-back (GMMG) to my catless 3" H-pipe duals. Not bad for an H, but I think those increases in peak probably came from me removing the cats more than anything (and not so much from the the Y to H switch). However, it's like I said in my original post from this thread...Under the curve is where the difference should show and my car feels like it's night and day in the low to mid range (which is nice around town as that is where I do all my driving). Traction is much harder to come by now than it was before.
But I'm guessing as the motor is opened up for a cam or heads/cam, that is where the true duals might really shine up top.
But I'm guessing as the motor is opened up for a cam or heads/cam, that is where the true duals might really shine up top.
yeah, i felt a lot of mid range difference when i installed mine and when the car goes into 2ed at wot traction is now a problem. im also on an ls1 intake manifold, i figure when i get the ls6 the duals might help a little more since more air is going in and out.
On street tires, I've broke the tires loose on a hard shift into 4th. That will pretty much shut up the "three inch true duals are too much for a bolt on car" crowd. Let that **** breath and when you start getting into heads/cam or cam only that exhaust will really shine and you won't kick yourself for getting a Y set up. Another thing, over-the-axle setups are expensive. My TSP true duals (sweet thunder mufflers), manual cutouts, under the axle setup was a grand total of about $700. The only thing in my car right now as far as interior is my driver's seat, dash, and shifter. I can still carry on a normal conversation and my car is stock ride height so I have plenty of clearance. The lowest spot on the entire exhaust is where it dips down to clear the floor pan right behind the driver's side collector.