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Gmmg vs. Speed Engineering True Duals vs. Texas Speed True Duals

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Gmmg vs. Speed Engineering True Duals vs. Texas Speed True Duals

Old 10-25-2017, 02:49 PM
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Default Gmmg vs. Speed Engineering True Duals vs. Texas Speed True Duals

So I've been itching to change my current exhaust setup (Arh headers and catted y with a gmmg out the back) I love the sound. Very loud but not obnoxious even with a cam. But I have been tempted to switch to a catless true dual over the axle setup. I don't want my car to be any quieter and if it's louder that's not a problem.

So if you were me would you keep what I got, or switch? And if I did switch which one is preferred/would fit with my headers?
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Old 10-25-2017, 03:02 PM
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I have had lt's and a catless gmmg. I now have tsp dumped duals and it's much better
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Old 10-25-2017, 03:28 PM
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I don't want dumped though, if it was a camaro or a formula I wouldn't mind but it just looks weird with such big openings on the trans am imo
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Old 10-25-2017, 03:52 PM
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What don't you like about your current setup?
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Old 10-25-2017, 04:16 PM
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How would adding a cut out before the rear axle near the rear passenger's seat would be for a cost effective change? It will add some noise and with the catt'ed Y pipe not be too excessive with noise. If you don't like the sound just cap the cut out.
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Old 10-25-2017, 07:09 PM
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I had went from LTs, cats and GMMG to LTs cats with kooks TDs and the Kooks is quieter. Also the GMMG is a heavy ******* pig, weighed within a few lbs of the Kooks TDs.
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Old 10-25-2017, 07:36 PM
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You'll have shitty ground clearance with either true dual setups if the car is lowered. I went back to stock height shortly after installing Speed's TD.
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Old 10-25-2017, 08:22 PM
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Originally Posted by _JB_ View Post
You'll have shitty ground clearance with either true dual setups if the car is lowered. I went back to stock height shortly after installing Speed's TD.
Not all that fair, it depends on your fabbing ability.
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Old 10-25-2017, 09:09 PM
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Originally Posted by AnotherWs6 View Post
Not all that fair, it depends on your fabbing ability.
Then why even purchase any TD kit then? If the OP can make his own exhaust I'm sure we wouldn't have this topic.
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Old 10-25-2017, 11:32 PM
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FYI - Texas speed & speed duals are very similar whether be dumped at axle or over axle. Also both companies built the current kits for stock height cars.

unless you are planning to lower with coilovers, the premade kits from speed or Texas will have poor ground clearance .
kooks although comes at a price , will work on low cars.

If ground clearance is an absolute concern then, gmmg.
if doing coil over or regular low car springs isn't concern then either of new dual kits mentioned above is fine.

Exception to this for affordable duals kit is hooker black heart true duals . Although not on your list and exhaust pipe size is stock fbody size (2.5") and is cheaper than looks.

If none of that works, mufflex single 4".
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Old 10-26-2017, 12:51 AM
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hooker blackheart wth 1 7/8 mid length headers here on a lowered car
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Old 10-26-2017, 06:46 AM
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Clearance with the kooks isn't terrible, I'm lowered 1.25" and have a few scrapes all after the x pipe. The speed eng mid hanger helps. But yeah, the system is expensive and still a bit loud.
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Old 10-26-2017, 01:58 PM
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I also should mention that I plan on running a 2 step, and I know cats will not last long with that. So basically I figure now would be the time to switch to something new. Basically there is nothing wrong with what I got now, it was more just along the lines if switching to duals would be worth it. Also currently I am stock height soon to be on coilovers, and I wouldn't have a problem adjusting the exhaust to get it to tuck up and fit better.
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Old 10-26-2017, 04:39 PM
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I hated the rasp with my off-road y and gmmg. I have run a mufflex system system with custom y and it wasn't bad. My vote is for duals
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Old 10-26-2017, 07:03 PM
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Video of the Kooks True Duals with Dynomax UltraFlos.

You can see the ground clearance well here...

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Old 10-26-2017, 07:44 PM
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Sounds good! Nice looking ride too, BTW. Doesn't lope as much as I thought it would considering the cam you have. But then you DO know how to tune correctly...
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Old 10-28-2017, 01:19 PM
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That clearance is very impressive, it sounds great as well.
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Old 10-28-2017, 05:16 PM
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If you have a mostly stock car, the Speed Eng clones of the Kooks system is going to be hard to beat. It'll sound good and have pretty good clearance.

If you modify the car pretty extensively, it's going to be loud. Very loud. Those bullets don't do jack to help. The TSP system is even worse since it dumps. That leaves a catted setup with the GMMG as a good alternative... or the TSP Catback with the built-in cutout.

That's what I'm planning to do on the turbo car I'm building to have a very nice cruiser... then open the cutout when I need to release some backpressure...
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Old 10-28-2017, 10:01 PM
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Well I have ported 241s and a si5 cam so I could see it being pretty loud. However that doesn't bother me since I'm still young and still like very loud cars
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Old 11-06-2017, 09:25 PM
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If you don't care how loud it is I would go with the Speed engineering duals. You didn't mention being low but others did. Several people worked with it and got it tucked up nicely. Which you will have to do with any exhaust kit.

For the price you could add whatever mufflers you wan't to get it to sound the way you like and still save a ton of money, IF you want to change it at all. And there aren't many exhaust systems that can out do a true dual 3". I'd like to see the motor that is choked by that exhuast.. Most of us will never own a motor that will need more than that.
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