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Dynatech Longtube options for 2011+ GT500


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The Dynatech 1 7/8" LTs phsyically bolt up to all 07-12 GT500s because they use the same motor/chassis, but there are some minor differences on 2011+.


The 2011+ GT500 uses a new 2.75" exhaust and switches to an H pipe instead of the X found on 07-10.


They also use wideband front O2 sensors with a different connector.


On 07-10 we traditionally use the Dynatech LTs and 2.5" or 3" x-pipe (retails for $1199).




If we use the 2.5" x pipe its much smaller than the stock catback, if we use the 3" x pipe its larger and requires the catback be cut down and adapted, which I prefer not to do.


I had a 2011 in the shop last week for TVS and LT install, and this is what I did:



The Dynatech LTs were installed and the 2.75" powercat converters bolted up. Then I cut the the stock H pipe, I believe it needs to be around 22-23" long, measure your individual car first.. The H pipe can be clamped or welded into the cats. Depending on how everything goes together, the H may need to be cut a little bit so the tubes can spread open 1/2" where they go into the cats, this can be done by cutting the back side of the H which allows the tubes that go into the cat to spread out a little, and then welding the H back up. If you weld onto the cats, you may want to bolt everything up a little loose, tack in position, drop it down to weld, and then bolt it back up tight.


Doing it this way allows you to keep the stock H (some prefer it for sound vs an X) and it is actually a little cheaper too, ($1050 total with cats, or $758 without cats):








I also sell the parts to do this on 07-10 too, you can buy 2.5" collector adapters or cats and mate them up to your stock 07-10 stamped X pipe (or H pipe on KRs):



This reduces the cost to $758 no cats or $1048 with cats for LTs on an 07-09.


I will say that my 07 with LTs, 3" X-pipe/cats, and stock mufflers sounded pretty good. If I did it with 2.5" x pipe it would probably be a little quieter with no loss in HP for a sub 800rwhp car. I probably not not be afraid to run LTs/no cats/stock mufflers from a noise perspective on an 07-09 with 2.5" exhaust..


On the 11 with LTs and cats, it is a tad on the loud side (for me), which some may like, but not unbearable IMO. I think the factory exhaust is a little louder with its H pipe and 2.75" muffler, so the LT/cat setup is louder.


For anyone with a 2011-2012 that purchases these, I can include the correct style O2 extension for the new factory widebands.

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Do you think any header manufacturers will offer a bolt on system for the 2011? I imagine if I change the entire exhaust front to back to 3" I can bolt it all right together but at a much higher cost? If its as loud as you say it is it sounds perfect to me. I just like to pull factory stuff off and bolt new stuff on, that leaves me the option to change things back whatever the reason might be.


Is there a downside to not running cats on these cars? How loud are they? Videos on you tube are hard to tell. I have an old Camaro with LT's, 3" exhaust with 2 chamber Flows, Its too loud LOL. My brother has a 2009 GT with a Corsa cat back its way to quiet.


No other GT500's in my area that are modded to listen to.



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