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      01-20-2012, 05:17 PM   #1
ucla bruin
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Unhappy RPI GT and GTM confusion

Can anyone clear this up for me? I've tried searching and have heard conflicting things from different people.

Is the RPI GT axle back the same as the axle back from the GTM exhaust? In other words, is RPI GT exhaust only referring to the rear section?

GT + x pipe = GTM?


Thanks!
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      01-20-2012, 05:46 PM   #2
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GT and GTM refer to the axle back. GT is the old version which has rasp and ring noise. GTM is the newest version which cleans out the ring noise.
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      01-20-2012, 05:48 PM   #3
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So the 2 axle backs, although look the same, are internally different and sound different?
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      01-20-2012, 06:10 PM   #4
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Quote:
Originally Posted by ucla bruin View Post
So the 2 axle backs, although look the same, are internally different and sound different?
That's correct. The GT unit is discontinued and currently on clearance sale I believe. The RPI GTM superseded the GT unit.
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      01-20-2012, 06:12 PM   #5
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Quote:
Originally Posted by ucla bruin View Post
So the 2 axle backs, although look the same, are internally different and sound different?
They are 2 different axle backs, both offered by RPI. The GT was introduced first and most hated that annoying tin can ringing sound, so they came out with s second version, the GTM. Visually they look different because the GT has its inlet pipe out of the side of the muffler while the GTM's inlet pipe goes in through the back of the muffler.

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      01-20-2012, 06:27 PM   #6
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***I thought the "ting" sound came from the rpi mid pipe+gt axle back...

gt+stock mid pipe produced no ting...perhaps I am mistaken...

either way..rpi section 1 and section 2 pipes are still the same for both gt and gtm...
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      01-20-2012, 07:22 PM   #7
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Quote:
Originally Posted by geneatals View Post
***I thought the "ting" sound came from the rpi mid pipe+gt axle back...

gt+stock mid pipe produced no ting...perhaps I am mistaken...

either way..rpi section 1 and section 2 pipes are still the same for both gt and gtm...

The "ting" sound comes from the dramatic increase in exhaust velocity when the cats are removed on the GT system. The side inlet muffler design on the GT doesn't allow the exhaust gases to flow properly. The GTM mufflers have the rear inlet and are very loud!
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      01-20-2012, 07:36 PM   #8
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Thanks for all the info.

Hoping to hear GTC in person this weekend.

GT for sale if anyone's interested for a low price!
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      01-20-2012, 08:42 PM   #9
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danny you getting a bmw???
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      01-20-2012, 11:21 PM   #10
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Haha nice seeing you on here. I picked one up recently. Sent you a PM!
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      01-21-2012, 01:26 AM   #11
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gtc has been installed on a so cal e92 (axle back only)...today IIRC...said to be 50% quieter than the gtm....have not heard in person yet tho...
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