RPI GT and GTM confusion

ucla bruin · 01-20-2012, 05:17 PM

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!

avex8 · 01-20-2012, 05:46 PM

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.

ucla bruin · 01-20-2012, 05:48 PM

So the 2 axle backs, although look the same, are internally different and sound different?

Cal@Sonic MS · 01-20-2012, 06:10 PM

Quote:

Originally Posted by ucla bruin

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 The RPI GTM superseded the GT unit.

dvpouldar26 · 01-20-2012, 06:12 PM

Quote:

Originally Posted by ucla bruin

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.

PS: Go Bruins!

geneatals · 01-20-2012, 06:27 PM

***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...

Raptor251 · 01-20-2012, 07:22 PM

Quote:

Originally Posted by geneatals

***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!

ucla bruin · 01-20-2012, 07:36 PM

Thanks for all the info.

Hoping to hear GTC in person this weekend.

GT for sale if anyone's interested for a low price!

kchu221 · 01-20-2012, 08:42 PM

danny you getting a bmw???

ucla bruin · 01-20-2012, 11:21 PM

Haha nice seeing you on here. I picked one up recently. Sent you a PM!

geneatals · 01-21-2012, 01:26 AM

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...

01-20-2012, 05:17 PM	#1
ucla bruin Second Lieutenant Drives: daily moped Join Date: Dec 2011 Location: CA Posts: 235 iTrader: (0)	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, 06:27 PM	#6
geneatals Ninja Drives: 2011.5 E90 M3 Join Date: Dec 2007 Location: So Cal (SFV) Posts: 2,995 iTrader: (2)	***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... __________________ 2011.5 E90 M3 AW l Black Novillo Leather \| Carbon Fiber Leather Trim \| ZCP \| ZP2 \| M-DCT \| Navigation \| Moonroof \| 6FL l Pics/Mods Retired: 2008 535i l AW l Black Dakota Leather l Bamboo Anthracite l ZPP l ZSP l 6FL

01-21-2012, 01:26 AM	#11
geneatals Ninja Drives: 2011.5 E90 M3 Join Date: Dec 2007 Location: So Cal (SFV) Posts: 2,995 iTrader: (2)	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... __________________ 2011.5 E90 M3 AW l Black Novillo Leather \| Carbon Fiber Leather Trim \| ZCP \| ZP2 \| M-DCT \| Navigation \| Moonroof \| 6FL l Pics/Mods Retired: 2008 535i l AW l Black Dakota Leather l Bamboo Anthracite l ZPP l ZSP l 6FL

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01-20-2012, 05:46 PM	#2
avex8 Lieutenant Drives: 2011.75 E92 M3, 2013 X3 35i Join Date: May 2011 Location: San Diego Posts: 560 iTrader: (2)	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.

01-20-2012, 05:48 PM	#3
ucla bruin Second Lieutenant Drives: daily moped Join Date: Dec 2011 Location: CA Posts: 235 iTrader: (0)	So the 2 axle backs, although look the same, are internally different and sound different?

01-20-2012, 07:36 PM	#8
ucla bruin Second Lieutenant Drives: daily moped Join Date: Dec 2011 Location: CA Posts: 235 iTrader: (0)	Thanks for all the info. Hoping to hear GTC in person this weekend. GT for sale if anyone's interested for a low price!

01-20-2012, 08:42 PM	#9
kchu221 JDM whore Drives: 2012 E92 6MT Space Grey Join Date: Jan 2012 Location: los angeles Posts: 2,309 iTrader: (5)	danny you getting a bmw???

01-20-2012, 11:21 PM	#10
ucla bruin Second Lieutenant Drives: daily moped Join Date: Dec 2011 Location: CA Posts: 235 iTrader: (0)	Haha nice seeing you on here. I picked one up recently. Sent you a PM!