G8 GT Performance buildup
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G8 GT Performance buildup i am looking into making my ls2 in my 09 g8 gt a bit faster i and looking into intake exhaust cam custom tune and a 175 shot any help on brands or what will give me the best outcome
On The Tree
Joined: Aug 2009
Posts: 156
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From: Iuka, MS
we just did american racing longs tubes and magnaflow exhaust, cold air, ud pulley, yank 3200 and tune on a 09 g8 gt and it runs like a beast. i recommend the same exhaust it sounds awesome. i'm tring to talk him into a cam now and i think he's putting a 175 shot on in a week or two.
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Joined: Nov 2005
Posts: 459
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From: Arlington, TN
Just to clarify: It's a L76 not LS2. Lower compression, active fuel management, better head and manifold design -vs- the LS2.
Since its a GT:
Ported Throttle Body, get a AFM cam (with springs), a stall to match the cam (cause the GT's are only auto), Long tube headers, full dual 3" cat back, and a cold air intake.
This is going to set you back a couple of grand but will turn that 360 crank hp 6.0L into a 400 to 450 rear wheel hp 6.0L (if not more).
Cam: Livernois has 2 AFM cam's available (1 is low lift and the other is high lift). Both are listed under there G8 engine section.
The FAST LSXR 102 for the L76/LS3 was just finished (like yesterday one of the shops in Memphis got 5 of them). This combined with the other components could help finish off your engine/exhaust setup.
Once you are done with the motor, look into a stronger driveshaft and upgrading the cv joints and possibly the half shafts. As those will start to wear out once the motor has been upgraded.
You can also look into having your heads shaved .030" combined with a thinner head gasket to raise the compression.
The L76 has a 10.4:1 compression compared to the LS2's 11.0:1 and the LS3's 10.98:1.
If you do this though you will need to check the Piston to Valve clearance for the cam you choose to install.
The G8's have a better suspension then the previous generation (what the GTO was based on) but have an exhaust system similar to the 04 GTO (dual 2"). The 05/06 GTO and the 5th Gen Camaro's have a better exhaust system from the factory.
I never could understand why GM did that to such a great sedan?
Since its a GT:
Ported Throttle Body, get a AFM cam (with springs), a stall to match the cam (cause the GT's are only auto), Long tube headers, full dual 3" cat back, and a cold air intake.
This is going to set you back a couple of grand but will turn that 360 crank hp 6.0L into a 400 to 450 rear wheel hp 6.0L (if not more).
Cam: Livernois has 2 AFM cam's available (1 is low lift and the other is high lift). Both are listed under there G8 engine section.
The FAST LSXR 102 for the L76/LS3 was just finished (like yesterday one of the shops in Memphis got 5 of them). This combined with the other components could help finish off your engine/exhaust setup.
Once you are done with the motor, look into a stronger driveshaft and upgrading the cv joints and possibly the half shafts. As those will start to wear out once the motor has been upgraded.
You can also look into having your heads shaved .030" combined with a thinner head gasket to raise the compression.
The L76 has a 10.4:1 compression compared to the LS2's 11.0:1 and the LS3's 10.98:1.
If you do this though you will need to check the Piston to Valve clearance for the cam you choose to install.
The G8's have a better suspension then the previous generation (what the GTO was based on) but have an exhaust system similar to the 04 GTO (dual 2"). The 05/06 GTO and the 5th Gen Camaro's have a better exhaust system from the factory.
I never could understand why GM did that to such a great sedan?
Just to clarify: It's a L76 not LS2. Lower compression, active fuel management, better head and manifold design -vs- the LS2.
correct here
Since its a GT:
Ported Throttle Body, get a AFM cam (with springs), a stall to match the cam (cause the GT's are only auto), Long tube headers, full dual 3" cat back, and a cold air intake.
incorrect here, scrap that garbage DOD system, no need for 3" exhaust, I would go with Kooks long tubes, their corsa connection pipe, and a corsa catback.
This is going to set you back a couple of grand but will turn that 360 crank hp 6.0L into a 400 to 450 rear wheel hp 6.0L (if not more).
from what I see most g8's are 300-320 rwhp stock, and I think the lowest rwhp car Livernois has done made 418 rwhp with their stage 1 cam
Cam: Livernois has 2 AFM cam's available (1 is low lift and the other is high lift). Both are listed under there G8 engine section.
incorrect, livernois does not manufacture, or (from what I have read) recommend cams that retain DOD. The DOD system seems to be the direct cause of premature cam bearing wear, and many other shortcomings. I have also seen (in person and online) G8's that, when using an aftermarket DOD cam have numerous valvetrain issues, like lifter failure, or valve float
The FAST LSXR 102 for the L76/LS3 was just finished (like yesterday one of the shops in Memphis got 5 of them). This combined with the other components could help finish off your engine/exhaust setup.
the jury is still out on how it will perform, I am not saying it will or wont
Once you are done with the motor, look into a stronger driveshaft and upgrading the cv joints and possibly the half shafts. As those will start to wear out once the motor has been upgraded.
so far the only failed driveshafts are carrier bearing related, and this is a factory flaw, bone stock cars have some issues, some dont, some modified cars have issues, some don't. it's luck of the draw. to my knowledge no one has broken a driveshaft or an axle due to power, in fact I haven't read where anyone has even broken an axle period.
You can also look into having your heads shaved .030" combined with a thinner head gasket to raise the compression.
The L76 has a 10.4:1 compression compared to the LS2's 11.0:1 and the LS3's 10.98:1.
If you do this though you will need to check the Piston to Valve clearance for the cam you choose to install.
while I agree with milling the heads, I would not use a thinner gasket, the piston comes out of the hole too much for my comfort (one measured .013 out of the hole) also, the L74 is 10.4, but the LS2 is 10.9, and the LS3 is 10.8. if you mille .030 a Livernois stage 1 is a very proven cam on these cars and clears by a wide margin.
The G8's have a better suspension then the previous generation (what the GTO was based on) but have an exhaust system similar to the 04 GTO (dual 2"). The 05/06 GTO and the 5th Gen Camaro's have a better exhaust system from the factory.
I never could understand why GM did that to such a great sedan?
this is not true, the factory g8 exhaust is NOT 2" its 2.5", infact the style of system is extremely similar in concept to the new camaro...
correct here
Since its a GT:
Ported Throttle Body, get a AFM cam (with springs), a stall to match the cam (cause the GT's are only auto), Long tube headers, full dual 3" cat back, and a cold air intake.
incorrect here, scrap that garbage DOD system, no need for 3" exhaust, I would go with Kooks long tubes, their corsa connection pipe, and a corsa catback.
This is going to set you back a couple of grand but will turn that 360 crank hp 6.0L into a 400 to 450 rear wheel hp 6.0L (if not more).
from what I see most g8's are 300-320 rwhp stock, and I think the lowest rwhp car Livernois has done made 418 rwhp with their stage 1 cam
Cam: Livernois has 2 AFM cam's available (1 is low lift and the other is high lift). Both are listed under there G8 engine section.
incorrect, livernois does not manufacture, or (from what I have read) recommend cams that retain DOD. The DOD system seems to be the direct cause of premature cam bearing wear, and many other shortcomings. I have also seen (in person and online) G8's that, when using an aftermarket DOD cam have numerous valvetrain issues, like lifter failure, or valve float
The FAST LSXR 102 for the L76/LS3 was just finished (like yesterday one of the shops in Memphis got 5 of them). This combined with the other components could help finish off your engine/exhaust setup.
the jury is still out on how it will perform, I am not saying it will or wont
Once you are done with the motor, look into a stronger driveshaft and upgrading the cv joints and possibly the half shafts. As those will start to wear out once the motor has been upgraded.
so far the only failed driveshafts are carrier bearing related, and this is a factory flaw, bone stock cars have some issues, some dont, some modified cars have issues, some don't. it's luck of the draw. to my knowledge no one has broken a driveshaft or an axle due to power, in fact I haven't read where anyone has even broken an axle period.
You can also look into having your heads shaved .030" combined with a thinner head gasket to raise the compression.
The L76 has a 10.4:1 compression compared to the LS2's 11.0:1 and the LS3's 10.98:1.
If you do this though you will need to check the Piston to Valve clearance for the cam you choose to install.
while I agree with milling the heads, I would not use a thinner gasket, the piston comes out of the hole too much for my comfort (one measured .013 out of the hole) also, the L74 is 10.4, but the LS2 is 10.9, and the LS3 is 10.8. if you mille .030 a Livernois stage 1 is a very proven cam on these cars and clears by a wide margin.
The G8's have a better suspension then the previous generation (what the GTO was based on) but have an exhaust system similar to the 04 GTO (dual 2"). The 05/06 GTO and the 5th Gen Camaro's have a better exhaust system from the factory.
I never could understand why GM did that to such a great sedan?
this is not true, the factory g8 exhaust is NOT 2" its 2.5", infact the style of system is extremely similar in concept to the new camaro...
TECH Resident
Joined: Sep 2003
Posts: 848
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From: Working in the shop 24/7
Teching In
Joined: Oct 2009
Posts: 23
Likes: 1
From: Smyrna, TN
I'm making 427rwhp and 397 rwtq with the following...
Livernois Stage 1 cam, valve job, milled heads, ported intake, kooks mid length 1 7/8 headers, corsa cat back, rotofab CAI.
Ditch the DOD...
and if you haven't heard the kooks and corsa combo you don't know what a good exhaust sounds like with little to no drone on the highway. race car loud at WOT and quiet enough to not make your neighbors cry at 2am in the morning. look on youtube for livernois gxp corsa and kooks Dan Millen's car should be on there and mine sounds pretty much the same.
my dad is nearing 60 and said wow this really isn't bad at all loud when you want it to be and you can hold a conversation with the hearing impaired (old) people at 75 LOL
He thought it would be louder even at cruising speeds as when you are WOT you can hear it 4 blocks away. My neighbors and my wife can confirm that
Livernois Stage 1 cam, valve job, milled heads, ported intake, kooks mid length 1 7/8 headers, corsa cat back, rotofab CAI.
Ditch the DOD...
and if you haven't heard the kooks and corsa combo you don't know what a good exhaust sounds like with little to no drone on the highway. race car loud at WOT and quiet enough to not make your neighbors cry at 2am in the morning. look on youtube for livernois gxp corsa and kooks Dan Millen's car should be on there and mine sounds pretty much the same.
my dad is nearing 60 and said wow this really isn't bad at all loud when you want it to be and you can hold a conversation with the hearing impaired (old) people at 75 LOL
He thought it would be louder even at cruising speeds as when you are WOT you can hear it 4 blocks away. My neighbors and my wife can confirm that
