GTO 6.0 Vs. G8 6.0 Differences? | LS1GTO Forums

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eng943 Just wondering what the internal differences are that account for the disparity in power between the two. Cam profile I would assume, but I'm not sure. #1 · Oct 23, 2008 Just wondering what the internal differences are that account for the disparity in power between the two. Cam profile I would assume, but I'm not sure. Sort by Oldest first Oldest first Newest first Most reactions #2 · Oct 23, 2008 Displacement on demand. Tuned for 87 octane. #4 · Oct 23, 2008 And different heads/cam/intake and a few more things. Show more replies 0 Reply #3 · Oct 23, 2008 Isn't the G8 an iron block? #5 · Oct 23, 2008 daisy's and rose peddles to be exact. 0 Reply #6 · Oct 23, 2008 The G8-GT has an L76 car engine, it has AFM (DOD) but not VVT. Aluminium LS2 block,L92 heads,LS3 intake....thats all the good bits. Where it's below par are: G8 Comp ratio 10.4.......v..............GTO LS2.....10.9 G8 Cam 200/208 0.472 0.479 ......v........GTO LS2 Cam 204/211 0.525 0.525 Cam swaps are not easy with the G8-GT because the 8 collabsible lifters require a slightly different grind on their cam lobes than the normal 8 lifters. The collapsible lifters also do not tolerate big lifts. If an owner was to sacrifice the DOD hardware and software, fit normal LS2 lifters, then the L76 car engine would be a better base for performance mods than an LS2 IMO. #9 · Oct 23, 2008 Excellent info. Seems bass-ackward to lower the compression ratio though. If you disabled DOD in s/w would the standard rockers withstand a higher lift then? Or is it that the DOD lifters are taller overall and there's no change in pushrod length (ergo you can't increase cam lift anyway)? 1 Reply #7 · Oct 23, 2008 basically the cam and the tune. that's really it. #10 · Oct 23, 2008 Nope disabling the software alone wont help. The lift limitations of the lifters is inherent in their design...even if not collapsed. For performance the only long term reliable method found has been to replace the camshaft and lifters. The static compression ratio difference between 10.4 and 10.9 is not really an issue. Maybe it is if you're chasing the last 10 hp, but it's way less important than selecting the right camshaft IMO. #11 · Oct 24, 2008 I basically had an L76 engine in my car, and with a mild/medium cam made over 500hp (flywheel). The heads are better, the intake is better, but the cam and tune are weaker. Just like HSV said. #12 · Oct 24, 2008 GTO better than G8 thats all there is to it :] #26 · Oct 25, 2008 not really. they are fairly equal in my opinion. better suspension in the G8 makes up for the LS2 GTO's superior acceleration. 0 Reply #13 · Oct 24, 2008 If I was the proud owner of a G8 GT ... I'd be going the Magnacharger route and leaving the cam and heads (less a valve spring upgrade) alone. Get a nice set of headers and a 2.5in cat-back and you'll make more streetable power than you need to take out 98% of the street cars out there. #14 · Oct 24, 2008 I totally agree. I have seen one supercharged G8 run and it was dang impressive. 0 Reply #15 · Oct 24, 2008 So how much better are the L92 heads than the 243's.......i mean every one glows about them being a GREAT cheap Head that make good power........yet I haven't seen stock vs stock flow numbers. Not that I really am that concerned because my 99mm bore (LS1) isn't quite big enough for the L92 heads, but im still interested #16 · Oct 24, 2008 they flow 330cfm out of the box. i think 243s are under 300cfm if i remember correctly. i remember reading they were suppose to come out with a l92 style heads for ls1s, anybody know anything about that. #17 · Oct 24, 2008 LS2 v LS2 with L92 heads.......same stock LS2 cam Stock LS3 intake manifold (as per G8-GT) v Stock LS2 intake manifold L92 heads (as per G8-GT) v 243 heads (as per LS2) LS2 head flow data L92 head flow data #20 · Oct 24, 2008 Do you think Pontiac didn't want to build a car that would beat its Flagship brand...GTO?? #21 · Oct 24, 2008 Not at all. As much as we all love the Goat, the fools in the rest of the world didn't, and the General would've loved everything that would allow them to say "Hey, we did better this time! Please buy our stuff!" Besides, the G8 (& the Commodore) didn't come out until a well after the GTO/Monaro cleared the lots, so Pontiac wouldn't care about cannibalizing sales. Also, look at the upcoming G8 GXP for proof that Pontiac isn't worried about staying below the GTO's power rating. If anything, they would've been more concerned with stealing the limelight from the CTS-V (which had 400 horses in the '07 MY & wasn't produced for the '08 year)...since the new CTS-V has so much more going for it, that's what cleared the road for the GXP. IMO anyway. 0 Reply #25 · Oct 25, 2008 I drove a G8 GT automatic yesterday. VERY nice car! I have to have a four door and this may be the one. Insert Quotes Post Reply

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