http://ls1gto.com/forums/showthread.php?t=114824

Since the 04-06 GTO is the closest thing to a G8, I thought I would post this for some ideas for your mods. Just remember you are 40 hp less, and probably weigh more. Per the Nov.07 Car and Driver, they are estimating a curb weight of 3900-4000 pounds, while my GTO weighed around 3950 with my big butt in the drivers seat. C and D also estimated 0-60 in 5.4 and quarter in 14 flat.

Hope the above thread helps.

http://ls1gto.com/forums/showthread.php?t=114824

Since the 04-06 GTO is the closest thing to a G8, I thought I would post this for some ideas for your mods. Just remember you are 40 hp less, and probably weigh more. Per the Nov.07 Car and Driver, they are estimating a curb weight of 3900-4000 pounds, while my GTO weighed around 3950 with my big butt in the drivers seat. C and D also estimated 0-60 in 5.4 and quarter in 14 flat.

Hope the above thread helps.

Well written – and the time as well as $$s to do all that certainly imply a real dedication to improving the acceleration.

Interesting – thanks for posting.

And you are correct in that the GTO was in several key respects similar to the new G8.

Here are my thoughts:

Yours being a 6.0L, that is the most comparable version to the G8.

I think that the G8 will offer a slight improvement, all else being roughly equal, ‘stock vs stock’ & ‘automatic vs automatic’ due to gearing.

Of course, all else is not really equal.

For example, I believe that the G8 GT’s A6 trans. has a deeper \ more aggressive first gear than the A4 in the 4L65-E in the GTO:

[ G8 A6 = 4.03 first & 2.92 final drive = 11.78 to 1 ]
[ GTO A4 = 3.06 first & 3.46 final drive = 10.59 to 1 ]

And the closer spacing between ratios = less RPM drop at each shift – providing an opportunity for somewhat better overall acceleration.

Though the peak HP number is down in the G8, the TQ numbers are very close between the GTO 6.0L and the G8 V8 6.0 – so close that I believe a ‘stock’ G8 recording mid-13 second quarters is at least possible. My current ‘bet’ is 13.5 or 13.6 or 13.7.

Since I have no interest in personally duplicating your path to running in the 12s, and I am particularly not interested in modifications such as the drag radials, any modifications I’d make would be confined to something I’d be comfortable with in daily street driving.

Yet I recognize here that with the stock tires, the possibility of non-productive wheel spin on standing start launch certainly exists. And this may impair the G8’s ability to achieve the best 60’ times, the best quarter mile and 0 – 60 times.

For me, however, the rate of acceleration ** AFTER ** the car is moving is ** MUCH ** more interesting. I will not be leaving thousands of miles of my rear tire tread when I accelerate from a stop. Yet once moving, I revel in the acceleration my Corvette provides. And that is what I’ll be looking for when I test drive a G8 GT . . .

- Ray
Addicted to TQ and acceleration – and seeking a 12 step program . . .

Jim / Old Goat: Wow, very nice post. There is a lot of very useful information in your GTO post, especially about the X pipe info. and other mods that were more beneficial than others.

Thanks for sharing your GTO modding & racing!