Pontiac G8 2008-2009 - Numbers on the Twin Turbo G8 GT




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rocket5979
09-27-2009, 10:11 PM
I took the car up to Birmingham to hang out with my buddy James and to play with the car a little and get some numbers on it with his dyno.

Preliminary numbers were 450rwhp and 507rwtq SAE @ 6.3psi boost with 93 octane pump gas.

Final numbers were 498rwhp and 570rwtq SAE @ 8.5psi boost with 93 octane pump gas. This was accomplished with a REAL conservative tune. If we got aggressive the car probably had 550 in it the way it sat. I didn't want to take that chance with my only DD car down here. BTW no meth or anything else was used for these pulls.

First gear??? USELESS!!! Felt like I was free revving the car in neutral.
Second gear??? Haven't tried it yet but I bet with damn near 500rwtq available at 3000rpms that the tires won't like it.

Another item worth noting is that I averaged 27mpg on the 300+ mile drive back home; and there was more than a time or two where I romped on it. Probably would have seen 28+mpg average if I stayed easy the whole way. Not shabby for a 6.0 V8 twin turbo vehicle weighing 4000lbs.

Even though things are darn near wrapped up I do plan to tweak the transmission a little more to my preference before making any passes at the dragstrip this fall. I figure that as long as things go to plan the car should be good for a middle 11 second ET.

Edit: I almost forgot to mention that I didn't get any videos of the dyno runs. I had my flip cam there and took videos of the other cars that we played with on the dyno but when we got to mine we got so preoccupied with the car itself neither one of us took a video during any of the pulls. Sorry.

Here is the dyno graph.


mystic98ls1
09-27-2009, 11:50 PM
Congrats man thats awsome

SSGoat
09-28-2009, 12:28 AM
damn! thats fuken nice!
so you got these pulls with JUST 93 octane/tune/twins/cai/exhaust?
does your tune have the 4cyl mode disactivated?
as ive read the g8's tranny can hold up to alotta power right?
you sir have my dream car.. (a powerfull DD that i can actually afford lol)
i hope to one day have the car and a similar set up.. heck id be happy with just the car stock:nod:

how much would u estimate youve spent for your set up btw?


rocket5979
09-28-2009, 05:46 PM
damn! thats fuken nice!
so you got these pulls with JUST 93 octane/tune/twins/cai/exhaust?
does your tune have the 4cyl mode disactivated?
as ive read the g8's tranny can hold up to alotta power right?
you sir have my dream car.. (a powerfull DD that i can actually afford lol)
i hope to one day have the car and a similar set up.. heck id be happy with just the car stock:nod:

how much would u estimate youve spent for your set up btw?


Yeah, just the TT system itself, FAST 65lb injectors, 93 octane fuel, tune, and Magnaflow exhaust.

I deactivated DoD (4cyl mode).

The G8 6L80E transmission can hold some pretty good power as long as it is tuned right. These tranny's are kind of picky, but once dialed in they seem to be pretty stout.

I have spent right around $7,500 or so for everything and that includes TT's, injectors, exhaust, HPT Pro, and gauges. Since I did all work myself or had a buddy help me that is just a parts pricing. If you pay someone else to install expect to pay for 20+ hours of labor just for the kit install itself; let alone the tuning and dyno time.

spaz1
10-21-2009, 12:28 AM
any pics of the setup?

Mike in LA
10-21-2009, 08:32 AM
any pics of the setup?


YES, pics please:chug:.

edmanet
10-21-2009, 09:51 AM
Hope you have some DRs........

WSsick
10-21-2009, 10:17 AM
do we get any videos of this beast? looks to spool pretty quick. very nice work man. how hard was it to install yourself?