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Discussion Starter #1
Ok, so as you all know by now, I have a G8 GXp in Liquid Red with M6 and Onyx interior.

This vehicle has plans and I have alot of work I am doing to it.

Lets start with a pic of the car itself. and some background


The GXP was a car I wanted from first discusson of the equipment and price but became an afterthoiught initially when I had heard the new Camaro SS was to be lighter, more powerful and start at near 30k. Eventually, the truth came out and I learned that this near 30k number for for what is basically going to be a stripped down car, great for a single purpose car, but not for the all around street machine. So I decided to take this car after a customer backed out.

Initial impressions brought me to believe that this was the angry Pontiac. The new sibling in a long line of poorly advertised and mismarketed vehicles that promised excitment and never truly delivered. This car was not the same. The tame smooth and comfortable ride quickly changes to a shove into the seat from the extremely responsive throttle and a healthy growl from under the hood. This car does not look back at nearly 3 decades of piss poor supposed performance sedans and simply makes its own statement. If the car could talk it would say the long enjoyed bumper sticker phrase. "Get in, sit down, and shut up". Having owned and M5 I can see the comparisons that are made and yet, I feel that this vehicle outperforms the M5 in several categories most importantly the driving experience. I am very happy about my purchase. More to come.
 

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Discussion Starter #2 (Edited)
Dyno results!

Today was the day for baselines. I started at 9am on a trip to Strcitly Performance and their dynojet dyno and found myself in a sea of Mustangs and Ford Trucks. I told the owner it was great to be at a shop that was so involved in the Chevy community. :p He followed up with asking if the car was FWD and I answered no. He strapped the car to the dyno and away we go. First pull after the 30 minute drive... 357whp and 364 wtq. Not bad but not what I expected. Hey, its stock right...Another immediate pull netted a lower figure of 355whp and 362 wtq. and a 11.25afr which seems a little rich to me for a N/A car, but what do I know. I have only tuned about 200 turboed cars?? Ok, so we did a 15 minutecool down before the next and final run and I finally got what I expected... 365whp and 369wtq and followed by an immediate second pull of 361whp and 365wtq and some 11.5 afr's.

Video of the 3rd and best pull


Chart of 3rd run


Chart of all 4 runs


My best guess is that everything I heard was true. This vehicle is limited by tempurature. Something that I can easily solve with some tuning, a T-stat and some real coolant. ;) Overall the results are pretty satisfying. There isn't much in this price range that makes this type of power to the wheels. I will update with track times this evening.
 

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09 G8 GT Owner
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What were the shop owners impressions after the pulls? Did he really think it was FWD?
 

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Discussion Starter #5 (Edited)
What did we learn today at the track?

Well, a couple of things.

The first one is that I am way out of practice. Having driven AWD cars for the last 8 years has not helped my skills with RWD at the track.

The second one is that 245 all seasons are not the correct tire for this car.

Launching was an adventure. Go easy and it bogs, go hard and it spins, try to slip the clutch and I fry it. LOL Not a great day.

Ultimately, the result was a best run of 2.17 60' 13.60 at 105.84.

Not impressive by any means but considering this was the very first run, I bogged on the launch an d missed third, There is plenty of room here.

The more enjoyable run was the hard launch attempt that netted me a 2.45 60' and 14.41 at 104.23 that made me think the car was going to fall to pieces from the wheel hop.

Ill continue my post in a little while. Busy at work right now...

Ok, the rest of the details.

Weighed the car with me in it... 4275lbs.

Not really light by any means, but what can I say, its a bigger car than it looks like. I will try to get that down as well.
 

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Discussion Starter #6 (Edited)
The headers are installed!

I went with SLP Longtubes with high flow cats. The fact that they are direct bolt on's to the factory system and come pre-coated was my major reasoning behind choosing these.

I realize they are not as large as kook's but frankly, I dont think I need anything any bigger. These should do just fine for what my plans are.

They look great, fit great and should make a very nice difference.



Plenty of clearance in every single direction. They may as well have been factory.



Lined up with everything just as it was supposed to. No bending, prying or hammering.



Everything needed is included and no welding required!



They even came with factory GM gaskets which is a plus. I hate to deal with leaks and dont expect any here.





Ill post some sound clips and vids later today.
 

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I could've had a GXP
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Okay you know what everyone will be asking...

How's it sound and perform???
 

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Great baseline numbers for one (my GT baselined at 300 today, tuned it up to 320 with some KR). Very interested to hear what you get with the headers and a tune!
 

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Do you feel a little loss in torque down low? Sounds mean.

Now get the charger already! :)
 

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Discussion Starter #14
Yeah. It sounds different to say the least.

No loss of torque, thats why I prefered these 1 3/4 over 1 7/8 headers. There is no need for something as big as 1 7/8 on a street car. It just wont move enough air to ever make use of them.
 

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Um... will your service shop do this for customers? :)
 

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Overspeed... you set it where you want
 

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Discussion Starter #19
Did a couple of the "free mods" today...My own versions.

First, I modified the intake snorkle. Sorry, no pics as I hate crawling under the car on jack stands ad it was tighht. Needless to say, It should breath alot better. I also took my heat gun and modified the lower plastic covers into a small scoop to redirect some cold air into the fender for the intake to breath. Hopefully it can create some extra HP up top. It may need a little more molding to be perfect, but not bad so far.



Then, The hood scoops. I wanted to make them into more of a underhood heat solution so I modified them to push cold air into the engine bay and hopefully push the hot air out from behind the radiator and under the car (the way a corvette essentialy works)

So heres what I did.

Pop off the rubber


Remove scoop piece, as you can see its blocked off


Remove blocking plate


Freedom! It can flow now


Under the free flowing scoop reinstalled


Reused the blocking plate as a diverter to divert air into the engine bay. It snapped into position like it was supposed to and fit perfectly. I may add a dab or two of silly putty to make sue it stays in place.


To the naked eye, looks like normal


I then trimmed the rubber parts to open them up as well.


and reinstalled them. All done


Will it do what I want, who knows. But I prefer making a scoop flow airover making it useless. Next will be the intake manufold lower cover, but that will be when its not raining.
 

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2009 G8 GXP
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Nino, did you do the Header install yourself? If you did, how much of the PITA was it? Did you have to jack up the engine or transmission?

ALso how is your ground clearance? Was that reduced?
MR B
 
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