Pontiac G8 2008-09 & Chevrolet SS 2014+ - GXP Twin Turbo Project coming along...

06-21-2011, 06:34 AM
Hey guys,

I've been at work on this car for a few weeks now. We built headers and exhaust for this car right off the showroom floor for the customer, BEFORE the title was signed over. The customer has enjoyed the car for two years and wanted to take the next step. He jumped a mile.

My primary build goals throughout the process:

-No cutting or permanent modifications of the chassis.
-Build as an efficient setup as possible while adhering to the first goal.


58/62mm Precision Billet Vband turbos. Went with B covers in order to fit between the engine and frame "rails";
TiAL MVS wastegates;
LoveFab Turbo Manifolds - places the turbos high enough for a gravity drain back into the pan;
LoveFab Twin-core Water to Air Intercooler. Only modification to the car is the upper radiator hose.
62lb injectors
Hobbs switch, inline pump.

I am finished with fabrication and will begin the full installation today.

Pictures of some of the process:

Bulky stock motor mounts won't do:

http://a5.sphotos.ak.fbcdn.net/hphotos-ak-ash4/263463_182689395117439_146390618747317_440040_3423 110_n.jpg


http://a3.sphotos.ak.fbcdn.net/hphotos-ak-snc6/255727_182689398450772_146390618747317_440041_6833 533_n.jpg

Drivers side manifold, turbo, WG, DP/DT combo. Yep, its tight!

http://a7.sphotos.ak.fbcdn.net/hphotos-ak-ash4/255099_175165159203196_146390618747317_396464_5167 837_n.jpg

http://a6.sphotos.ak.fbcdn.net/hphotos-ak-ash4/226357_175165135869865_146390618747317_396463_9014 06_n.jpg

http://a2.sphotos.ak.fbcdn.net/hphotos-ak-ash4/226357_175165099203202_146390618747317_396461_4216 947_n.jpg

http://a4.sphotos.ak.fbcdn.net/hphotos-ak-snc6/226357_175165119203200_146390618747317_396462_7605 320_n.jpg

Early mockup stages:

http://a8.sphotos.ak.fbcdn.net/hphotos-ak-ash4/215933_170865996299779_146390618747317_370949_1524 822_n.jpg

Dual-Core WAIC:

http://a1.sphotos.ak.fbcdn.net/hphotos-ak-ash4/264881_181811361871909_146390618747317_435637_1528 904_n.jpg

http://a8.sphotos.ak.fbcdn.net/hphotos-ak-snc6/248820_181852975201081_146390618747317_435700_3706 341_n.jpg

http://a6.sphotos.ak.fbcdn.net/hphotos-ak-snc6/251250_181852971867748_146390618747317_435699_7999 67_n.jpg

http://a4.sphotos.ak.fbcdn.net/hphotos-ak-snc6/261889_181852968534415_146390618747317_435698_6448 959_n.jpg

Charge piping built:

http://a6.sphotos.ak.fbcdn.net/hphotos-ak-ash4/252572_182052448514467_146390618747317_436838_8071 818_n.jpg

Air filter tubing:

http://a8.sphotos.ak.fbcdn.net/hphotos-ak-snc6/259964_182552335131145_146390618747317_439404_6346 38_n.jpg

http://a6.sphotos.ak.fbcdn.net/hphotos-ak-snc6/261294_182552565131122_146390618747317_439407_4559 104_n.jpg

http://a3.sphotos.ak.fbcdn.net/hphotos-ak-ash4/252993_182552911797754_146390618747317_439409_3293 263_n.jpg


http://a1.sphotos.ak.fbcdn.net/hphotos-ak-snc6/263992_182689655117413_146390618747317_440042_4932 622_n.jpg

I will update as the car comes together. Tuning before the weekend.

06-21-2011, 10:53 AM
That is fucking nice. No joke.

06-21-2011, 12:58 PM
That is fucking nice. No joke.


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06-21-2011, 04:52 PM
those filters are tiny!!

06-21-2011, 10:58 PM
Very nice! Thats going to be a blast to drive.

06-21-2011, 11:34 PM
Pretty cool!

06-22-2011, 09:05 AM
Nice work! What kind of power numbers are you aiming for with the setup?

06-23-2011, 07:03 AM
Thanks guys!

We aren't going for the moon here, maybe 550-600WHP. I think this can be reached at just 5-7psi, though I'll know for sure.

The customer doesn't want issues with engine or drivetrain so I figure this is a good way to start.

If we crank up the boost, larger filters are an easy modification. For now, they will flow plenty of air for the power we are shooting for.

06-23-2011, 09:17 AM
Wow that's gonna be one seriously sick ride. The owner obviously has a healthy disposable income.

06-23-2011, 10:06 AM
Looks good! Bet it will be fun when completed!

06-23-2011, 10:19 AM
Here's a quick snapshot of the setup mocked up off of the car:

http://a1.sphotos.ak.fbcdn.net/hphotos-ak-snc6/264643_183184335067945_146390618747317_442320_8296 723_n.jpg

06-29-2011, 02:08 PM
VERY Nicely done! :cheers:

07-02-2011, 07:41 AM
Fuel system complete. Boost controller and wideband wiring almost complete.




I will be installing heat shields on the turbo manifolds this morning before the Dyno this evening.

07-02-2011, 09:50 AM
very nice

07-02-2011, 11:49 AM
That is insane. That thing is going to be a beast!! Can't wait to see the results!

07-03-2011, 09:51 AM
:corn: looks efficient for sure

Beaflag VonRathburg
07-03-2011, 08:03 PM
That intercooler is super cool looking. I really like the way you guys have everything put together.

07-04-2011, 09:00 PM
Damn... Do I even want to know what a setup like that cost?

07-07-2011, 08:59 PM
Damn... Do I even want to know what a setup like that cost?


07-07-2011, 09:00 PM
Fuel system complete. Boost controller and wideband wiring almost complete.

I will be installing heat shields on the turbo manifolds this morning before the Dyno this evening.

"This evening" was 5 days ago. What's the word?

07-08-2011, 05:21 PM
542WHP and 600+WTQ at just 8psi on a Mustang dyno. The tires were spinning at peak torque(3700rpm). Graphs up soon.

I was REALLY crunched with time, struggling with EFILive as it was my first time using it. I figured it out the morning the customer demanded the car(WHEW!!!) and had the car conservatively tuned in under two hours.

Two problems:
Fuel pump was pegged at 8psi. Tried a 9psi run and had to abort due to plumetting fuel pressure.

Snow tires were still installed on the car(its his daily driver!!!). These were a huge drawback for power getting to the ground.

Three days later the customer is reporting nothing but great results! I'm thinking he will adjust to the crack pipe and be back soon for an addtional fuel pump.

07-08-2011, 10:46 PM
Very nice results. With a proper fuel pump it should make over 600rwhp at around 10# with no problem.

07-09-2011, 06:53 AM
Easily. I don't know if it's because I was on low quality 92 octane, but the car liked timing down around 12 degrees. I was hoping to run up around 15-18, but the car likes what it likes.

07-09-2011, 07:30 AM
Baseline pull at 8psi:
http://a5.sphotos.ak.fbcdn.net/hphotos-ak-snc6/269813_189612507758461_146390618747317_463415_4070 399_n.jpg

After timing adjustments, tires started spinning at 8psi:
http://a1.sphotos.ak.fbcdn.net/hphotos-ak-ash4/268093_189612877758424_146390618747317_463417_6990 60_n.jpg

9 psi attempt. Tires spinning, fuel pressure dropping, so the run was aborted(good thing!):

http://a2.sphotos.ak.fbcdn.net/hphotos-ak-snc6/264282_189613204425058_146390618747317_463418_4655 187_n.jpg

07-09-2011, 04:46 PM
How do you plan on keeping IATs reasonable without constant filling that intercooler with ice?

07-10-2011, 06:48 AM
These aren't transmission coolers....

http://a3.sphotos.ak.fbcdn.net/hphotos-ak-ash4/262127_184804018239310_146390618747317_447879_7657 727_n.jpg

07-10-2011, 09:08 AM
I know they aren't. You think that will be enough? Dumb question I guess, you obviously do :)

07-10-2011, 09:09 AM
Do you have any detail pics of the coolers?

08-09-2011, 08:51 PM
being new to michigan i wouldnt mind swinging by the shop and seeing some of that work in person.

08-09-2011, 09:31 PM
Wow, nice work.

08-23-2011, 11:40 PM
After timing adjustments, tires started spinning at 8psi:
http://a1.sphotos.ak.fbcdn.net/hphotos-ak-ash4/268093_189612877758424_146390618747317_463417_6990 60_n.jpg

Wow, I know dynos are different, so it may have something to do with it, but I thing the extra displacement is the big difference in that car and mine. I'm running 8.5psi and 93 octane. The torque on that car is 150ftlbs higher than mine at the 3385 mark. Very nice.

09-12-2011, 09:44 AM
Thanks!! I sized the turbos to the customer's needs as well, ie, pretty small.

The customer called me with a big exhaust leak concern; my heart dropped. Come to find out, he ripped a Vband clamp off going through a carwash. All is well! I'll be stopping by to check his tune in the next week, as it's getting cold, I want to make sure everything is functioning as its supposed to.