G8 Tire and Wheel Package -- 275/35/19 on 9.5x19 W

**JusticePete** · 12-12-2008, 10:36 AM

We have now completed three more upgrades to Pedders USA Pedderised and ProCharged G8:
Forgeline 19x9.5 ZX3 Wheels
Bridgestone Potenza REO50A Pole Position 275/35/19 XL W
Eg Calssics Grilles

Working with Dave Schardt we developed a set of light weight 19x9.5 inch set of wheels for our G8. Our Forgeline ZX3 wheels use titanium bolts and military-spec lightweight jet-nuts to reduce weight in the most critical point - the perimeter of the wheel. The forged wheel center also has unnecessary aluminum removed to reduce the weight as much as possible without sacrificing strength. And to optimize further, the rim material is lighter and stronger with the use of 6061-T6 aluminum.

Our new wheels were tested using computer stress analysis. The computer model enables Forgeline to analyze the design under a simulated load and optimize it before machining begins. ForgeLine centers are created using a 6000 ton hydraulic press - a modernized version of forging proven successful for hundreds of years. The press forges the wheel center into its general shape. Forging aligns the grain structure, reduces porosity, and increases uniformity in the material, thereby increasing the strength to weight ratio with consistent results. Forging also allows the use of 6061 material which can be heat treated to be 40% stronger than cast aluminum. The wheel centers are then CNC machined to create the design style. The end result is a set of 19x9.5 wheels for our G8 with a 43mm offset that weigh only 20 pounds.

Our G8 rides on Pedders eXtreme Xa adjustable coilovers,with eXtreme Sway Bars and Sports Ryder urethane. Since our initial installation the G8 has been lowered and aligned so many times we have lost count. In OE trim the front ride height was 660mm with the rear at 660.mm. It is now at 615mm front and 585mm rear. Because of the Xa design with height adjustment achieved by screwing the 46mm high pressure monotubes into the clevis / lower bracket ride quality remains the same.

When Pedders designs a suspension it fits. Take out the OE black part and replace it with Pedders red. No cutting, pounding or grinding are required. That was the same standard we set four our tire and wheel package. Because of the excellent work done at Forgeline, the wheel and tire combination fits within the restrictions of our G8's OE sheet metal. We removed the OE 19x8 wheels and bolted on the Forgelines using the OE lug nuts and caps.

**JusticePete** · 12-12-2008, 10:36 AM

Our new 275/25/19 XL W Potenza RE050A Pole Position are loaded with race-inspired technology: UNI-T for outstanding wet and dry traction, a tread pattern that promotes rapid water evacuation, variable dimensions in the tread blocks, and a smooth shape to reduce noise. An asymmetrical pattern in the RE050A Pole Position tread increases surface contact to enhance acceleration and cornering. Put this Potenza through the paces and discover what ultra-high performance really means.

Tie Bar Rib; 3D Shape; Semi-Slick Center Rib
Improves handling response

High Lateral Stiffness Block
Improves cornering

Block & Slick Combination
Improves traction and braking

XL - Extra Load
Most passenger tires are designed for Standard Load Ranges. XL tires are reinforced and designated as such and identified by "XL" in their descriptions, 275/35/19 XL.

W Speed Rating
With the engineering advancements in suspension design demands on tires have increased. W rated tires are designed for speeds up to 168 MPH.

These features are mission critical for our G8. One of our goals is to reach a minimum of 1 G in lateral acceleration on the skid pad. The upgrade from the OE 245/40/19 REO50 Potenza to the Pole Position along with an increase in contact patch should get us there. At our Texas Dealer Conferences on a poorly surfaced skid pad we measured a steady .94 with a peak of .97.

Along with our Bridgestone Pole Positions, our original eXtreme coilovers have been replaced with Pedders new Adjustable eXtreme Xa coilovers. The front ride height is now 5mm lower and the rear ride height is 15mm lower. This has improved the front to rear balance. The alignment has been refined to:

FRONT
Caster +7.75 No Bias
Camber -1.5
Toe -.21 -.19
Total Toe -.41

REAR
Camber -1.6
Toe -.18 -.20
Thrust Angle +.01
Total Toe -.38

This is an aggressive alignment. It works because this G8 is fully Pedderised. We do not recommend these alignment specifications for those that drive G8s with OR suspension or are concerned with tire wear. Pedders uses our G8 as a test vehicle with skilled professional drivers.

Witt Pedders Buick in Muskegon Michigan did an outstanding job with the alignment. The steering wheel is dead nuts straight, turn is is excellent, straight line high speed stability -- it was great before the upgrades and we expect it to be better but the weather has limited our ability to test the new setup. On the highway at street legal speeds the G8 is incredibly planted. It feels rock solid. The difference is significant compared to the OE wheel and tire package. The 36 series profile did exact a toll on ride quality. It was no unexpected and it is a trade-off most enthusiasts would make in a heartbeat. As we get more miles on the setup we will adjust the damping settings front and rear to find the optimal combination for daily driver comfort and handling along with the maximum setup for the track.

With our Forgeline ZX3 Wheels and Bridgestone Pole Positions we achieved a weight reduction over 40 pounds. Reducing un-sprung weight improve virtually all aspects of a vehicles performance. Even though our wheels and tires are much larger the reduction at each is just over 10 pounds. eXtreme G8 Sway Bars are set full hard rear and one off full hard front. These refinements to the alignment along with a wider track and larger tire contact patch should bring us withing reach of our goal.

To give the G8 a more aggressive look to go along with the incredible performance we selected a set of E G Classics grilles. These Stainless Steel Fine Mesh grilles are designed to install over the factory grilles. At Pedders we take things to the eXtreme and that is what we did with our grille upgrade. The upper grille have no restriction. The lower grilles are blocked at the outer edges. Pontiac closed the outer areas to match the duct in the center that directs airflow to the radiator. That lower insert went away with our ProCharger less than a week after we took delivery. We decided to open them up. Why you may ask. There may be brake cooling ducts in the future and it just looks mechanically nasty.

Installation including cutting out the OE material was straight forward. The polished stainless steel trim rings cover the edges of the OE grille work we left to act as the mesh back plate. Installed they are invisible. You do see the channels that front bumper. You can see the same material with the OE grille work. As the OE grilles are black there is little contrast and it is barely noticeable.

The rear E G Classics grille was damaged in shipping. The items were well packed so we attribute this to holiday temporary help or maybe it was air freighted and dropped from an altitude of 35,000 feet. As soon as the replacement arrives we will install it removing the material in the lower rear fascia. We have one or two more tweaks and then we will be Pedderising our 2010 Camaro.

E&G Classics
8910 McGaw Court
Columbia, MD 21045
O 800-394-2774
http://www.egclassic.com/inventory/index.php
http://www.egclassic.com/inventory/item.php?itemid=676
http://www.egclassic.com/inventory/item.php?itemid=711

Bridgestone Americas Holding, Inc.
535 Marriott Drive
Nashville, TN 37214
O 615-937-1000
http://www.bridgestonetire.com/Index....aspx?src=home
http://www.bridgestonetire.com/tires...ProductID=1113
http://www.driversedge.org/

Forgeline Motorsports
3522 S. Kettering Blvd Suite A
Dayton, OH 45439
O 800-886-0093
www.Forgeline.com

**shady milkman** · 12-12-2008, 10:40 AM

nice..i love that rim combo with the g8..you need to get the matching hood nostril grilles so it fits with the rest of the grilles...and maybe not so many eXtemes

..ahh only giving you a hard time...nice work on the G8..good stance and killer looks

**third_shift|studios** · 12-12-2008, 11:19 AM

simply menacing...

**Sweet Chops** · 12-12-2008, 11:33 AM

Over all I like it. But I think the rear sits too low, wheel to wheel well gap.

Ryan

**JusticePete** · 12-12-2008, 03:18 PM

Originally Posted by shady milkman

nice..i love that rim combo with the g8..you need to get the matching hood nostril grilles so it fits with the rest of the grilles...and maybe not so many eXtemes

..ahh only giving you a hard time...nice work on the G8..good stance and killer looks

I have mentioned that to E & G. We'll see what they do. I also want to do cowl induction hood. I have been talking to a buddy. The idea would be a bit old school. The style lines on the hood could be but. We would add in a fillet of metal starting about 1" higher in from the windshield. The modest bulge would not be over done, but it would be functional.

I would be interested in hearing what you think.

**JusticePete** · 12-12-2008, 03:22 PM

Originally Posted by Sweet Chops

Over all I like it. But I think the rear sits too low, wheel to wheel well gap.

Ryan

Ryan,

It is not classic muscle for sure. We arrived at this height as we dialed the car in for optimal handling. It has taken me a while to get used to the stance. The response at the steering wheel has convinced me to get enjoy the look. It will be interesting when we start setting up 5th Gens. Will the 5th Gen owner accept this look if it is accompanied by amazing handling?

**Sweet Chops** · 12-13-2008, 12:19 PM

I see what you are saying. I guess I would get use to it, if it means I would enjoy the ride more.

Ryan

**Sweet Chops** · 12-13-2008, 12:25 PM

One other thing, how is a G8 in snow. I am talking stock ride height with stock wheels and tires. My wife loves the G8s and in about a year we will be looking for a new car for her. Its time to get rid of the GTP. I just don't feel she would be safe in a RWD car in winter.

Ryan

**shady milkman** · 12-15-2008, 05:00 AM

Originally Posted by JusticePete

I have mentioned that to E & G. We'll see what they do. I also want to do cowl induction hood. I have been talking to a buddy. The idea would be a bit old school. The style lines on the hood could be but. We would add in a fillet of metal starting about 1" higher in from the windshield. The modest bulge would not be over done, but it would be functional.

I would be interested in hearing what you think.

i love the stock g8 hoods..but i am digging the idea

**JusticePete** · 12-15-2008, 12:43 PM

Originally Posted by Sweet Chops

One other thing, how is a G8 in snow. I am talking stock ride height with stock wheels and tires. My wife loves the G8s and in about a year we will be looking for a new car for her. Its time to get rid of the GTP. I just don't feel she would be safe in a RWD car in winter.

Ryan

With the summer performance Potenza 050 not very good. With winter tires it would be great because it is a well balanced car. I am driving my 275/35 Pole Positions with close to 500 RWHP in the snow and have to be VERY careful. I should say eXtremely careful!