Almost Live G8 Pedders Build

[Pedders USA]

G8 Evaluation

The Pontiac G8 arrives from Australia in GT / Sport Package trim with the front ride height at 660mm and the rear ride height at 559mm. It sits rather tall as though it were an AWD sedan. These heights are deceptive in that the rear wheel arch is lower and smaller than the front. The result is that while the ride heights are virtually identical the rear of the vehicle sits considerably higher than the front. It sits high in the bum. The OE dampers fitted to the G8 are NG – No Gas. These are basic oil and air units installed to keep the price point down – perhaps due to the increase strength of the Aussie dollar.

My initial drives of the G8 left me both impressed and disappointed. The VE chassis delivers almost everything we expected and yet disappointed at the same time. It is a tiger that feels tamed - it feels light and floats in sweepers and at high speeds. This is the Pontiac flagship and I wanted this tiger to claw through a turn. The car sits too tall, is sprung too soft, damped too light with a too much body lean and roll in. Even the ride is too light in my opinion

The all new rear suspension architecture is excellent. The integrity of the chassis design adds depth to the driving experience. The rear suspension has sufficient structure to support the most aggressive driving. The three point differential mount is a significant improvement over the GTO. The sub-frame attaches with a four point mount. The upper and lower control arms are another significant advance over the VZ chassis. Adding trailing arms puts the G8 on another level.

The front suspension is more evolutionary than the all new rear design. The familiar GTO strut assembly mounts to the vehicle with the exact same strut mount as the GTO. The lower control arm runs from the knuckle to the front sub-frame. The radius rod Z bar GTO design has been replaced by a more modern arm. The radius rod mounts to the front with a steel-jacketed hydraulic bush. It ties to the knuckle with a joint.

The G8 uses a virtual pivot point suspension in the front. The benefit is that the wheel pivot is moved out from the inside of the clevis / knuckle to a virtual point of intersection that is closer to the outside of the tire. Where the GTO plowed through turns the G8 storms through turns. The scrubbing that was typical on my GTO with a highly tuned complete Pedders suspension is gone from the OE G8 suspension. This is a direct result of balance -- the weight distribution is spot on – almost 50/50 though most magazines have weighed the G8 in at 51/49 – chassis integrity and a more advanced design.

The G8 is an excellent car in OE trim. It has the potential to be dramatically better. While the GTO arrived in the USA with a more traditionally tuned performance suspension as would be expected in a performance coupe. The higher than the sedan version of the VZ chassis coil and damping rates were judged to be too soft for a performance coupe by many owners in the USA. The G8 arrives as a performance sedan. The difference in obvious is ride heights, spring and damping rates. On your first G8 test drive you will notice that there is an enormous amount of body lean and roll. This is directly related to ride height, spring and damping rates. With smooth driver inputs and modest amounts of throttle the G8 will blast through twists and turns. As a driver you must ignore the lean and roll. The car will go where you point it.

If you accelerate hard out of a turn you will identify the primary weakness in the G8 platform. The rear –sub-frame connectors allow far too much twisting and turning of the sub-frame in relation to the monocoque. This is very different from the GTO. The new G8 sub-frame mounts to the monocoque with four sub-frame bushes. The G8 rear suspension design is similar to the excellent Mercedes derived Chrysler LX platform (Charger, Magnum, 300C and Challenger). The sub-frame bush squirm does not explode in violent wheel hop as you would encounter in the GTO. In the G8 the sub-frame motion results in rear end step out and rear end bumpsteer. This is evident when you run an aggressive slalom using heavy braking and acceleration.

Judging the G8 by the spring rate, damping rate or body lean in relationship to older less advanced vehicles would be a mistake. The bone stock G8 is a more advanced design that performs better than the previous generation GM / Holden / Pontiac VZ chassis.
Suspension is always subjective. What is too hard for some will be too soft for others. The G8 in GT trim with a Sport Package feels too light and floaty to me. The car leans an enormous amount, but does hold the line through tight turns. High speed cruising feels just a bit light. It is not in any way unstable, but it is too light for my taste. It doesn’t inspire the same confidence you would experience in a Benz or BMW. Just as the GTO was a significant step up in the GM performance coupe tradition from the F-Body the G8 is a huge advance from the GTO. There are differences of substance. The G8 should be a smooth ride luxury performance sedan. If you are expecting ZO6 Corvette flat corning, you bought the wrong car. If you were expecting a BMW the G8 is close but not close enough.

G8 Low Hanging Fruit

1. Sub-Frame Bushing Inserts, Pedders EP1169
2. Front and Rear Lowering Coils: Pedders 2954 & 2955
3. Pedders GSR Front Struts: 9464L & 9464R
4. Pedders GSR Rear Struts: 9295
5. Front Castor Correction: 5421

Adding Pedders sub-frame inserts to the G8 completely changes the character of the vehicle. GM did it right with the mounting point. The G8 sub-frame mounts with two long ‘pilots’ from the monocoque passing through the larger rear pair of sub-frame bushes. The installation of these eight inserts seemed to reduce the trace amounts of noise from sub-frame to monocoque contact under extremely aggressive maneuvers. The car becomes significantly more predictable which is a surprise as the platform was already very good. Pedders engineers did a brilliant job of using the existing sub-frame bushes. This simplifies installation and reduces your completed costs for parts and labor. This is hands down the biggest bang for the buck mod for the G8.

With a more predictable rear suspension from the installation of Pedders EP1169, your next limiting factor is the ride height and damping rate. The G8 is a luxury performance sedan. You don’t want top turn this world class vehicle into a boy-racer kidney-belt required hot rod. To that end the changes in ride height for the G8 are roughly 20mm in the front with fresh Pedders 5851 strut mounts and 40mm in the rear. These changes allow the car to sit with a slight front to rear rake 622mm rear and 640mm front.

The G8 does use the same strut mount, the exact same strut mount as the GTO. We are finding 4 to 6mm of compression in fresh off the boat G8s. A modest increase in spring rate paired with Pedders nitrogen charged GSR dampers bring the G8 to life. Pedderised it drives like true performance sedan while retaining a luxury sedan like ride. It is easy to drive this car hard. The light sensation at high speed is gone. The rear step out, the rear bumpsteer, is banished. Suspension travel with your lowered ride height is long enough to be supple over most any road while delivering an amazing driving experience. Does it have more body lean and role than a maxed out GTO – it does. Does it ride better than a GTO – yes it does. Does it drive better than a GTO – yes it does.

Because the Pedderised G8 is so quiet and composed, high speeds seem to occur in slow motion. The G8 is a serious vehicle for the sophisticated driver that truly appreciates sophisticated automobiles. Because it is so balanced the Pedderised G8 is almost effortless to drive. Stability and Predictability are the primary characteristics that will leave you with SEGS. Take your time and learn the limits of your newly Pedderised G8 on a road course or an autocross. A Pedderised G8 is as weapon of higher priced vehicle destruction with minor suspension upgrades.

Concerns

There are some concerns I have after getting into the G8 Pedderisation. While the wear of the OE strut mount bush in the GTO is well documented, there is some cause for concern with the use of the same mount in the G8. In the GTO, the upper spring perch / bearing plate had a rather modest angle. In the new G8 the upper spring perch / strut bearing plate is on a more aggressive angle. This increases the clearance between the strut tub and the tire sidewall. There is no cause for concern that we will see strut rub in the G8. What we will see, in my opinion, is wear in the strut mount as a result of the increased load on the strut mount from the angle of the spring perch / bearing plate. New information from GM indicates the design of the G8 bearing plate / upper spring perch will decrease the loads on the strut mount. When examined out of the car, it appears to be under load before being installed in the vehicle. According to GM, when installed in the vehicle there should be less load on the strut mount bush. We will all know from real world experience as we accumulate miles on the Pedders G8 and see more G8s with miles iin Pedders Shops in the USA and AU. The update from Pedders Shops in AU -- they are seeing no unusual where on the G8 OE strut mount bush.

Before we wring our hands about this, the removal and installation of new strut mounts is roughly a 90 minute job. Replacing the mount with an OE or Pedders bit will be roughly $80 in parts. That is a small price to pay in annual maintenance cost to drive such an exciting luxury performance sedan. If you visit the BMW forums you will find that BMW has numerous issues with various suspension bushes. Even the ultimate driving machine has bush failures. Once again it is my opinion that the driving style of the performance luxury sedans contributes to the issues. Performance vehicles require performance based maintenance programs. An annual alignment, strut mount replacement including parts and labor is less expensive than picking up a cup of coffee at Starbucks on your way to work.

On two of the G8s I have seen on racks, the driver’s side parking brake cable was stretched across a hard metal sub-frame edge. GM / Holden / Pontiac seem to be aware of the chafe potential. The cable is protected by a yellow plastic anti-chafe device. These two cars had already shown signs of wear in the yellow plastic. We wrapped them with a piece of heat hose zip tied in place. It is a short list of concerns.

Pedderisation: Pontiacs, Businesses and People

Pedders USA, LLC will be campaigning a Pedderised G8. I pick up and Pedderise my new G8 at Brian Harris Pontiac Buick GMC on April 8, 2008 – THANK YOU William Southall!. With the help of their lead Pedders technician we will install a full Pedders eXtreme Suspension before my family and I drive our new G8 from Slidell, Louisiana to West Olive, Michigan. We’ll post photos of the car before, during, after and include our road trip. That is the first leg of our trip in the G8 build.

Step #2 With the assistance of Disc Brakes of Australia (DBA) we will be installing a DBA Big Brake Package.

Step #3 is courtesy of ProCharger, our original marketing partner. ProCharger will prototype and install their G8 forced induction system. Sounds familiar, doesn’t it?

Step #4 Corsa will handle the exhaust. I love the G8 quiet cabin, but this tiger does need a bit more growl….

Step # 5 Early on, we’ll be adding coolers for oil, trans and power steering. We have yet to determine what we should do with the interior, tires and wheels.

Step #6 More Road Trips and Events! The Pedders USA, LLC G8 will be on the Hot Rod Power Tour, the GTOAAs, the LX Nationals in Ohio, the Camaro Superfest and a couple of other events before the year is over.

As I close this initial installment of Pedderise My G8, I want to mention how excited I am to be involved with Pontiac community, the GTO community, G8 Community and the automotive community. Our car culture is an amazing blend of diverse groups of people with a common interest. The G8 project will take me to places I had never dreamed of and people that I would never have met as did my original journey with my GTO. As many of you know, I lost my mother last month. The support provided from people I would never have known had I not become involved with the GTO and Pedders was incredible. In 2008 armed with a G8 and a GTO I can only imagine what the year will bring. Life is an adventure best traveled in a Pedderised Pontiac!

#####

We took delivery of the Pedders USA, LLC G8, GT, Sport & Luxury Package. It didn't move. William Southall was expecting my family and the car was already in the #1 service bay. Having already drive a number of G8 GTs and GT + Sport Package we know the car. The starting ride heights were 660mm in the rear, 658 LF and 655mm RF.

We are doing an eXtreme setup on this G8. You can review the parts and packages here: http://www.peddersusa.com/Pontiac%20G8%20Zeta.htm

Track eXtreme
2955 GM Zeta Rear Spring Ride Height: 642mm with 19" Wheels $ 89.62
2955 GM Zeta Rear Spring Ride Height: 642mm with 19" Wheels $ 89.62
5422 GM Zeta Extreme toe link - inner lock washer $ 77.95
5030 Strut Bearing, Two Required. Yellow to Spring. White to Strut Mount $ 38.57
5030 Strut Bearing, Two Required. Yellow to Spring. White to Strut Mount $ 38.57
5421 GM Zeta Extreme Control Arm - Caster Lock Washer $ 77.95
5851 Strut Mount, Requires 2 packages $ 42.99
5851 Strut Mount, Requires 2 packages $ 42.99
E9295 GM Zeta Rear eXtreme Coilover $ 581.64
E9295 GM Zeta Rear eXtreme Coilover $ 581.64
E9464L GM Zeta Front eXtreme Coilover Left $ 582.22
E9464R GM Zeta Front eXtreme Coilover Right $ 582.22
EP1167 GM Zeta Differential Bush Kit $ 108.36
EP1169 GM Zeta Extreme Sub-Frame Connector Kit $ 238.99
429006ADJ Kit GM Zeta sway bar Heavy duty adjustable kit $ 649.87
EP6560 Radius Rod Bush $ 161.59
EP6561 GM Zeta Front Control Arm Bush - Inner Bush $ 134.98
EP7265 GM Zeta Trailing arm - Front $ 96.20
EP7266 GM Zeta Control Arn Rear Lower Outer $ 96.20
EP7267 GM Zeta Toe link - inner $ 96.20

The complete system is $4,400







We'll be doing almost live updates as the build propgresses. During the build we are doing a Shop Certification and Sales Education. It will take a bit longer than a normal installation.

G8 Evaluation and Pedderisation

Over the last week we have started Pedderising G8s in the USA. My personal G8 will be a GT with the Sport Package and Sunroof – Pedders style. If you have seen the Pedders GTO, you’ll know what that means. Before any one even thinks about it, and that includes my wife, the G8 is an addition to our garage. You’ll see both of us at a number of events this year. Both of us meaning the G8 and GTO. We will start with the driving impressions of a bone stock G8 with the Sport Package.

[Pedders USA]

Brian Harris Pontiac Buick GMC is located in Slidell Louisiana. William Southall is the primary Pedders conact and a ProCharged GTO owner. He has an arrowhead tattooed on his.....

William Southall
Brian Harris Buick GMC Pontiac Mazda
293 Howze Beach Road
Slidell, LA 70461
(800) 773-0831

williams@brianharrisslidell.com
http://nitra.gmpsdealer.com/brian-harris/en_US/

The Lead Pedders Tech is Kenric for the G8 build.













The most important person to me today as he holds my life in his wrenching skills Kenric the Lead Pedders Tech.

[Pedders USA]

Once the rear suspenion is stripped we start with the upper inner control arm bushes, the sub-frame bushes, the trailing arm bushes and the upgraded sways.
The OE Rear Upper Control Arm Inner bush is voided fro NVH reasons. There is minimal front control surface. There is minimal lateral support.



The Peders EP7263 is vioded for NVH reasons but offers substantially larger control surface.

[Pedders USA]

Suspension is all about stability and predictability. Making a suspension rock hard does not increase stability or predictability. Rock hard is only good on pavement as smooth as glass. To have stability and predictability in a street driven vehcile that has limited tire contact patch in comparison to race prepared vehicles requires controlled compliance. The design of Pedders G8 suspension components delivers more than just stability and predictability. It delivers a phenomenal ride.

The rear OE sub-frame bushes on a GTO required replacement to correct severe axel tramp. The rear sub-frame bushes on a G8 require upgrading to increase stability and predictability. The advances in the ZETA platform rear IRS control wheel hop quite well. The voided limited control surface OE sub-frame bushes allow the rear sub-frame to squirm under load. They create what some would describe as rear end step out when navigating bums in turns or when accelerating over pavement irregularities.





You can see the small control surfaces in these pictures of the OE rear sub-frame bushes. What yo can't see is how liable they are. With a four pint mounting system, the rear of the G8 is reasonably stable -- for the reasonable driver. There is no such thing at Pedders and if you are reading this you did what we did last weekend at the track... Unlike the GTO that required full replacement of the OE rear sub-frame bushes the Pedders EP1169 sub-frame bush kit consists of eight inserts. The sub-frame is dropped low enough to insert the upper urethane bushes. The lower metal caps are pried out of the OE rubber and the Pedders inserts clocked an inserted.





The difference is nothing short of amazing. The G8 comes out of the blocks in OE trim as a well mannered sports sedan. Installing Pedders EP1169 Sub-Frame Bush Inserts transforms the car. Accelerating on most any pavement is completely predictable. eXtreme slalom maneuvers become almost mundane. The limits of the car grow disproportionately to the the bits. A Pedders EP1169 is the single biggest bang for the buck money can buy for the G8. In terms of NVH -- I can tell no difference. I am deaf in my right ear. Mike White a.k.a. dms could also tell no difference -- but he is deaf in his left ear. So we tossed Brandon in the car and he isn't deaf -- but we couldn't get the car over 20 MPH with him in the car. So we grabbed William Witt and he confirmed what we already knew with his well functioning ears -- the is no difference in the NVH, but there is a huge difference in the stability and predictability of a G8 with EP1169 sub-frame inserts installed.

By the end of the day we were behind in our build. Two of the rear upper control arm bracket bolts had been galled when installed at the factory. Vic and Kenric patiently worked through the removal of the damaged bolt, tapped both holes and chased the threads on the bolts. The location made this especially challenging and set us behind about two hours. We'll get back at it in the morning and I should have my driving impressions of the eXtreme system posted tomorrow.

Kenric and Vic -- here is a big THANK YOU for the extra effort. They tell me it is all in a days work at Brian Harris Pontiac Buck GMC Pedders.

[G8V8]

Great stuff. Keep it coming!

[batwood]

What do you mean Pete,

Over 20mph. I think we were going quite a bit faster than that

[Frank@Rocksand]

Looks great.....Frank

[Pete]

It has been a rough todays at the shop. We lost power for hours both days. The power surge fried the alignment computer. We did most of the installation with hand tools becuase of the power issues... The car is on the alignment rack right now. The computer si working and I have a lot of pictures to post. Stay tuned.

[Rob@WretchedMS]

don't you love when that happens

[Pete]

The power outages gave me some insight into doing this job at home. Had tools are cruel and unsual punishment.