Cantech Automotive

A fast road car is a lovely thing and for the majority of performance enthusiasts the capability provided off the shelf is more than adequate for any public road. Very few cars out of the box can turn this road prowess into usable track performance, the Porsche GT3, Z06 Corvette, Ford Mustang Boss 302, and BMW M3 CSL prove exceptions from the norm. Here at Cantech we see track vehicles often and provide tuning options to optimize a car for the heavier demands of track use.

A customer of ours has a very unique car and has caught the track day bug bad. The car is a Pontiac G8 GXP. A limited production 4 door saloon very similar to the Australian born Holden Commodore. The beast already has big Brembo brakes, an aluminum block LS3 V8, and the ubiquitous Nürburgring tuned chassis.

 

Pontiac G8 GXP

  Holden Commodore HSV E3

This car is proving to be quite the monster on the track. It has already been equipped with upgraded engine internals and a supercharger boosting output to near 550 horsepower. After consultation with the owner we learned that while the car devoured any straight, corner exit speeds were slower than would be expected, and there were signs that the rear end of the car was experiencing unwanted geometry changes under hard acceleration and cornering.

The rear subframe is flexing in the chassis to the point that this bushing is contacting the body, as can be seen by the grooves in the upper right.

 Here is the rear subframe of the car with bushing inserts installed. Control arm, trailing arm, and radius rod bushings were replaced with solid polyurethane. The subfame bushings seen above used an insert that stiffen the existing rubber units.

Though the G8 chassis is very similar to the latest generation Camaro, we learned during a previous visit of this car to the shop that very few parts developed for the Camaro work on the G8. Fortunately there is a company with roots in Australia that offers a bevy of go fast goodies that are compatible. Pedders (www.peddersusa.com) has been in the suspension tuning business for over sixty years and has an extensive line-up of products for the G8. The folks over at Pedders were very helpful with recommendations and provided much appreciated support that was provided to us and the vehicle owner. A package was put together to address the excess chassis flex that included a comprehensive bushing kit and in order to fine tune the ride on the track a gorgeous set of coil-over shocks/struts were purchased.

Pedders Supercar Coil-overs provide adjustment for compression and rebound damping plus independent spring pre-load and ride height tuning.

While the GXP was here our customer requested mounting and match/mount balancing of new Hoosier slicks and Hankook rain tires on some lightweight OZ Ultraleggera wheels.

 

Pedders Supercar Coilover kit. Top photo:Front ; Lower Photo:Rear . Red polyurethane bushings help to quell unwanted flex.

Aggressive alignment Specs provided by Pedders Suspension based upon their experience with the chassis.

Final ride height-shown with stock wheels and street rubber.

Track season will soon be upon us and we look forward to hearing reports from the owner of this car concerning feel, stability, and trap speeds. Preliminary test drives show a car that is more eager to turn in and a more stable rear end less likely to do the chicken dance on track. Stay tuned right here as this car progresses closer and closer to race spec.

An unsettlingly common problem on various Porche motors manufactured between 1997 and 2008 is the failure of the IMS (intermediate shaft) bearing. A customer of ours brought in his Boxster for a clutch and we found that his RMS (rear main seal) was weeping and needed replacement. We recommended that he also upgrade the IMS bearing since the majority of labor for an IMS bearing retrofit is accomplished after removing the transaxle.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The intermediate shaft runs below the crankshaft and is responsible for camshaft rotation through a chain or gear drive depending on engine. This hollow shaft spins on a bearing that is mounted below the RMS (rear main seal).

 

 

 

 

 

 

 

 

 

 

 

 

IMS bearing failure has been attributed to the choice of bearing for the application and/or a lack of lubrication caused by seal failure that allows the permanent grease in the bearing to be washed away by engine oil. This engine oil, which was not intended to lubicate the bearing, is not pressurized enough to provide adequate lubrication. Catostrophic engine damage may be the result of IMS bearing failure as the bearing literally tears apart and metal detritus travels throughout the motor.

 

 

 

 

 

 

 

 

 

 

 

 

As can be seen in the photo below, the intermediate shaft is hollow. The IMS bearing outer race presses into the hollow shaft with an interference fit. Unlike many bearing applications, in this instance the outer race rotates and the inner race remains stationary. In extreme cases of bearing failure the intermediate shaft may develop a wobble so severe that the bearing bore may be damaged beyond repair or even skip cam timing.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

A proven, preventative upgrade has been developed by LN Engineering. The replacement bearing uses ceramic balls and an open design that utilizes the small amount of oil available for lubrication. This bearing was created for and thrives in a low lubrication environment and has much better heat tolerance and distribution of load than the oem design.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Our customer now has the confidence and needed insurance against a catastophic IMS bearing failure for his sportscar investment.

 

 

A couple of great customers of ours track their F430 Scuderia’s extensively. The carbon ceramic braking system that Ferrari equipped these vehicles with works fantastic but is pricey to replace. The gents who run these cars were replacing brake pads every two track events. A more cost effective solution is GiroDisc’s steel rotor conversion. Utilizing the stock six piston calipers, the GiroDisc system requires no major modifications and the vehicle can be returned to stock quickly and easily.

The conversion kit was installed on two of these F430 Scud Missiles.

 

Due to differences in coefficient of friction, the steel rotor is able to provide the same level of braking with less pad material. In the below photo, notice the difference in swept area of the brake rotor and pad size.

The increased diameter of the steel rotors required a relocation of the calipers. Ferrari designed these cars with a radial mounted caliper. This eased the install and required very little hardware to accomplish the correct position. We have found this does limit the choices available for aftermarket wheels.

 

The owners of these cars report that braking with the steel rotors yields a positive pedal feel with better initial bite, good modulation, and no discernable fade. Both customers who had their cars undergo the conversion are very pleased with the braking performance and longevity offered by the conventional rotors.

Ferrari fans rejoice as Fernando Alonso took his first win of the season at Silverstone. Alonso took advantage of a Red Bull pit error to score the win.

 

 

Find out more