Just how many handling mods are available for the new Dodge Challenger?! Judging by the seemingly bottomless pit of choice upgrades plucked out of the air by Eibach and its supporting cast - apparently loads! Not only is this great news for anyone out there in reader-land running one, or a Magnum/300c, of course but it also means that the American car scene suddenly has a GT/Sports platform to rival the best that Europe can offer - given a few tweaks and a little time and money...
To jog your memory - or to bring new readers up to speed thus far Eibach’s sizeable SRT-8 had been dynamically shrunken with the addition of its Pro-Street S coil-overs and adjustable anti-roll bars. not only had this allowed for a far more aggressive stance, giving the Dodge a real sense of purpose, but perhaps even more importantly, the improvement in lateral stiffness had made the considerable bulk of the Challenger much easier to handle in the twisty bits.
The only problem when you make such a comprehensive change like this is that the new, more brilliant componentry starts to reveal inadequacies elsewhere in the drivetrain. After a full shakedown session at Bruntingthorpe a few weeks previously, Eibach’s UK chassis team still felt a huge amount of inaccuracy in the steering and handling of the car. ‘You can actually feel some of the components moving on their factory bushes when power is applied quickly, or during hard cornering,’ explained general manager, Greg Kirby. Not only is this reducing the effect of the accuracy we have achieved with the Pro-Street S coil-overs and the anti-roll kit, but it also doesn’t really inspire any confidence when driving at speed. We need to change that.’
As is often the case with these things, the answer comes from the track. Eibach’s technical partners SuperPro make an extensive range of polyurethane bushes for a wide range of cars, fortunately offering a simply bewildering away for this Chrysler platform(1). In days of old urethane was always a mixed blessing on a road car, with the precision and lack of movement being a real boon, but the noise and harshness created by its fitment being anything but! Thankfully, moulding and plastics technology has moved on considerably in the last decade or so and these days, thanks to a top-secret formula more closely guarded than even Tony-the-Tiger’s Frosties recipe.
SuperPro has managed to achieve an impressive balance where ride quality and refinement are barely affected, but precision and feel move up several notches. These aren’t just your author’s findings either - the range has recently been granted ‘Official Accessory’ status by Subaru UK after the product had been tested proved to be a huge advantage dynamically, without any NVH issues. So, if it’s good enough to gain manufacture approval, you can probably guess that it’s more than up to the job in the aftermarket!
As the pack shot shows, there are an awful lot of bushes in the SuperPro kit. Every single rubber bush on the Dodge can be upgraded if required, which are you can imagine, is quite some job. Not only is this all made considerably easier with the right tools, which we will come to in a minute, but also with the right talent. Stepping into the breach once again for the camera. They work pretty fast, these guys!
Unbolting most components on the Dodge was still thankfully relatively easy, with the car being so young(3). Carnetix has an impressive set of press tools which allow each old bush to be precisely pressed out without damaging the arm that it came from - and then ensuring that the new bush can be re-fitted without any damage to its outer shell(4). The care and attention that was taken here was truly impressive - everything was measured and checked (5), correct threaded extraction tools were used for inaccessible bushes and every arm had its surface rust removed (6) before being coated with black paint to ensure that the corrosion is kept at bay, before being refitted (7).
As well as the inner and outer control arms, trailing arms and every single suspension pick-up point, the SuperPro kit also included uprated damper top bushes for the rear (8) and even steering rack bushes (9)! Any factory bush that has a load-bearing steel shell is faithfully replicated in higher quality urethane, but many of the other bushes are recreated in a much simpler-to-fit ‘halved’ design that simply bushes in each side of the carrier before a crush tube is slid inside after being well lubed with the special grease supplied (10).
As one would expect from an outfit of this level of ability, nearly every bolt was only ‘nipped’ whilst the car was in the air (11). ‘We don’t torque anything until the car is on the four-post lift and under load.’ Said Glenn with a serious look. ‘it’s the only way to ensure the bushes are sitting correctly and you’re not inducing any pre-load into each component from the bush acting like a small torsion bar.’ Once everything had been fitted, checked, and re-checked, Becky moved the car onto the four-post lift to allow for final fettling and precise torquing up.
Dave then fitted the light plates for the Hunter rig(12) which allowed for toe and camber settings to be adjusted to get the car pointing in the right direction. The team spent well over an hour on this bit making sure everything was perfect(13), before rolling it out into the Autumn sunshine to allow us to try difference for ourselves. Driving the Dodge on the superb Leicestershire back-roads around Carnetix revealed what a very worthwhile exercise this had all been . Gone was the ‘slop’ of the factory bushes and in its place was a very palpable feeling of being viscerally connected to the moving parts of the car. The steering suddenly felt very precise and direction changes were communicated back in a most un-American way. Best of all, as promised on the packaging, the SuperPro bushes have in no way trashed the ride quality. Sure, it’s a little bit stiffer than the factory’s ‘chewing gum’ offering, and there’s a tiny bit more road noise, but neither are in any way an issue. In fact, conversely, the ability to ‘feel’ the road through the Challenger’s chassis now encourages much more spirited cornering, with the car really letting you know what’s happening and allowing you to explore the grip much more. So, yet again, another worthwhile mod and a great one for many of you to consider out there. Each of those bags can be bought separately, so you can spread the cost and effort over a longer period if you don’t have a team like Carnetix to fit them for you... but our advice? Give them a call and let them sort it out. Their attention to detail, alignment skills and constant supply of chat and tea will make the trip to the Midlands worthwhile!
Source: American Car Magazine
