Got Roll? Upgrading the Anti-Roll Bar

The Putra runs a pretty archaic and basic anti-roll bar setup. As you know an anti-roll bar is a very useful component to dial in a car’s handling by controlling the understeer/oversteer characteristics apart from reducing body roll. Mike Kojima’s excellent article on dialing in the ride and handling for a Sentra which has a similar setup) is a useful reference. Uncle Sam people like to call the anti-roll bar an "anti-sway bar" while most manufacturers typically call anti-roll bars "stabilizer" bars in their brochures. They are all the same.

For some apparent reason the 99 year and post-spec Putra runs an 18mm diameter front arb setup with a 13mm rear. Not sure why Proton reverted to this setup as ealier pre-99 spec Putras were running a 23mm front arb. Maybe to ensure the Putra handles inferior compared to the GTi? ;) The Wira/Satria 1.6 and 1.8 runs a similar (23mm front) setup. Compare this to a DC2 Integra Type R for example with 24mm front and 22mm rear 96 year spec setup and 25mm front/23mm rear for 98 year and onward models. BTW the Wira/Satria 1.3 & 1.5 runs a front 18mm arb with no rear arb. You get the picture? Arrrggh! The anti-roll bars use a horizontal blade attachment point and the arb links are merely vertical rods with 2 pieces of rubber to act as the arb bush with the arb sandwich in between. This is the same for the front and rear. Pix of the front arb attachment point below.

The front arb is attached to the front lower arm and the rears also to the rear lower arm. GTI in comparison use a "direct acting" front setup with the arb itself directly connected to the front strut via a ball joint type arb link. The arbs have vertical end blades. The rears also use a similar setup but with the same mounting points as the Putra. The ball joint link is far superior to rubber bushes as unwarranted flex is eliminated. It is however far more expensive than rubber. A set of GTi arb links will cost you RM300+. Per end of car! The end links cost more than the arb itself! If you must know the GTI runs an 18mm front setup and 13mm rear too but the front direct acting setup and the use of much better quality arb end links means the arbs give a much better effect equivalent to going to a bigger diameter bar.

When I upgraded the SP’s arbs I was looking to reduce some roll inherent with the DMS 50mm setup as the double progressive springs are wound pretty soft at the beginning compared to a linear spring setup. I decided to "upgrade" the front arbs back to 23mm stock Proton/Mitsu arb instead of going the GTi route. The Proton/Mitsu part number for this arb is MB844453 and the arb is pretty cheap @ around 200 smackers. Reason is if you go to a larger diameter (>18mm) GTI front arb setup there is a tendency for the arb mount flange on the strut to fail. I am not sure if this problem is only inherent with the DMS shock’s flange but the fact that Mitsu reverted back to the front arbs being linked to the lower arm for the EVO4-9 tells the story. One of my Brudder’s actually cracked that flange twice on the track and had to send the shocks back to DMS for additional welding and reinforcement. Not a nice experience. I also upgraded the "D" bushes (Part No: SPF1572-23K) and the arb end link bushes (Part No: SPF2092BKP) to Superpro polyurethane (PU) items. PU is stiffer than rubber and has way less flex. For those of you in the know, Whiteline already supply Superpro oem PU "D" bushes which come free along with the arb itselft so why am I buying them separately? Pix below shows why.

No offence but no way I'm going to put yellow arb "D" bushes along with my silver arb. They look more like sorbet or egg tart. Got rice? At least the Superpro ones are dark purple blue. If anyone's interested these VERY YELLOW 18mm rear arb PU "D" bushes are yours for RM25. Buzz me. If you must Whiteline sells a stiffer front arb too but at only 24mm diameter I personally feel this is not a big enough upgrade in stiffness ratio for the price you are paying. The part number for this arb is BPF14. Pls ensure you change the "D" bushes to one that allows a 24mm arb.

For the rears I decided on the trick GTI ball joint setup. This means that I will have change and upgrade not only the arb but the end link itself. Now this is going to sound most interesting to those who think the GTI is Lotus Tuned Handling. The part numbers for both Mitsubishi Mirage/Lancer EVO1-3 rear arb end links are the same. Still unconvinced I purchased the links from Proton and a similar link from Mitsubishi Japan to compare. Picture below of the EVO3 rear arb end link and packaging with part number. Make your judgement.

Worse of all PESC is charging bout RM320+ or so retail for a set of these end links whereas I can get a similar set of brand new end links air freighted from Mitsu Japan for less than RM290. And guess what! The same also applies to the fronts! Also purchased new nuts and washers from Mitsu Japan for this project. I decided to go to an adjustable rear arb from Whiteline. Part Number: BPR16Z. An adjustable arb means there are more than one mount holes on the arb end blades for you to adjust the stiffness ratio of the bar by connecting the end links via these holes. The "closer" hole mount point will give a stiffer ratio vs a "further" mount point. The Whiteline adjustable arb has 2 holes. I have seen some setups with 3 holes. And yes, Whiteline sells both adjustable and non-adjutable front and rear arbs for our cars with different diameters. You can look at them all here in Whiteline’s comprehensive on-line catalog
The newer Whiteline arbs have a silver powder coating and look way better aesthetically compared to the Smurf Blue older versions. Quality is pretty decent but I was pretty unhappy bout the end blades. They look uneven compared to say something from Cusco. Pix of my arb below.

Also upgraded the rear "D" bushes (Part No: SPF1826-18K). Pix of the installed setup below. You can clearly see the new GTi/EVO2-3 spec end links and how the arb is connected to the end links. Also in the pix is the purple bling coloured Superpro arb "D" bush. At least it's not yellow. Can hear Coldplay singing that darn song in the background. Urrrgh!

Another pix of the new setup. The project was done way back when I was still using Yokohama AVS ES-100 tyres. Pardon the confusion.

With these upgrades installed, understeer is greatly minimized and you can rotate the Putra during corners far easier than the stock setup. Overall a very worthwhile but expensive upgrade. The whole project cost me in excess of RM1.5K with the Whiteline arb being the biggest hit at 750+ smackers or so a piece. If you think this is not hardcore enough Jacko Whacko is currently on a project using spherical bearing end links. These bearings were actually being passed around for licking during his wedding dinner! Lotsa customized machining being done to fabricate the bearing mount shafts. Sneak pixs of the project below. Just look at these end links compared to the stock GTI links. Farkin Huge! No limits to the Madness!

The longer link is the front btw. Pix below of the rear arb setup on a Realtime Acura RSX aka Honda Integra DC5 touring car participating in the US World Challenge Series. The arb blade and end link is shown in the red bordered box.

The arb is in the boot itself and is an adjustable hollow tubed assembly. Still the arb rate is unbelievably stiff. If engineered correctly a hollow tubed arb can be made lighter while maintaning the same stiffness as thinner solid tubed arb. Also noticed that there are no bends on the arb as there is no need to clear chassis and suspension arms in this setup. Not sure of the material used for the arb but on World Rally Car's it's titanium.
Another pix of the rear arb link and the funky looking rear suspension arms. The next time a manufacturer proudly boasts their Civic, Integra, Impreza, Evo or even the Hyundai Accent RXS is nearly the same as the works car being raced/rallied in top level competition you will know better!

Will talk about my rear suspension arms and links next. And also a feature on Superpro suspension arm bushes. Stay tuned.