Tuesday, February 28, 2012

Set Up Part 4: Suspension & Handling for the AP2 S2000

The S2000 is blessed with the combination of a stiff chassis with race derived suspension design which makes it a very able candidate for the building of a race track performer. Having come from a coilover equipped 4WD turbocharged sports sedan, I did feel there was some room for improvement in the overall setup as it seemed to me that the shortfalls in the production car were attempting to address both sporty handling while hoping to still provide a modicum of comfort within the production budget of the car. It suffices to say that the final result may not have won many fans on either end of the spectrum. I decided to focus my attention on building handling to optimize it's track ability eschewing the comfort part of the equation as this car would spend much of its time at the track.

The tyres on the stock S2000 are the Bridgestone RE050, which must not be confused with the more grippy Bridgestone RE050A, and come in 215/45/17 front 245/40/17 rear. Feeling that the front lacked turn in and tyre grip, I decided to go for a non-staggered setup with 255/40/17 tyres all around which I have detailed here . The result was vastly improved turn in and grip far above what the stock tyre configuration could achieve. Realizing that tyres are probably the most critical part of the suspension, I went with the choice of the razor sharp feeling Advan Neova AD08 which cost me about 380 SGD per piece. An all round performer, this tyre wears at a very reasonable rate while delivering class leading wet & dry grip even when worn down past the tread markers.

Next up, I focused on the suspension and since my heavy track use over the last few years had pretty much worn out the stock suspension, I decided to replace this with a six month old second hand set of Tein Super Racing Circuit (SRC for short) Master coilovers which I had managed to purchase from a fellow S2000 track buddy. Brands such as KW, JIC, Bilstein and Ohlins had suspension models selling in the 3000 SGD range that I did consider but realized that since the suspension choice would be crucial for my handling on the track, it would be best to go with a suspension that has been proven on the track. I did briefly look at the Ohlins TTX but this quality comes with a very steep price and I rationalized that I would not have much left over to develop the rest of the car should I opt for these.

My choice of the Tein SRC's come with 16kg/mm spring rates front and rear which may seem overly stiff for the street yet damping seems to be relatively compliant which makes it bearable in terms of comfort while managing the bumps of the street pretty well. The recommended ride heights for the Tein SRC are far too low to be running daily on the street so I have had the suspension raised to clear day to day driving with the aim to lower the car as recommended the next time I hit the track. The external canister design of the shocks helps cool the suspension and the short stroke design of the suspension is clearly a track derived design originating from the Tein N1 race coilovers. Although I have not had very long track sessions on this suspension due to unfortunate disruptions in my track schedule, I am confident from the winning track record of s2ki.com competitive trackies that this will be a key component to help me outhandle the competition.

With the non staggered setup that I am running, the alignment I run would correspondingly need to be altered to match. After researching on many settings for camber and toe, I finally settled on a setup with the following numbers:
Front Camber 3.0
Front Toe 0
Caster : Max (usually ~6-6.25)
Rear Camber 3.0
Rear Toe 0'20 per side
These settings are subject to change as I have purchased a LongAcre probe type pyrometer to help determine how well this alignment suits the overall setup of my car. The pyrometer will also put certainty into determining optimum tyre pressures at the track when properly utilized and is thus a crucial investment in sorting out handling. It is rather surprising that little to no people I know actually venture to use a probe type pyrometer to determine and tune optimal alignment/tyre pressure settings which points once again in inherent gaps in the approach in local motorsports with regards to building competitive setups. I have not mentioned any changes to sway bars or stiffening structural bars and the like as it is my opinion that outside of building a full roll cage, the car would not appreciably improve from such fitments. This thought is once again shaped heavily by feedback from s2ki.com amateur racers who openly discuss their winning setups to share with the local community.

I would like to share some thoughts about how my approach to tuning or setting up the car was viewed by "old birds" in the local community as I find a significant gap in the thought process as opposed to search for actual performance when I discussed my setup in the local community. Most make their decision on a brand before even looking into what technology the brand accesses and if that is cost effective to deliver the end result desired. I will not go into length about how many times I faced derision on taking a path atypical from most FR setups (sometimes this derision was backed up by shockingly flawed theory!) but understanding that it is the malaise of the local industry to focus on fiction (hearsay) above fact, I soldiered on resolutely. In short, the typical local build up of a car is a piecemeal bit by bit addition process that is usually disjointed and not particularly focused while relying on potentially outdated theories (often from hearsay) to base the build on.

I hope that the fact that I do specific targeted research to focus my efforts on the current build allows the true potential of the S2000 to be realized with valid fact to back up the principles underpinned. Being heavily influenced by the open ways of the folks on s2ki.com, I look to share my knowledge through the above series of set up pieces and help any S2000 owners on their journey to enhancing the performance above their stock S2000.


  1. Sometimes, suspension handling can be really that hard if brought to the wrong state. You'll need a specialist to do that.

    1. So far I think I'm keeping the settings fairly simple and focusing on the key areas of tyre pressures, temps and the corresponding alignment.

      Being an amateur means I cannot afford the time to constantly test which is why data acquiring equipment helps greatly.

      Having a specialist is great I'm sure if the budget allows but not in my case.