Sunday, December 30, 2012

Final(e) Stage…Rain battle!

December heralded big hopes for the beginning of my push for competitive rankings among the local scene of trackies as I had emerged from November with an excellent time of 2:38 on a slightly damp Sepang track while data analysis showed I still had some way to improve so lower times were highly possible. Having signed up for ZeroToHundred Time To Attack Finale, I was very keen to show my mettle on the time attack stage and hopefully take a podium position or two back as a sign of progression.

Accompanied by my friend Wayn riding shotgun, we made a fuss free 300+km drive down to Sepang on the morning of 16 December and were excited to see the bevy of cars that had descended to take part. The list of cars was endless including the usual suspects of FD2Rs, Evos, WRXs and S15s. Some of the rarer entries included Lotus Exige, Toyota 86, 350Z and Toyota Altezza. Plenty of supercars had come down to take part including E63 AMG, Maclaren MP4-12C, Lamborghini and Ferrari F430 but my focus was drawn to the competitors in the class I had entered myself in. I was greeted at the registration table by the friendly smile by Angeline of the ZeroToHundred team who had taken great pains to help me with my slightly more complicated registration process.

Here is a video by Kenny Tang showing the huge range of entrants:

The Street NA RWD and Super Street NA RWD were the two classes I had entered to try to get a chance to podium and although I had more realistic opportunity to do well in Street NA RWD, I wanted to see how well I would do in Super Street NA RWD. A familiar name in Street NA RWD was my friend Steve Toh in his "chilli padi" AP 1.5 who has been clocking excellent times and so far was the quickest S2000 driver I know on street tyres with a personal best a scant 0.7 secs quicker than me so in my mind he was the man to benchmark against. Another participant which seemed strong were a Wing Hin sponsored Toyota 86 which apparently had about 80K of parts just in from TRD including a gorgeous Endless front and rear big brake kit. I was also wary of the competition from the a certain Toyota Altezza which I was told was now sporting an individual throttle body kit for more power and had further handling tweaks done to it.

The Super Street NA RWD class was occupied by rather few participants this round but all had strong potential to knock me out of contention from a podium. The cars included a Lotus Exige, Nissan 350Z and a V35 Skyline. It would have to take a combination of luck and skill to be competitive in both these classes and the final result was quite surprising as I would find out later. A further challenge that presented itself was that 57 cars had entered to run in NA class and it was likely that the time attack runs would have to be done with significant traffic.

Here's how crowded the line up to head out to the track were:

While I was rushing back and forth to ensure all the preparations were done right for the run, I noticed the cloud cover getting darker and darker, a really ominous sign. The Turbo and SuperCar classes were enjoying the dry but cool track temps whilst clocking properly quick times but as I began getting my helmet on, I noticed with a sinking heart that a light drizzle had begun. I queued up for the entry into the track and while we began on the warm up run got stuck behind some traffic for a lap or two. I opted to go for a gradual warm up and to get in a quick lap before the rain started in earnest. Big mistake!

The rain escalated into a full on downpour just minutes after the NA run began meaning that the first complete lap of the circuit was the only chance anyone in the NA run had a chance of clocking a good lap. Having wasted that due to poor strategy, I was now consigned to running on a wet track with wipers on full, having lousy visibility of not being able to see cars in front of me due to the spray and dodging spinning cars left and right. I had never raced in the rain before and it was truly a challenge considering my tyres were inflated for dry run pressures, I had plenty of camber on all four corners and my spring rates were very stiff.

Knowing that I had to clock the times despite the crazy conditions, I soldiered on and what a drive it was. I would be sideways at Turn 2 at the slightest provocation, sideways at Turn 3 at the end of 3rd gear, sideways at Turn 4 due to some oil, understeering at Turn 5 while very twitchy at Turn 6 and the wild nature of my setup showed itself on and on. The bad weather presented an added complication by way of a windscreen that threatened to fog up every so often and I had to constantly manage the situation with blasts of aircon to keep my visibility. The Toyota 86 proved itself excellent in these conditions probably due to better setup and was very quick in the torrential rain. I believe much of this was in part to the skill of the driver who was Kenny Lee, an S1K driver. The Lotus Exige competing in Super Street NA RWD had a driver who proved to have guts of titanium by entering corners at speeds I couldn’t muster and even after an off track excursion into the gravel at similar fast speeds, came right back on and kept on racing at the limit. It was the first time I saw FD2Rs spinning left and right with such frequency they would make one reconsider if they were front wheel drive or rear wheel drive!

This fabulous video by K.Kopter shows how tail happy the FD2R's were and how heavy the rain was:

Ending the first run exhausted from the mental and physical challenge of wrestling the car in the wet, I was dismayed to see my times almost 30 seconds slower than my personal best and in my mind, my poor strategy might have cost me any chance of a podium. Poring through the competitor times made me realize that things might not have been that bad after all as my timing might still be good for scraping through a podium or two. I decided to stay positive and rest a little while waiting for the 2nd run for the NA group later in the afternoon and try to improve on my standings. A rumble of thunder awoke from me from my half an hour shuteye and a huge downpour began just an hour before the NA run. I knew from that moment that it was likely that the timings from the 1st run would probably determine the standings for the day considering how wet and cold things had become. To give you an idea of how bad conditions were, safety runs by the ZTH organizers needed to be done to decide if the track was safe for competition.

Here's how wet it was and you can see how dark the sky was:

Despite how nasty the conditions had become, I decided to still go down and run as best as I could for the 2nd NA group to see if I could improve on my times somewhat. A repeat of the earlier run's challenges played out, made worse by a much colder track, fast disappearing daylight and a strong wind which exacerbated the heavy rain. The conditions became so bad that eventually most of the NA run group decided to throw in the towel and pit. The track also was closed due to poor conditions for a bit and I decided to adopt discretion for the better part of valor and end my run for the day. Tallying up the times for the day including the slower runs for the 2nd NA group run, I realized that I had sneaked in podium finishes in both of the categories I had entered myself for. Although the manner of which I had achieved those finishes were slightly different from what I had expected, I was still happy to achieve this testament to my perseverance despite the challenges I was up against.

Taking stock of my performance in 2012, I realized that despite the 1.5 years of absence from the racetrack due to family commitments and only returning to the track in August, I was still able to give a strong showing with comparison to available benchmarks for similar cars. The reality is that I still have a long way to go in my quest for improving as a driver as seen very clearly by data logs of my driving. In fact, on my personal best lap, some of the flaws were pretty obvious which makes me wonder how far I can actually push the limits of my machine to clock the fastest time. That will be my challenge in 2013: To prove the limits of the S2000 are greater than many have imagined them to be and refine my driving technique to live up to the potential this excellent chassis creates…

Photo & video credits to:
Wayn aka Bruise Wayn
Kenny Tang
The Right Wrong
Traffic Magazine Online

Saturday, November 17, 2012

The day personal barriers were smashed...

We form barriers in our mind when we are told certain achievements are not likely and even sometimes try less hard to exceed the limits previously set because we are influenced to feel that the odds are against us. Just as drivers are told to look where they want to go not where they are trying to avoid, the frame of mind can sometimes steer the driver beyond pushing their personal limits. It was with these obstacles that I attended the Über Garage Anniversary trackday.

2:38 & 2:39 were lap times on street tyres set by experienced S2000 drivers very familiar with Sepang International Circuit as they had the opportunity to track pretty often on bolt on modified setups (simple aero, intake & exhaust with coilovers). In this respect, I was severely disadvantaged as I had one crowded trackday and one brief time attack practice after 1.5 years of absence from the track with which to familiarize myself with a vastly different from stock setup that I was running before. As such, it was easy to assign oneself a much lower  chance to exceed those benchmarks with such a huge gap in track seat time.

To complicate things further, the car was constantly in a state of flux in terms of feel as braking, aero, alignment and tyres were changed from each of those events to the next. Going from old tyres to fresh tyres of a different brand, constantly fiddling with tyre pressures, a change to pads with vastly different friction characteristics, experimenting with alignment and tweaking aero grip meant I couldn't have a consistent setup to concentrate on  the driving. Even an attempt at using data to speed up the finalization of the setup by analyzing tyre temperature & the data-log of the racing line fell flat on its face as it became apparent that I was under-driving the car rendering the data virtually useless.

The gloomy clouds above when the track opened seemed ominous but I got down to warming up the tyres and stiffening the suspension up to what I felt was optimum. Within a few laps I was consistently lapping less than half a second slower than my personal best. Some traffic got in the way and I got held up leading to mid 2:40's laps. I was pleasantly surprised that the Über Garage crowd was very polite and friendly both in the pits and out on the track. It must be said that some on track courtesy & etiquette goes a huge way to make a track day enjoyable and safe.

A light shower slowed things down so I pitted for a break and waited for the sun to come out and dry the track up somewhat. Heading out again, I noticed a fellow S2000 passing me as I exited the pits and decided to try to play catch up as I knew this particular S2000 had clocked some decent times previously. Some messy driving at Turn 7 and 9 created a bigger gap so I was not surprised when I saw the RaceLogic Performance Box log a low 2:40's time. Pushing harder with late braking while  being careful to take an apex which was wasnt too late and focusing on higher corner exit speeds, I saw the widened gap began to narrow. As I inched  nearer my target  ever so slowly, I had a feeling this would be a flyer with a good time, maybe a 2:40 flat? Getting a high 2:39 woud be a job well done in my book so you can imagine how ecstatic I felt crossing the mid way of the front straight and watching the magic numbers flash out: 2:38.30 This timing would likely rank me among the quickest street tyre S2000's at Sepang!

Pitting quickly after to keep the tyres hot, I logged my tyre pressures which had given me this excellent time. Regrettably, I had neglected to get new batteries for my tyre temperature probe I couldn't get a gauge of the temperatures for record keeping. I sat down for some refreshments provided by Über Garage and mulled over what I had done right to slash more than 3.5 seconds off my personal best. Interestingly enough, despite the euphoria I felt from the result, I found myself picking out all the mistakes I made and thinking how much quicker I could have been.

It was then that I realized that not only had a barrier in laptime been swept away,  a personal barrier of mine had been overcome; the mental barrier of being limited by guess work, comparisons to other setups and references to other drivers. I no longer had to be concerned so much with what was consensus on what sort of extensive (and expensive!) modifications were "required" to hit quick times or how it was common knowledge that the S2000 would always be slower than the current favourites on the track such as the FD2R. In building this car, I had certain reference points which were now redundant considering I knew that quicker times than I had expected were capable from both car and driver. With that in mind, a fire burned brightly anew within me to surpass the limits of what common knowledge deems possible and to bring out the true potential of the racing DNA of the Honda S2000.

Watermarked pictures courtesy of Cyber Imp Productions

Saturday, September 22, 2012

Track newbie reborn, cue the shenanigans...

The plan went as so: I would wait until my son turned 6mths old then be back to the tracks full tilt with a tricked out ride so that after detailed testing and practice set scorching new personal best lap times. As these things often pan out, virtually none of this came to pass.

Sigh. Cue the shenanigans...

Things got complicated at home mostly revolving around my son & housing issues so after prioritizing and settling things into relative stability, I finally got back to booking a track day with  Traction Circle Club only after my son turned 8 months old. Being a regular previously, I knew to expect a fairly large turnout as Traction Circle track days were fairly popular with the tracking community combined with the fact that the track day I'd booked was a Sunday. The increased traffc combined with my relative unfamiliarity with the track after 1.5 years of absence meant I'd have to significantly moderate my expectations on the kind of results I'd be looking forward to.

Another major issue I had to handle revolved around my unfamiliarity with the car which had evolved from a virtually stock car with budget drift tyres on all 4 corners to a stiffly sprung, aero grip enhanced, lightened and more powerful built up ride. Virtually everything was different and this would prove an additional hurdle to overcome. I had to also manage the hardened Yokohama tyres the car was shod with as I had only planned to use fresh tyres for an upcoming event so felt that these would suffice for a shakedown.

The scale of how badly of all these issues would conspire together to utterly disappoint me was shocking. I was clueless at every corner with an awkward combination of fumbling to figure which gear to use for the corner,  braking far too early, cornering at far too conservative a speed with unnecessarily slow corner entries and simply grasping at straws with the change in steering balance due to wheel and aero effects.

Compounding all of this was the traffic and you'd have to see how ridiculously bad it was to really understand what I mean. An 80 car track day attendance meant there were cars in front and behind me at virtually every corner thus reducing the opportunity to take lines freely without worrying someone was going to go mad and dive bomb hopelessly late into the corner or spin in front of me with disastrous consequence.

Some evasive action to avoid an incident on the track forced me to go full speed into the gravel which messed up my alignment for the remainder of the 3 hour trackday. I would later find how that off track excursion had messed up more than my alignment. Track etiquette is something that benefits all in the most critical part of tracking, namely safety. It suffices to say I hope that proper guidelines and courtesy on the track can eventually be more commonly practiced to allow more enjoyable & safer track days.

Reduced to The Incredible Sulk after posting a wretched 2:45 despite playing with tyre temperature readings and tyre pressures with grease monkey help from my friend Wayn,  I decided to just not focus too much on times and gave my Malaysian friend Steve a joyride so he could maybe give me some tips to go quicker. Back from our laps out, he noticed a knocking sound under braking and after investigating, I found out to my dismay that my remote reservoir for one of my dampers had come loose and was dangling freely. Probably due to that gravel surfing incident caused by the track incident? While wasting 30-40 mins fixing the loose part, I was aghast to realize that my damper settings were all over the place and that the weird handling that I had encountered all day might be due to the messed up settings. Unfortunately, by the time I realized it, it was too little too late as I only had 2-3 laps before the track day ended.

On the way back from the track, it would suffice to say that I wasn't the best company. Black faced and moody, I spent the rest of the night utterly grumpy. After a good rest and spending some time to take stock of all that had transpired, I came to understand that perhaps I had simply been too ambitious. All the factors I had been undone by were absolutely critical to get right in order to post decent times and I had reminded of the stark reality that I couldn't expect magical results from the get-go. Coming to terms with my failings would be the only way I'd make progress so I decided to get my act together, stop moping and prepare for a time attack event I had signed up for before knowing how badly I would do on this shakedown. Sucker for punishment as they say...

Wednesday, May 23, 2012

Quick note on 2012 hopes

2012 has been a whirlwind of activity so far on the family & work front so I have been unable to devote any time to getting down to any race track events. I still hold hopes for the later part of the year for me to get some way down to working out the setup (and any necessary changes) and most importantly to get precious seat time on the track. To say I may have lost touch with the track is probably putting it lightly but I think with some effort and focus, I should be able to get some progress. My friend and tuner has kindly volunteered to join me for a shakedown session to render any advice or assistance while other good friends have been equally supportive. I'd like to believe that the reason they are so forthcoming is that they discern my genuine desire to grow as a driver. My wife has been very supportive throughout and we jointly agreed to attend to more pressing priorities first before I get back to the track. Life has twists and turns but coping with the changes while not losing sight of your passions is very important, even so as driving is pretty much my sole passion. On a side note, I have decided to cease active involvement with a certain group and reduce interaction to the bare minimum as I realized how untenable relations have become. I have always been open with sharing and helping but if I am to face potential negative impact (even possibly spreading to career impact) then it is simply no longer possible to continue. I had been inspired by the open culture of the scene overseas where I had received advice and help without restraint while being free to give and open to accept criticisms. Trolling, profit scheming and narrow minded bullying manners were quickly chided yet it is regrettable that such positive ways mostly never found their way past off the shores they originated. Perhaps it is simply a culture I do not fit into. Hereon, I'm eagerly awaiting my chance to get into the seat or some proper driving and dearly praying things run smoothly until then so I can at least do one or two competitive events come year end. Wish me luck!

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 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 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, 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.

Tuesday, February 21, 2012

Set Up Part 3: Braking in the S2000

Consistent and good braking power is of critical importance at the track as it allows you to carry as much speed as possible from the straight, helps you to turn in certain corners, allows you to dictate position when challenging for a corner and helps you allow the car to take a set before the corner entry to be as stable as possible. An optimum combination of pads, fluids, brake lines and discs used in consideration of the conditions the brake system, as a whole, will be exposed to will be necessary to achieve the desired braking. The stock brake system on the S2000 has pads & fluids which are not equipped to take the stress of track racing while the rotors may crack frequently if heat management modifications are not undertaken.

I decided to modify the stock brake system to suit my track use as opposed to replace it with an aftermarket big brake kit due to the massive cost that a brake system would entail which would be in excess of 5500 SGD just for the front set. The other 2 reasons why I chose to stay with the OEM stock caliper setup would be that most aftermarket brake kits only sell brake kits for the front whilst those that sell kits for the rear are either extremely expensive (exceeding 1500 SGD) or sell a kit that deletes the hand brake mechanism & the fact that staying with the OEM calipers allows me to keep the stock brake balance thereby removing an additional variable in troubleshooting brake related issues.

I opted to use quality brake fluid by Motul, currently RBF660, which has high fade resistance together with braided steel brake lines on slotted OEM discs. This setup combined with Ferodo Racing DS2500 brake pads, has proven relatively reliable when coupled with the grip of the stock suspension and Federal 595SS budget tyres while being able to deliver approximately 1G of straight line braking on both of the long braking zone of my local circuit. These results were with the addition of a brake ducting system, as previously discussed here, which helped stave away fluid fade in most part. The choice of the brake pad did give me rather low, although easy to modulate, bite especially when track temps were high although pad fade/degradation would eventually rear its ugly head. 

With recent upgrades to a track focused coilover, high downforce aerodynamics, higher speeds capable on the straights due to an increase in the power of my car and much gripper performance tyres, I have decided to look for high performance pads which are able to give high consistent bite throughout the heat range. I had used Seido-ya N1 500 pads but the compound was extremely heavy on disc wear which is not comparable performance when considering the advances in ceramic brake pad technology which can give good pad/disc wear, flat torque and high bite throughout the heat range. 

Options considered were the Pagid RS19 and Ferodo DS 1.11 as there was a possibility to get these in both front and rear sets as opposed to most major brands which only sell performance pads for the fronts. Having the same front and rear compound is important in my view when your car is of a 50-50 weight balance much like the S2000 so you can maximize the braking potential at both ends of the car. This will help bring out one of the comparative advantages that the S2000 commands in terms of braking.

Monday, February 20, 2012

Set Up Part 2: Aerodynamics of the S2000

Big leaps in aerodynamic improvements on road cars have been made in the span of the recent two decade. Items like the "shark tooth" vortex generator, rear underbody diffusers & specially designed front bumpers aiming to reduce drag have made their appearance on virtually every part of the spectrum of modern road cars. In comparison, the S2000's 1999 design has remained virtually unchanged even until its end in 2009 with the exception of the Type S.

The combination of the boxy shape of the front end, relatively high angle of the front windscreen and the lack of a rear diffuser exposing the rear bumper to collecting underbody air flow culminate to a Cd around 0.34. Certain modern sports cars also have Cd's of around 0.34 but usually incorporate aerodynamic aids to increase downforce at the expense of some drag yet the S2000 has little to none of these and thus generates large amount of lift at higher speeds. It suffices to say that aerodynamics would be one area where the S2000 falls short when compared to the current models of sports cars.

Lowering any car will improve aerodynamics significantly and this would be done by my change of suspension to a high end coil over suspension yet the problem of overall lack of downforce would still need to be addressed with further modifications. I decided that a combination of a front lip or splitter and rear wing would be the first changes needed to be done to add downforce, hopefully without a huge increase in the Cd.

OEM options to increase downforce on the front of the car included the Honda Modulo lip and the Type S (or CR) front splitter but I ruled both of these out as I felt that a splitter extending out from the bumper would be a more effective way to generate downforce. This effectiveness comes from the pressure created on the top of the splitter to push the splitter down and air flow underneath the splitter which helps to suck the splitter down.

 The APR carbon fiber splitter extending about 2.5 inches from the front of my bumper was my choice but decided against mounting the splitter on the bumper which is a typical fitment by most buyers. This is because I have had feedback from folks running on high speed tracks that the additional downforce created could be so high that it could cause huge pressure on the bolts holding the bumper on and in some cases even tear the bumper off. My decision was then to mount the splitter to the chassis with the construction of a splitter frame bolted to the splitter. This had a two fold benefit: 1. To create a frame strong enough to hold the splitter firm during high downforce situations 2. To create a linear increase in downforce transfer to the chassis. The result after fitment was noticeably large amounts of grip which increased with the higher speeds I drove.

The next on the list would be the hunt for a rear wing which my S2000, being a non-Type S version, did not come with from the factory. Various choices abound for the S2000 including even chassis mounted offerings but needing to balance the need for the boot (for carrying of my spare tyre to the track) with best available downforce ability, I chose a Voltex wing for my car. I selected Voltex Type 2 with a 1600mm wingspan over a Voltex Type 3 as my car would fall under the lower power category and the drag from the Type 3 might be excessive compared to the acceleration ability of my car. 

To enhance the downforce capability of the Type 2 wing, I had it mounted the highest available mounting at 275mm to put the wing in the cleanest airflow above the profile of the car. Looking at wind tunnel tests on the S2000 showed me that the high windscreen of the S2000 does necessitate a high mounting for a rear wing to be effective. I also specified a gurney flap (or wickerbill) to be included to be fitted to the wing which would increase downforce without a large increase in drag. The result of the fitment of the wing was a significant improvement in high speed stability to a point that high speed corners that usually made the tail feel light and prone to oversteer now could be taken with more aggression with the large increase in grip delivered by the wing. 

I did not feel a noticeable increase in drag at with the aerodynamic setup and a check of my fuel consumption showed little or no difference in my fuel consumption on day to day highway driving so I am pretty satisfied with the balance of grip and drag offered by this setup. Setting of the wing rake or Angle Of Attack would need more frequent track sessions for me to determine what would be optimum so I will need to wait until later this year to get a bit more feedback. The key point I have learnt with aerodynamic modifications is the need to balance the grip you add to the chassis as too much front or rear grip will result in a significant bias to the car's balance which could lead to a poor handling at speed.

The final part I added to my S2000 to enhance aerodynamics was a Mugen FRP hard top. The soft top of the car flapping in the wind combined with the ribbed profile of the soft top mechanism disrupts the airflow above the car and causes drag which a hard top would reduce. This would increase the Cd and may significantly reduce the effectiveness of a rear wing. The OEM hard top is slightly heavier with a bigger glass rear windscreen but is more expensive to purchase locally and probably slightly less aerodynamic in my view. Being given a good offer for the Mugen FRP hard top, I decided to bite the bullet on the high cost and go for it. To be honest, I am not able to discern the aerodynamic gain of the hard top as I have had some other modifications done at the same time but feedback from various owners who kept everything else the same while changing to a hard top reported improved gas mileage coming from the improvement in aerodynamics.

The final item I am toying with getting to further improve the rear aerodynamics would be the addition of the rear diffuser but as I do not want to run too far off the budget I've set for myself, I am still putting that move on hold for the moment. There is also a concern on streetability as the low ride height of the S2000 (especially since I am on a race derived coilover suspension) might result in damage to the parts after contact with humps. Companies such as Spoon, Downforce and J's Racing do have splitter setups for the S2000 costing slightly more than 1000 SGD.

Sunday, February 19, 2012

Set Up Part 1: Engine power in the AP2 S2000

Coming in at 240bhp from the factory form, the 2.2 litre F22C in the AP2 2000 is already highly tuned with a power to displacement ratio of 109 bhp/litre. This is why many S2000 owners tend to feel that additional modifications to intake, exhaust and header do not give huge increases in output for the amount of money spent. 

An example based on local pricing shows that a combined cost of a combination of possibly the best performing intake, header and exhaust for the S2000 tuned with a Hondata Flashpro may cost upwards of 7500 SGD. This would likely yield gains of around 40hp at best which seems pretty low on the bang to buck scale compared to similar but lower cost setups on the K series VTEC engines. If we, however, look at the absolute power to displacement ratio post modifications, we can see that approximately 280 bhp for a 2.2 litre gives us 127 bhp/litre which is in itself already a high level of tuning for a naturally aspirated engine.

Going further than 280-290 bhp naturally aspirated would require significant work on the engine and consequently cost a fair amount. Estimated costs for an engine rebuild up to a 2.4 litre setup, individual throttle body intake, standalone ECU and required engine headwork would probably exceed 20,000 SGD. To go to these levels of performance at this cost will require a huge commitment on the part of the owner and at this stage, it is probably relevant to consider your long term goals versus the budget allotted for the car's running or upgrades.

In my case, I have decided that the current level of 280-290bhp would be sufficient to run longer term and reliably on the track as I retain stock compression ratios and most of my modifications are simply bolted on with a tune. Although I will not have performance numbers like 12.X quarter miles numbers to boast, my personal view is that the strength of the S2000 has never been in its engine power but rather in the handling potential of the chassis thus spending should correspondingly focus on highlighting its strength in that area.