Sunday, September 18, 2011

My writing for s2ki.com

Of late, I have been more involved in off track activities such as writing for s2ki.com as a part of their News team. As an editor, I proof read and give suggestions on articles which are contributed by various members of the News team while contributing as often as I can with my own articles. I would consider any and all of my writings there as a joint effort by the hard working and committed News team folks. They have been nothing but welcoming and open even though we are separated by thousands of miles and have only chatted online before so it is my greatest pleasure to be working on this mini-project role with them.

Here are a list of my articles to date:

http://www.s2ki.com/home/2011/09/19/add-lightness/  (LATEST)

http://www.s2ki.com/home/2011/09/10/brake-ducting/

http://www.s2ki.com/home/2011/08/26/got-downforce/

http://www.s2ki.com/home/2011/07/22/to-hold-and-drive-forever/

http://www.s2ki.com/home/2011/06/25/a-reliable-sports-car/

http://www.s2ki.com/home/2011/06/10/heel-toe-or-heck-no/

http://www.s2ki.com/home/2011/05/16/what-safety-equipment-do-you-pack-for-the-track/

http://www.s2ki.com/home/2011/05/11/are-s2000s-racing-competitively-worldwide/

Happy reading! :)


Sunday, September 11, 2011

Brake ducting article on s2ki.com

I've had the honour of having my brake ducting article, albeit in a slightly revised fashion to be S2000 owner specific, posted up on s2ki.com as part of my ongoing effort as part of s2ki.com's News team. The News team is an excellent group of folks to work with and I've enjoyed every moment of contributing to s2ki.com which has helped me greatly as an S2000 owner over the years by being a treasure trove of S2000-related information resource. It has also allowed me to get to know some wonderful S2000 owners throughout the globe, making it truly an international forum in every way!

Here is the article in its revised form.

Faded brakes resulting in reduced stopping force remains a constant concern when attacking our favourite tracks. Spongy brake feel culminating in heart stopping moments and inability to brake well on the way back from the local track are typical. We spend hundreds, if not thousands, of dollars on modifications to increase the braking ability of our beloved rides and enjoy the results when tracking.

A moment of reflection leads us to ponder if this money was well spent. Could money saved on excessive brake modifications be better used on items such as better suspension or even other safety equipment? Let's examine, by way of cost benefit analysis, and discuss the effectiveness of current expenditure regarding braking modifications and their practical impact to track day enthusiasts.

A simple understanding of the brake system is necessary for us to begin. The friction generated between the brake pad and the rotating brake disc converts the energy of the moving vehicle into heat. The heat is lost through the surface area of the disc to air when the car is moving. Buildup of heat in the disc will mean that the generation of heat is at a rate higher than the ability of the braking system to dissipate the heat of the disc.

Faded brakes, spongy brake pedals, burnt discs and crumbling brake pads are all symptoms of a simple problem of accumulated heat overloading the braking system. I will use a virtually stock Honda S2000 (unmodified except for a bolt-on exhaust and slightly more aggressive alignment) tracked at Sepang International Circuit in Malaysia as a reference.

Tracking the S2000 on stock brake components proved a bad idea considering the searing 50°+ C (122°+ F) track temperatures. The stock brake pads quickly disintegrated with 80% thickness pads dropping to 10% in one 3-hour track session. The stock brake fluids boiled after a few laps and remained dangerously spongy even after a long rest in the pits. The brake discs turned a funny burnt tinge after a taxing session and smoke could be seen pouring off them on entry to the pits.

Upgrades to address these issues soon followed by way of Ferodo DS2500 brake pads (which are rated from 50° C to 750° C), stainless steel brake lines and Motul RBF 600 brake fluid for a total cost of about 800 SGD (equivalent to about $662 US) including labour cost (Note: Labour costs may vary from workshop to workshop). The rate of wear of the pads was halved and sponginess was staved away. Brake fluid changes could be done after every other track day although continuous lapping on the track was still limited to about five hot laps before the brake fade begin to significantly impact driving. The condition of the brake discs remained relatively unchanged.

This meant the heat overload experienced by the braking system had clearly not been significantly addressed. However, certain components were now able to handle the heat slightly better. A possible reference to how much deep braking was used was that the confidence level to begin threshold braking for Turn 1 was that the driver was confident to brake just before the 100m marker while still being able to make the corner for at least the first two or three hot laps of a full five lap outing from the pits. Braking that late for the remainder of the five laps was risky as brake fade had begun to appear and by the second half the entire three hour track session it was increasingly difficult to have more than one or two hot laps before the brakes began to feel extremely spongy.

The next step, to most of the tracking community, would certainly be obvious. To increase lapping longevity (to get as many hot laps per track session to maximize seat time), extensive brake modifications were necessary. 4-pot monoblock calipers, brake pads exceeding the current already high temperature ratings and bigger discs, at least for the front brakes (at a cost possibly ranging from 3000 to 5000 USD from brands such as Endless or AP Racing), would need to be fitted to generate more powerful and consistent braking.

There is no doubt on the benefits such modifications confer. However, would it be possible to have approximately 80-90% of the benefits at a lower cost? Tracking isn’t the cheapest of hobbies and being cheap on vital components, such as brakes, isn’t something most enthusiasts want to be seen doing and yet the cost of a “proper brake” upgrade system is clearly prohibitive to many. Perhaps we should examine more closely our desired brake performance objectives.

Upgraded stopping power is greatly desired. A simple explanation of braking “power” is that an increase in the braking “power” can be defined as a small application of force resulting in a larger than typical braking forces. One could upgrade the brake booster (master cylinder) to get this result or simply step harder on the brake pedal. The S2000 test car with stock tyres achieved over 1G of braking in straight line braking on the front straight without the use of a big brake kit so clearly there was no lack of braking power, however, a big brake kit would greatly improve modulation characteristics under threshold braking.

To address brake fade and a spongy brake pedal, another S2000 fitted a 4-pot big brake kit (including large calipers and upsized discs) from a leading brake manufacturer and achieved good consistent braking but fade still began to rear its ugly head by the end of the 3-hour track session. Brake fluids did boil a little less, fluid change intervals were slightly increased but three track sessions on the same fluids would probably be the absolute limit. A definite improvement, to be sure, but it was clear that the problem of fade still remained. Some other S2000s fitted with aggressive street brake pads and no ducting or only basic brake cooling setups tended to crack rotors much like the picture below.

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The S2000 test car was then modified with a commonly overlooked modification, namely, brake ducts but remained entirely stock elsewhere with the exception of the brake fluid and brake pad changes as stated earlier. The initial setup was with ducts channeling air by a regular piping to the calipers on all four corners, evolved to add a funnel head on each pipe to concentrate air flow to the same four calipers and finally to a setup where both front and rear brake discs and calipers are individually cooled with their own piping.

Here is a picture of the front funnel setup:

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Here are some pictures of the funnel setup leading to the caliper and disc:

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Testing of the system was done over the course of a year with seven track days at both Sepang International Circuit and Johor Circuit, also in Malaysia, and the results were: With the same Ferodo DS2500 brake pads and Motul RBF 600 brake fluid on the stock brake system, brake pad life was increased to at least double of the usual service interval while discs ceased to smoke and exhibited no visible burn marks.

The result with the brake fluids was not only that sponginess was eliminated for all the track sessions and not evident on the 300km drive back to Singapore, over five laps could be easily done without a hint of fade, braking could be done consistently on every lap at the 100m marker without fade appearing and no change of fluids appeared necessary even after the seventh track day. The S2000 test car could now repeatedly do multiple stints of over 15 hot laps without fade on the stock calipers and discs which is clearly a huge improvement in fade resistance over even usage of an expensive big brake kit.

An added potential benefit, which is not immediately evident, could be that of the heat being taken out of the drive train components (such as CV joints and wheel bearings) thus reducing the heat stress on them and possibly prolonging their lifespan. Usefulness of brake ducts is nothing new in racing (virtually every race car has them) but strangely a search within some aftermarket brands concluded that you will be hard pressed to find them selling an effective and comprehensive brake duct solution in their product ranges.

The downside of such a system would be some time spent to customize a proper system, maintenance of the fittings and probably some hindrance to certain modifications as the ducts would require some space to fit. The benefits are, however, numerous and obvious to the track enthusiasts. These would be namely, cost, maximizing seat (practice) time, safety and prolonging the lifespan of various components in the car.

Every track day enthusiast should consider having a brake duct system in place to complement their existing brake setup. The actual cost versus benefit result derived varies from car to car, the class of competition that the enthusiast is running in and with the type of brake duct system constructed.

What brake modifications have you performed on your S2000? Has that improved your braking performance?

Sunday, August 28, 2011

Finalizing the mechanical setup and budgeting ahead...

The mechanical setup of the car has been pretty much finalized with the addition of the Mugen Hardtop I have fitted to my car. The only few things remaining would be minor tweaks like corner weighting, repair of my brake caliper seals due to wear and tear etc. The key benefit would be the aerodynamic improvement of the hard top versus the flapping in the wind of the rib framed soft top. I also removed the soft top entirely including the motors to lighten the car as much as possible. I had the option of spraying the entire car together with the hardtop but frankly I was too lazy to do so considering how pitted the paint would eventually become from track and high speed travel paint chips. Here are some pics (pardon the low quality iphone pics):











So far, the setup would be as follows:

J's Racing Exhaust Header
J's Racing Dual Titanium Exhaust 70RS
Invidia 70MM test pipe (for track use only, stock cat on for street)
Password JDM Carbon Intake
Hondata Flashpro
Odyssey PC680 battery
Toda Baffled Oil Pan
Greddy NS1310G oil cooler
5zigen ProRacer oil catch tank
Koyo Aluminium Radiator
Brake Ducts customized to my specifications by Lye Design
Ferodo DS2500
HPI Brake Hoses
SPC Front Camber Joints
Tein Super Racing Circuit Master Coilovers
AP1 Flywheel
GT Motoring 4.44 Final Drive
Enkei RPF1 Rims
Advan AD08 tyres
APR Carbon front splitter with custom bracket
M and M Honda Thermostat
Mugen Radiator Fan Switch
Mugen FRP Hardtop
Voltex Type II GT Wing with Gurney Flap
Recaro Profi SPG driver's side seat
Mugen seat rails
Defi gauges: Exhaust Temperature, Oil Temperature, Oil Pressure, Water Temperature
Defi Tachometer
Motul Chrono 10w-40 engine oil
Motul RBF660 brake fluid
Moty's M409M 75W-140 Gear oil for my gearbox and differential


I've kept everything else, which isn't mentioned, stock to ensure that parts are always available and running costs are being kept reasonable. By not having a budget and sticking to it, the amateur runs significant risk of overspending with the constant lure of better performance and reliability. This is unacceptable to me as it would go against my ethos of what I had set out to accomplish and the constant expenditure (My budget is limited of course!) would ultimately limit my opportunity to track as often as I need on a fixed setup in order to isolate where I need to improve as a driver.

A rough budget of recurring costs would include the factoring of the following:

Brake pads
Brake discs
Potential repairs
Alignment adjustments
Additional oil/fluid changes

End 2012 or 2013 seems the earliest that I can begin to track as committments take precedence so I will patiently await the return to the track. Let's see then how power, light weight, aero modifications and combined with tuning my tyre/suspension setup with the proper tools delivers on the track. I expect to be formally taking part in competition once I have become consistent as a driver.

Thursday, August 4, 2011

Maintenance problems, just part and parcel of journey...

Recently some issues have cropped up which I attribute to the normal maintenance problems that come with a long term tracked car. My brake pedal has gone soggy for a bit and replacing the worn pads and discs with newer 2nd hand spares havent solved it. A cheaper brake pump repair kit hasn't really worked so I may have resort to a whole new brake master pump.

My brakes seem to engage one first and then another which points to a potential sticking caliper on one side of the car. A brake seal repair kit is the solution but thats got to be ordered and it would take time to come in not to say for it to be fitted.

My aircon compressor clutch was jammed and I had no choice but to resort to getting a reconditioned one so that I could get the car going. Although its a 2nd hand unit, it seems to be running fine.

Finally, temperatures seemed to get high on my car and at first I thought it was the thermostat so I swopped it out for a low temperature thermostat with a low temperature fan switch. I then found that coolant temps rising on idle and pinpointed it to a failed radiator fan. I swopped out both fans for new units as this is probably due since my car is about 115,000kms to date.

A couple of hundred spent in total in maintenance but it goes a long way to keeping the car track ready for next year. At least I can focus fully on tracking without delays then! :)

Sunday, June 12, 2011

The priorities of life

One of the matters that has occupied my mind lately is how the fun of racing and motorsports must often take a backseat to the priorities of life. In my life, there has been almost a single minded focus on my car as a hobby and I have had recently to re-align myself to focus on the priorities which are clear and present before indulgent expenditures on my car.

To put it clearly into perspective, there are compromises in every facet of one's life and there must be a appropriate balance between your hobby versus priorities of daily living. I've decided to put my energies and resources into my personal & work matters first and thus will have to put this project on a temporary hold until those issues are attended to properly which may take close to a year. To recognise that a hobby is merely for entertainment is simply to look at it critically and to put things in their proper place.

Thankfully, nearly 90% of my expenditures to date are complete and I need no longer wonder how much more I could build my car up to. That is an important step as I have already decided some time ago to stop at this current juncture and focus on simple maintenance once the current level of modifications are finished. I've also put forward my budgeting for yearly tracking and consumables in order to ensure I'm very comfortable with expenditures as regular tracking can take it toll on the budget.

I've seen many go bust due to over-indulgence and lack of prioritization on personal matters versus hobby expenditures so I'd like to take a leaf from that book before heading down that nasty path. Thankfully, I've not needed to take the drastic step some others have had to due to compromises and I'm indeed mindful of how lucky I am. In order to enjoy my hobby in the future, self moderation is due so I can have a longer time to enjoy motorsports and tracking in my life.

Tuesday, May 10, 2011

Modifications Update

I'm currently closing in on my goal of just under 300bhp Normally Aspirated (NA) with the addition of two power adding modifications, namely the Password JDM Carbon Fibre Intake and the J's Racing Exhaust Manifold. These additions along with the J's Racing FX 70RS Titanium Dual exhaust will be tuned in 1-2 weeks with a Hondata Flashpro with the goal of getting to 280~290bhp on engine. Here are some iPhone pictures (do forgive the poor quality of the iPhone camera):





So far the feedback I have on the PWJDM intake is that fitment is not easy in the slightest requiring hood cutting as per this pic:



A spacer on the bonnet joint end was also required to ensure proper closing of the bonnet. My oil cooler had to be relocated and my brake ducting also needs to be re-aligned. In the picture below you can see how the funnels have been relocated to relatively ineffective positions.



As per an s2ki.com posting, there seems to be a penchant for this bonnet to suck in alot of debris and I will check this periodically, say every month or two, to validate this claim.

The gains are feeling good from the seat of the pants feeling and people who have driven my car before and after the intake + header modification are noticeably impressed by the increase in low-mid range torque. I can't discern much higher rev range outperformance and a look at a posting on the PWJDM intake by gernby of s2ki.com does hint that the higher end performance may only be fully unearthed by a custom tune which I will be getting done via Hondata Flashpro.

The next modification which is slated to be completed in July-August would be an aerodynamic cum lightening modification. The targeted weight of the current project would be ~1180kgs with a half tank of petrol.

Monday, April 4, 2011

Non Staggered Setup Thoughts

Some S2000 owners, including myself, have gone to a setup where the front tyres are the same as the rears called the non staggered setup. This may seem a step towards increasing the high potential for snap oversteer as many S2000 owners have experienced yet based on my experience, it has delivered so much in gains that I would not look back to regular staggered setup, where front tyres are narrower than the rears, until I can find evidence that the staggered setup performs better.

Let's look at the S2000 setup in stock form. With 215/45/17 tyres up front and 245/40/17 tyres out in the rear, the feel I get is that the intial turn-in is lacking in grip. The result of this is that the driver tends to add more lock to get the car to turn and when the car finally responds, there is excessive steering lock and the tail of the car snaps around. This tendency remains even when camber angles are increased to give more grip to the fronts and it is my thought that this is wholly due to front tyres that are too skinny.

When I shifted to a non staggered tyre setup with front tyres as wide as the rear, the turn in was excellent. Feedback did seem a little numb but you would pretty much know how much grip there was as the steering was still communicative. At higher speeds, due to the high amount of rear lift the S2000 generates along with the fact that I had fitted a large front splitter, the front gripped far more than the back and resulted in a rather white knuckled ride. This left me with doubts about how the non staggered setup had upset the natural balance of the car.

I subsequently fitted a high mount GT wing to balance the tail of the car and the result was phenomenal. Not only did the rear lift get cancelled out, I also retained the excellent turn-in characteristics of the car. This was far more pronounced when I got to the track. When turning in, the car would simply grip and go and I had no need to add any excessive lock but was rather using far less steering lock than before which is easily seen as much more efficient. In the slower corners, I was able to turn in sharply and get the car to rotate (as the rear wing grip was far less due to lower speeds) while at higher speeds, the slight oversteer would change to slight understeer as the balance of grip shifted to the rear. Braking was also a much more stable affair with the increased stance of the car.

I was hampered by a leaking brake master pump, torn in half shifter bush, leaking clutch pump, overly understeering alignment & wrong tyre pressures at the latest track day I attended. This resulted in only a very slight improvement in my personal best laptimes which was a definite disappointment. However, I am confident that after the repairs, the car will be able to hit the benchmark times I have aided by the transformed characteristics of the car.

Even though it seems counter intuitive to conventional wisdom (you can't imagine how many "old birds" of the tracking scene scoffed my new setup) seeing how many performance cars have rear tyres much wider than the front, deeper analysis into racing cars seems to favour the non staggered setup. Many racing cars have front track & tyres as wide or wider than the front to aid their turn-in and front grip with the rear aero dynamics compensating for rear grip. Although its hard to tell on paper which is better, having experienced the difference on the road and track, I am definitely of the opinion that non staggered is the way to go for track-biased cars. The only caveat would be that the driver needs to be experienced enough to measure his steering inputs accordingly.

Considerations on non staggered fitment are the following:
1. Rolling and pulling of the fenders are mostly necessary (there seems no point in my opinion to run tucked in offsets just for fender clearance when the increased track of lower offset will deliver great gains)
2. Camber requires to be to tuned to your driving style (it seems necessary to have a proper data to support better alignment to optimize the alignment)
3. Improved aero i.e. GT wing is necessary (you will be resetting the balance of the car and an adjustable efficient wing will go a long way to ensuring your setup is effective)
4. Some rubbing of fender liners and suspension cars will be experienced (this is an eventuality non staggered owners will have to accept)
5. Fender tab relocation and bumper trimming is necessary(again this is necessary to prevent rubbing of your tyres)

The ultimate caveat here for fitment of a non staggered setup is that owners who want the aesthetic appeal of the car maintained may be disappointed. To clear non staggered setups, the car may be raised slightly, may need body work, may have slightly wavy paint due to rolling & cutting, may have protuding tyres etc. Everyone chooses how they want their car to be and I think its important that owners know the impact of non staggered in the aesthetic sense before they embark on this journey. The track-crazy S2000 drivers wouldn't be too bothered by these sacrifices as the on-track performance would likely be sufficient to compensate.

I welcome any non staggered owners to discuss their setups openly or in private and hope my anecdotal thoughts are of use to any readers out there :)

Monday, February 14, 2011

Service & Maintenance for my S2000 and suggested track modifications

Coming from an older version WRX, the excellent reliability of a normally aspirated Honda S2000 was a real comfort. The only maintenance parts (wear & tear excluding regular servicing parts such as spark plugs) I've needed for the past 3 years of ownership are the following:

1. a new battery - pretty cheap to replace
2. air-con condensor coil - a few hundred solved it
3. a bulb in the air-con display panel - never bothered replacing it
4. an ABS sensor (probably got hit by a rock during tracking) - about a 100 only
5. Pedal Position sensor - under 200

And that's it. None of these even required my car to be placed overnight for repairs.

The stock parts are very reliable and I've never changed my suspension mounts, gearbox mounts, engine mounts or wheel bearings which gives you a clue how suited the S is in entirety for use as a track machine.

For the folks who want to know what might be used to service their cars, here is my list:

1. NGK Iriway spark plugs
2. Motul RBF600 brake fluid
3. For Rear Differential - Moty's 75w/140 rear differential fluid or Motul Gear 300 FF LSD 75w/90 or ATS diff oil 85w/90
4. For Gearbox - Motul Gear 300 or Honda MTF III
5. For engine - Motul 300 V
6. For engine oil filter -  Previously Honda PCX filter (Note: after fitting a Greddy oil cooler, due to the thickness of the sandwich plate, the Honda filter will not sit as securely and have less threads to lock the filter in. It is known that engine vibrations can dislodge even a well torqued oil filter) Now Juran oil filter with deeper thread
7. Brake rotors - Stock (OEM rotors work perfectly and cracking can be mitigated by brake modifications, there is hardly need for a full big brake kit unless you are running huge power)
8. Brake pads - Ferodo DS2500 or Seidoya N1-500
9 Clutch - The stock clutch is both reliable and cost effective, there is no need for single/twin plate clutches

For modifications relating to track use, here are some suggested items you would want to consider for your S2000 to enhance your tracking experience and increase safety.

1. Oil cooler - I am using a Greddy turbo oil cooler core and the additional cooling is a huge bonus on Sepang International Circuit where track temps >50deg C
2. Brake pads - Stock brake pads WILL disintegrate on the track, better pads are essential
3. Brake lines - There is no proof that stock brake lines are unsuitable for track use but for peace of mind, stainless steel brake hoses are cheap insurance
4. Brake Fluid - Good brake fluid is a must as the stock fluid will boil very quickly
5. Brake Ducting - This is a commonly overlooked modification. Here is my article on the benefits for brake ducting for a track day enthusiast.
6. Baffled oil pan - This is a good and affordable modification if you are an avid trackie by reducing the chance of oil starvation in high G situations on the track. I'm currently running a Toda pan.

I hope this is useful to any S2000 owners for maintenance and track related modifications.

Sunday, January 9, 2011

Competitor Analysis

The reference cars I'm using to bench are the Cayman S & Exige S. It is true that the S2000 will never be any other car other than itself so no amount of modification can make the S2000 like the Cayman or Exige. That said, achieving the same or better track times on a street legal modified S2000 that the reference cars can do on my car would firmly put my car as a viable alternative to the 2 cars with the notable exception being some lack of refinement and less badge appeal.

The Cayman S in its current iteration produces 320bhp of power & 340N.m of torque while lugging around 1340kg of curb weight. It also benefits from excellent drag coefficient of 0.29 & a virtually flat underbody design adding to its slipperiness at higher wind speeds combined with less lift.

The Exige S is renowned, as all Lotus cars are, for its impressive lightweight body which is only about 933kgs. This lightweight combined with 218bhp & 215N.m of torque makes for a car thats built as an out and out cornering machine. A completely flat underbody with a well balanced wing and front aero make this car virtually track tuned right out of the box.

Both cars are mid engined and rear wheel drive with excellent static front to rear weight balance. The track width of both cars are 1507-1528 which contribute to their excellent stance for cornering. Shod with sticky tyres, even semi slicks in the case of the Exige S, right out of the factory, the cornering G's generated are nothing short of phenomenal resulting in excellent track timings on Sepang. I have spoken to a local racer who quoted a stock Exige S as being capable of around 2:32 while my best guess on a stock Cayman S would be at least around 2:37.

Now that we know where we stand on the comparison from car to car in terms of track times, its time to have a look at what the fastest cars in actual competition are. A recent time attack at Sepang had some machines doing some very impressive times. These would be ~2:39 for NA FF Street Tyres & 2:33 for Turbo 4wd Street Tyres. A time within this ball park would be decent and probably something I will be shooting for. I have left out the Semi Slick class as this is not a class I want to compete or benchmark against and the NA RWD is so under represented that there are virtually no proper benchmarks for me to form a reference against.

S2000 times at Sepang have been seldom talked about probably due to scarcity of the car and difficult to reference since it is not part of the local culture to be upfront about the full disclosure of the modifications on the car when a certain lap time was achieved. Nevertheless, I have managed to be privy to the times of a fully stock S2000 doing about 2:45-2:46 & a modified street tyred (with engine works) S2000 doing about 2:35-2:36.  These times could be taken as a reference for me to consider my progress.

All in all, the stated comparisons are only to serve as a general guide of how I should view my progress. As I will probably not have completed my build til much later this year, to be truly competitive is left til I get more seat time at the track & complete the setup proper (along with appropriate settings). As always, my budget & restriction of time to track due to my job (along with comparative lack of natural driving talent!) will be the barriers I will need to surmount whilst trying to hit the objectives stated. Either way, the S and me are going to have alot of fun getting there :)

Cheers to an excellent 2011!