Nov 12: Race Day

Woke up this morning, excited! It’s Race day today, its been awhile that Sepang has excited me. I guess thats what happens after 6 years of tracking monthly..

The afternoon is the Ignition.my trackday and also my a practice session for me as its my first time on the Sepang North Track. Tonight’s my first race with Saturday Night Fever (SNF).

Last night, I managed to catch some SNF Sepang North Track videos on youtube but most werent very clear and I had no idea what to expect out of the new Sepang Turn 7&8.

Tweaking my suspension damping setting to something I tried out the week before, I guess the tyre temperatures and pressure readings taken last week might not have been so accurate as the tyres were very ‘green’ the week before. This week they are ready!

Heres’ my team support crew. Think she’s playing a driving game too!

The difference between the Sepang North Track and the Sepang full track is the new Turn 7 & 8 which brings me back to the Sepang front straight again.

My first impressions are that it is actually tougher on the brakes because the car carries a higher speed through the new turn 7 & 8 compared to full track Turn 15, which in turn means a higher top speed along the front straight. Instead of redlining in 4th gear before braking into turn 1, now, I’ve gotta shift into 5th before braking.

My last practice outing, I thought I will try out a few different approaches into turn 7 & 8 and compare it on the laptop. I figured with the right line, I could be on throttle out of the corner very early.

Screenshot of the Racelogic Videovbox Lite data page… now where to find another 3 more seconds?

On my final practice run for the day, well I wont spoil the story, and I’ll let the video do the talking.

yup.. thats right.. I limped back to the pit garage… and tried to identify the problem.
Resigned, I called a tow truck and had the car towed to a friend’s place, EricT Racing to have the car checked out. I’m out of the race even before it started.

on a tow truck headed to EricT Racing in PJ, KL.

On the bright side, the mx5 has been incredibly reliable, lasting me 45 plus trackdays these past 4 years. In these 45 trackdays, this is the first time I had to call tow truck. a pretty good record.

on the 11th hour on the 11th day on the 11th month

I took a moment out at 11am this morning to just remember all those who gave their lives in wars past so that we can have the freedom we enjoy today. Thank you.

After that I started the engine and drove off towards KL for this weekend’s Saturday Night Fever race. I’m abit anxious as last weekend’s TCC trackday, with the setup adjustments I’m still struggling to get enough pace. All the mods and I’m still driving around slower then previously. Argh.

Saturday Night Fever’s organised by the Malaysian Ignition.my, it’s a clubman level race, that has just gotten AAM approval. Currently for this year, the only requirements are a firesuit, helmet and gloves, Next year, the requirement goes up one step with participants needing a half roll cage and possibly a fire extinguisher and an electrical cut-off switch.

Oh yeah and its a night! I’m also wondering if I should have installed foglights in the car too. drat, too late now.

oh well lets see how I fare.

Wheel Alignment Rants

I think in the last 6 years generally I have had less changes to the kind of wheel alignment that I run then I do changes to my rims or exhaust or other settings of the car in a typical year.

I think during the era of my first proper car for the track, my old EG6, some gurus handed down to me some secret wheel alignment settings only which in 20 odd trackdays, did I tweak ever so slightly

Alittle toe in on the rears to help the braking, 1 degree less camber on the rear than the fronts so that the car could still slide around or be chucked into a corner. but that was about it.

My point that perhaps I still havent quite reached, is that why are we so fixated with all these arbitrary numbers for our wheel alignment, everyone I know seems to run some sort of stagger on their wheel alignment, in nice round numbers too, most people seem to be running a 1 degree difference between the front and rear, be it a Honda Civic or an Evo or an STI,

From a theoretical stand point, the reason why we run more negative camber on the track, is because a tyre actually has the most grip when it has 0′ degree camber. However, when a car corners, the inner wheels (meaning the wheels on the inside of the turn, Left turn, left wheels) begin to decamber (becomes positive camber). Therefore we run some negative camber so that during a turn the inside wheel becomes 0′degree camber.
Cars running on stock suspension (soft with little negative camber and probably lots of body roll) will see excessive tyre wear on the outer shoulders and probably some understeer wear on the fronts.

Having said all that above some modern asymmetric tyres are designed to have more grip on the outer shoulders, so a little bit of lean outwards might prove to be alittle quicker around the track, of course not so much til the shoulders wear out!

How do I know how much camber I need to run?

well besides listening to the guru’s,

Start by measuring your tyre temperatures, ideally after a quick cleanly driven hot lap around the circuit, not doing a cool down lap and coming straight into the pits to measure the temperatures. And measure it with a tyre pyrometer and not an infra-red gun that I see so often, a pyrometer reads the core temperature inside the tyre, not the surface temperature as that is not a good measure of how hot the tyre compound is.

Once you’re done measuring, quickly head out to finish that cooling down lap.

Ideally we should be looking at as small a temperature spread between the inner shoulder, middle and outer shoulder, with the inner shoulder being the highest, getting slightly cooler to the outer shoulder. This is because in the end we can not avoid running on the slightest bit of front camber and due to the long braking zones on Sepang, alot of heat is built up on the inner shoulder.

Based on the heat in the tyres, camber should then be adjusted for more or less negative camber. Tyre air pressure and suspension settings should not be changed too much in this time.

Ok I have to end here cos looks like we’re crossing over into the realm of car suspension setup which will leave me here on my computer typing for weeks!

Gymkhana

Here’s a little video I created for TCC participants, so that they have an idea of what lies in store for them in the upcoming TCC gymkhana. This was filmed during the miataclub’s annual gymkhana on the 10th of September.

Man, it was tough, climbing up the hill in the heavy rain, getting myself covered in mud. But the bird’s eye view was spectacular.

2 weeks left before the gymkhana and I still need to setup the newly installed Fightex coilovers, what wheel alignment should I run?

4 years old, part 2!

OK, so today was an incredibly busy day for the Mx5, just 2 days before its birthday, I managed to get insurance renewed, the weekend licence plate inspected, this including sneaking past several LTA bikes at the inspection centre who eyeballed me as I coasted gently out of the centre, before quickly zipping away.

In all that drama, I forgot to bring out a set of Titan brake shims for a customer, argh another day then.

So with the car now 4 years old, I spent the rest of the day carrying out Part 2 of the refreshing of my car.

freshly back from Japan, my Fightex coilovers oh and pleasant surprise, seems like not only did they refresh the suspension, they left alittle note saying that they have upgraded the suspension too! Horray! oh wait, but that means all the years of setting up the shocks gone to waste and I’ve gotta restart that again. Argh I cant win them all..
Also being installed today, Spoon Rigid Collars, and a Nielex Knuckle Brace for the front wheel hubs.

First up was the SPOON Rigid collars, and the nielex knuckle brace. oh wow, after a quick drive around the carpark, over many humps, the car felt so much better planted and more comfortable.

Next was the Fightex, no drama there. I’ve gotta give the car a week to run-in before readjusting the ride height and doing a wheel alignment, I’m still not quite sure how high or low should I set the car up, too low and wouldnt that affect the roll centre?

Later we took all these bodypanels out, here’s the little surprise that I’ll talk more in the next blog entry.

what am I up to? =)

MX5 NC ‘mx5 1g suspension set’

Earlier week, on a friend’s car, we took out the original suspension, as the car was driving alittle strangely,  it had 70,000km on the clock and I was quite sure that the old suspension, especially the bushes and bumpstops were worn out.

(something to note) MX5 NC and RX8 suspension are designed to corner on its bumpstops and bushes and when these wear out, the car’s handling suffers.

One of my favourite suspension for the MX5 NC is one called ‘the mx5 1g’ suspension. It was originally created in 2007 by Mazda Motorsport engineers in the USA, under growing competition from Honda and GM who released club racer editions in that same year. The name 1g comes from the project title because the goal was for the car to be able to pull 1g on a skidpan using only this suspension setup and Yokohama Ad07 street tyres.

It was then sold in the USA  under the name MS-R edition. The MS-R then went on to win many competitions til in the following year, SCCA changed the rules once more, making the MS-R illegal to compete in, and Mazda stopped selling the MS-R.

Thanks to the friendly Mazda Motorsport engineers, we now know what components they used to assemble the suspension and we’re able to assemble it ourselves.

The suspension ride height only lowers the car by abit, I figured this was not to change the car’s roll centre by too much. Which also incidentally allows the car ride over humps comfortably and clears all the carpark humps/slopes that I know of.

In terms of ride comfort, the suspension is incredibly comfortable over humps, however over a road with ruts, it does hop about abit, due to the super heavy duty anti roll bars, that the MX5 1g kit uses, but this can be adjusted and some chassis brace are recommended to help to reduce the chassis flex.

On the circuit, due to the soft spring rates that the MX5 1g uses, the car does dive and squat abit, compared to my Fightex coilovers & V’s Ohlins, laterally theres virtually no roll again thanks to the roll bars, how this translates into driving on the track is that, the car communicates very clearly the weight transfer between front and back and side to side as the car dives into and turns and begins to exit a corner. A very good practice setup for drivers new to track driving basics. (note: weight transfer in a car cornering remains the same regardless of stock or aftermarket suspension, the difference is how much of the transfer are you able to feel)

Also because there is no height adjustability, this is one of the ‘just go out and drive’ setups that I love. All the thinking and headaches that we would need to do for a height and damping adjustable suspension has all been done for you by the Mazda engineers.
Thank you Mazda Motorsport!

4 years old!

this september, my trusty MX5 turns 4 years old! While its been a good 4 years, I’ve decided that with current coe prices at an all time high, its worth while to give the trusty mx5 a ‘refreshening’ and an upgrade.

so first up, refreshing the worn old speakers in the car

I installed a set of Clearwater speakers, these speakers are specifically for the NC Mx5 with a set for the Bose and non Bose equipped cars. They come with a comprehensive set of instructions and actually make for a fun DIY project, though I do recommend preparing more spare door clips as mine were all brittle and broke when I removed the door panel.

Sound quality? well I was never much of an audiophile but WOW! The audio quality difference is incredibly obvious.

Next up, upgrading the car,  I installed the Beatrush harness bar too, all ready for the 4point  harness. Because the harness bar mounts rigidly across the roll brace behind the seats, I think the car feels alittle stiffer too!

Refreshening and upgrades, more to come