Back on the road

I've had the car back a couple of weeks now, and all is well. I can't wait to hit the track again, but the wallet says otherwise. For now, it's just great to have a car back.

Greg has done an amazing job re-assembling the car. Very few dramas to report. About three weeks after I picked it up, I took it back to Autosport and he ironed out the last of the bugs. Couldn't be happier.

The new turbo installation also meant that the car needed to be retuned. Yavuz at Unigroup Engineering looked after the car, and I think the results speak for themselves:

Based on airflow meter readings, Yavuz says the turbo can flow up to 250rwkw of air, but at the moment, the exhaust is restricting flow and so he's had to keep the boost conservative to prevent knock. It's most likely the cat restricting flow, so i'll look into extracting that extra potential power down the track.

Anxious wait

Have had some great news from Greg recently; the car is complete and ready to be tuned.

I've chosen Unigroup Engineering to tune the new turbo combination - Greg's own car is tuned there, and the old owner of my car was very happy with the service they provide.

Once it's tuned, it's just a matter of registering the car, and getting back to what I enjoy. That first drive is going to be great.

Turbo and diff

After not having much luck finding a used turbo of a suitable size, I have bitten the bullet and paid for a new Garrett unit. I decided on the GT2871R - it's a few sizes larger than the S15 turbo it replaces, but by no means a massive turbo.

It is available in 6 size combinations, and I have chosen the smallest of the six to maintain some of the throttle response and midrange power of a smaller turbo.

For a little extra dough, I also optioned a ceramic coating for the exhaust housing. The theory is that it keeps the exhaust heat in the housing rather than dissipating. Hotter gas travels faster, and so the coating has a two fold effect - the turbo spools up faster, and also reduces heat soak through the rest of the engine bay.

With the budget in mind, I've decided to stick with a factory Nissan diff for now. They're still a good piece of kit, and the price is right. I will keep an eye out for mechanical diffs down the track but for now, getting the car roadworthy is the main priority.

Aside from the turbo and diff, the car is coming along nicely. The engine and gearbox are in, so I should have my freedom again when I get back from my holiday in mid-August. Can't wait!

An extra two cylinders

I've been without a car for about a month and a half now, and it's pretty frustrating at times. On the plus side, you occasionally get to drive something else nice, like your brother's R33 Skyline. Sean was kind enough to lend me his car (see pic) on the weekend, and it was a great experience.


In comparison with the 4 cylinder Silvia, the 6 cylinder engine just revs so cleanly, with a minimum of fuss. The extra 0.5L of displacement means more torque everywhere in the rev range too.

On the inside, it also feels positively cavernous compared to the Silvia. For a tall guy like me, the leg and head room is awesome! It's a pretty compelling case to swap models.

There's a common analogy that the Skyline is the Silvia's bigger brother. Apart from literally being longer, wider, and heavier, I can really see why. The Skyline actually feels like a more "grown up" car.

I might have to think up a few more errands that "can't wait" so I can get back behind the wheel!

Progress on rebuild

The rebuild process is still plodding along, with a few bits and pieces making their way to the new shell. The car is now only missing a front lower control arm, so is basically rolling!

Upon closer inspection, there were a couple of further casualties. The turbo housing is cracked, and the impact has bent the impeller. The diff housing is also smashed, so I have two important decisions: what size turbo to replace the broken one with, and what sort of diff to run going forward.

The diff decision is pretty straightforward - get a limited slip one with a mechanical centre, if the budget will stretch.

The turbo decision is a little trickier, becuase there are a couple of affordable options in varying sizes. I want something that will still fit on a factory manifold, but am considering something with a larger compressor wheel. This has the potential for more boost and greater horsepower, but will also create more heat, put greater strain on the clutch and gearbox, etc etc.

Both decisions will probably be determined by budget, so i'll update when a decision has been made.

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Stripping the wreck

Greg from Autosport kindly opened up his workshop to us on the ANZAC day holiday, so only a week after the incident, we got to work stripping the crashed car. It was great to get the ball rolling and start to move on so quickly, as I was feeling pretty down about the whole thing for a few days.

Greg was an enormous help to Sean and I (or more accurately, Sean and I were a little bit of help to Greg), and within about 4 hours we had almost everything off the car excluding rear suspension and interior.

The following Thursday, my brother Sean donated his day off to get the remainder of the car stripped down and the engine out. With some more help from Greg, the car soon looked like this:


The shell will be wrecked and written off with the RTA in the coming week.

The good news is that there is a decent amount of stuff from the car to donate to the new shell. The engine, radiator, piping and exhaust are ok. The gearbox and tailshaft are fine, and most of the rear suspension arms are re-usable. The coilovers also appear to be ok.

There were also some casualties. A couple of the wheels are buckled, and the diff housing is badly cracked. The CV's have punched a big dent in the end of the driveshafts nearest the diff, and will need replacing (see pic).

On Thursday, we'll begin the process of transferring stuff to the new shell.

Crossroads

Crashing my car has been a very unique experience. Although I walked away basically unscathed, it did give me a mental battering. It forced me to consider a number of things, one of which was whether motorsport was the right hobby for me. It's expensive, dangerous, and time consuming. The crash seemed like a crossroad - a chance to get out, leave it all behind and buy something sedate, or to press on and take some steps down the road to participating again.

If you've read my last post, you know my mind was made up before I really thought about it.

I did, however find that while at the "crossroads", I spent a bit of time reflecting on what I love about motorsport, and also what I love about the Silvia. It's no coincidence i'll soon have owned four of them consecutively.

Motorsport. I guess it's one of those things that you don't really get until you give it a crack yourself. It's a risky, almost illogical past time, and yet I spend hours reading, talking, researching, and spending on the hobby. My squash racket cost 150 bucks, and will probably last 3 or 4 years. Prepping the Silvia for an hour of track time? Hundreds and hundreds of dollars. Scary when you think about it.

So why do I do it? Becuase no other sport I've tried compares. Apart from the concentration and coordination required, the challenge of extracting every bit of potential from myself and the car is huge. It's one of those challenges that is ongoing too, because every time you achieve your goal, the bar moves higher - there is always something to improve. And whilst there's no question that the more money you have the faster you will go, you can still learn so much about driving in the most modest of cars.

The S13 Silvia is the definition of said modest car. It's a daggy looking thing with the classic late 80's box shape and a big long bonnet. From the factory, it's got average handling and average power. It screams "entry level" sports car, and yet, in the hands of a capable driver, it can be bloody fast.

Something about the Silvia has captured the imagination of the Japanese motoring world. It may be an ugly bit of kit, but people saw it's potential - it's light, it's rear wheel drive, and it's turbocharged. Today, it's got one of the largest aftermarket parts bases of any car on the planet. They may be a modest factory performer, but with parts from big brother Skyline and some aftermarket help, they transform into cut price tarmac weapons.



And that is why i'm now embarking on my fourth S13 build up. For a young guy on a budget, there's really nothing that compares. The only other car in the price range i'd seriously consider is an Mx-5, but for a guy who is 6'6" it's just not going to happen.

My philosophy will always be to not modify the car beyond my skill level. With Silvia Mk4, I am aiming to replicate Mk3 as best as I can, but up the safety level substantially.

A crash will change your priorities like that.

People have said that the S13 is becoming the Datsun 1600 of the 21st century, becuase there are a million of them around and they are the budget motorsport workhorse. I reckon that's a pretty good analogy, and I really couldn't ask for more from my weekend warrior.

Crash @ SSCC Supersprint: Eastern Creek, 18th April 2010

Well, Sunday was certainly a memorable one, but not for the right reasons. I had a mishap in the early afternoon and am now without a car.

Up until lunch time, things were going well. I was getting more comfortable with the layout, and enjoying the improved braking performance. I improved my pb by over a second down to a 1:56.9 but In the first session after lunch, the day got a lot worse.

Turn one is the fastest corner on the circuit, and also my favourite. If you get it right, it feels great and you can make up a good amount of time. If you get it wrong, the speeds are high so it can be unforgiving. The incident unfolded pretty quickly, but in short, I should have braked a little more after the straight and carried a little less speed into turn one. Becuase I was travelling too fast, I ran wide on the exit of turn one, which put my right rear wheel on the grass. This unsettled the car a lot, and I suddenly found myself spearing toward the inside of the track.

In an attempt to recover, I countersteered back toward the track but it was too late at the speed, and the rear end flicked around, and the car speared off the track backward. After that, it felt like forever before I hit the wall. I remember checking my left rear view mirror and seeing the wall approaching.

Then, finally, the hit. Rear left first, then front left. In an eerie twist, the old owner sent me a video - he had a similar mishap on the same corner. Up until the point he recovers, the incident is almost identical:

http://www.youtube.com/watch?v=AapVJcxgS5k

As you could imagine, the car is worse for wear. I would love to get straight back "on the wagon" so to speak, but this is an expensive hobby and it might take a little longer than that. I've had amazing support from club members and mates, offering to help with repairs, so we shall see. Thank you again to all of you.

I've already considered a few options and the most likely is to transfer the undamaged parts to a new shell in an attempt to get something roadworthy in the shortest possible time. It will not be as pretty or as fast as Silvia Mk3, but if it keeps me out there, I will be absolutely chuffed. I'll be sure to write plenty about the build up process for Silvia Mk4 (or should I say, 3.5?), so stay tuned.

Three years in a Silvia

I was reading through some old posts recently and realised that my blog's been alive for one year today! I've also been driving a Silvia (of one kind or another) for three years. How the time flies (when you're having fun).

I'm really happy with how the blog is evolving - i've made 20 posts in the first year, discussed driving, modifications, and even managed to buy a new car! Over the next 12 months, the goal with the (still new) car will be to improve the lap times further, and hopefully post that 1:10 or better at Wakefield park. I think I can knock another few seconds off that Eastern Creek PB too. We shall see. I would also like to do a skidpan day and a hillclimb if the opportunity arises, and make some small but constructive modifications to improve the package I have.

Speaking of which, there will be a few updates for the car before my next track day at Eastern Creek on the 18th April. At my last outing, there were two key areas which I thought needed improving. The first was braking performance, the second was stability on corner-exit. A third thing that needed improving was me, but that's a given :)

To improve the car's braking performance, I have started with one of the simplest items - better brake pads. I have ordered another set of Project Mu HC+ - I was very happy with them on my Black Silvia and on paper, they are a superior pad to the QFM ones I am currently using. Along with a replacement of brake fluid, there should be a noticeable increase in stopping power next time out.

To improve traction on corner exit, I have bought some adjustable rear camber arms (see below) to allow a better wheel alignment. My car has been lowered on coilover suspension and as a result, the car has excessive camber at the rear which cannot be dialled out without the use of an adjustable suspension arm.

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The car also has excessive toe angle at the rear. An adjustable arm will again allow me to align the rear wheels at a more ideal setup for traction (see below).

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To complete the traction picture, I am also looking for a limited slip diff. This will allow the power to be applied more evenly to both rear wheels, again improving traction. Each of these suspension/drivetrain changes should allow me to apply more throttle sooner (and with more confidence), thus increasing acceleration out of each corner.

That's all for now. If you have been a regular reader, thank you for stopping by and I hope I have shared some useful information. If you feel like discussing the car or want some details on the events i've entered, feel free to email me: ljw8.au@gmail.com

Upping the grip: tyre pressures and temperatures

As I mentioned in my last post, I came across a great little device at my last supersprint which left me very impressed. A pyrometer (see pic) is a basically a temperature sensor, but it doesn't require contact with the object to take a reading. It measures thermal radiation, so you just point it at the object you wish to measure the temperature of and wait for the readout.

For the amateur track day goer, I think this is a great way to add a little "science" to my car setup - the idea being to take a little bit of the guesswork out, and make calculated changes to the car. So how would I use a pyrometer to help with my setup? By measuring tyre temperatures and drawing some basic conclusions from the data.

To maximise cornering grip, we want as much of the tyre touching the road as possible - how much of the tyre is touching the road is known as the contact patch. Wheel alignment plays an important role in maximising this patch, but so too does tyre pressure. If a tyre is over-inflated, it will "stand up" and not use the edges, and if too soft, it will flex - both detrimental to cornering grip.

Using a pyrometer, I can gather some useful information on how hard each section of the tyre is working and thus check if I have a good contact patch. After a session on the track, you can take three readings on each tyre - the outside section of the tyre, the middle of the tyre, and the inside section of the tyre. In this case, we are not particularly interested in the actual temeperature value, becuase it will vary a lot with the conditions. What is more important is uniformity - if the temperature across the three sections of tyre are similar, then the full tyre is touching the road the majority of the time, and thus being used to it's full potential. If, however, the edges of the tyre are cooler than the centre, it may suggest that the tyre is over-inflated. Conversely, hotter edges than the centre may suggest that the tyres are under-inflated. If the tyre is hotter on one edge than the other, it may indicate a handling bias which requires you to make a suspension change. This is pretty basic stuff, but as I said, it gives you an opportunity to inspect your car and take a more educated guess about making changes.

Given that it can read the temperature of anything you point it at, the pyrometer can also be used to monitor the temperature of brake rotors, your gearbox or diff, anything really! All these items have a safe operating temperature range, so I could check these periodically to make sure everything is in check.

So in summary, a great little device. I think that if I made the effort to do this at every track day, along with logging some basic weather information, and track temperature, it would help greatly in determining a suitable starting point for the conditions, and get me into that sweet spot sooner!

SSCC Supersprint: Wakefield, 14th March 2010

I spent yesterday at my second combined club Supersprint - this one organised by the WRX owner's club, and held at Wakefield Park.

I'm fairly familiar with Wakefield now, so I thought I'd have a good chance of improving my times significantly - but was brought back down to size early on. It was drizzly in the morning sessions, and my driving would probably be best described as "dog's breakfast". I was missing too many apexes and braking markers, leading to some off-road excursions and generally average times. In short, I didn't adjust too well to the conditions.

In the last session before lunch, I tried to change my mindset. My aim was to hit my braking markers, hit apexes, and build speed slowly. It was much more successful - I was more composed and the laps were more fluent.

After lunch, it cleared up nicely and I aimed to build a little speed with each session. I went from a best of 1:17 in the morning, to 1:14's, and by the end of the day, a 1:12.9. What pleased me more was that in my final session, I did four laps back to back within 0.2s of each other, suggesting i'd found some of that consistency I lacked in the morning sessions. On a side note, a pair of gloves was an excellent investment - no worries about sweaty hands; a nice bit of extra grip.

The Yokohama tyres were tough in the morning. They're a relatively hard tyre, and it was almost impossible to generate any heat in them. In the warmer conditions with a little less tyre pressure, they felt better but still lacked bite.

I also got some help from one of the SSCC regulars, Shane. He has a beautiful red Corvette which he's been taking to the track for ages, and he's pretty experienced. He commented that my rear wing angle was quite agressive, and might be hurting my straight line speed. By agressive, he means that the angle of the wing relative to the airflow is large. If you reduce the angle, less downforce is produced, but also less drag. And so there is a trade off - more straight line speed comes at the expense of some downforce. Shane reasoned that I probably had an adequate amount of rear grip, so the extra straight line speed may be more beneficial than the extra downforce.

And so in the last session of the day, I flattened out the wing angle. My top speed increased by around 5 km/h. Success? Maybe. The important thing to note is that there are several variables involved. It may just be that I was getting a better exit on to the straight, and so my top speed was naturally higher. This is why I value consistency in laps too - if you can lap consistently, it makes it easier to identify whether changes to the car have been valuable or detrimental.

Shane also game me some useful info about a little device called a pyrometer, which i'll make the subject of my next post.

I also took a bit of footage of the afternoon sessions:

SSCC Supersprint: Eastern Creek, 14th February 2010

Another track day, another success!

As per usual, I was excited leading up to the day and slept poorly, but the reason this time was a little different. I had a new, faster car, and a new event format - more unknowns, more things to look forward to. To make me slightly more nervous, the rain had been bucketing down all week. When I woke on Sunday, it was heavily overcast with rain threatening yet again - not great news for the track day fan, but a different challenge.

I arrived at the track nice and early, but it hardly seemed like long enough. As I mentioned in a previous post, Supersprint events are slightly more serious than the days i've been attending over the last couple of years, so there's some extra rules and procedures to be aware of. I also had my car scrutineered prior to the event - marshals check that your car is in good working order, and that there are no loose objects or dangerous items. In the excitement of the buildup, I forgot to remove my spare wheel from the boot, so was politely asked to do so. Other than that, the car went through without a problem.

The driving itself was an absolute blast. Before the day, I had decided that I wouldn't push out of my comfort zone too much, but just familiarise myself with the new conditions and make sure the car came home intact. The wet weather only reinforced that decision, so on the damp surface, I took it fairly gently the whole day. I finished with a best of 1:58.1, which is a full 8 seconds slower than the previous owner's best time. Plenty of room for improvement there.

I was really pleased with the car's performance. The suspension is superior in every way to my old Silvia - it is eager to turn in, and is very stable mid corner. The brakes are strong and don't feel as if they will fade as easily. The engine combination is excellent, and the midrange torque gives you great acceleration out of the corners. As my confidence in the car grows, it's only going to be more fun, and hopefully faster too!

The camera setup was a success too, so i've posted some footage of the morning sessions:

http://www.youtube.com/watch?v=s00aYkAndws

http://www.youtube.com/watch?v=nESBko_VPH4&feature=related

It's only four weeks until the next SSCC Supersprint, so I don't have to wait too long for my next fix. The event will be at Wakefield park, which I am reasonably comfortable with, having done a number of track days there. If the weather is fine, I might just find that bit of extra confidence to push this new car closer to it's full potential!

Preparation

In preparation for my first track day in the new Silvia (coincidentally also my first Supersprint), I've been kept busy with little bits and pieces both on and off the car. When I stopped and thought about it, I was impressed with what i've managed to get organised in the last month or so!

In order to compete in a Supersprint, you need to hold a CAMS (Confereration of Australian Motorsport) speed licence. You also need to have stickers on the car to tell officials where your battery and tow hooks are in the event of an accident. The organisers also expect that you have a secondary restraint on your bonnet (i.e something in addition to the latch), so i've sourced some bonnet pins to keep it nice and secure. The old owner already had a fire extinguisher mounted in the cabin, so check that one off the list.

Inside the car, i've decided to have proper harness mounting points welded into the parcel shelf. A harness not only provides additional safety over a lap sash seat belt, but also keeps you securely in place during cornering, meaning you can focus all your attention on driving rather than trying to brace yourself as you slide around in your seat. I'm really happy with the setup, should hold me perfectly (see pic).

On the car itself, i've had an oil temp sender installed to keep a close eye on those oil temperatures, and also purchased some new race tyres which should see me through 2010. I've chosen the Yokohama A048R (see pic) - it is the control tyre of the Improved Production Racing Series and the V8 brutes. It's not the grippiest semi slick on the market, but the price was right and it will be plenty adequate while I continue to learn.

And last but not least, my brother and I designed a simple little device to mount a video camera on the passenger side of the parcel shelf, so hopefully I will have some video to share of the first outing! We dismanted a tripod, and secured it to the child seat point using a lengthened bolt and a few washers. Very simple, very effective!

Until then, it's time to study a few more youtube clips of Eastern Creek, and get those lines in my head so the course seems like second nature. Can't wait for the 14th February!

Silvia Mk3

Nearly a month after I laid down a deposit on my dream Silvia, I took delivery of it yesterday night. Was it worth the wait? Hell yes. I couldn't be happier with the car, it's just superb. I've already had a few comments saying that the car looks like it's just rolled off the showroom floor! Not bad for an 18 year old car eh?

The seller mentioned that the car previously belonged to a fastidious owner, and it really shows. Things that rarely work in these old cars like electric mirrors, dashboard dimmer lights, ash tray lights, they're all in perfect working order. The paint doesn't have a single scratch, fade, or bubble. It's how a Silvia should be, and how i've always wanted one to be. With any luck, I can keep it that way. Shopping centre car parks are going to become an even more stressful place.

All that said, I didn't buy this car because it looks pretty. I bought it because it's also got the potential to set some solid lap times. Obviously there's no room for testing the car's potential on the Pacific Highway/Anzac parade, but i'll give my initial impressions.

The car has a mean, slightly bumpy idle from the aftermarket camshafts. The exhaust is loud, but more muffled that the straight pipe i'm used to - a big plus. The springs in the coilover suspension are firm, but the shocks are far better than the ones I am used to, so the car feels very settled at low speeds. The car pulls smoothly and evenly throughout the rev range - it feels ready to go at a moment's notice. The brake system is designed to pull up the Silvia's bigger brother - the Skyline - so they should be more than capable of the task.

My brother recently purchased his first SLR camera, so we saw last night as a perfect opportunity for him to test out a few shots. We drove to a deserted car park, and took some shots with the overcast and tinged night sky behind. I've posted a couple of my favourites. Thanks again to Sean for the shots!