Mx5, Chapter 2

[The American]

I have a number of issues to sort out following the day at Warwick and the Noosa Mid-Year Hillclimb.

(1) During the Warwick track day, the A/C line that runs past the turbo blew out, dumping the gas and a little compressor lubricant onto the exhaust, which created a flash of white smoke and a little distress. Either immediately or shortly after this, the compressor and the clutch mechanism was damaged and needs to be replaced. I’m not sure if I caused this by continuing to drive the car after the A/C line blew. My assumption (in continuing to drive the car) was that a low pressure switch in the system would prevent the compressor from operating without gas and lubricant in the system. By the time I returned from Noosa, the pulley/clutch were making a lot of noise. Unfortunately, not just the clutch is damaged.
This might make a good argument to myself for starting the build of a dedicated track car. No A/C. No P/S

(2) Fuel surge. At anything less than half a tank at Warwick, and with a little over half a tank remaining at Noosa, I’ve been experiencing fuel surge. The car feels like it’s momentarily running out of fuel in or just after a corner under hard acceleration. At Warwick, it was most pronounced in/after the corner leading under the bridge. At both events, topping the tank up from half to full immediately solved the problem. My suspicion is/was the filter sock. AutomotivePlus have had a look at this, and while the factory filter sock is in place, the height of the pump (too low) in the cradle may have been impacting the angle the sock sits at, so they have adjusted for me to test. Unfortunately difficult to test without doing an event/accessing a track, as I’ve had no issues at any fuel level when driving normally on the road.

(3) Brakes (issue 1). I’ve got standard NB8B brakes and whatever street pads were in the car when I bought it, and they’ve been fine for the hillclimbs. At Warwick, after a couple of larger braking actions, they faded pretty badly. Following Magpie around the track, I could stay with him heading into a corner, but he was able to wash off speed much quicker, and I found I had to brake much earlier in order to maintain a comfortable distance between myself, the back of his car and the edge of the track. He was significantly out-braking me! I’ll be thinking about some different pads before I do another long track event.
I don’t really want to go for a fully track oriented pad, as I plan to stick with short sprint or hillclimb events and want brakes that work well when cold.

(4) Brakes (issue 2). I left to drive to Noosa on the Friday night prior to the event, and had not dríven the car for the two weeks prior (after Warwick). It was immediately apparent that the brake pedal felt odd, and did not appear to be vacuum assisted. I stopped and checked the vacuum line to the booster (fine), looked for any obvious fluid leaks (none), and gave bulge in the vacuum line that is the check valve a firm tap with a tool. I pumped the pedal with the engine off to eliminate any remaining vacuum (there did not appear to be any) and then held the firm pedal down while I started the engine to see if I could feel vacuum taking up and pulling the pedal down – it did a little. I then drove on, braking here and there, and the pedal feel gradually appeared to return to normal, and so I continued on to Noosa. I had no issues with the brakes all weekend. I suspect either the beginnings of a booster diaphragm failure, or the check valve is gummed up and was not holding vacuum.

Noosa Hill was brilliant fun, and would love to get back there in November. The next event on the calendar is Cootha Classic, which doesn’t look anything like as much fun a piece of road as Noosa, but should still be fun.

Just need sort out my superhero costume so I can blend into the crowd.

[Magpie]

Hopefully I can give you some feedback on some pads that work from colder than the W5's do, however they have a bit more bite and no idea on how much dust they make. After QR I now brake later and less of it when going into a corner hopefully I can repeat this when next at Morgan Park.

Good to read that you are identifying the issues and making plans for them. If wearing a superhero costume remember to wear the undies on the outside.

[Okibi]

Very happy with the HP+ but we're not doing lap after lap of hard driving so not sure how they'd hold up on the track.

[The American]

Make shift mudflaps:

[The American]

Trimmed to shape:

[The American]

Fitted:

[The American]

In preparation for future amphibious cornering:

image.jpg

Some say these merely add 1.6kg (a side) of greenery. Some say they give your wings legs.

[The American]

In prep for tomorrow's Cootha Classic I found these at BCF:

image.jpg

$3 a pair

[The American]

I have a number of issues to sort out following the day at Warwick and the Noosa Mid-Year Hillclimb.

(1) During the Warwick track day, the A/C line that runs past the turbo blew out, dumping the gas and a little compressor lubricant onto the exhaust, which created a flash of white smoke and a little distress. Either immediately or shortly after this, the compressor and the clutch mechanism was damaged and needs to be replaced. I’m not sure if I caused this by continuing to drive the car after the A/C line blew. My assumption (in continuing to drive the car) was that a low pressure switch in the system would prevent the compressor from operating without gas and lubricant in the system. By the time I returned from Noosa, the pulley/clutch were making a lot of noise. Unfortunately, not just the clutch is damaged.
This might make a good argument to myself for starting the build of a dedicated track car. No A/C. No P/S

(2) Fuel surge. At anything less than half a tank at Warwick, and with a little over half a tank remaining at Noosa, I’ve been experiencing fuel surge. The car feels like it’s momentarily running out of fuel in or just after a corner under hard acceleration. At Warwick, it was most pronounced in/after the corner leading under the bridge. At both events, topping the tank up from half to full immediately solved the problem. My suspicion is/was the filter sock. AutomotivePlus have had a look at this, and while the factory filter sock is in place, the height of the pump (too low) in the cradle may have been impacting the angle the sock sits at, so they have adjusted for me to test. Unfortunately difficult to test without doing an event/accessing a track, as I’ve had no issues at any fuel level when driving normally on the road.

(3) Brakes (issue 1). I’ve got standard NB8B brakes and whatever street pads were in the car when I bought it, and they’ve been fine for the hillclimbs. At Warwick, after a couple of larger braking actions, they faded pretty badly. Following Magpie around the track, I could stay with him heading into a corner, but he was able to wash off speed much quicker, and I found I had to brake much earlier in order to maintain a comfortable distance between myself, the back of his car and the edge of the track. He was significantly out-braking me! I’ll be thinking about some different pads before I do another long track event.
I don’t really want to go for a fully track oriented pad, as I plan to stick with short sprint or hillclimb events and want brakes that work well when cold.

(4) Brakes (issue 2). I left to drive to Noosa on the Friday night prior to the event, and had not dríven the car for the two weeks prior (after Warwick). It was immediately apparent that the brake pedal felt odd, and did not appear to be vacuum assisted. I stopped and checked the vacuum line to the booster (fine), looked for any obvious fluid leaks (none), and gave bulge in the vacuum line that is the check valve a firm tap with a tool. I pumped the pedal with the engine off to eliminate any remaining vacuum (there did not appear to be any) and then held the firm pedal down while I started the engine to see if I could feel vacuum taking up and pulling the pedal down – it did a little. I then drove on, braking here and there, and the pedal feel gradually appeared to return to normal, and so I continued on to Noosa. I had no issues with the brakes all weekend. I suspect either the beginnings of a booster diaphragm failure, or the check valve is gummed up and was not holding vacuum.

(1) Issue 1 sorted with a new a/c hose with a longer metal section that extends past the turbo (means the rubber bit is not so close to the turbo housing).

(2) The adjustment in height of the pump and filter sock made by AutomotivePlus appears to have sorted the surge issue. Before and after the adjustment it was running the factory filter sock, but was suspected to be sitting too low and pressing the filter sock into the bottom of the tank. No issues at all during a Mt Glorious test run with the fuel light on, and no issues at all during the Cootha Classic with a near empty tank (with the fuel light also on).

(3) sticking with the street pads I have for now, as they are working fine for the hillclimbs.

(4) No issues with missing vacuum assistance have reappeared.

[The American]

Cootha Classic 2015

I didn't think I'd get to run in this competition due to the way the event was marketed as an exclusive event for 'some of Australia's fastest cars'. I do believe however, that if you don't ask, you'll never know, and so I lodged an application for consideration. I don't have a superman costume, race suit, Lamborghini, or even a car with sponsor stickers or serious (read 'any') aero so nothing about my entry says 'Australia's fastest'. In the end, there were around 90 cars competing, and some of the event organisers communications suggested the event might have been a little undersubscribed.

I saw at least two entries for the Mt Coot-tha event either destroyed or seriously damaged at the Noosa Hill mid year event. I also met a competitor at the scrutineering on the Friday, who did not know he needed a CTP extension. He left to get one and never came back.

As I don't have a trailer for my car, and no other way of getting to the event without it, I did not leave my car there on Friday night. I was told that I had to be onsite before 6AM in Saturday for traffic management reasons. It was more than 4 hours from arrival until my first run of the day.

Race day organisation left a little to be desired. The CAMS officials appeared to do a good job, although the main lady doing marshalling in the pit area was getting a serious workout on a push bike to get around the spaced-out pit zone.

There was an issue with leaky portable barriers that were causing dampness on the downhill side of the track that eventually led to the track length being shortened.

There also appeared to be a shortage of traffic cones and there was a delay of approximately an hour at the beginning of the day, while a madman with a car and trailer was seen - by himself - wildly collecting traffic cones from outside the pit area for some urgent purpose.

There was no convoy sighting run. The finish line was not well marked. Class rules were not scrutineered. Spectators escaped the spectation areas. There were various obvious examples that the event was a first for the organisers. I hope they made money out of it, or at least covered their costs.

After all that, you might expect me to report that the event was rubbish. But it wasn't, it was brilliant fun!

The track

The launch off the start line is on a reasonable incline and I found little grip, with wheel spin through first and second gear. There was just enough road to grab third briefly before braking into the first chicane.
The run up the hill from the first chicane leads into a right hand, left hand, right hand corner combination that found me starting to drift/slip towards the Armco in the long left hander, prompting an ease off the throttle, then WOT briefly again before braking into the second chicane just before the hairpin. Once in the chicane, a shift back to second gear for the run to the hairpin.

I tried first gear and then second gear through the hairpin, and found keeping second more effective, but it might have been quicker to go deeper into the corner, turn slower and tighter and extend the first straight down the hill to the third chicane. The hairpin is off-camber and turns downhill so there is a combination of corner and the road falling away under the car to unload the suspension and keep things interesting.

From the hairpin, there was a short downhill run into the third chicane, which (as they all did) had an entry and exit on the left.

The run to the fourth and final chicane is down hill and around a left-hand corner. This fourth chicane caught out some drivers on the day with its position relative to the corner allowing more speed to be carried into the entry, and for some, leading to a collision with the right hand kerb. By the last run of the day, there was a good collection for tyre rubber leading to that kerb!

From the fourth and final chicane, the less-than-obvious finish line was not far away, around a sweeping down-hill and right-hand corner.

The section of road immediately after the finish continued right, and down hill, and tended to encourage the car to tail out to the left (oversteer nose right) even with light acceleration or throttle lift off.

And that was it! A short run from there led to the staging area and the return road to the pits.

It was a lot of fun, and I'd do it again.

My only disappointments:

1. I clipped a cone and incurred a five second penalty on my fastest run. If I'd got through cleanly, I'd have landed in the top 5 shoot out. (Actually, as I was on semi slicks, I should have been in modified class - which I pointed out to the scrutineers - so should have been nowhere near the top five). It would have been great to sleep on the practice of day one and come back for a second attempt had there been a day two.
2. The track was shortened as a consequence of the leaking portable barrier which means if I do attempt this again, I won't have a PB to chase.

There was not quite enough time between runs to get to the food area or to see the display of MX-5s on site, but some of the team including Adam Shipway came down to the pits to say hello, which was great.

The organisational issues were annoying on the day, but unsurprising for a 'first time' for a particular group. If the same crew puts this on again next year hopefully they can pull off a smoother schedule.

Most importantly, it was fun. It was a fast track, with a good crowd, and lots of interesting cars, and friendly people.

As I'm writing this, I'm realising just how much more challenging the Noosa Hillclimb track is. I only drove around the Cootha Classic track 5 or 6 times, and I can basically visualise the whole course, and put together a mental picture of how I'd attack it next time. Noosa, on the other hand, I've dríven around 10 times over two days, and watched my own recordings (plenty ) and I still could not describe it to you corner by corner.

[The American]

I just worked out that my turbo is a 2560 and not a 2860, so there's less ultimate potential there than I thought. A little disappointing, but fortunately the knowledge doesn't change how it drives as it is!

[The American]

Flashback!

Many thanks to Simon Corston for capturing and sharing these images with me.

This was my NA8 (dec'd) before any modifications, and probably still on 10 year old tyres. This would have been shortly after we rescued it from under a tarp in a back yard with a slipped timing belt:

MX-5 NA Hansen Wheeler by Hanson Wheeler, on Flickr

[The American]

The sheer volume of body roll was a sight to behold, coupled with the poor rubber made for some dramatic cornering:

MX-5 NA Hansen Wheeler by Hanson Wheeler, on Flickr

[The American]

but still loads of fun to drive...

MX-5 NA Hansen Wheeler by Hanson Wheeler, on Flickr

[The American]

After finding some marginally better tyres, the first modification was a set of front and rear adjustable Whiteline anti roll bars. You can see in this shot that it's cornering flatter than before:

Hansen Wheeler Autotest November 2012 by Hanson Wheeler, on Flickr