Sunday, June 28, 2009

Brake update

Yesterday I finally got a chance to work on the car a little. I swapped out the rear pads with new new ones. It had been a while since I had replaced the rear pads so it took me some probing around to figure out how to do it. The handbrake/piston thing would back with no issues on each side. I remember doing this on the RX-8 and it was a nightmare. I guess this is how it is supposed to work. Easy...

Anyway, the left side pads had 2mm and the right ones 3mm. I wonder is this enough to be causing the problem that I was seeing. Seems like lots of pad to me (although it definitely needed changing at 2mm).

I'm in two minds about putting in fresh front pads too as they are down to about 5mm but I figure it will at least get me though the first gymkhana day on the 4th.

Sunday, June 21, 2009

Braking brakes

Last weekend the 13th, I did 2 runs at Tsukuba. The first session, I had just rotated my front left/right tire so I was getting huge oversteer for most of the 1st hairpin until I'd shaped the fronts into their new positions. Likewise, I was under-steering around the right handers. The 2nd session, I felt more confident that the tires were working a bit better again so I set out to do a fast lap or two.

Needless to say all didn't go well but it wasn't the tires. I locked brakes into the 2nd hairpin for a brief period and after that braking was a bit of a gamble. When braking hard, I'd push down on the brake but instead of the peddle sinking down, it would sometimes remain hard under my foot and not sink to its usual depth. This was very disconcerting arriving at a hairpin at around 130kmph and wondering if your brakes would work or not. I peeled into the pits and had a look at my tire pressures and the brakes. Front pads seemed ok - a little slim but no problem. The rears as always were hard to see but with my helmet on, they seemed like they had meat. I decided to take it easy for the rest of the session and just work on tire shaping and bring the car home alive.

Asked a few people about the problem. They suggested fluid. But I'd recently had a fluid change and the peddle feeling was actually fine. I know what it feels like when I've got some air in the pipes. Somebody else suggested the brake booster which makes sense when you think about it, but I think it was more than just extra effort to brake. Something else perhaps. Someone else suggested piston problems but braking seems fine now as it did when it wasn't acting up on the track also.

Today I had some free time to play with the car a little even though it was pissing rain all day. I finally took a look at the rear pads and although they do have meat on them they are looking rather slim. I wonder what the inside pads look like??? So I decided to buy some new rear pads (MazdaSpeed) and will install them the next sunny day and take it from there. Hope this will resolve the issue!

Tuesday, June 16, 2009

Karting 09/06/14

As the previous day in Tsukuba was such a disaster brake-wise, I thought I'd blog happier news first and show you all some karting photos from Sunday.

We did the 8pm night race again at the New Tokyo Circuit. That place is great fun and the karts are all decent for the most part. Highly recommended!

I managed to grab pole again much to the dismay of my fellow racers. K was looking pretty fast though sitting up in 2nd place and at the start the 52kg lightening rod took off and left us for dust quickly opening up a 7 or 8 car gap by the 2nd corner where he got into a little over steer and happily enough for me I got the lead back. From there on, my goal was to break into the 48s mark so I tried various things.

The most important corners are 3 and the last first part of the chicane on the last corner. Those also happen to be hard bloody corners to take just right so its very challenging to get the best out of a full lap. I got a few 48s laps with the best being a 48.736. I wonder what the ultimate lap time would have been for my car with a 70kg driver in it. I reckon there is perhaps 0.7 there for some god to steal yet. I notice the best lap time so far is 46.9 and judging from the photo that guy weighs about 50kg or there abouts. Would be fun to weigh 50kg for a day to try and beat that!

Anyway, great fun. Can't wait for the next time.

Monday, June 8, 2009

Ebisu East 5/31 another video

Here is another 3 laps from Ebisu as the course was drying out and I was on my own in the car so I could go a little faster.

Thursday, June 4, 2009

Ebisu Circuit (East) 09/05/31


Wet/Semi-wet day at Ebisu Circuit. It was my first time there in the roadster. We had 5 sessions altogether. Only the first one was dry really. My best time of the day was around 1'14.699. Semi-wet or mostly dry it didn't seem to make much difference.

Looking at the videos, I was pretty cautious through the chicane. The rear end seemed very light on turn in to the left part which was a little disconcerting although I probably could have tried more different approaches to see what worked and what didn't. I also slowed a little too much around the first corner but I did find the car quite prone to over-steer on accelerating out of that corner also. Looking back I would like to try more keeping speed there. I should also have tried a few different things on the last corner to see if I could keep more speed for that cruel uphill. There are chunks of time left in this circuit yet. I'll try post more videos later.

One of the cool things (apart from the track itself) was that we were allowed to bring passengers aboard our car during the sessions as long as they had helmets and gloves. This was my first time to give some friends a spin in the car beside me on a largish circuit such as this. It was as interesting for me as I'm sure it was for them.

In a way, the car actually felt a little more balanced with someone in the passenger seat. The lap times didn't vary that much although I took it a little easier when I had someone beside me to be responsible for - particularly as the track got that bit wetter. I actually did a 1'15.2 with James in the car beside me :-)

Here is a video of me taking my mate Derek around for a few semi-wet laps.