Sam's build thread

[sambb]

oh and that's why when I go to 215 mediums (rather than 195 softs or 205 mediums) i'll still be running 195 softs on the back for the hillclimbs.

[metalhead]

At the last Eastern Creek meeting (A050's Medium compound) on Saturday morning we had air temp at 11 degrees and track temp at 10 degrees (cloud, high humidity, no sun). In the afternoon it was 13 degrees and 15 degrees (no cloud, more normal humidity and sunshine). From drastic oversteer due to a lack of rear tyre temp (FWD of course) in the morning (46's) we were 2 seconds a lap faster (44's) with understeer in the afternoon. Air temp change of 2 degrees = who cares, track temp change of 5 degrees = huge difference.

Tyre pressure gain over 10 laps of 4 psi in the morning that went to 9 psi in the afternoon. Another measure of the difference track temperature makes.


Obviously I record air and track temps before every session on the iPad, together with the chassis settings. It's all stored in the cloud, so next time I have an 11/10 to 13/15 day I can look back and not make the same mistakes again.


Cheers
Gary

Good info. I've been recording times, splits, dates, tyres, and tyre pressures, but no weather data. Also it's worth noting that I abandoned my third run (of 4), when the track was seemingly at its best, due to tossing a belt (thought I'd fixed that problem ).

How are you measuring track temp Gary?

My brother ran his set of AR-1s (on his mx5) at Wakefield yesterday for the first time, and he was pretty happy with his. He ran a PB by over a second and felt like there was more in it. His previous PB was on Potenza RE003s (ok street tyres, but not great) on a very hot day.

I agree with you 100% Gary re the heat in the brakes and rim bleeding into the tyre. At the hillclimbs where you have the pits at the top and have to form up as a class and drive down to the bottom of the hill before starting, eg King Edward Park, both days at Mt Panorama, I always felt comfortable. I'd spend that time accelerating and braking the whole way down to just get as much heat into the brakes as I could and you could feel that the tyres were hot due to it. But Ringwood where there's so many trees, Huntley where you are packed in like sardines on grass, Tamworth where you are on dirt etc you have no options really. At Canberra what I learnt (road reg) guys were doing was going out of the lot and doing runs up and down the road into Queanbeyan before coming back in and staging up. That jack stand idea is bloody awesome. I've always been conscious of heating the loaded side of the cars tyres with the sun, so would change how I parked up to account for that, but not as elaborate as that. - nice.
I think your Nankangs will have their day Andrew. Believe me my softs can feel like ice blocks on those first runs at Ringwood when its still like 7 degrees and even the late arvo runs when the sun drops behind the gums. Hilllcimbs are just a bitch like that and you'll always have first corner grip jitters but especially on a circuit or those 3 lappers at Tamworth or eastern ck rally sprints is when you will really get that surprise you were expecting.

Yeh ok... I'll need to run them there a few more times to get the full picture I suppose.

[Sydneykid]

How are you measuring track temp Gary?

I have a Longacre tyre pyrometer with a Type K thermocouple probe (cost $A200 or so a few years ago now). I mostly use it for tyre temperatures (the probe gets below the skin temp zone) plus ambient and track temps. Some guys use the infrared gun style for measuring tyres skin temp and track temp, but they have problems measuring air temp. There are higher temp versions for brake rotors, exhaust etc.


Cheers
Gary

[metalhead]

Still curious, how are you getting to measure the track temp with a pyro probe? I've been meaning to get one of those for better tyre temp measurements, I only have an infra red temp gun at the moment.

[Sydneykid]

Still curious, how are you getting to measure the track temp with a pyro probe? I've been meaning to get one of those for better tyre temp measurements, I only have an infra red temp gun at the moment.

It's pretty simple, poke probe (gently) onto the tarmac and read the temperature off the display. I avoid the gravel chunks and try and find an uncontaminated piece of tar. As usual I'm not looking for an absolutely perfectly accurate number, just as long as it is consistent. The probe does most often read the same as the infra red gun on dry tarmac, but wet tarmac it seems more accurate.


Cheers
Gary

[seangti]

We'll just drive out there that morning. If you get stuck with anything in Sydney give me a call.

Good to hear it's all coming along. Sounds like we'll have plenty of track time so can chip away and make tweaks. The Amaroo format will be a good comparison for Wakefield, more low/mid speed corners rather than high speed of the national circuit.

I had an uninteresting drive down over the weekend so sitting in Nowra atm. Will head up Friday night for a Saturday kick-off.

Out for a good time, not necessarily a fast time

[sambb]

Cool. For me it depends on the tune. We had to go back to the 2.5in maf because the load numbers down low were too low and making it hard to set up the timing apparently. The 3in maf was nearly ready to go, but the 2.5in maf is a bit behind now. So if the tune is cracking, i'll push. If its not finished then there's no point wringing its neck and i'll just look to fiddle, tune dampers etc and get into a few fun little races.

[sambb]

YouTube


Vid of Senna in CRX/civics again doing his throttle pulsing thing mid corner in a FWD.

[Water Boy]

You coming on Saturday mate?

[sambb]

yeah I am. Car is getting tuned at the moment. Probably only time for one more revision to flash in tomorrow so I hope its a good'n.. Got a mate in a little Clio RS W172 coming too. He's pretty keen to see how he goes against any NA MK1's and 2's. What car are you in?