Sam's build thread

[sambb]

i'll look into it. Only way that will happen is if my wife drives the kids up in the other car (convoy style because she hates long freeway runs), watches me race that day or something and then we all continue on to see some relatives at the border. Its a possibility. I'll let you know. No I haven't raced it but its narrow, lined by rock walls and yep short wheel base cars love it apparently. Put it this way if it was only 3 hours away I'd be there with bells on.

[seangti]

How are you looking to run next weekend? I'll start heading down tomorrow and take the scenic route. I'm thinking I'll just run my federal RSRR tyres rather than carry the semi's down... Out for a good time, doesn't need to be the fastest.

[sambb]

Um looks like it'll be a go. Was really worried the tune wouldn't be ready. Its still ongoing and wont be finished for the track day but I just loaded anther revision this morning and I'd say its at a comparable stage to how it was running previously so I don't think i'll be turning up with a slower car at least. If I can even get one more update in before the weekend I think itll go ok.
I took the belly pan off and gave the car the once over. Turbos water fitting (which I still haven't gotten too) still isn't leaking somehow so hoping that will hold together. Re checked everything I did with the gear linkage to make sure I don't get a repeat drama from that. Got my hillclimb softs stripped off the enkei's and my mediums put back on. I'll swap onto them at the track and run my street Toyo R1R's if its properly wet. It'll be my first time at a circuit with the rear toe done. It was fine at Bathurst hillclimbs like that but I was on softs, so i'll maybe have to get used to that and test out upping the rear bar to max. If I settle on a setting I'd like to have a go at some damper adjustments if there's time. Really I want to get a good understanding of the car so that I can give Wakefield a good crack next time around.
Should be fun. A guy we have hillclimbed with will be there in his Skoda Fab vRS on some new Nankangs and he's pretty familiar with the circuit (and quick) so hopefully we can all be out there together at some stage. We'll just drive out there that morning. If you get stuck with anything in Sydney give me a call.

[metalhead]

First time at Ringwood on the Nankang AR-1s today. It was a cold track, and not very grippy by all accounts, and admittedly I didn't feel I was driving my best. Ran very similar times in the first and last splits (the only ones I can compare, I hadn't run this layout before) to most of the times that I've run when I've been there on my Continental ExtremeContact Sport street tyres. I was a fair bit slower than my quickest splits, which were at the state round on the street tyres last year, though the track was exceptionally good that day and I'm sure I drove better with the stronger competition (I was more than 5s quicker than the next person in my class today). At least they weren't significantly slower than the street tyres - the last set of semis I put on the car were. I'll hold off a verdict until I've run on them there another couple of times, in case it was heavily influenced by track conditions, but figured it would be of interest to others on here. A little disappointed at this stage, they're fine, but not a big improvement over my street Continentals (which admittedly are a very good tyre - tested as significantly quicker than a Michelin Pilot SuperSport).

[sambb]

I still reckon give them a chance. I think hillclimbs was going to be more of their strong suit. Ringwood is like that though. In the state rounds I've seen it where you just cant even get near your practice times from the day before, so it could be the track. How do they compare for say front end feel - communicative or dull? What sort of pressures were you running as r specs can be dropped way down for hillclimbs compared to UHP street tyres.

[Sydneykid]

It's been a while since I was at Ringwood, but from memory a lot of corners were shaded by trees, by various amounts at various times of the day. As a result, when I measured the track temperature there was 10+ degrees difference in some corners and it changed for every run during the day. R type tyres get their additional speed (over road tyres) from the increase in frictional grip (not carcass construction or tread pattern), which is of course very temperature dependant. If we can't get any temperature into them they aren't going to have any more grip than a road tyre of similar carcass construction quality.

There are all sorts of tricks for getting temperature into the tyres, for example in the Evo just before each run we'd stick it up on jack stands and "warm up" the engine and transmission. With the left foot on the brake pedal it's amazing how much heat transfer you get from the disc rotor to the inside of the wheel and to the tyre.


Cheers
Gary

[metalhead]

I still reckon give them a chance. I think hillclimbs was going to be more of their strong suit. Ringwood is like that though. In the state rounds I've seen it where you just cant even get near your practice times from the day before, so it could be the track. How do they compare for say front end feel - communicative or dull? What sort of pressures were you running as r specs can be dropped way down for hillclimbs compared to UHP street tyres.

Oh I won't be tossing them or anything. I don't think they're slower than the Contis, or not much if they are - just a bit disappointed that they definitely don't seem much quicker. It is making me wonder if I should have jumped on the ao50s that Matt Cole was selling a couple of weeks ago though! I've generally been running around 28-30psi in them (hot). Figured I probably wouldn't want to go much lower given the weight of the car, and the wheels being minimal on width for the tyre size (295/30 on 10" wide wheels). The feel is pretty good I think - to be honest the Vette (having recirculating ball power steering) doesn't have the best steering feedback anyway. On my to-do list is adding an adjustable valve to reduce the power assist and hopefully provide some additional feedback, as well as replacing the rag joint with a uni for the same reasons.

[metalhead]

It's been a while since I was at Ringwood, but from memory a lot of corners were shaded by trees, by various amounts at various times of the day. As a result, when I measured the track temperature there was 10+ degrees difference in some corners and it changed for every run during the day. R type tyres get their additional speed (over road tyres) from the increase in frictional grip (not carcass construction or tread pattern), which is of course very temperature dependant. If we can't get any temperature into them they aren't going to have any more grip than a road tyre of similar carcass construction quality.

There are all sorts of tricks for getting temperature into the tyres, for example in the Evo just before each run we'd stick it up on jack stands and "warm up" the engine and transmission. With the left foot on the brake pedal it's amazing how much heat transfer you get from the disc rotor to the inside of the wheel and to the tyre.


Cheers
Gary

Yeh true, and it was pretty cold with a cool breeze yesterday. Good points! It was a ~60s layout, so a bit of time to warm the tyres, but perhaps not enough. I kept the long sleeves on all day yesterday, which is very rare for me. Guess maybe I need to start keeping a record of temps and track conditions to help me with my comparisons. I just had so many people tell me that changing to semis was such a huge improvement... Hard not to feel a little disappointed when my times are effectively unchanged.

[Sydneykid]

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

[sambb]

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.

[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