The Roadster NA Journey Begins

[madjak]

I also collect a lot of data but I rarely look at it after the event unless there is something to query. The only data I monitor throughout an event is coolant temp, afr values and oil pressure and generally it's just a quick glance at lunchtime to make sure all is good.

Ironically when I spun a bearing and needed my oil pressure data logs, they were missing due to an earlier tps sensor failure which wasn't triggering the recording of my logs.

In terms of on track live data, I have my race capture showing delta times to my fastest time of the day. Under that I have various pressure and temp values that are only there if I need to look. I find the only performance metric I really find useful is the delta time. If I try a new line then a quick glance to the delta time tells me if I was quicker or not without the need to go back afterwards and look.

Like Magpie I'm interested in the data side... but I find I don't have time to analyze it the way I'd like. There is value there if you can learn to understand the data... but it's complex and easily misinterpreted. I can certainly see why some drivers prefer to live in blissful ignorance as electrics are a nightmare for most. For me, the potential to catch an issue to prevent a grenaded engine is worth the occasional checking.

[Magpie]

[Magpie]

Work has decided to send me off to NZ to work (possibly just Mon-Fri) for a month, however do not have a return flight booked just yet so no QR next weekend. Will be home for 27/11 and the dodgy day

Weekend saw the upper control arms removed to check on the eccentric bushes. Both sides had moved, so these were reset and the long bolts torqued up to specs. Made sure I jacked the arms up to where they would be at normal position before they were tightened. It would appear in the past I may have left them a little loose

The bushes will need to be replaced soon anyway due to the corrosion and 'rifiling' in the passenger side. Time for some of the extended tie rod ends and spherical bushes. These are the LH side

DSCN3575 by Eipeip, on Flickr

DSCN3582 by Eipeip, on Flickr

DSCN3584 by Eipeip, on Flickr

DSCN3585 by Eipeip, on Flickr

Also pulled the front calipers off and replaced with the spare set. looks like the seal on the drivers side has perished and this could explain the uneven pad wear. The LH side has even pad wear and the seal in intact. Will order some new kits (including pistons) and rebuild the set taken off.

DSCN3586 by Eipeip, on Flickr

DSCN3587 by Eipeip, on Flickr

DSCN3591 by Eipeip, on Flickr

DSCN3590 by Eipeip, on Flickr

Brake fluid has been changed. Waiting on some dust boots and helper springs for the BC ER's then the car can be aligned again. Also finished off the install of the coolant flow alarm, tested and works. Now time to pack the bags.

[lucass]

I hope you lubricated those poly bushes... If not they're probably sticking to the crush tubes, that's probably why they look so beat up and have moved.

[Magpie]

There are grease nipples installed on the bushes, just need to add it to my pre-track maintenance routine. May pull them off again and make sure the grease hole goes through to the crush tube as well. I did lube the inside of the bushes. Learning to do more and more myself now.

The drivers side was a lot better.
DSCN3563 by Eipeip, on Flickr

[Magpie]

When ordering some replacement boots for the BC's from Just Tap I also ordered some BC helper springs. Whilst not really required to fix the inceptive spring at full droop it was a good opportunity to get them.

DSCN3595 by Eipeip, on Flickr

DSCN3596 by Eipeip, on Flickr

With 4.4kg of weight the helper springs were compressed by about 7mm, fully compressed they are about 30mm thick. The suggestion from JustJap was to lower by about 20mm. However I went for 30...

DSCN3600 by Eipeip, on Flickr

DSCN3599 by Eipeip, on Flickr

DSCN3598 by Eipeip, on Flickr

DSCN3603 by Eipeip, on Flickr

The car ended up at about 102/110 (F/R) ride height at the pinch welds and this was a bit low even to get on the trailer (almost 25mm lower than previous). Sensibility got the better of me and I raised it 13mm.

DSCN3605 by Eipeip, on Flickr

It is off for an alignment next week at TTS Tyre & Auto then its final run of the year at QR Street Sprints on the Sunday. However, pending approval it will be at QR on 11/12/16 for the sponsor thank you day. Maybe able to sneak in some laps for non sponsors

[Magpie]

Chefie is herby appointed my offical motivational source!

[pepejesus]

Those helper springs look like a very light rate. Do you know if they have heavier options, ie something that would actually be useful as a tender spring?

At that rate it looks like all they'd do is stop the springs from rattling around at full droop.

[Magpie]

You could check with BC Racing if they have 'stiffer' rates for the helper springs. Yes you are correct they just stop the main Spring rattling around at full droop.

what are you looking to do?

[chefie]

Chefie is herby appointed my offical motivational source!

Ha ha

just keep your foot OFFFFFF the slow pedal and ONNNNN the fast pedal

good fun today tks

2016 QR sprints you have grabbed more time than me, so seat time is the best modification

second best modification is a diet

[Magpie]

Will do a more detailed post on the weekend (including videos of some of the more interesting moments). Had a small laugh when a person following me came up and said they had no idea how I 'caught' the car and kept it under control going through the dipper

The car did not go for an alignment prior so not sure what the camber/toe was. Major change was 9kg in the rear and 15mm lower all around.

Started out with the car on its normal setup (dampers/pressures) and the car was prone to oversteer and did not inspire confidence, backed up the front/rear dampers by 3 clicks. However times were OK. Tyres went to about 32 hot and based on temps increased them to 34.

Second session, car still oversteering and a handful, not happy with the times. Chefie commented that like in the past I was braking about 20m too early and whilst he could catch me on corners, straights were another matter. Tyres were bumped up to 35 psi and the front/rear dampers softened by a further 3 clicks. Tyre temps again showing that slightly underinflated. Note the ambient air temp and the track temp was very hot.

Third session feeling better with the car, oversteer reduced. Tyre pressures tweaked based on tyre temps to around 35.5 psi on the RH and 35 and the LH. The couple of quick looks I got at the infra red tyre temps whilst on the track was showing the rears at over 80°C. Softened the fronts up by another 3 clicks, was reminded by Chefie that I was still making the same mistakes (braking too early).

Fourth session, car felt a lot better, tyres pressure/temps almost spot on. Times getting respectable, started to brake later/less and wash off speed on the turn in, Chefie found it difficult to catch me in corners this session. Felt a lot more confident in the car.

Fifth session, no changes to the car and really started to get into the 'groove', the afternoon was a lot cooler but the car felt good.

WIll be staying with the rear spring rates, however may order some 8kg just to be safe, plus I need to lower the rear a bit as well.

For the maths geeks, 200kg on the front sees 29.7mm of wheel movement with 10kg springs and 30.7mm of movement with 9 kg springs on the rear.

A few negatives for the day, the cost for 20 laps is not really worth it, not to mention one of our sessions was cut to 3 timed laps Further, 78 cars is a lot, there was 5 groups for the day, but only 2 groups for non 86 cars to be grouped into and one group that only had about 12 cars in (visiting club from NSW). Personally, if everybody is competing in the sprint series then there should have been 4 groups based on times.

The MX5 Car Club QLD should consider doing something similar to the 86 club and running their own group(s). Bonus is that you can run a dual competition, that is club points as well as points for the QR Sprint series AND you have your own dedicated group(s).

The visiting club from NSW (2 MX5 as well) has a yearly trip where they visit other tracks. This year they did Lakeside (26/11) and then QR on 27/11, from conversations with them they enjoyed themselves. Maybe a group from QLD could do a similar thing, a road trip to visit some tracks in other states.

[pepejesus]

You could check with BC Racing if they have 'stiffer' rates for the helper springs. Yes you are correct they just stop the main Spring rattling around at full droop.

what are you looking to do?

Wondering whether you could get a dual-rate spring on the BCs similar to what the XIDAs use, where it has enough rate to provide more (usable) droop travel. Not that it's a big issue for me or anything, just daydreaming, really!

[Magpie]

The BC springs are 62mm ID so any spring of this size could fit.

[Magpie]

Video from QR Street Sprints Round 6. Sorry Chefie no footage of yourself, but you can probably see the few time I kicked up a dust screen coming out of the dipper.

Tyre temp data suggests that initially the car was understeering initially (fronts hotter than the rears) but it did not feel that way initially. This was more than likely due to not having the tyre pressures correct. I did start out very warm and it was not until the end of the day that things cooled down.

Personally I have enjoyed 2016 in the car and it is good to see the car closer to the top than the bottom, well excluding WTAC

[Magpie]

My uni studies have finished and since the dodgy day was over I decided to do some mental exercises... data analysis.

A common thread in feedback being given is that I brake too early. Whilst I do not think I am a video sent to me PROVES that I am...

How to improve this aspect, well understanding where the problem is helps. The tyres have a finite level of grip and can be used to brake/corner or a combination of both. A combined G value will highlight points where you are not using all the available tyre grip https://www.vboxmotorsport.co.uk/index.php/en/news/155-a-useful-trick-to-gain-lap-time, however it does not really show in what axis where you are deficient (lateral/horizontal). You could look at each value or use a G Plot instead.

Looking specifically at T3/T4 (Dipper) on the QR Sprint and assuming a 1.2g maximum level of grip with the AD08R's it becomes obvious that on the transition from braking to turning I'm only using 50% of potential tyre grip. For me, I brake hard, then turn in, the slow in fast out route, also the safest as the risk of destabilising the car is reduced.

G Plot by Eipeip, on Flickr

What I should be doing is aiming to achieve the maximum amount of grip for the maximum amount of time (orange line), however there is not the same safety margin as the 'slow in fast out' but this is what is required to do fast/consistent laps.

I can do this at T6, which on the Sprint layout, at least for me is not really a corner that you brake into. This G Plot shows that at least when I'm accelerating I can be at the limit of grip. The blue line represents about 7 seconds of data. The orange again is at 1.2G. Would be nice to have 1.2g of acceleration

T6 G PLot by Eipeip, on Flickr

This is the plan for 2017, focus on this one aspect (turn/brake at the same time to the limit of grip) by tweaking the suspension/tyre pressures/alignment as well as the desperately needed 'balls' mod.