The Roadster NA Journey Begins

[Magpie]

Again a very hot day in Purga today. A certain Volvo driver dropped in for coffee today as he was in the area!

Today was a get thing ready day as well as a chance to test the brakes. WOW on the brakes, could be one of the best mods ever done....

Making a list of what goes into where, need to customise the generic lists that I have and make them specific to the type of track visit (local, over night, more than overnight).

DSCN3955 by Eipeip, on Flickr

Apple remote not going
DSCN3956 by Eipeip, on Flickr

Pit trolley (12v power, USB, air compressor, etc). I cut this down as it was a little too high for the amarok.
DSCN3957 by Eipeip, on Flickr

Still deciding if to take spare set of tyres. Long range weather suggests that there could be showers on 21/01.
DSCN3958 by Eipeip, on Flickr

On the subject of the Amarok, the fuse panel does not identify what fuses go where. So needed a multi meter to check the resistance on over 30 fuses before I found the offending one!

[MattR]

Mark, re the brakes....

I'm not gunna say told ya.......

Yes i am....

Told ya so, should have done it years ago.........

The pedal feel is so much better and you have so much more control at the limit with modulation of the brakes. The S14 will not run a booster, the Zed didn't run a booster, and as it was in the early '70's, my Chugger doesn't run a booster.

Maybe I do know a little bit of what I supposedly dribble on about.....

[Magpie]

Initial feedback on the booster delete...

Looking at data from QR National in late 2016 and Sandown in Jan 2017 as the only change in the car (with the exception of different rear spring rates) is the delete of the brake booster. The pads were the same Winmax W6.5's front/rear. Tyres were AD08R's. Whilst they are not the same speed, the distance 'washed' off is the same. Therefore you would expect to see similar G forces and braking distances.

QR - Blue (G's), Purple (Speed), Mauve (F brake Pressure)
Sandown - Yellow (G's), Pink (Speed), Light Green (F Brake Pressure).

Have also looked at some braking from 125 km/h to 65 km/h, including data from July 2013

It is obvious there is the more F Brake pressure on the QR Trace and the higher G Force developed. In addition, the QR trace shows the brake pressure increasing again after being backed off. This is not optimal (bad skill/technique)

The Sandown trace shows less G force being generated on the initial application. This could have been lack of experience with the brakes, however at no time at Sandown did I have brake lockup ...

What is promising in the Sandown brake trace is the constant pressure used and the trail braking at the end.

When you consider the OEM NA6 prop valve above the knee point increases the rear brake pressure by 1psi for every 3.34psi above 427psi. Therefore at QR when the F brakes were at 664psi the rear was at 498 psi. This equates to a bias of 75%. However, what is evident is the actual reduction in brake pressure using the W6.5's over a 'normal' pad, this could also start to explain why, if using aggressive pads that the rear feels like it is doing less, simply the pressure in the system is less. In the OEM system you would expect to see almost 1,000 PSI on the fronts if using OEM pads.

At Sandown the F/R brake pressures were the same. At times this made the car feel 'unstable' at hard braking, but not impossible to control.

What needs to be done is develop more G in braking to see if the change was a positive. So, the jury is out, but it is looking very promising if I can use all the available grip of the tyres.

QR SAN 001 by Eipeip, on Flickr

Sandown 2017 Braking (W6.5's F/R, no brake booster, AD08R's)
Sandown Jan 2017 by Eipeip, on Flickr

Morgan Park E July 2013 - NB8B brakes A1RM's in the front and EBC green in the rear. R888's (from memory). Note the 'wave' in the brake trace...
Morgan Park E July 2013 by Eipeip, on Flickr

Eastern Creek Oct 2015 - Winmax W5's F and W3's R on AD08R's. Braking from 125 km/h to 65 km/h (with brake booster). Note the 'wave' in the brake trace... (starts to see pattern)
WTAC 2015 by Eipeip, on Flickr

QR National June 2016 - Winmax 6.5's F/R, brake booster on AD08R's. Whilst this shows better performance over the non boosted brakes, it highlights (again) the lack of brake pedal control by the driver.
QR National June 2016 by Eipeip, on Flickr

[Magpie]

Opened the shed door for the MX5 today, first time since it was parked after Sandown.

Mission was give it a check before Lakeside. As normal no issues, however a small oil drip on the floor. Could not find the source, there was a little on the PF but this could have been from ages ago when I spilt oil whilst topping it up. The reason could have been because when I was jacking it up it was left on an acute angle longer than normal. Wiped down the PF and will check after Lakeside.

IMG_1665 by Eipeip, on Flickr

IMG_1666 by Eipeip, on Flickr

Even checked the oil catch can...
IMG_1667 by Eipeip, on Flickr

IMG_1668 by Eipeip, on Flickr

Also did some trailer maintenance, an ongoing issue has been the jerry can holders. Between vibration and heat expansion another weld failed on the way back from Sandown. Also took the opportunity to remove some tie down points that have never been used and could wreck a wheel.

IMG_1675 by Eipeip, on Flickr

IMG_1676 by Eipeip, on Flickr

IMG_1677 by Eipeip, on Flickr

Used the new passenger seat cover
IMG_1678 by Eipeip, on Flickr

Also looked at the rear end when changing the muffler on how to save some weight. Ages ago a cover was made up for the spare tyre to mount an oil accumulator on. Therefore is their a saving in weight by using this plate and removing the steel below it.

The shell looked like this
IMG_1670 by Eipeip, on Flickr

Not long after
IMG_1671 by Eipeip, on Flickr

VERDICT
Panel removed - 2.54kg (excluding heat shield)
Proposed cover - 3.06kg

Therefore will have to use a lighter thickness aluminium or a sheet of CF.

[Magpie]

Lakeside Round 1 of the MX5 Car Club QLD went better than expected, despite the early noise issues, which I was prepared for...

Now to the critical review of the data from the session.

What more of an obvious picture do you need, I can hear MattR saying "I told you so". Not much time was spent at full throttle or even above 80%. However, less time was spent at zero%, this is a welcome change! From an RPM perspective almost all the data is above 6,000, this implies that the car was kept above where the torque curve is rising.
1 by Eipeip, on Flickr

Another 'bad' picture is where on the track I was either using full throttle (green or not (blue) as well as hard (red) and trail (yellow) braking. I can only see this in a negative and it shows nothing positive
The information for the brake is from the brake sensor and not interpolated from G's as done by other software. Hence even a light tap on the brakes will show
2 by Eipeip, on Flickr

GPlot - A small positive from this is that I'm starting to fill out the middle parts of the plot, that is brake/turn at the same time and using all the available grip of the tyres. I have to add the circle feature that a very helpful person on the Racepak forum has given me the code for.
4 by Eipeip, on Flickr

Fastest Lap - Yes MattR the data shows lifting off at the Kink...
Negative

1. Lifting off at the Kink
2. Lifting off going around the Bus Stop. However the G's around here was about 1.1 hence getting close to limits of grip.
3. Why the throttle modulation after the change to 4th out of The Karrussell.
4. Throttle modulation out of Hungry and into Eastern Loop
5. Lift off/trail brake before the final corner

Positive

1. Brake booster delete, however yes MattR I need to count to 3 when I think I want to brake
2. Less time between braking and acceleration. This is something that I'm really trying to work on this year.
3. Shape of the brake curve shows less hesitation in application
4. The brake trace shows less pertinacity to have more pressure applied late in the braking.
5. I think I can improve by at least 2 seconds

3 by Eipeip, on Flickr

[plohl]

64 is a good time dude. Don't be too worried about the data, everyone already knows the cars fast and your chipping away to catch it. Good thing is, you know where you can improve... and lakeside is scary.

I agree, 2s improvement isn't out of the question. I have done a 63.6 on the same tyres, so 62s in your car sound about right. Should be close to 60s on semis. Some of the 2f cars run sub 60, they have similar power.

I'll see if I can find a throttle trace.

Sent from my SM-N9005 using Tapatalk

[Magpie]

Thanks plohl!

[SKYHI]

Lakeside is definitely a place to "chip away at", rather than all out attack to improve times.

It's great to see you using data to improve the car setup and your driving style. Way too many people under estimate the value of good data logging and analysis.

[Magpie]

TCR thanks! It is a fine balance between over thinking and putting theory into practice. However, I do enjoy my data collection and analysis. However would rather use Motec's software than Racepak's

The screenshots I posted are probably the ones I use the most as they are quick/dirty and an indicative snapshot of good/bad... I have others to monitor the car 'health' but do not normally post these. For example comparing each EGT to the average of the EGT's and seeing how close each cylinder is to the average, this gives an early warning sign to compression/tune issues. Also watch oil pressure by RPM/temp to see if any low oil pressure to be concerned about.

[ManiacLachy]

Glad to see it's all coming together, Mark. What was the solution to the noise? Any noticeable impact to power output?

[Magpie]

Solution to the noise was to put on the Racing Beat muffler which was packed just in case. I was asked if the car was running when I came up to the starting line for session 2

No impact on power, at least that I noticed.

Yes it is coming together, slowly. I just need to keep focused on what I want to do each time I go out, the ear plugs do help with the concentration.

[madjak]

I have a suggestion. I constantly talk out loud to myself when I'm in the car as I find it keeps me really focused on the goals for that session. It can feel a bit stupid but no-one can see or hear me so it's all good! The only downside is that my race voice can get a bit abusive when it goes wrong and I don't manage what I'm aiming for, but I try to balance it out with good praise when I nail it.

With braking points, if you have a visual point that you know you can hit. Aim a few meters past it and say "Hold Hold Hold.... NOW"... I find it's easier to override the self preservation measures of my brain and keep my foot planted on the throttle instead of it involuntarily lifting early. It is often followed up with some creative swear words as I'm fighting for control of the car but actually that's the part I think I'm addicted too. When you manage it, that extended braking point becomes the new standard and I'm aiming even further down the track next session.

[Magpie]

Thanks Madjak, may try that suggestion. If in the future the sound on the video gets beeps you will know why

As I stated, ear plugs help me concentrate, this will be mandatory each time I go out now.

I was slowly resetting my brake points at Lakeside as I got more confidence. Big test will be at QR on 18/02.

[Magpie]

May have found the 'loss' of power that I felt in sessions 3 and 4. Fuel pressure dropping!

A look at the data from Sandown shows that by session 5 there were some fuel pressure drops, but nowhere near as bad as Lakeside. The trend is the same first session no drops, but as more sessions are performed the more significant the drops become.

FP by Eipeip, on Flickr

[plohl]

Do you log fuel temp as well?

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