Dan's NC track toy

[Charlie Brown]

Dan, let me know how the Reds go. I've been considering them to.
What spring rates did they suggest?

[Dan]

Dan, let me know how the Reds go. I've been considering them to.
What spring rates did they suggest?

Cool, happy to let you have a drive next time we are at a club day together

The rates they suggested when we first spoke was 10kg/5kg but we ended up at 12kg/6kg.

[Dan]

It's been a little bit of time since I last did an update, unfortunately at the SMSP South SuperSprint in early October my day ended at around 3pm as I got a rear O2 CEL, speaking to Russ he said he'd had these a few times before so I didn't think much of it, cleared the code and called it a day.

Driving home the car died suddenly on the highway and it wouldn't start, the immobiliser light was flashing and it didn't even try to crank so initially I thought it might be an immobiliser issue. Looking under the car I realised there was the O2 cable hanging down so what happened was the plastic clip ground itself down on the road and then because the wires frayed it managed to short itself and popped the engine fuse. I didn't get to the bottom of the problem on the side of the road so I just got a tow home since I wasn't far away and then Daniel Deckers called me and told me exactly what happened (great having an expert to tell you what went wrong instantly).

Looks like the rear O2 shorting out is a fairly common issue, here's 3 Examples from the US forum of the same problem, something to think about for NC owners:
http://forum.miata.net/vb/showthread.php?t=434354
http://forum.miata.net/vb/showthread.php?t=573909
http://forum.miata.net/vb/showthread.php?t=557785

Sad car on the side of the road:


How the short happened:


Having that issue I decided I should also probably just do some preemptive replacement of some simple parts for reliability since nothing sucks more than a track day being cut short and by replacing parts I'll have a track spare of the old working ones I’m pulling off the car, so I now have all the parts either in the car or sitting at home:
- MAF Sensor
- Spark Plugs
- Replacement coil on plug harness connectors
- Front O2 Sensor (planning to disable the rear O2 with ecutek)

Since the car needed to go into the shop anyway and with the end of my season of Supersprints and Club events it meant I can now do mods which push me out of the classes I was in and start building the car for 2B Prodsports but having fun before I start racing it door to door so I’m in the process of preparing to do a round of mods which should be done in time for the December Circuit Club Track Day I’ve got booked in.

Weight Reduction:
I’m doing a few things to do some weight reduction on the car which should get 50-55kg out of the car, in addition to pulling the passenger seat out which is worth a 16kg weight reduction those mods are:
Battery - I changed the stock battery to a Deka ETX15L battery which I weighed at 5.0kg which is a 5.1kg weight loss from the stock ‘Super Charger’ battery that was in the car before which was on it's way out anyway (it had been drained a couple of times and I think it was pretty old), the battery with mounts and everything wasn't

The reason I settled for this model over the popular lightweight option of the Odyssey PC545MJ was the ease of installation (see this guide http://forum.miata.net/vb/showthread.php?t=451899), slightly lower weight, better CCA (220) and Ah (14).

The total cost for the battery plus terminals was $170 from Batteries Direct (http://www.batteriesdirect.com.au/shop/ ... tx15l.html). The guy when I went to pick it up was nice enough to throw in the tie down for me as well which had the additional thread you need to install the shorter battery.

Old POS:


New:



Stereo:
I removed the stereo since I don't really use it (I use earbuds connected to my phone so I don't get ear raped by the exhaust drone on the highway), with the speakers and amp it was a 5.9kg weight saving.

I’ll be pulling out the antenna as well to improve looks as soon as I get the Honda Antenna delete grommet which apparently fits the NC perfectly (part number 82871-671-000, it only cost a couple of bucks).

To make it not look ghetto I got one of the replacement facia's and a double DIN blanking plate (the blanking plate needed a bit of shaving to fit), I think it came out ok



Hardtop:
I’ve got a Deckspeed carbon hardtop sitting at their shop which will go on when I go in to get the Cams and Coilovers put on which should take approximately 25kg of weight out of the car by removing the soft top and frame and adding the super light hardtop.

I have some of the 3M door seal stuff which I plan to use to make the hardtop waterproof and reduce the noise, similar to what these guys do https://www.youtube.com/watch?v=nAZXk4OC_tk

Based on my calculations the overall weight loss is roughly worth the equivalent of a 5kw gain and I made a calculator that others might find useful to calculate equivalent power gains from losing weight https://jscalc.io/calc/qwfcwcFHtvvL6xGR - This calculator isn’t exactly scientific as weight reduction changes the way the car accelerates differently to adding power but I think it’s cool to start thinking about how much you gain by removing weight.

Obviously there are other advantages as the hardtop has a side benefit of being more Aerodynamic and less weight also improves the car in the corners.

Diff:
I changed my diff to a Cusco 1.5way LSD and had the rear diff bushings replaced with SuperPro PU ones as well.

My impressions from driving the car on the track once at SMSP South with the Diff is that the push from the extra grip is noticeable and I need to adjust my driving style, it’s even obvious looking at the wheel speed sensor data the elimination of wheelspin in twisty sections and low speed corners (speed spikes on an individual rear wheel shows this in data).

Red and blue traces are without the diff, grey is with (I had no need to cherrypick data as every lap is the same):



The diff clunks like a mofo at low speeds but I think that’s pretty much par for the course. I’m about to put some fresh oil in since it’s now been broken in and hopefully it will quieten a bit over time.

Cams
I'm waiting for a set of Cams to come in, they are a brand that Deckers has used before but not this size of cam (we went a bit milder since I drive it on the street) so I'm looking forward to seeing how much power they make.

New road tyres:
Since I need to pass rego and get the Z221’s stripped off the stock rims to put them on my race wheels, I got myself a set of Michelin Pilot Sport 3’s with the $100 discount promotion they were running which killed two birds with one stone.

RX8 Brakes:
I also got myself a set of the RX8 Sport calipers cheap off a wrecker in the US when ebay had the 15% discount going. Unfortunately half of the package went missing in shipping (the front calipers) so now I'm left with only the rear calipers but I got a full refund so I just need to track myself down a set of fronts and I'm good to go

Outside of the car I brought myself a new race suit which Sparco RS-4 - The construction is pretty cool, it’s ‘Hocotex' material which allows them to have a single layer with SFI 3.2A/5 and FIA 8856-2000 certifications.

I'd really like to do some Aero mods as I just finished reading the book I put a photo of below which I'd recommend to anyone interested in learning about aero (this is the revised version released in March this year). I've done some measuring of the car to start thinking about 2B compliant splitter design and wing sizes. The thing is the car is a road going car at the moment so I don't want to go too crazy with the splitter so either I'll make a conservative splitter with a wing or just start with a wing which should still yield dividends by itself at SMSP.

Great book!


The only other thing I've done which is the cardinal sin of racing is add up the costs of my MX5 (parts, labour and consumables including tyres) as well as the other things I've purchased as accessories for the car (race suit, helmet, hans, datalogger etc..). The cost of everything was nearly double what I paid to purchase the car (I did get a bargain) which was a bit shocking but the majority of that cost is in the parts I purchased and I can't really find any mods that I regret doing so I'm not upset, it just makes me feel like I should be using the car more to get the cost per track day down ;)

[Regie]

Awesome work Dan, I still remember the first track day you attended, actually i think that was the last time i was on the track no good!

very, very keen to see the results form the cams, id love to got a set of cams in my car also

[Dan]

Haha those were the days, stock Spec..

Circuit Club 6th of December ;)

Sent from my SM-N9005 using Tapatalk

[Dan]

The thing I was most looking forward to getting rid of when I pulled out the stereo out was the antenna. I thought I’d post how I covered the hole as I don’t think anyone has posted about it here and I couldn’t find any pictures online of the grommet I used working on an NC.

There was a thread about this on miata.net where one guy on the US forum used a painted drain plug which looked pretty good and one guy said he used a grommet he got from Honda - part number 82871-671-000, he didn’t provide much info other than saying it fit like a glove so I thought I’d give it a try.

I probably could of got it locally but I’m lazy and just wanted to order it without having to call dealers so I brought it online from here which ended up costing me $13 AUD shipped to my door http://www.partzilla.com/parts/detail/h ... 1-000.html

Took me 10 minutes to remove the old antenna using a set of circlip pliers to get the nut at the top off and then the grommet was a perfect fit, a bit tight putting it in but once it was in it doesn't wiggle at all. I think it looks much better than an antenna and should be weather proof.

This is a side view of the grommet:


Antenna base:


Plug installed:

[Dan]

Picked up my car from Deckspeed today which I was pretty excited about, I need to give the car a good wash but I think the Carbon hardtop makes it look very racecar, looking forward to driving it at Circuit Club on Sunday and seeing how these MCA Red’s perform!



I thought when I took my car in I would be able to just put the carbon hardtop on the car but unfortunately it turns out the Brown Davis roll bar for the NC is not designed for any removable hardtops so with that I decided to have a half cage welded into the car which can be extended to a full cage when I take it off the road. I think Daniel did a cracking job making the cage, also the way it sits further forward than the Brown Davis means It can sit higher giving more headroom than before which is a nice benefit.




A GV Replica polyurethane front lip also went on the car to get the front down by around 50mm. I’m not happy with the fitment without screwing into the front bumper but it seems to be fairly solid in the way it’s mounted without screws so I’ll make a decision on what to do soon.. 3M tape didn’t seem to work as the fitment is slightly off so I might need to do a bit of trimming or something.



I made a new pickup as well which I’ve been testing which is a SmartyCam GP HD. I have been using a GoPro for a while and rendering when I got home but not needing to render videos with overlays, power coming from the car so I don’t need to think about batteries and automatic turn-on when the car goes onto the track sold me on it. Seems like a cool bit of kit which integrates with my datalogger and it was easy to fit on the roll cage with RAM mounts.







One big improvement came from changing the diff fluid to Cusco 80W-140 oil, that made the Cusco 1.5way silent which very nice, quite amazing because it was making loud thunk noises before when taking tight corners at low speeds.

[mx5002]

Getting serious mate!
My cusco used to clunk so bad. Everyone was royal purple this redline that. Don't touch the cusco stuff. Used the cusco oil and have never looked back. So much smoother

[Dan]

haha yeh it’s getting a bit silly.

I had a similar experience with people recommending different oils to fix the problem (or a different diff), funny how we don’t trust the manufacturer of parts to know what’s right

[Dan]

Hot day out at Circuit club today with 30+ degree weather from early morning, ended up with a 1:10.98 on Natsoft.

It was a good test of MCA Red’s. It took a bit of getting used to them and not having the sways, the good was the car was much more settled between turn 3/4 but the car also seemed to have some understeer on fast corners particularly T9 onto the back straight which took a bit of getting used to. Not sure how much the tyres contributed because I was on half worn 215/45/17 Z221 Mediums rather than 235/45/17 Z221 Softs which I've been running for a while.

Need to sort a few things with the new video setup like getting rid of the splits and mapping the throttle data with the video but it was nice not needing to do an overlay, here’s me chasing Matt (Wasabi) in his SE during my fastest lap of the day.

[wasabi]

^^^

Always a good time with you at the track mate!

& you got the last minutes of life of my turbo on camera!

[Dan]

^ haha yeh, that drive down the straight was N/A vs N/A

Also I found a couple of professional photos of my car in it's natural habitat on the Circuit Club website over the weekend which I liked.

[wasabi]

Only one photo of me... In it's natural state for the day parked up

At least it was on the dummy grid

[Dan]

I put some carpet in the rear around the roll bar tonight, I was dreading doing it thinking it was going to be a complete clusterfuck but it ended up being pretty easy and only took a couple of hours.

I got carpet from Bunnings which cost just over $70 for 2mx2m and I trimmed the carpet while it was in the car with scissors and a stanley knife without even pulling the seats out.

I did the carpeting in 3 pieces, one big piece in the middle and then I did the sides separately so the carpet wouldn't be pulled in too many directions and fold up. To my suprise the carpet draped like I wanted it to, at the front I cut the carpet so it tucks into the center console section and then behind the chairs, since the carpet is black it blends in.

As Apu suggested to me in another thread instead of glueing it down like I originally planned I ended up just using the bolt holes that are up the top (normally used for the soft top) to position the carpet and I only used double sided tape around the sides to keep it centred and connect the pieces.

It's not perfect but I'm really happy with the final result and I think the interior looks much better with the carpet in.

[Apu]

That's really good work!