Andy's MX5 Race car

[AUZJDM]

Hay Andy goodluck with your MX5 for Time Attck, perfect platform car that is already way ahead off most off the field in terms off handeling, should be interesting too she the finished product. Will be buying products from your store for my project NB Track attack and daily!!
Keep it up! AUZJDM

[Andy_W]

Thanks guys!

For some reason I don't get reply notifications to this thread so I didn't see these until today!

It is a Bond cage, but they just do the bending and cutting to length; it still needs to be cut at oblique angles at the ends and welded in. Daniel Deckers did it for me, so I don't know if there's a Bond guy in Perth who would do the same thing. I contacted Bond originally to ask them for a cage and they put me on to Daniel. Hopefully they have another similar person in Perth.

Scrutineers didn't seem worried about it, they passed the car without the driver - we passed the driver's apparel and car separately because my car had a dead EFI relay and Ric had to leave.

I'll post another soon with some results

[Andy_W]

We ended up with a best lap time of 1’44”178 (on Yokohama Advan A050s), which placed us 39 out of 60 in open class, up against 600 kW Silvias, big power Evos and so on.

I did try to shake the car down at Wakefield and did a few laps to get some heat into her, but really I didn’t push her as hard as Ric Shaw was going to at Eastern Creek, so we discovered several things that I hadn’t discovered for myself (also be naïve and not knowing things that needed to be checked), and we had problems that we were dealing with at the track such as “unplanned variable suspension geometry”, too much camber, overheating problems and being too stiff in the rear. On the last run we think we pinched an apex seal (possibly due to overheating on the Friday afternoon, or having “leant” on it too hard in tuning) so that was out after the 1’44” lap.

There is a lot more potential in the car, even with the same power. Running the same suspension as Goldie (the MX5Mania race car) gives me confidence in the suspension itself, but I put in the prep time to set it up correctly for my car, so there’s a definite opportunity there, both to increase cornering speed and getting power down earlier out of the slow corners. There is also a significant opportunity in weight reduction. Building a stronger, more powerful engine will also help us get the speed up between corners.

Another significant result from the car is some excellent “baseline” data from this year’s competition; I have logs showing how many Gs we were pullling on each corner, when we were getting back onto the throttle, how fast we were going through each corner and so on, which gives me a good idea of what modifications the car needs to go much faster and allows me to test individual changes without relying so much on my driving ability!

Big thanks to:

1) Ric Shaw, for taking several days to help prep the car, corner weight, tell me the things I have to change, his excellent driving and fearlessness, and providing lots of very useful parts like alloy radiator, Blitz BOV, K&N air filter

2) Racecarparts, for providing the seat and harness

3) MX5Mania, for providing suspension, wheels and brakes, doing the suspension install/setup, assisting with the brake setup, and Dave going out of his way to drop off a bolt to replace one I snapped

4) Hoon Media and D&D Designs, for the media side of things, and doing a full bog and repspray in a single day

5) MRC, for the dyno time, general guidance and assistance, and dropping everything to change my clutch for me

6) Pivot Creative, for dropping everything to do my carbon fibre roof, rear panel and mirrors

7) Aztex and Tully Spry for doing the engine conversion in the first place

Boostbitz, for helping get the car ready and providing the “positive pressure components”

9) Race Technology, for their assistance with setting up the datalogging

10) Pulse Racing, for being awesome “garage buddies”, providing general mentorship and Superlap experience

11) Shamrock Racing for the pictures!

[deviant]

I have heard / been told that the 50mm rule does not apply if the car has a hard top on it?

[Guran]

I have heard / been told that the 50mm rule does not apply if the car has a hard top on it?

Nope not true. The revised regs clarify that an open car fitted with OEM hardtop is still an open car.

[Andy_W]

Hi all!

OK, I haven't been updating much because I've been really busy preparing everything.

We'll be having a stand at Time Attack this year and Kathy is running again. This time she has the boost cranked up, makes 270 kW at the wheels on Ric's dyno (which is probably 300 kW on anyone else's) on about 21 psi. I've upgraded the wheels to 17x8.25 - with 255/40/17 tyres they were a bit wide, so I'm changing to 245/40/17 now.

I think the rear springs are too hard - they're 12kg/mm, she bounces a fair bit at Wakefield. So I'm going to try some softer springs. Unfortunately the practice day at EC on Monday 30th July was cancelled so we won't get any testing time in at EC before WTAC. Here's some testing:

Me driving on full boost, but I'm not really a circuit driver so I wasn't pushing it too hard, wanted to test the tune on full boost on the track. I sent this link to Ric Shaw and he sent me an email back saying "The throttle's on the right!":


Me driving after stiffening the shocks and trying to find where it would let go (again I'm not much of a driver):


John Boston driving with shocks set really soft so it was bouncing a lot (also with fairly worn tyres):


Cheers!

[PaulF]

Nice update Andy. I thought it was interesting that John Boston was using a lot of left foot braking in that video.

[Andy_W]

Yeah, I was surprised! Maybe it's easier to control a car you don't know by holding throttle constant and modulating the brakes; throttle response varies a fair amount from one car to another...?