The Roadster NA Journey Begins

MattR · Postby **MattR** » Tue Feb 04, 2014 2:54 pm

All good then

But as the ITB's don't generate the vacuum the booster needs and you like the feel, get rid of the booster.

A few reasons, weight, better feel, more room, easier to fit a dual master cylinder set up with the obvious advantages for adjusting brake bias and one less thing to go wrong.

Now to get the times down to a level that is equal to the car :lol:

Use the data to get your driving right, such as video for lines as you can see where you are quicker with the lines you take and also the throttle and brake data tied into the video, and if possible distance traveled as measured by wheel sensors, like a terra trip or halda, to see where you are braking and accelerating so you can work out where you can brake later and get on the throttle earlier.

I am hesitant to use GPS data alone as unless you have DGPS the accuracy is only around +/-3m for the newest Sirf IV chips. For points close together in time the relative accuracy is good, but you don't know what the drift in accuracy is from lap to lap and when you are looking for a couple of metres it is very difficult when the accuracy is only good to 5m. Better GPS accuaracy is scary expensive with real sub metre accuracy on the fly $5k plus, and then that's not guaranteed for 100% of the time.

Magpie · Postby **Magpie** » Tue Feb 04, 2014 3:34 pm

MattR I come from a survey background so I agree with what you are saying. The VBOX system can use DGPS but it is not worth it. At the moment I have wheel speed logged (only 1 wheel). I need to play around linking the data to the video. Now that I have no uni study for a few weeks I can use work and home time to merge the data.

Most people do not understand the limitations of GPS. People confuse the accuracy of in car GPS navigation with the fact that the software snaps the location to a known road. Take a in car GPS off road and see how accurate it is. Another factor is level (z axis) is 4 times inaccurate as position, that is if the XY is 2m accuracy level (z axis) is accurate to about 8m. Hence why survey grade GPS is so expensive as the Z axis is so accurate (mm precision).

Another plan is to use the 4 additional inputs on the VBOX and run them in parallel from the Innovate. That way I can get brake pressure, TPS, steering angle and 1 other (linear 5 volt input). It is not possible to use wheel speed as it is a frequency and not a volt based sensor. I was going to use the ride height sensors, but whilst they are 5 volt they are non linear and the VBOX is limited to linear whereas Innovate can have linear, non-linear and or frequency inputs.

MattR · Postby **MattR** » Tue Feb 04, 2014 3:48 pm

I hated post processing 10 hours worth of data after a day in the field climbing towers and chasing tress and ridges for line of sight surveys for microwave links......

The wheel speed sensor should then be able to calculate distance traveled, if you could do one front and one rear and with some fancy thinking computer stuff get a set of rules for measuring distance, ie of front shows zero and rear is slowing, assume locked front and only use rear, if front is accelerating and rear is faster then it is wheel spinning so only use front. You should be able to sync with GPS dat post session to get start finish line location very accurate and then you can do the very fine analysis for braking distances and so on.

I'm looking at Motech with GPS in the S14, but more for the timing functions to know if I am quicker or slower for a qualifying lap, race, meh your trying to get past the car in front, not set a pole position. The other data collected will be more for the engine builder than for me when the car is going, though it will be useful to see how I am going and where more time can be made up over a day of testing. Racing it is too hard to worry about clean laps and using the perfect line when trying to overtake and defend at the same time.

But at this stage I would be just running around in the car getting as much track time as possible so your times are consistent to then get good use from the collected data.

speed freak · Postby **speed freak** » Tue Feb 04, 2014 5:39 pm

Good to hear the engine is still ok.

Magpie · Postby **Magpie** » Tue Feb 04, 2014 7:08 pm

MattR we should exchange more notes, provided brake booster is off topic

. I used to hand draw hydrographic survey charts in the RAN as well as lug tellurometers, 12v batteries and assorted other survey stuff up islands so we could establish where we were and calibrated the ARGO DM54 or Miniranger survey control. Now you just chopper in drop a GPS come back in a few hours and there you have it. I digress (again)

Using 2 g force sensors (front back) will allow slip angle to be calculated as well as detect under/over steer. I have been toying with the idea of 4 wheel speed sensors as that is a very simple and cheap thing to do. But seat time and experience are top priority now as well as listening to advice.

The way I learn though is to understand the mechanics of what is going on and I am not a visual learner. Once I understand the theory/process/rules I will learn visually because I understand the why.

MattR · Postby **MattR** » Tue Feb 04, 2014 8:08 pm

In all seriousness, some of the best seat time to learn the car in a safe and varied environment, plus learn some new skills, the performance day at Willowbank if it fits with budget and schedule. Won't hurt the car at all and will give you a variety of driving for data analysis at your leisure. There is multiple runs so you can see improvements for each exercise.

Though the important thing is to get the seat time wherever you can in a variety of events so you learn the car quickly.

Personally, I am a terrible development driver, but a good driver in making the most of a car with a problem. I can tell the car is sh*t and what it's doing to be sh*t and what i want to stop it being sh*t, but i need a good mechanic to make the car right, but i will still be driving the car as fast as it will go, my times don't drop off too much unless there is a serious problem. A good friend, John, who I bought the green Zed off was the opposite, was a good driver at developing the car to get the most out of it for set up, but if there was anything wrong, say a tyre going off or the balance was upset by whatever reason, wheel out of round, alignment knocked out, his times dropped off terribly.

The workshop that looked after us used to get John to set the car up initially and then get me to go faster after the fine tuning was done. All this was before telemetry was heard of, so I am still very much a seat of the pants driver, which can be seen when I jump in a car and am quick pretty much straight away. My MX has got the improvement in times from the tyres and suspension rather than me. There is still a little time left at QR, but at Lakeside not enough margin for error for that car to go faster.

Magpie · Postby **Magpie** » Thu Feb 06, 2014 9:39 am

Car is back and all is well

Temporary splitter bracket made last night. I'm talking to Danny about getting a permanent solution designed that could be used by anybody with a NA6/NA8. My temporary version is made from 40x40x3 aluminium angle, two holes were drilled and a cut out made so it can attach to the orginal mounting points, however I had to use longer than standard bolts to attach this time. The temporary version does not extend as far as the origonal brackets so I had to adjust the rod lengths and rotate the heavy mounting points on the splitter. All I have to do now is paint it black and it is complete. Lakeside should be a good test for the temporary bracket!

The reduction in air flow now requires that I need to get some foam to seal around the radiator to make sure all the air going in the front is passing through and not around the radiator/oil cooler. A job for this weekend, but only after coffee at the Burpengary PB on Saturday.

Lokiel · Postby **Lokiel** » Thu Feb 06, 2014 12:23 pm

"Spidey-mobil"

Jeo · Postby **Jeo** » Sat Feb 08, 2014 2:52 pm

A web was exactly my thoughts when I saw the first image too Lokiel. Great minds eh?

Magpie · Postby **Magpie** » Sun Feb 09, 2014 4:35 pm

Thanks for the web observations!

Some more small jobs knocked off today. Radio now works pulled out 2 other antenna plugs. I may need to replace 2 of the innovate gauges as the constant pulling off the tombstone is causing earthing issues and this could explain the temp variance.

Also need to adjust my driving style now that the wing is off and running on stock tyres, plus need to learn to control oversteer, I put the car sideways sat morning (damp road, lost grip through corner, snap oversteer when I lifted off the throttle (it is all caught on tape).

One good thing was I used dashware to merge the VBOX data and the innovate data so I can now overlay all the innovate data onto the video captured by the VBOX.

I still need to tap into the TPS, but I am concerned that this could potentially cause issues with the Haltech. Solution is to install another TPS as the Jenvey can have a TPS either end of the ITB's. Then I can take the TPS, brake and steering outputs direct to the VBOX as well as the Innovate.

Next Sunday I'm attending the Darlings Down run then coming home to put the FZ201's on and load the car on the trailer for Lakeside on Monday.

Magpie · Postby **Magpie** » Tue Feb 11, 2014 7:56 pm

Well it looks like I'm on another journey, working (and living) in Blackwater! No confirmed start date but in the next 4 weeks I'll be living there with the family a few weeks after.

I have negotiated the QR time Attack series and they will give me the time off, just need to look at club track days and mid week sprints. Plan is now to improve the trailer for long distance car/track transport as well as discuss with MX5 Plus how to keep the MX5 serviced etc.

It probably means I will not be getting to the BP Burpengary for coffee each Saturday in the near future.

sailaholic · Postby **sailaholic** » Tue Feb 11, 2014 7:57 pm

So this is a semi permanent move mark?

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Magpie · Postby **Magpie** » Tue Feb 11, 2014 8:03 pm

Possibly, depending on how long I want to stay sort of permanent. Construction is taking a turn down again and whilst my current employer wants me to stay they have nothing really to keep me engaged (read bored and getting into trouble). Funny thing Thiess advertised internally for the role that I will be dealing with when working for my new employer.

The new employer is aware of my racing intentions and they are willing to work with me on it, plus they are happy to wait for me to close out my current negotiations for Thiess. This role has had discussions since October 2013!

Plus it will force me to part with the left over parts from my NA6, I'll make a post soon. Parts include 2 x RH side rear callipers, Throttle body, air meter, vented headlight covers (so so fit), 2 x blue side mirrors, from park/indicator lights (1 set of plug removed), soft top and frame (soft top so so), stock end links (Front/rear), Air conditioner (complete), power steering complete, alternator, GV front nose cone (minor damage, not a perfect fit), NA6 exhaust CAT back, by the way the Brake Brace has already been spoken for (I just need to find it at MX5 Plus). The stuff will be real cheap as it will not be moved with me.