MADJAK's NA8 - 200+HP N/A

[bruce]

DIY shift light?
Make me one to work off Nisstune (I dream)!

[madjak]

It's not really DIY... well only partially.

The shift light you can buy from AutosportsLabs for only $20, but you need a device to control it. I'm using the RCP to control the light via a custom script. It's three stages so I can set 3 RPM ranges to light it up. I've also scripted it so the red light blinks when oil pressure is under certain thresholds, and also the yellow light will blink if coolant temp hits over 100 degrees.

Pretty cool actually... here is my script: (I'm more a hack than a coder, this isn't very elegant!)

Code: Select all

BlinkArray = {0,0,0,0,0,1,1,1,1,1}
BlinkCount = 1

function ShiftLights()
  local ErrorOn = 0
  if (ctsId > 100) then
    BlinkLight(1, true)
    ErrorOn = 1
  elseif (rpmId < 3000 and opsId < 10) or (rpmId >= 3000 and opsId < 25) then
    BlinkLight(2, true)
    ErrorOn = 1
  end
  if ErrorOn == 0 then
    LightOn(0, rpmId > 7000)
    LightOn(1, rpmId > 7500)
    LightOn(2, rpmId > 8000)
  end
end

function LightOn(l, on)
  if on then
    setAnalogOut(l, 0)
  else
    setAnalogOut(l, 10)
  end
end

function BlinkLight(l, on)
  if on and BlinkArray[BlinkCount] == 1 then
    setAnalogOut(l, 0)
  else
    setAnalogOut(l, 10)
  end
  BlinkCount = BlinkCount + 1
  if BlinkCount > 10 then -- try #BlinkArray
    BlinkCount = 1
  end
end

I'm in an event this weekend so I'll take some GoPro footage of it all in action. The lights are very bright so they should be easy to spot in my peripheral vision. I haven't figured out yet how fast I need the shift lights to operate. I might even have to modify the script with different rev ranges based on the gear I'm in. I have another script calculating the gear I'm in based on GPSspeed and rpm.

[madjak]

My next experiment is to try something new with my suspension bushings. I've never liked the idea of using Urethane as a bushing material as it can bind and needs to be greased constantly if you want to keep the suspension movement free. It is a nice and rigid material with some flex so I'm going to be only using it as a packer and making a slip bearing that fits inside the bushing for the suspension to rotate on. This is based on a user on MT.net that did the same idea but with bronze bearing.

I've ordered some 20mm bar stock of 4140 (Chrome Moly) that I'm going to drill and cut to length. Over this I'm going to be using some Igirdur bearings that will fit inside the existing Urethane bush. These are very cost effective at around $2 each. At each end I'll get some washers laser cut that will transfer the crush load of the concentric adjuster bolts onto the 4140 tube. The idea is that the inner sleeve and bearing slide over each other rather than the Urethane over the sleeve. I don't think the wear rate will be high given they are designed for use on earthmoving equipment etc.

Here is a quick 3D model of it:

[madjak]

I 3D printed a battery holder out of ABS this morning. It's nice and light at around 110 grams and feels strong enough to take a beating. I like this sort of prototyping, 5 mins with a tape measure, 10 mins 3D modelling and half a day of printing and I have a prototype that should just work. It beats hacking it out of ply.



It is the same base size as a standard MX5 battery with a hole in the middle to suit a Deka ETX12. If I got it right, it should hold the battery in a nice position for the stock clamp.

here is the battery I'm using. It cranks my engine fine though it's first real test will be the sprint day this Saturday.

[Apu]

Auuugh...I am so envious when I see the 3D printing stuff you do. I best get off my a$$ and go take up a CAD course.

What printer do you use?

[speed]

Auuugh...I am so envious when I see the 3D printing stuff you do. I best get off my a$$ and go take up a CAD course.

What printer do you use?

Me too!

[madjak]

Auuugh...I am so envious when I see the 3D printing stuff you do. I best get off my a$$ and go take up a CAD course.

What printer do you use?

Makerbot Replicator 2 with an aftermarket heated pad for printing ABS. To be honest they are tricky to use... it's taken a while to get the knack of printing successfully. In terms of learning CAD, download Rhino3D and use that for a while. There are lots of online tutorials and its probably the best and fastest package to learn. I use 3D Studio MAX over Rhino now because I'm faster in it, but it's harder to make certain types of models cleanly.

Here is what happens when you get a print wrong! (Not my print btw, this is the base of a 3D printed Ukulele). The printing head hit the center cone bending it over and then knocked the print off the base off the bed. It continued printing plastic into the air creating nice spaghetti sculptures!

[beavis]

I use the EXT12 in my car and it's been awesome. It can sit for 3 months and starts the car no problems on a cold day, all day long.

[bruce]

Thanks for that info re the shiftlight.
I do like reading what you're up to.

[madjak]

The EXT12 so far has been fine and would be ideal for normal mx5s. My engine is hard to crank because of the steep ramps on the cams, heavier valve springs and high compression making it really hard to start even when warm. My ait is on the manifold and I suspect that its getting heat soak between runs causing the air temp correction map to richen the tune. This then fouls the spark plugs making it even harder to fire up.

Well thats my theory anyway. The entire tune needs some fixing...

0 throttle running sounds like antilag and it inhibits accelerarion until you hit over 10% throttle where it suddenly tries to take off. So it's near on impossible to drive slow fluctuating between decelleration to power on... Sighting laps at 40kph are painful! Makes it feel and sound like a rally car though and brings back memories of the wrx rally car.

[Kuncha]

Very interested in how the suspension bushes work out.

Great work.

[Zabinskii]

possibly stupid question, but have you looked at the superpro bushes? theyve got that weird cross hatch type of finish so they hold grease alot longer
or you could always install zerk /grease fittings

[madjak]

possibly stupid question, but have you looked at the superpro bushes? theyve got that weird cross hatch type of finish so they hold grease alot longer
or you could always install zerk /grease fittings

Yeah I have. I really want free movement, even with grease the urethane bushes have a fair bit of rotation resistance. The superpros I looked at but they are very pricey. If I was going to spend that much I'd go sphericals all round.

I think this solution, if it works will be fairly cheap and offer very low friction rates as well as a little bit of joint flexibility with little to no maintenance. The 4140 bar I have ordered cost $34... The bearings are $2.23 each x 40ish, laser / waterjet SS washers should only be $30 and the Urethane bushes I have. If I don't factor in my time on the lathe (might be several hours) it's a pretty cost effective option for what should be a high performance result.

We'll see! I won't be able to get to these for a few weeks, but I'll report back when I'm underway.

[Zabinskii]

possibly stupid question, but have you looked at the superpro bushes? theyve got that weird cross hatch type of finish so they hold grease alot longer
or you could always install zerk /grease fittings

Yeah I have. I really want free movement, even with grease the urethane bushes have a fair bit of rotation resistance. The superpros I looked at but they are very pricey. If I was going to spend that much I'd go sphericals all round.

I think this solution, if it works will be fairly cheap and offer very low friction rates as well as a little bit of joint flexibility with little to no maintenance. The 4140 bar I have ordered cost $34... The bearings are $2.23 each x 40ish, laser / waterjet SS washers should only be $30 and the Urethane bushes I have. If I don't factor in my time on the lathe (might be several hours) it's a pretty cost effective option for what should be a high performance result.

We'll see! I won't be able to get to these for a few weeks, but I'll report back when I'm underway.

if they turn out great, just make a set for me yeah ;)
shotgun first on the list

[madjak]

There will be a fair bit of drilling required which I'm not really looking forward to especially into the 4140. I think around 1.8 meters of drilling in total. If they work out I can organise a group buy through a machine shop to make them because I doubt I'd have the patience if it wasn't for my own car.

Driving my car last night, a 6 speed box and a 4.778 diff makes for an exciting drive. I'll take some video on Saturday but I'm really looking forward to running on the track with this new gearing.