Hoolio's NA race car

[Hoolio]

Does it have adjustable cam gears?

Naturally; can't really use aftermarket cams without.

[Hoolio]

My order from Amayama arrived this morning, so today's wonderful task was to replace the throttle pedal bushes. Not an easy place to access at the best of times, and even worse with a fixed seat and a safety cage to work around.

While I was in there I stretched a bit further and replaced the throttle cable too, using one from an NB. The car was originally an NA6 and still had the original cable, but it's too short for a BP engine so someone had made this glorious contraption.



Apart from being decidedly ugly it had proved to be unreliable, with the cable falling out of the bracket whenever the zip ties became tired. There was also increased fricton due to the bracket holding the outer cable at an angle to the inner.

With a more freely moving throttle pedal and the slop gone from the pivot, I'm looking forward to improved throttle modulation. Now i just need to fit my NB throttle body so that I can try it out…

[888]

Hi Hoolio
My son was following you and the Porsche when you had your off at L/S, there was another MX -5 behind to make a line of 4 cars! Watching it unfold from the pits was worth the entry fee.... We have just fitted Tighe Cams, not as much lift as yours but we are running stock ecu. Santa dropped off a few NITTO's under our chrisy tree so with nice weather we hope to lower cars PB, currently at 65,0xxx set on Kumho ku36's. Dean Tighe was great to deal with, helped with dial gauge specs for our cam timing etc ( Wacol BNE )

[beavis]

Dear god that throttle cable setup! Credit to you for fixing it up.

[Hoolio]

I've been busy changing the trigger sensors on the engine, and adding additional sensors to monitor engine vitals.

For the trigger sensors, I'm discarding the NA style one on the back of the exhaust cam and using a crank position sensor on the front of the crank plus a syncronisation sensor on the front of the cam. This should help to improve driveability at low engine speed for two reasons: Firstly I was getting some unstable engine speed reading and ignition timing scatter, which may have been caused by vibration in the timing belt, and secondly I will now be able to run sequential injection and therefore set accurate injection timing.

I'm using OE NB sensors.



I was going to use the NB trigger wheel on the crank, until I realised that the four teeth are not quite evenly spaced! An internet search for trigger wheels revealed that some US market Mazda Protegés used a 36-1 trigger wheel which is otherwise a direct replacement. Very handy! Part number is ZM01-11-408.



I have also added sensors for the engine vitals: oil pressure and temperature, and fuel pressure. These will all be monitored and logged by the engine ECU, which will activate driver alert lights as appropriate.

The oil pressure sensor is in the usual place in the block, and the temperature sensor is in the oil cooler adaptor between the oil filter and the block (on the side which sees oil before it goes through the cooler). The fuel pressure sensor is in a fitting I welded directly into the end of the fuel rail.



In that last photo you can also see that I have re-terminated the car's wiring harness which goes to the engine, using Deutsch DT series connectors.

I also made a completely new engine harness.



While it was all apart I had the injectors tested and ultrasonically cleaned. As it turned out the spray patterns and flows were fairly good anyway, but now there is one less unknown to deal with when I retune the engine.

And here it all is back together, with an NB throttle body and the correct throttle cable.



Next job is to terminate the wiring inside the car for the ECU. In addition to these wires in the OE harness there are another 14 wires from the new sensors on the engine plus driver alert lights in the dashboard, so I am going to get rid of the existing patch loom between the OE harness and the ECU, and re-terminate it all with a new ECU connector…

[S2-13BT]

Awesome work!

Seems like this car has never been in better hands.

[Hoolio]

Awesome work!

Seems like this car has never been in better hands.

Thanks. My philosophy is to do things once and get them right.

I also set myself high aesthetic standards. That aspect can take a long time, but I just can't help myself.

[Hoolio]

Well I have finished rewiring the engine management and over the weekend have been retuning it. It's very handy at times like this to have the car road registered

I am very pleased with the result – it's now got a beatifully stable idle both cold and hot, and most importantly the part throttle driveability is a huge improvement.

[chrons_rotary]

Great work on the NB engine swap.
Where did you order your electrical connectors from?
Also where did you buy the 36-1 wheel from?
I'm after a loom side connector for the crank sensor, as I currently have my crank sensor hard wired into a lead going back to the Megasquirt.

[Hoolio]

Great work on the NB engine swap.
Where did you order your electrical connectors from?
Also where did you buy the 36-1 wheel from?
I'm after a loom side connector for the crank sensor, as I currently have my crank sensor hard wired into a lead going back to the Megasquirt.

I got the connectors for the cam position and throttle position sensors from www.efihardware.com (Mitsubishi EVO Mivec and Toyota 1JZ respectively). I also got the injector connectors from the same place (standard Denso).

I couldn't find a match for the crank position sensor connector, so I cut it off and used a Deutsch DTM. The Deutsch connectors are readily available, but I have been buying them from www.connector-techals.com.au (they list on eBay too).

The 36-1 wheel came from a vendor in the US who lists on eBay AU; just search for the part number I gave. I couldn't find a local source for this, so I presume that it is not used in any Australian market cars.

[Hoolio]

Here's the ECU wiring tidied up.



While I was hanging up-side-down under the dashboard I had a good look over everything for any signs of potential unreliability. There was some suspicious looking non-original insulating tape over the heavy wires leading to the ignition switch, so I peeled it off to have a look inside. Here is the horror story I found



Soldered jonts are a bad idea in a vehicle at the best of times, but How can anyone manage to make so many in such a small area? Perhaps they thought that they were trying to make a necklace…

The best thing to do with that is to cut it all out and splice in some new wire. Here it is ready for heatshrink.



This seemed like a good time to try to remove the steering lock. Unfortunately it's all riveted together and there looked like a good chance of making a mess of it if I tried to disassemble it, but I did manage to drill a hole through the housing and the tenon part of the lock. A split pin now keeps the tenon down and effectively disables the lock.

[Hoolio]

Next up was to tidy the cockpit area. I made a new switch panel for the radio area of the dashboard. I haven't got any good pictures of the old switch panel, but trust me when I say that it was pretty ratty. From this:



To this:



You can see that I also gave the tombstone a quick lick of paint. The heater control panel then looked a bit out of place with peeling and faded decals, so I painted that too and made some new labels. I'm not trying to make an art project of this car, but I do like the clean, simple ‘retro’ look it has now got.

And the back of the new switch panel. All new wires and connectors of course.

[Hoolio]

As a stop gap before installing a proper racing dash display I thought that I would see how useful I can make the OE instrument cluster. The aim is to not have to actively monitor any gauges, but have my attention drawn to them by alert lights if any temperatures or pressures go out of range. With just two gauges available, and a limited number of ECU outputs to drive alert lights, the best arrangement is to have the gauges show engine (water) and oil temps, and three alert lights.

I'm using the ECU to drive the original oil pressure gauge so that it reads oil temperature instead. Also I modified the original engine temp gauge to give a more useful scale. In standard form these gauges have a large dwell in the centre of the movement, where the pointer hardy moves form about 70º to 110º which is useless for judging actual temperature in a critical environment. Now it has a movement which is fairly linear.

I managed to graft three high intensity LEDs into the lower part of the tacho. It was a lot of work, but it has got them neatly into the line of sight and the end result works very well. I can drive without normally having to look at the instrument cluster at all. The LEDs are all different colours, and if one of them does light I know straight away what is happeneing and whether I need to look at a temperature gauge.

[Hoolio]

The next job was to install brake presure sensors.

[plohl]

Nice work dude! Looking forward to seeing your brake pressure data