Rexanne!

[Steve-A]

Haha. I think it'll be ok to post pictures as long as they are appropriately censored



Steering wheel is on the back burner for a little while. There's plenty of places offering a complete re-trimming service but its £££. I shall keep investigating

In more cheerful news I ordered my Megasquirt today! Woo!

[chc]

Shock & horror - I would never have guessed on the potential project Me thinks you have a special passion for this model - hmmmm .... I can't understand why

This time last year mate, you were still hard at it lying underneath and playing with your favourite girl, so this year you deserve a break

Never had the need for refurbing a steering wheel and surprised to hear there are a few companies out there touting for work.
I must say, way back in the early 70's I fell in love with a white/cream steering wheel (can't remember what make it was on now but I thought it was the best!) Never had a suitable car to have one fitted though - not even an RX7 (but thinking about it, would it look nice with the white exterior and wine interior .... hmmmmmm ?

[Steve-A]

I had to say I've never been a fan of pale car interiors full stop. But a white wheel might be cool against the red, I'll stick to black

As for the italian girl, she's on hold for a number of years I fear. Just gonna be too costly, and I'm too attached to Rexanne to be without her!

Wow, almost a month since an update, thats a bit slack of me! Work, christmas and spending time with the lady friend has rather slowed progress to a snails pace. I guess that counts as a break

The only real work I've done is rebuilding my ignition switch. I smelt a kinda hot plastic smell for a hour or two well driving then the engine cut out I did the best I could with the tools I had with me, but I had to drive 20 miles home in the rain with the choice of engine or windscreen wipers and heater blower, which was fun....

I had it to bits and cleaned the contacts and it seems to be working now. Looked pretty grim inside though.



Well I've been kicked back into action seeing as my megasquirt arrived today!



Plenty of hours to be spent on that yet! I'm hoping to make a start in the next day or so. Just need to pick up some more solder and some heat shrink.

With enthusiasm running high I've also made a start on the adapters to fit my throttle bodies to the Weber IDA manifold.



It's good practice for my new die grinder. As you can see I've not got far but it's a start! I plan to end up with the throttle bodies welded to those alu plates that will be port matched to the manifold. The bodies would have been silicone mounted on the bike, but supporting them properly with the silicone and making room under the bonnet for that and air filters is going to be tough. I figure I've gotta hack these bodies about quite a bit to make them fit anyway so making them a bolt on fitment isn't a big deal.

Aside from the solder, my shopping list before I can start assembling the EFI is just a swirl pot and various connectors and clips. So I'm hoping to be fuel injected by the end of January Very excited!

On the downside my exhaust is knocking again

[ian65]

I'm fascinated to see how this all goes together Steve and the end result.... I wouldn't know where to start!
Keep the updates coming.... good stuff!

[Steve-A]

Cheers Ian.

I'll make sure to post plenty of info on the megasquirt as I build it up for you The actual building is fairly easy, the hard part is working through the hundreds of pages of online documentation to make sure I'm setting it up to make the most out of it. Because it can be fitted to any engine, there are lots of variables as it's built, the instructions kinda read like ons of those chose your own adventure books!

[chc]

Hi Steve, sorry to hear you trouble with the ignition switch - did you manage to find the problem or did you simply fix it best as?
Was it your original switch or the replacement I sent you?

TIME OFF !!! Yeah think it was justly deserved and what better reasoning than somebody of the opposite sex - without wheels too !!!

Excuse my ignorance mate but I know nothing about 'megasquirt', is this something that can be simply fitted to a standard ignition setup or do you have to change carb etc?

Cliff

[Steve-A]

The ignition switch seemed to be ok after a good clean up. I guess I'll just keep an eye on it.

Megasquirt is a diy engine management system. So it will drive electronic ignition and fuel injection setups. I've got a set of coils from and fd and a crank sensor from the fc for the ignition side and some Suzuki motorbike throttle bodies for the fueling side.

The megasquirt arrives as a bare circuit board and a bag of components to solder in. Then with a laptop hooked up to it the megasquirt is programmable for pretty much any engine configuration. Finally it can be tuned on the street or dyno and should result in more efficiency and more power!!!

[chc]

You make it sound so simple mate - like you have when bringing Rexanne back to life. I'm sure it will go well.

[Steve-A]

Thanks for the vote of confidence Cliff

I made a start on building my Megasquirt last night / today. After Ian said he was interested to see how this all come together I thought I'd go into more detail than I would normally here and explain a bit about the Meagsquirt experience.

Megasquirt is a brand of open source, sortta DIY, engine management. After initially being the project of a couple of guys it's now developed and updated by a whole group of guys on the internet. The upsides to this are the cheap cost, large feature list and it is hugely adaptable to any application. If the feature you want isn't there and some other people want it, they'll probably write it into the next update! One of the original designers / programmers had an FC Rx7, so from day 1 it's been built to work well with rotaries too.

The downside is that the documentation can be a bit confusing and there can be plenty of searching of forums to find answers to uncommon questions.

There are essentially 3 versions of Megasquirt. Ms1 is the earliest design and most basic feature set. It was originally designed to just control fuel injectors. It reads all basic engine sensors ( manifold pressure, throttle position, air and coolant temperatures, etc) and has outputs to control fuel injectors. A firmware update called 'ms1extra' gave it the ability to control electronic ignition too with a few simple modifications to the basic circuit board. I used ms1extra on my 1.6l 4 cylinder turbo in my mx5 and for my n/a 13b in my mx5.

Ms2extra is based on the same circuit board as ms1extra, but uses a much more powerful processor chip with more ram. This means the firmware can be much more advanced and offer many more options for tuning. For example the algorithm that calculates the extra fuel for throttle pump in ms2 is considerably better than ms1.

Ms3 is the latest version of Megasquirt. It is a fresh design and has all the features of ms2 plus lots of additions so it can be used in modern cars with CAN bus systems, and can control AC and all the other tat modern cars use the ECU for.

For this build I'll be using ms2extra, because it has all the features i need and more and there are many documented set-ups on the internet using ms2 on rotaries.

Phew, as you can see it takes lots of reading to get to the bottom of it all.

So if you buy an ms2 kit, this is what you get...



There are comprehensive step by step instructions online, and as you can see I've made a start by the time that photo was taken. The instructions start as if you've never done any electronics or soldering before, and are a great tutorial, but if anyone wants to do build one I'd certainly recommend having a practice with some other PCD soldering first. Maplin do some great DIY electronic kits that are a good introduction.

This is where I got to last night, the power supplies are built and tested.



Next up was to build the circuit for the rs232 serial connection to the laptop. I ordered my kit from DIYautotune in the US. They do a really good job in the kit building. One of the best things is that every component is in a little bag, labeled with a part number and a component number. And all the component numbers match up to the online instructions and are marked on the PCB itself. Its kinda like painting by numbers!



About an hour later the rs232 coms circuit was built and I was able to send data from the computer to the board. At this stage it was just a simple loopback, so anything I typed on the keyboard went from the keyboard to the Megasquirt board and back before appearing on the screen.



Sucess! Next up was to build the input circuits that decode and condition the sensors readings. It's coming along quite nicely here.



All very neat and tidy. Now we start to get into the modifications side of things. The megasquirt board has one crank angle sensor decoding circuit built in, but the FC cas I'm using has a twin sensor in it. So they make a little add on board that decodes the second sensor. The board is designed with the FC in mind so it also has extra outputs to control an electric fan and to drive the tacho specifically for the rx7.

It started like this.



Half an hour later it was built.



Now the messy bit, the two boards are wired together and then hooked upto the computer to test all the inputs.



There it is hooked up to the laptop with the tuning software open reading the sensor inputs from the megasquirt simulator. No RPM reading because my simulator can't simulate the twin sensor crank angel sensor.

Next time I get to do some work on it I'll be building the output circuits that will drive the coils and injectors.

[myatt1972]

Thats great info Steve, Ive been wondering about this voodoo stuff for ages.