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I've been busy (pics)
matt_claydon - 25/7/06 at 06:43 PM

Well, been busy the last few weeks getting started on the megasquirt conversion but am getting near fitting it all to the car.

Here's the re-spaced GSXR 750 bodies and the manifold I made for them. The manifold is a 1/2 inch ali plate with 38mm holes cut using a holesaw and 30mm long bits of ali scaffold pole (which happens to be exactly the right diameter) attached with lumiweld. I was skeptical about this stuff but am actually reall impressed with how well it worked once I got used to it.



Another pic showing close-up of lumiweld joint:


And here's the megasquirt unit that I soldered up on Saturday, note the pair of VB921 coil drivers/heatsinks on the proto area, this allows me to run a wasted spark coil pack directly from the ecu without the need for any EDIS clutter:


still need to run wires from the VB921s to the output pins on the DB37 connector.

Finally the relay board, thought I might as well make one of these to to make all the wiring simpler and tidier in the engine bay:



Although I've got it all wired for fuel and spark and am running MSnS-E, I'll be getting all the fuel sorted out perfectly before I even look at the ignition!

Update 18/08/06:

Bodies mounted to manifold
Bodies mounted to manifold

Cheers,
Matt.

[Edited on 18/8/06 by matt_claydon]


BKLOCO - 25/7/06 at 06:51 PM

Just as a matter of interest.
Why do you feel, in your words. EDIS is "crap"?


matt_claydon - 25/7/06 at 08:34 PM

I don't actually think there's anything wrong with it, it's just that this solution does away with some wiring and the extra control unit. 'Crap' was more just a description of the fact that it was unnecessary clutter than that there's actually anything wrong with it.

I've changed the above post now to be more clear

[Edited on 25/7/06 by matt_claydon]


darrens - 25/7/06 at 09:14 PM

looks good,

I'm still at a bit of a loss, I can't see the advantage of the relay board. I've just installed MS and fair enough I spent qute allot of time doing the loom making it tidy round the engine, can't see how the relay board would simplify this, you still have to run the wires back to the MS at some point.

Just my two penny worth
Cheers


matt_claydon - 26/7/06 at 07:28 AM

quote:
Originally posted by darrens
looks good,

I'm still at a bit of a loss, I can't see the advantage of the relay board.


I guess it just gives me a convenient place to put the relays/fuses and having a terminal block in the engine bay to connect all the input/outputs seems a nice convenient starting point for wiring everything up. Also when I want to add, remove or change any inputs/outputs I won't have to fiddle around with the DB37 connector but simply play with the screw terminal in the engine bay.

Having said all that, it is about £40 (inc the relays) and not necessary by any means. So you could more than happily do without to save a few quid.


MikeRJ - 26/7/06 at 07:44 AM

The lumiweld welding looks pretty good, what did you use to actualy apply heat, oxy-acetylene?

Just wondering why you put the coil drivers in the proto area, there is already space for a second coil driver on the top row of power devices IIRC?

The relay board is a good idea, I bought one for my setup as well. It means you don't have numerous relays screwed to various chassis rails/body panels with messy wiring around them. It also provides self restting overcurrent protection to both the ECU and the 5volt reference output from the ECU. It also provides a handy point to connect all the sensor grounds together which are taken back to the megasquirt on a single wire, avoiding ground loops. Injector and fuel pump outputs are also fused.

It's perfectly possible to wire up the MS without one, but it simply provides convienience and a good level of protection for the ECU that isn't present if you use a discrete solution.

[Edited on 26/7/06 by MikeRJ]


matt_claydon - 26/7/06 at 08:21 AM

MikeRJ,

For the lumiwelding I pre-heated the parts to 250*C in the oven then put the plate over a gas hob (moving it for each tube) to give heat from underneath and used a normal blowtorch to provide heat from above. The first tube I welded I was a bit OTT with the heat and whilst tinning the edge I actually ended up melting away quite a bit of the tube wall which left a huge blob inside the tube once it had set on the manifold. Simple enough to file off but one the lumi has mixed with the ali it's bloody hard stuff! What impressed me was how once the lumi had melted onto the ali, the ali itself melted too - obviously the lumi does actually mix chemically with the ali somehowand thus it is, as the manufacturer says, a real weld as you are melting the base materials together.

There is only room for one coil driver on the heatsink strip unfortunately (see my pic above, the only empty space is where the standard single driver goes). You can put an extra there if you remove other components (apparently the two resistors that 'protect the FETs' are optional). Not knowing that much about electronics though I opted to install everything as detailed in the instructions!

Using MSnSE, the coil drivers are activated using two of the LED channels, so by putting the drivers where I have it's nice an easy/neat to connect them to both the LEDs and a ground, leaving the only long (untidy?) connection going to the DB37 connector.

[Edited on 26/7/06 by matt_claydon]


MikeRJ - 26/7/06 at 09:56 AM

Thanks for the explanation, sounds like it's worth having a go, as I've been leaning towards making a steel inlet manifold for ease of welding. Where did you buy the lumiweld rods from?

It's ages since I assembled my megasquirt, I vaguely remebered something about the second coil driver and thought they had made provision for it, seems not! I will also be using MSnSE so I don't have to mount another trigger wheel on my XE (already a 60-2 wheel built into the crank).


matt_claydon - 26/7/06 at 09:59 AM

I got the lumiweld from Frost: http://www.frost.co.uk/

There are other similar products available, e.g. Technoweld. I think you can get Techno from Machine Mart but they only do kits with three rods and don't sell extra rods IIRC.

I actually chose aluminium for ease of welding, as I don't have any welding kit but I do have a cooker and a blowtorch! Also using ali obviously makes the machining a lot easier.

The scaff tube is 2mm smaller ID than the bodies, however the inlet ports are smaller still so I've just got a chamfer where the bodies meet the tubes, and then the holes through the manifold plate taper from the ID of the tubes to the ID of the ports. Ideally it would obviously be a smooth reduction in section from the bodies to the ports, but you can't have everything perfect when you're doing it on the cheap!

[Edited on 26/7/06 by matt_claydon]


MikeR - 26/7/06 at 01:38 PM

so what is the dia (ID / OD) of the scaffold tube and how did you get it - just ask the local scaffolding company?


matt_claydon - 26/7/06 at 09:40 PM

OD 48, ID 40 - i.e. 4mm wall thickness. I believe you can also get it in ~3.2 wall which is perhaps more appropriate. I looked around various local scaffold 'constructions' but everything seemed to be steel. In the end I found a company called Stage Electrics who have a branch just down the road in Bristol where I got half a metre for 6 quid. Perhaps more than if I'd just given beer money to a scaffolder but it's brand new and not all scratched up, painted, corroded etc. They have depots around the country and can be found at http://www.stageelectrics.co.uk/


darrens - 26/7/06 at 10:45 PM

quote:

Also when I want to add, remove or change any inputs/outputs I won't have to fiddle around with the DB37 connector but simply play with the screw terminal in the engine bay.


Actually that is a good point

[Edited on 26/7/06 by darrens]


BKLOCO - 27/7/06 at 03:49 PM

quote:
Originally posted by darrens
quote:

Also when I want to add, remove or change any inputs/outputs I won't have to fiddle around with the DB37 connector but simply play with the screw terminal in the engine bay.


Actually that is a good point

[Edited on 26/7/06 by darrens]


It also enables you to run a single multicore cable, terninated with "D"types at each end, through your firewall bulkhead, instead of numerous screened and unscreened sensor and power cables. Which you then have to "loom up".

It also greatly reduces the possibility of wiring errors.