Speeduino install update.

Speeduino install update.

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Fenderer

Original Poster:

137 posts

101 months

Wednesday 6th April 2022
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I thought I'd share some of my trials so far in getting a Speeduino ECU installed in my Chimaera.

It's been a bit if of a surprise just how much time it's taken to do all the ancillary work. I think I could have built about 10 Speeduino ECUs in the time it's taken so far and there is a ton of work still to do before I get to try and start it.

Some photos:

Here's the ECU, probably the easiest part of the project. Having said that I royally screwed up the first board when I soldered the IDC header upside down and then couldn't desolder it. Basically had to start again but it's quick to assemble with basic soldering skills.


The trigger wheel install took a long time to get right. I made it really hard for myself by starting with a generic 36-1 trigger wheel from ebay.. It was too large to mount behind the damper so had to sandwich it between the front pulley and damper. This at least enabled me to re use the splash shield on the rear. I'm using a BMW E36 Hall sensor and I fabricated a 2 piece bracket which adjusts for clearance on the wheel.


If you look closely you'll spot my original mistake welding in the bung for the wideband. That wasn't a good day when I tried to refit the Y piece. On the flipside I managed to get my Y piece both in and out without dropping the exhaust, or even undoing the support bracket on the system. No tie straps needed either to get the manifold flanges to go into place.


AFM delete pipe fabricated, from a 150mm long 3" diameter steel pipe and welded on a M12 nut. IAT sensor screws in here.


Trial fit for VW coil packs, bracket and custom HT leads. This took forever to get right but it kind of looks like it should be there from stock.


Still working my way through this lot. I've ripped out all the old stuff and now installing new wiring loom. Hoping to bypass the old fusebox and install a new 'sub' fuse/ relay box for the critical ignition and fuel pump relays and fuses. Going to be here a while as it's taking forever to work out the wiring. Thanks Steve_D on here for help with wiring diagrams.


Lastly just for fun...Make sure your inlets are well covered if the plenum is off when working in the engine bay. I dropped a drill tap somewhere and couldn't find it for days. I convinced myself it had gone in one of the intake trumpets. eBay came to the rescue with a endoscope camera for the princely sum of £6. It wasn't in the ports but the scope eventually found it under the rad!

Loads still to do - Also need to sort a fix for the Tachometer. I want to run it from the ECU - It has an output but will need some sort of conversion box to get the voltage up to the usual levels it would see from the negative on the old coil. Suggestions welcomed there. Can't decide either whether to run without a cold start valve or get a simple PWM 3 port one. I've already bypassed the stepper valve I think it will be a nightmare to implement on the new ECU. Fan control is another issue. Again can control run from the new ECU but will need some thinking about.

More soon.

Zeb74

375 posts

128 months

Thursday 7th April 2022
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Impressive challenge, I think that I would have already cried a lot before doing the third of your job (specially when I see the picture of the loom).


ric355

215 posts

148 months

Thursday 7th April 2022
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Fenderer said:
I thought I'd share some of my trials so far in getting a Speeduino ECU installed in my Chimaera.

The trigger wheel install took a long time to get right. I made it really hard for myself by starting with a generic 36-1 trigger wheel from ebay.. It was too large to mount behind the damper so had to sandwich it between the front pulley and damper. This at least enabled me to re use the splash shield on the rear. I'm using a BMW E36 Hall sensor and I fabricated a 2 piece bracket which adjusts for clearance on the wheel.
As you may remember me mentioning, I have been running a speeduino on my Chimaera for several years now.

I used the RV8 specific trigger wheel from trigger-wheels.com. This was a lot easier as it's a simple bolt in job but I guess you know that now ;-)

Fenderer said:
AFM delete pipe fabricated, from a 150mm long 3" diameter steel pipe and welded on a M12 nut. IAT sensor screws in here.
I also made an AFM delete pipe, and I also put the IAT sensor in there. However, I don't run it there anymore because it suffers from terrible heat soak and I presume this comes from the exhaust manifold just below it. That makes the IAT correction curve very hard to tune. In fact it should not need tuning at all really beyond the one in the base tune (which is based on the ideal gas law), but you'll find hot starts are awful with it there and it'll start leaning out in traffic with resultant rpm oscillation.

Mine is now "installed" in the nose cone away from the heat soak. I say installed, what I mean is it is tie-wrapped to the inlet hose just as it comes out of the inner wing on the air filter side. So it's out of the wind but the other side of the bulkhead away from hot engine air. This works a lot better.

I'll be interested to see how you get on with tuning it with that delete tube. One thing I have struggled with is getting it to rev up under no-load conditions i.e. if you blip the throtttle while it is idle. You can hear it gulp a load of air and then the RPM catches up. It's not quite as good as it was with the 14CUX. I've always wondered if removing the restriction of the AFM was affecting the air speed and turbulence in a negative way, but never got around to trying the old AFM in its place to restore the restriction. My car is road tuned though, so it may just be an issue with ignition and/or fuel maps.

Fenderer said:
Loads still to do - Also need to sort a fix for the Tachometer. I want to run it from the ECU - It has an output but will need some sort of conversion box to get the voltage up to the usual levels it would see from the negative on the old coil. Suggestions welcomed there.
The tach output is any easy one. You can drive the standard tach using a coil from a relay and a transistor. There is a standard circuit out there if you search for megasquirt solutions but if you can't find it drop me a message and I'll dig it out. You can just feed it into the original wire that goes from ECU to tacho and it'll work. You'll need the tune to be set to 1ms pulse time otherwise it'll run out of pulse time at higher RPM and the needle will fluctuate.

I don't run that relay coil solution anymore though as I now drive my digital dash via the serial output so it's sending a number directly to the tacho instead of a square wave pulse train.

Fenderer said:
Can't decide either whether to run without a cold start valve or get a simple PWM 3 port one. I've already bypassed the stepper valve I think it will be a nightmare to implement on the new ECU.
I'm actually using the idle stepper and it is easy enough to get working in open loop mode. You won't get it to work well in closed loop mode though as it just doesn't have a fast enough response time. The stepper driving algorithm doesn't quite work the same as the 14CUX either. There is the possibility that it can get out of step but I think that's no worse than with the 14CUX.
If I were doing it again I would probably use a PWM valve but you should also take a look at the advance based idle control.

Fenderer said:
Fan control is another issue. Again can control run from the new ECU but will need some thinking about.
Fan control is similarly easy but it does depend how much you've ripped out wiring loom wise. All you need is a relay and you can use one of the unused medium current outputs (I think I chose Boost but can't quite remember) to control it directly. Just connect the output of the relay across the original otter switch connections.

Edited by ric355 on Thursday 7th April 10:24

Fenderer

Original Poster:

137 posts

101 months

Thursday 7th April 2022
quotequote all
Yeah the loom is proving to be the hardest part. I'm fairly sure I've cut through a few things I shouldn't have and I'm expecting a few problems with gauges not working when it comes time to turn on the ignition again. That's if there's not a fire first! haha.

geordiepingu

336 posts

60 months

Thursday 7th April 2022
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Fenderer said:
Yeah the loom is proving to be the hardest part. I'm fairly sure I've cut through a few things I shouldn't have and I'm expecting a few problems with gauges not working when it comes time to turn on the ignition again. That's if there's not a fire first! haha.
Relatively few things you will cut through, oil pressure, oil sender, coolant temp and alternator excite light. Otter switch return is on the same bunch of connectors, you can use a low - medium current output to trigger it as stated above to bypass the otter switch. For your tacho, you can get a conversion box from Extra EFI. I think a few other places like trigger-wheels.com will sell the same unit

steveo3002

10,493 posts

173 months

Thursday 7th April 2022
quotequote all
'll be interested to see how you get on with tuning it with that delete tube. One thing I have struggled with is getting it to rev up under no-load conditions i.e. if you blip the throtttle while it is idle. You can hear it gulp a load of air and then the RPM catches up.

^^ accel enrichment

ric355

215 posts

148 months

Thursday 7th April 2022
quotequote all
steveo3002 said:
'll be interested to see how you get on with tuning it with that delete tube. One thing I have struggled with is getting it to rev up under no-load conditions i.e. if you blip the throtttle while it is idle. You can hear it gulp a load of air and then the RPM catches up.

^^ accel enrichment
Unfortunately accel enrichment does not fix it. Adding any more than it currently has causes it to bog down in actual driving.

Fenderer

Original Poster:

137 posts

101 months

Thursday 7th April 2022
quotequote all
Polly Grigora said:
This is an amazing project

Great job

Wiring loom should be good fun

Is the battery up-front or down the back?
Thanks! Battery will be up front for now - Just going to tidy up the rats nest and get the main and fuel pump relays into a nice mini fusebox. I'm also really tempted to bypass the main fusebox which is probably corroded and way past its best and take a good ignition live into the mini fusebox to do the critical ignition, ECU and fuel circuits. Will be easier to access too. I ditched my immobiliser already so that at least isn't a concern.

Fenderer

Original Poster:

137 posts

101 months

Thursday 7th April 2022
quotequote all
geordiepingu said:
Relatively few things you will cut through, oil pressure, oil sender, coolant temp and alternator excite light. Otter switch return is on the same bunch of connectors, you can use a low - medium current output to trigger it as stated above to bypass the otter switch. For your tacho, you can get a conversion box from Extra EFI. I think a few other places like trigger-wheels.com will sell the same unit
That sounds hopeful thanks. biggrin . I think I've sorted the tacho last night. Found a circuit online which converts the low voltage pulsed output from Speeduino into a bigger pulse for the tacho, using a 2N5551 transistor and a relay coil to create the spike. I had the bits already and built it, just to find a nice little enclosure for it.

Fenderer

Original Poster:

137 posts

101 months

Thursday 7th April 2022
quotequote all
That's great, thanks for that and the info on the connections on the fusebox. I saw it on the other thread and forgot to comment.

Fenderer

Original Poster:

137 posts

101 months

Friday 8th April 2022
quotequote all
ric355 said:
I also made an AFM delete pipe, and I also put the IAT sensor in there. However, I don't run it there anymore because it suffers from terrible heat soak and I presume this comes from the exhaust manifold just below it. That makes the IAT correction curve very hard to tune. In fact it should not need tuning at all really beyond the one in the base tune (which is based on the ideal gas law), but you'll find hot starts are awful with it there and it'll start leaning out in traffic with resultant rpm oscillation.

Mine is now "installed" in the nose cone away from the heat soak. I say installed, what I mean is it is tie-wrapped to the inlet hose just as it comes out of the inner wing on the air filter side. So it's out of the wind but the other side of the bulkhead away from hot engine air. This works a lot better.
Hey ric355. Thanks for all your comments above, really useful stuff particularly on the heat soak issue. This might actually inadvertently solve another issue I have in that my new silicon 90 degree hose isn't actually long enough to reach the delete pipe. If I relocate it further down and bring the old inlet pipe to meet the hose it could solve both problems.

Belle427

8,857 posts

232 months

Friday 8th April 2022
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I welded an adapter into the air filter metal connector in the nosecone for the air temp sensor, keeps it away from most heat.
As for the afm delete you can get a length of silicone hose to go from the afm down to the nosecone and connect it to a short length of the oem tumble dyer hose using a connector or reducer, looks neater as the joint is right at the bottom and hardly visible.

Fenderer

Original Poster:

137 posts

101 months

Tuesday 19th April 2022
quotequote all
OK, I'm fairly close now to being able to power up the ECU for the first time.

I took the good advice here and relocated the MAF delete pipe down the front of the car with the IAT sensor to avoid heatsoak from the exhaust.

The new wiring loom is in, sensors are all connected, wideband is all wired up, and cooling fans now set up to control from the new ECU, but I need to sort some remaining earths. I have 3 black wires, one thick gauge and 2 smaller gauge that are running from under the engine and past the alternator along with the alternator cable, oil pressure sender and switch wires.

These appear to be earths of some kind and originally terminated in the old ECU and I think the green A/C socket which isn't used. Since I chopped out the old ECU I now have 3 loose earths in the passenger footwell. Can someone confirm what the 3 earths are for and do I still need them?




Belle427

8,857 posts

232 months

Wednesday 20th April 2022
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Pretty sure they are all Ecu grounds that are no longer needed, they were on mine.
Can’t remember if the old lambdas grounded here too.
Make sure your grounds on the new install are good and are accessible for inspection, there may be some notes on your install about avoiding ground loops and separating some to avoid interference.

Fenderer

Original Poster:

137 posts

101 months

Wednesday 20th April 2022
quotequote all
Thanks. Yes they are checking out as earths on the multimeter. I think to be sure I best jack the car up and see where they terminate. Will be a good chance to check that the condition of starter cable is ok too.

Good advice on the ecu grounds. My plan is to earth it on the back of the cylinder head with the new earth for the main relay. The Speeduino ECU doesn't have a dedicated 0v pin for the negative output of the AEMs AFR gauge so it's that currently tied to a ground in the ECU so I do need to check for ground loops.

Belle427

8,857 posts

232 months

Wednesday 20th April 2022
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They terminate on a difficult to reach bolt lower down on the drivers side front of the engine.

ric355

215 posts

148 months

Wednesday 20th April 2022
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Fenderer said:
Thanks. Yes they are checking out as earths on the multimeter. I think to be sure I best jack the car up and see where they terminate. Will be a good chance to check that the condition of starter cable is ok too.

Good advice on the ecu grounds. My plan is to earth it on the back of the cylinder head with the new earth for the main relay. The Speeduino ECU doesn't have a dedicated 0v pin for the negative output of the AEMs AFR gauge so it's that currently tied to a ground in the ECU so I do need to check for ground loops.
Use the ECU for sensor grounds (there are several pins available for this) but not for power grounds.

Fenderer

Original Poster:

137 posts

101 months

Wednesday 20th April 2022
quotequote all
Belle427 said:
They terminate on a difficult to reach bolt lower down on the drivers side front of the engine.
Great. thanks. Might try and rip these out as it will neaten up the new loom no end.

Fenderer

Original Poster:

137 posts

101 months

Wednesday 20th April 2022
quotequote all
ric355 said:
Use the ECU for sensor grounds (there are several pins available for this) but not for power grounds.
Thanks, yes this is what I thought might be best. Got them all now distributed on the GND pins. Then I guess the Speeduino board will tie these to a power GND which I'll probably earth on the bolt behind the LH cylinder head.

Belle427

8,857 posts

232 months

Wednesday 20th April 2022
quotequote all
Just try and make everything easily accessible and not hidden away like Tvr did, easy to check in the event of an issue.