Speeduino - ECU - Chimaera?

[Monsterlime]

Even though I have yet to pick up my Chimaera, I already have a list of projects (largely things I never got round to on my first Chimaera but want to address on my new one).

One of these is the ECU. I always intended to go with a Megasquirt or Emerald to modernise the ignition and make adding FI easier. I was looking around the other day and found this - https://speeduino.com/wiki/index.php/Overview

Now, I am not an expert at all, but I do work in IT and have built a few gadgets with Arduino/ESP8266 chips, can solder etc, so that side doesn't scare me. The car side/feature set is more of an issue, but reading through the current features I THINK it would work for a TVR.

Has anyone else seen this? Been tempted? Any thoughts on its current feature set and if I would be totally insane to even consider fitting it to a TVR?

It isn't really cost (although that is a factor) that is driving this, more that I like to tinker and the Arduino is a great platform.

[Sardonicus]

Read up a little on this project just out of interest/curiosity (am a 8th year Megasquirt user) and know that it can also use Tuner-studio software for tuning purposes but thats where my interest ends

[Dougal9887]

As a Megasquirter for two cars I can't be much help but it does appear to have all the required attributes including a UK kit supplier. On a brief look I didn't find the speed of the processor and as all the other electronics will be similar to others, this might be a deciding factor. The fact that it uses the well developed Tuner Studio software is a big plus.
You may get a better insight on MX5 forums as I notice MX5 plug 'n play is available so presumably some demand, there is also mention of a support forum which would be worth a visit.
If you go down this route, let us know how you get on!
Dougal.

[blitzracing]

Id love to see something like that work in an TVR engine bay that is more glitches and HT interference than a thunderstorm........

[Monsterlime]

I have poked around the support forums, and there are a couple of people working on and running it with LS3’s, so that is a positive thing.

Surely properly insulated wiring would deal with any interference issues? How do Megasquirt and Emerald deal with that?

[ric355]

I have previously mentioned my ECU project on here but never said what it was. It's a Speeduino implementation. I DIY installed it last year.

I am also a contributor to the project from time to time; I spent quite a lot of time getting the stepper motor control to work properly for example, as it just didn't really work due to a few bugs.

Rather than bleat on about what I did for pages on end, I'm happy to answer any questions as needed. My installation uses the original loom together with a sub loom but I did that mostly because I seemed to be the first with a TVR (but not with an RV8 - there is an SD1 3500 running around somewhere in a different country on one). If I were doing it again I'd rip the old loom out and make a new one but I didn't have the confidence at the time that I wouldn't have to reverse it.

I have not been near a rolling road; all of the mapping was done on-road. It's a never ending project !

Interference is no more an issue on this ECU than it is on any other. Don't know what the basis for that suggestion is. The ECU still sits the other side of the bulkhead just like 14CUX.

[Steve_D]

I think you will need to be very well versed in computing and the like. Megasquirt has arrived where it is by very carefully controlling the development in an open market. Without this control everyone will go off and do their own thing which is fine for them but no amount of good will and forum support will help them or others when things go wrong as nobody else will know how it has been changed or configured.

The existing TVR wiring is fairly basic example of the issues. Lots of circuits are common across the models but there is still a staggering amount of questions come up on our forums. We can only support them and answer questions when we know the wiring has not been messed with.

Steve

[Monsterlime]

ric355 said:

I have previously mentioned my ECU project on here but never said what it was. It's a Speeduino implementation. I DIY installed it last year.

I am also a contributor to the project from time to time; I spent quite a lot of time getting the stepper motor control to work properly for example, as it just didn't really work due to a few bugs.

Rather than bleat on about what I did for pages on end, I'm happy to answer any questions as needed. My installation uses the original loom together with a sub loom but I did that mostly because I seemed to be the first with a TVR (but not with an RV8 - there is an SD1 3500 running around somewhere in a different country on one). If I were doing it again I'd rip the old loom out and make a new one but I didn't have the confidence at the time that I wouldn't have to reverse it.

I have not been near a rolling road; all of the mapping was done on-road. It's a never ending project !

Interference is no more an issue on this ECU than it is on any other. Don't know what the basis for that suggestion is. The ECU still sits the other side of the bulkhead just like 14CUX.

This is excellent! After some more investigation (I only looked at the first page of the User Projects initially), I have found your thread on the Speeduino site and that has already answered a few questions!

While I am not going to rush anything, I want to enjoy the car, this is high up my list of projects to complete. How has the driveability of the car been since you have had it all working? I assume you are still tweaking your map?

Do you also have enough spare inputs to cater for adding FI at a later date?

[ed_crouch]

Hi.

I've got one of each. I'm on my second megasquirt install, MS3X this time with most of the toys.

I also own a VW T25 camper van which will be getting the Speeduino.

It kinda depends on what you want to do with the car. If its just a road car and you have no plans for superchargers or other exotica, then on a simple engine like the Rover V8, a Speeduino ought to work just fine.

I opted for the more expensive MS3X for our Chim because we're going to do a lot more development on it, so the extra grunt of the MS3X, plus things like CANbus, in addition to the more mature firmware design mean I can concentrate on getting the most out of the engine rather than spending what might be a lot of time on firmware tweaks/development.

Don't get me wrong - from the tinkering I've done with the Speeduino, I'm very, very impressed with what £100 gets.

So, that's my take on it. Great little ecu, but ultimately less mature and less sophisticated. But, it still squirts fuel and makes sparks, and if that's all you need........

Ed.

[ric355]

Monsterlime said:

This is excellent! After some more investigation (I only looked at the first page of the User Projects initially), I have found your thread on the Speeduino site and that has already answered a few questions!

While I am not going to rush anything, I want to enjoy the car, this is high up my list of projects to complete. How has the driveability of the car been since you have had it all working? I assume you are still tweaking your map?

Do you also have enough spare inputs to cater for adding FI at a later date?

Driveability has been excellent. Torque and throttle response is definitely improved in the lower RPM ranges by comparison with the distributor (I'm on VW logic level coil packs for those that haven't seen the aforementioned thread). You do have to spend time in the 'shunt' zone to get the fuel and ignition right - retarded ignition and a bit extra fuel usually does it. I am still working on some things, particularly cold starts which I still haven't got quite right. It always starts, but occasionally it needs a second turn of the key once the afterstart enrichment has completed. This stuff just takes time when you start from nothing as it is highly temperature dependent. There have been some recent firmware updates that I haven't moved to yet that affect the way you tune starting and should resolve these issues for me once I upgrade.

You will find that positioning of the IAT is critical. I used the AFM location for mine initially but there is too much heat soak there and I had to move it into the front by the air filter where it soaks a lot less.

There is no info out there for standard injectors, so you have to either guess a bit regarding voltage correction and dead time, or take them out and build a rig to measure them, or alternatively buy injectors that have published information that you can enter.

Forced Induction is covered on the standard board and I have not used the boost pin for anything as far as I can remember. There are also additional medium current outputs available via the proto area with the addition of a chip that costs a couple of quid so that should not be an issue. I would recommend going paired injection straight away (all 4 channels); do not be tempted to use the two injection channels already on the loom; I've been there and paired is a *lot* better - just build out a new injector loom from the beginning.

As you will have seen I am running a wideband but am still running open loop fueling at the moment. Closed loop is available but I still haven't switched it on as I'm still changing the map at times. It's a PID control loop so it needs tuning in and of itself when enabled also.

It has to be recognized that Speeduino is most definitely a product for people who really want to get their hands dirty and don't mind having to solve a few problems along the way. Obviously I've solved all of them for my Chimaera, including getting the tacho to work which requires external circuitry that you must build (or buy a 3rd party module, but it's only a couple of transistors and a relay coil). It's nowhere near a drive-in-drive-out solution. You will need external circuitry for the wideband as well to make sure it only powers on when the engine is running. At this stage you should not need to tweak the firmware to get a running engine. Everything I've done to support my car has been pulled back into the master and made available to everyone and I now take standard firmware updates.

Throttle response in gear is great, but there is some hesitation if you stab the throttle hard at idle. It doesn't affect regular driving but would frustrate you a little if you are a heel/toe track day type. I'm pretty sure this is down to my tune in part but I'm not convinced that is the whole story. I suspect it relates to the fact that I've removed the AFM restriction, and now it struggles to match the fueling to the available extra air when you rapidly open the throttle from low RPM where the gap between injection events is relatively long. Whilst I do have accel enrichment tuned for driving, it doesn't help with this at the moment. This is where the limitations and level of sophistication of the firmware start to show themselves a bit. For example it does not support an asynchronous injection to match the increase in air asap. but I'm OK with that as I know it can and is being regularly updated. I have a couple of things to try yet but haven't had chance (my MAP signal is set on cycle average and I want to see how well it runs on instantaneous).

My total outlay from nothing to a running engine was £650 which included buying a dial back timing light, so it's an incredibly cost effective way to go aftermarket ECU if you're up for it. I would not recommend it to someone who never wants to open TunerStudio again once it is up and running. Get a pro install if you want that. I do not know what the appetite is for mappers to go near it if you want someone else to tune it for you. It's just like tuning a megasquirt but I know sometimes tuners can be a bit fussy about the hardware.

There is a lot of support available in the community but you have to remember there is no-one doing lots of the same car so you're on your own to an extent (apart from me of course). There is a community on Slack as well as the forum (same people on both) which is excellent for help, and another on Facebook but that is mostly full of people who seem to just want to produce flames and don't know their exhaust from their inlet elbow joint.

The standard Mega is a 16Mhz chip, which is plenty of performance to run the V8. There is loads of spare capacity. There is also a teensy implementation in the early stages which is a 150Mhz chip that a few people are running, although board designs are mostly prototypes with that chip (firmware is formally supported). Future hardware designs look destined for STM chips which are arm cores IIRC.

Sorry about the essay I got carried away...

[Sardonicus]

Interesting sounds like its coming on leaps and bounds the more ECU solutions the merrier far as I'm concerned , good write up

[spitfire4v8]

The fact it uses tuner studio means that anyone who currently works on megasquirt should be able to tweak it for you too!

[Monsterlime]

This is very interesting and exciting, thank you! I have very little patience and just want to do everything NOW NOW NOW, but will wait and get the other jobs on the car done first before jumping into a new ECU.

[blitzracing]

Monsterlime said:

I have poked around the support forums, and there are a couple of people working on and running it with LS3’s, so that is a positive thing.

Surely properly insulated wiring would deal with any interference issues? How do Megasquirt and Emerald deal with that?

You need to make sure any electronics is in a grounded metal box, preferably outside the engine bay. In addition you need suppression on the 12v supply, typically wound coil "chokes" you see on some computer cables and even better some sort of voltage regulation if the ECU runs at less than 12v. It also needs some very careful sensor wiring, each sensor needs its own earth wire (not chassis) feeding back to a common earth on the ECU. The aftermarket ECU world is full of horror stories about ground loops and DC offsets on sensor inputs that completely screws the signals the ECU is working with, so a good loom and understanding of your wiring is a must. The HT on the RV8 is pretty nasty as it has long HT leads all over the top of the engine that act as radio transmitter antennas, made worse if you use low resistance HT leads that produce lots of RF interference, so if you look at the 14CUX you will see the lambda wiring is all screened to prevent glitches. Also on the TVR you dont have a lot of metal to soak up interference. All Im saying is the box of cheap electronics is just the start, but its a pretty hash environment to get reliability.

[ric355]

blitzracing said:

You need to make sure any electronics is in a grounded metal box, preferably outside the engine bay. In addition you need suppression on the 12v supply, typically wound coil "chokes" you see on some computer cables and even better some sort of voltage regulation if the ECU runs at less than 12v. It also needs some very careful sensor wiring, each sensor needs its own earth wire (not chassis) feeding back to a common earth on the ECU. The aftermarket ECU world is full of horror stories about ground loops and DC offsets on sensor inputs that completely screws the signals the ECU is working with, so a good loom and understanding of your wiring is a must. The HT on the RV8 is pretty nasty as it has long HT leads all over the top of the engine that act as radio transmitter antennas, made worse if you use low resistance HT leads that produce lots of RF interference, so if you look at the 14CUX you will see the lambda wiring is all screened to prevent glitches. Also on the TVR you dont have a lot of metal to soak up interference. All Im saying is the box of cheap electronics is just the start, but its a pretty hash environment to get reliability.

All good advice, applicable to any ECU installation. I took the time to research what needed to be done and avoided problems like those being described from the beginning but it would be easy to make mistakes - you don't know what you don't know.

I run a 14point7 wideband. The controller for this sits a couple of feet away from the sensor and its output is then routed into the loom so at this point it's the same as any other sensor output. It's an LSU 4.9 so has the appropriate screening from sensor to controller. So there's no need for screening all the way back to the ECU (you must still route it appropriately of course). Note you can't just plug a lambda into the ECU; there has to be an external controller as there isn't one on the Speeduino board.

The Speeduino board includes a voltage regulation circuit, so there's no issue there. It needs a heat sink adding though in my opinion.

The board is designed to be of a specific size so that it fits a 'hammond' metal case which is readily available.

The Mega that runs in tandem with the speeduino board (the board is basically an over-sized 'shield') is not rated for engine bay temperatures so you definitely can't run it there. I'm not sure why anyone would conclude that's where they should put it in a Chimaera though, given the original ECU location.