Megasquirt on a V8 build

[snowrx]

+1 for the MS3X board, it just makes adding features easier.

[v8GTmac1]

13 hours ago, cammmy said:

How have you got it setup so that the Stock ECU does idle but the MS controls everything else?

If you already have the MS3 then I would get the X add on and ditch the factory ECU entirely. It will hugely simplify the setup and reduce the chances for issues. If there's one thing I've learned, it's that wasted dyno time due to ECU issues is a lot more expensive and frustrating than spending a bit more time and money up front.

the MS3/X should do everything you need and more.

THe oem BOsch ECu has no idea Megasquirt it feeding off the same sensors. Yes it triggers CEL for missing injectors and coils but does not effect it's functionality.  

As long as Megasquirt keeps the engine humming and the ckp and cam are putting out a RPM then the Bosch will continue to do whatever it can with what is still connected to it.

[v8GTmac1]

2 hours ago, snowrx said:

+1 for the MS3X board, it just makes adding features easier.

I'm taking baby steps 🤨 .on Megasquirt, I didn't think I would get this far since I had no other V8 to feed information off of. So i'm using what I have at my disposal and working out all the bugs. 3x time i'll be feeding info of you you and anyone else here that has it for sure😝

[cammmy]

Have you got the pin out/wiring diagram for your stock ECU?

I'm not sure if you can feed two ECUs from a single sensor by splitting the signal. You might need some kind of splitter that has smarts.

I don't think it would be much extra work over what you've done already and I think you would get more reliability out of it. I would give you my pinout for the MS but it's a 4 cyl.

Also, check your earth's. I had an issue where it was going lean at about 4,500 which led me to replace the fuel pump. After two Dyno trips I discovered my earth's weren't good enough. Bad earthing can cause all sorts of issues.

[snowrx]

13 hours ago, v8GTmac1 said:

I'm taking baby steps 🤨 .on Megasquirt, I didn't think I would get this far since I had no other V8 to feed information off of. So i'm using what I have at my disposal and working out all the bugs. 3x time i'll be feeding info of you you and anyone else here that has it for sure😝

Baby steps are best, get the base tune, cold starts and idle well set up over a range of temperatures before wading into the extras.  For example MS3X Idle Control sounds great, but there must be 25 settings and 5 tables in TunerStudio on closed loop idle alone. You don't want to be chasing bad AFR's  when you're working your way through that lot, so just set the throttle stop and live with a varying idle (or let OEM ECU handle it) while you get the main tables established.  

[v8GTmac1]

SHe lives!!

 

[snowrx]

Datalog, or it didn't happen!   

Just kidding, sounds good on the road. 🏆

[v8GTmac1]

what’s happening with my fuel  

need more upgrades  

 

[mike_sekinger]

Looks like you may have an air leak in the exhaust

[v8GTmac1]

Exhaust leaks from blocking off my egr system hmmmm

 

my initial plan is to hookup 2 LED lights to the secondaries. I will then see exactly when the oem ecu is activating them. And then I may have to hook them back up and adjust my fuel for them. If the activations is consistent then I can tune for them  

mid it’s not consistent then I need Megasquirt 3 to control all 10 injectors  

btw I installed 252cc mustang EV injectors  

Too much confusion as to when they are used. Hi load, high boost , high speed ....questions questions. 

Edited December 23, 2019 by v8GTmac1

[snowrx]

Personally, I'd avoid the complexity of staging secondaries. Just get the primaries the pulse width they need, or go to bigger injectors if you exceed your duty cycle (or fuel pressure) availability. Two additional injectors would seem like they would never give you truly equal fuel distribution to all the cylinders, unless they only come on with enough WFO airflow and heat to completely vaporize the fuel before the runners separate.

[cweeden]

Hi Michael,

Great progress and very interesting to follow but can I cause you to digress a little, back to the coils please.

I was wondering if the Toyota coil on plug coilpacks would be suitable for use in the Esprit V8? I don't have any dimensions so that's one aspect that would need to be investigated but I don't know if they can they be driven by the standard ECU (with wasted spark) or would they need additional electronics to drive them?

There are a range to choose from and some interesting info can be found here https://www.sq-engineering.com/tech-articles/coilpack-info-guide/. This explains that they have inbuilt igniters (not sure if that helps or not) and that they can be controlled for dwell if the signal is for longer than the minimum dwell time set within them that cannot be reduced.

Does anyone know if the standard ECU provides the igniter (not entirely sure what that is) and if it controls the dwell or not? I suspect a bit more Googling would provide me with further insight but I figured I would ask those wiser than me on the forum hoping others can learn too. 🙂 

-Chris

 

 

[cammmy]

Have a read through this thread, there are a couple of links to some good books. I would consider at least one of these mandatory reading before embarking on any aftermarket ECU setup.

 

[cweeden]

Hi @cammmy, I have been following that thread too and even made it onto Amazon but I would rather work with the standard ECU or just copy the good work of someone else, I think it's a case of knowing my limits. 🙂

I like the idea of COP to improve the control of the spark and getting the coilpacks somewhere more accessible wouldn't be a bad thing for when something needs troubleshooting perhaps.

I may still get one of the books mentioned but I am not a good bookworm and wonder how much I would actually get through if I am honest. 

cheers

-Chris

[v8GTmac1]

On 26/11/2019 at 00:57, cammmy said:

Have you got the pin out/wiring diagram for your stock ECU?

I'm not sure if you can feed two ECUs from a single sensor by splitting the signal. You might need some kind of splitter that has smarts.

I don't think it would be much extra work over what you've done already and I think you would get more reliability out of it. I would give you my pinout for the MS but it's a 4 cyl.

Also, check your earth's. I had an issue where it was going lean at about 4,500 which led me to replace the fuel pump. After two Dyno trips I discovered my earth's weren't good enough. Bad earthing can cause all sorts of issues.

 Never responded here  

 I have a copy of the  manual with the yellow Esprit on the cover   

 But I still had to back trace every wire due to Lotus not clearly specify the colors of each wire  

By the way sharing the sensors for the crank in the Cam was an issue  and anything above idle That’s why all my initial videos were just idling  that’s why all my initial videos were just idling   Something to do with bias resistors in both ECUs conflicting with each other. 

But if someone still wanted to use them easily enough just remove the factor ECU from the equation and I already posted the trigger settings for the factory sensors

[v8GTmac1]

On 07/01/2020 at 10:21, cweeden said:

 

Does anyone know if the standard ECU provides the igniter 

-Chris

 

 

This remains to be answered

[v8GTmac1]

I posted some pics of the ecu internals. 

All someone needs to do is hook up some LEDs to each of the 8 ignitors transistors  to see if they are all actually being triggered. 

Then to make it more complicated you would have to organize them in the firing order and watch the LEds in slow motion to verify. Haha sounds fun?

Edited January 8, 2020 by v8GTmac1

[v8GTmac1]

On 07/01/2020 at 10:21, cweeden said:

Hi Michael,

Great progress and very interesting to follow but can I cause you to digress a little, back to the coils please.

I was wondering if the Toyota coil on plug coilpacks would be suitable for use in the Esprit V8? I don't have any dimensions so that's one aspect that would need to be investigated but I don't know if they can they be driven by the standard ECU (with wasted spark) or would they need additional electronics to drive  

-Chris

 

 

https://www.lotustalk.com/threads/esprit-v8-coil-on-plug-conversion.77429/

 

You could look look into this as well. I almost did but I’d have to call AEM to better understand the install. 

 

 

 

[cweeden]

18 hours ago, v8GTmac1 said:

https://www.lotustalk.com/threads/esprit-v8-coil-on-plug-conversion.77429/

 

You could look look into this as well. I almost did but I’d have to call AEM to better understand the install. 

 

 

 

Hi Michael,

I'd seen that article but found it lacked enough technical detail, for example I am not sure why the Pro-14 CDI Ignition Box is needed? I don't know enough about modern ignition systems but my book that @cammmy recommended arrived from Amazon today will be my reading material on a long haul flight tomorrow. 

It's what prompted my question about the standard ECU having an 'ignotor', I don't know what one is but the Toyota coils claim to have one built in and can simply take an ECU signal to trigger. It sounds too easy and so I suspect I simply haven't understood the challenge properly. 🙂

cheers

-Chris

[cammmy]

I don't believe any ECU will have an ignitor built in. Generally it's either a seperate module or built in to the coil on modern stuff. I'm not sure what the V8 does for ignition but the 4 pots use GM DIS. I kept this so the ignition side was much simpler as it was only a few wires and a simple signal from the MS

[v8GTmac1]

 I always like a good discussion so I’ll reiterate what I’ve been trying to state 

 The factory computer does indeed have the built-in igniter’s posted it in my picture in the link I posted above you can see them all lined up but as I mentioned only 4 are being used for the factory coil packs  which are dumb coils  without built-in igniters   

Without built-in igniters they require 12 V pulsed signals from the computer instead Of 5v. Signals on the Toyota coil’s you mentioned

 The factory computer has been built with eight igniters for a reason unknown so my question is what vehicle did they take this computer from or was the original plan to run 8 individual Dumb coils until they cheaped out at the factory and re-wrote the code to only trigger 4 of the  igniters in wasted spark  

 

 But of course there’s always a possibility that all eight igniters are being triggered and only 4 are used which are the correct 4 in this firing order. 

 

Thats why why I mentioned LEDs as a test. Its a project I don’t expect anyone will tackle but I sure can since my factory ecu is still running but None if the original ignitors are connected to anything so consequently I have 8 CEL codes for each lol

8 LEDs to the 12v pulsed leg of each of the 8 ignitors 

run the engine at the lowest rpm and record them flashing with camera in slomotion to capture their firing order. 

Then you know which is for what cylinder and have an attack plan. Is any of this clear enough to understand? Or do I need to tackle this job and post a vid ?

 

[v8GTmac1]

16 hours ago, cweeden said:

Hi Michael,

I'd seen that article but found it lacked enough technical detail, for example I am not sure why the Pro-14 CDI Ignition Box is needed?

cheers

-Chris

Here’s an explanation. That system is using Dumb coil Without ignitors. 

The CDI box has the ignitors instead. The AEM system has another small module with the brains taking the crank and cam signals and with your programmed settings will run engine. 

More the AEM brain is taking the existing firing signals intended for the factory coilpacks and re-directing them to the CDI box to fire 8 coils instead but still are fired in wasted spark Not sequential. 

 

[swindon_alan]

7 hours ago, v8GTmac1 said:

The factory computer has been built with eight igniters for a reason unknown so my question is what vehicle did they take this computer from or was the original plan to run 8 individual Dumb coils until they cheaped out at the factory and re-wrote the code to only trigger 4 of the  igniters in wasted spark

Hello Michael, I have just received some interesting info on the factory ECM. It isn't in fact a programmed EFI MT-501 as I thought but a custom version specifically for the V8 which EFI subsequently modified and sold as the MT-501 (!) Having said that, I'm convinced that it is similar internally and you are quite right, there are eight individual ignition coil circuits but only two are used. So by default there were eight but with multi-coil packs Lotus didn't have to use the other six.

 

 

[Barrykearley]

@swindon_alan I spoke with a technical guy at EFI many moons ago about this. They would release absolutely no technical information whatsoever as still bound by client confidentiality. The ecu was confirmed as unique to the lotus V8 though and used on nothing else - oh other than the exige S1 - but that was more likely to be Lotus reusing the ecu stocks they had on the shelf or committed to buy under contract

[swindon_alan]

As above @Barrykearley, I only found out tonight from who I shall call a very well informed source that EFI developed the ECM for Lotus from scratch and then modified it to sell on the open market as the MT-501 (different case, some connection differences, obviously no Lotus proprietary content). I was advised to look at the EFI Euro-4 as an alternative that is in production. Price to you Mr Kearley? (although you don't need or want one!)

£2,100

Including VAT.

Then all of the pain of setting it up. Nope, my ECM target price is well under a grand...