Author Topic: Best ECU for a Turbo  (Read 5940 times)

Offline prankstar2003

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Best ECU for a Turbo
« on: July 27, 2012, 10:41:20 pm »
Although I haven't even built the carb turbo yet, I'm looking into EFI for the future. I've had a browse on't net about Turbo suitable ECUs but most of the info i can find refers to cars that already have turbos.

Obviously the standard G40 ecu can be made to work, but I'm just wondering what does it offers/not offer that aftermarket ones might provide and which ECU is considered the best for this application. So what are my options? So far I'v read about
M-squirt
Weber Alpha Plus
DTA
Emerald

Most of these don't appear to have boost control (do I need this?) and don't mention turbo applications. I have found a hardware add on for MSquirt 2 and 3 that allows for boost control.

So what should I look for in an ECU? Will the G40 one do, or should I look into aftermarke? What do aftermarket ECUs offer over the standard ones? I would like to be able to programme it myself (if i decide to learn in the future) but if that makes it a lot more expensive I can do without. Do I need all the flashy features and sensors, or will the basics surfice? The car won't be a racer so it doesn't need be super tuneable. It may either have a single throttle, or possibly ITBs (if that makes a difference to the choice).

Thanks for the 'elp

Offline Andy

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Re: Best ECU for a Turbo
« Reply #1 on: July 27, 2012, 11:15:03 pm »
DTA and Emerald can do electronic boost control - don't know about the Weber stuff. If my experience of the Emerald is anything to go by, it's not advanced enough to give any significant benefits over just actuator control. Granted you can run lower boost at the flick of a switch, but the rest of the time the boost is not consistent enough for my liking - and that was after 20 hours or so of calibrating the PID control!

What do you want from the EFI system? I wouldn't worry about having boost control myself.

The advantage of using a G40 ECU is that all the cold start mapping etc. is already done by VW - who have put thousands of man hours into the calibration. It works well with the 6psi boost switch modification, and can be mapped to a refined level in a day. I've yet to get my Emerald K3 ECU running my car as effectively as I did on G40 Digifant - despite putting something like 100 hours of effort into the calibration AFTER a visit to Dave Walker.

The aftermarket ECUs in the sub-£1k price bracket are good value for money - but have had nothing like the same amount of hardware, software or calibration development that original equipment ECUs have, and sometimes that shows. On the other hand, they're easily DIY configurable and calibratable - the same can't be said of OEM engine management systems!

Other systems to look at are MBE, Omex, and Nira. The likes of Bosch Motorsport and Pectel (Cosworth) and similar companies also do systems - but you need motorsport budgets too!

Offline prankstar2003

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Re: Best ECU for a Turbo
« Reply #2 on: July 27, 2012, 11:34:15 pm »
Thanks Andy. I think you've advised against Emerald before. My brother uses it on his Stratos rep and he rates it. However, I guess he had no OEM option for what he wanted.

Couple more Qs for you, whats the PID control, what's the 6PSi mod (i have read about this, but still don't fully understand) and are you able to map the OE software? Oh, and do you need a knock sensor for the OE ECU? I'm not using a PY for the build (probably and ABD or possibly the 1W i have).

Budget is a big part of the build, but I wouldn't want to cut corners to regret it in the future

Offline youngprodigys

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Re: Best ECU for a Turbo
« Reply #3 on: July 28, 2012, 10:47:26 am »
oh and andy, one more question- whats the search function do? i used it briefly and found this
http://www.polog40.co.uk/forum/index.php/topic,7962.0.html
which explains the 6psi boost switch.

and my god dont go into detail on PID, That Simon is the maths and theory behind controlling signals. I very much doubt you will need that as the option to get Andy to map the car is by far the bet option, his experience and knowledge in the subject will by far trump the reading you can do on the internet about smoothing signals. the fact that he charges an awesome rate for doing it is further reason.

Offline prankstar2003

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Re: Best ECU for a Turbo
« Reply #4 on: July 28, 2012, 04:31:23 pm »
Thanks for the info on the PID, something I'm not remotely interested in, so I'll leave that to the pros!

Are there other pressure switches available? I see the 6psi is recommended for a KO3. What if something larger, like a T25 was being used? Would the pressure switch need to be changed (higher or lower?) or is 6psi about the optimum for all turbos?
« Last Edit: July 28, 2012, 04:40:49 pm by prankstar2003 »

Offline youngprodigys

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Re: Best ECU for a Turbo
« Reply #5 on: July 28, 2012, 06:56:01 pm »
it is just to replace the WOT switch. 6psi is what is roughly needed, regardless of whatever turbo is used- it will remain 6psi and you set it to this yourself. the switch has a large range on it to adjust this- but it really doesnt matter

Offline prankstar2003

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Re: Best ECU for a Turbo
« Reply #6 on: July 28, 2012, 07:52:51 pm »
Thanks Kiz.

Another question then, can the G40 ECU be used with a different TB? I'm not a fan of the look of the G40 item (unless worked over like Kiz's) and I may want a larger TB (maybe even more so than 51mm) or ITBs. From what I can fathom, it would be a case of repositioning the WOT (now a pressrue switch) and the closed throttle sensor. Thinking of ITBs, the 6psi switch I can't see being too much of a problem (I'm unsure which side of the 'fly it goes, but it would have to be relocated to the plenum or maybe 4, one in each runner) but the closed throttle one may be more difficult. Would there need to be one for each 'fly (so 4) or would one surfice (since they all open at the same time)?

If the questions sound a little niave, I apologise. EFi is something I've avoided until now, but i'm begining to realise to get the most from FI then EFI is the way to go.

Offline cheys03

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Re: Best ECU for a Turbo
« Reply #7 on: July 28, 2012, 11:31:04 pm »
Just one closed throttle switch will suffice - it's there to inform the ECU that the engine is idling. The ECU then runs in 'idle mode' (trying to be as simple as possible and not go in to unecessary details).

Offline youngprodigys

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Re: Best ECU for a Turbo
« Reply #8 on: July 29, 2012, 09:26:11 am »
you an fit whatever throttle body you like really, Andy uses a GT item. aslong as you have an idle switch, and a WOT switch the ecu will be happy. i will soon be using a custom manifold and a modified G60 throttle.
my WOT is located after the butterfly and is part of my plenom- if 1 port is getting 6psi- then it is positive pressure and all 4 will be getting the same pressure so theres no need for 4 switchs.

Offline prankstar2003

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Re: Best ECU for a Turbo
« Reply #9 on: July 29, 2012, 06:48:16 pm »
Thanks you two. And kiz you've answered my next questions of whether a TB needs to be FI specific.

Offline cheys03

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Re: Best ECU for a Turbo
« Reply #10 on: July 29, 2012, 08:19:17 pm »
Worth noting Andy uses the throttle pot on the GT tb with his Emerald setup. You'd have to add an idle switch and ignore the throttle pot if using a GT tb with G40 management (as Kiz says).

Offline prankstar2003

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Re: Best ECU for a Turbo
« Reply #11 on: July 29, 2012, 09:06:15 pm »
Thanks again, begining to get an idea of how this all goes together now.

Another thing though, where does the CO Potentiometer live?

Offline cheys03

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Re: Best ECU for a Turbo
« Reply #12 on: July 29, 2012, 09:37:09 pm »
The CO pot is dual function - mixture adjustment and inlet air temp, hence it lives in the boostpipe, about 25cm from the throttle body at a rough estimate.

Offline prankstar2003

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Re: Best ECU for a Turbo
« Reply #13 on: July 29, 2012, 09:47:48 pm »
Sound, so before the throttle butterfly. Nice on