llyrmei
Hi all,

I intend on using the Cosworth SQ6 ECU to control a drive by wire system on an FSAE car. The first step towards this however, would be for me to purchase an OEM accelerator pedal assembly and an OEM Throttle body, and have both of them communicating with the SQ6. Has anyone been able to do this, or has anyone been successful in implementing a custom drive by wire system using the SQ6? 

Any help or advice would be greatly appreciated!

Kind regards,

Llyr
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gtihk
Yes, we have done it before. Be warned. It is not for beginners.
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llyrmei
Thank you for your response!

Did you use an OEM throttle body and accelerator pedal position sensor? Could you also expand on the difficulties you encountered?

Kind regards,

Llyr
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MarcB
Hi Llyr,

I'm using the DBW option also, on a VW VR6 turbo engine, and are using VW OEM throttle and pedal.

You could use probably any OEM hardware, as long it has a DC motor for the throttle, with two feedback position(potentiometer) sensors, the same goes for the pedal position feedback, but it needs to output an inverted signal to each other.

Mind you, this alone will take 4 analog inputs and one DC output.

I guess the biggest problem is safety, although the SQ6 has many safety rules built-in on the feedback position sensors, it's still you that will enter all the PWM, pedal position, etc. tables and PID figures, meaning if something is not quite right, you can end up with a wide open throttle when you don't want it.

On the other hand, when it's working ok, it's powerfull, because you're in control of many other things the throttle position can play a role in, like traction control, turbo boost control, etc. (if you may use it).

An other example, I've found that at a particular engine load and rpm, a slightly smaller throttle opening than wide open, made more power, this is something you can play with.

Regards,
Marc

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llyrmei
Hi Marc,

Thank you very much for your response! Nice car! I assume that was previously a mechanical system then on the VR6? Just out of interest, what power do you get out of that, it was originally 174 was it?

So I assume with the SQ6 it's not a case of 'plug in and play'? Did you use the SQ6 for this application?

Kind regards,

Llyr
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MarcB
No, it's not on the old VR6 12V, but on the newer BDE 2.8L 24V, which has originally DBW.

The engine is rebuilt with forged(and lower compression) internals, and depending on boost setting, it puts out +400bhp and 500Nm, but could easily go higher with the turbo(PT6262BB), but I like when things last a bit...
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MarcB
Yes using the SQ6, the BDE engine has also VVT, which is also controlled by the SQ6.
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llyrmei
Hi Marc,

Thank you for all the information up to now, it is very useful! 

How would you recommend me going about it then? Where did you start? Also do you have any links that you found helpful? How involved were Cosworth themselves with you?

Apologies for the attack of questions!

I appreciate your time and for that I'm also very thankful!

Kind regards,

Llyr
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MarcB

First I started with buying the hardware, the car the engine is in did not have DBW, and made the wire loom, then I bench tested the whole system.

The first thing I did was to run the auto calibration function, this will latch the minimum and maximum voltages of the position sensors(sensor curves).

Then its trial an error regarding the PID settings, it’s hardware related thus it will be up to you finding the best numbers. One thing that will have the most impact is the control frequency, mine worked best at 8000 Hz.

As for the help from Cosworth, when I started with this, this forum did not exist yet, but I received some help from Neel Vasavada, who owns Apex Speed Technology.

Hope this helps a bit.

Regards,

Marc.

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Robert Behn
https://www.rbracing-rsr.com/sq6m_flybywire.html

Bob
RB Racing
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llyrmei
Thanks everyone for your help. 

I have now run into a little problem, and wonder if anyone here knows the solution to it.

So I’ve managed to create the test bed, and I’ve got both the Bosch DV-E5 electronic throttle body and dual pot talking to the ECU. As I move both the dual pot and butterfly valve, PPS1 and PPS2 increase and decreases between 0 and 5V, as well as for TPS and TPSA1. However, once I enabled FBW, it came up with this message as I tried to upload the dataset to the SQ6:

“CalTool Error; Message from Device: THE FLY-BY-WIRE STRATEGY HAS BEEN ENABLED BUT FLY-BY-WIRE IS NOT AN ENABLED FEATURE ON THIS BOX, ENGINE WILL NOT RUN!”

I’m wondering if this is something put in place by Cosworth to prevent users from implementing their own DBW systems, as I can understand it is a safety concern.

Does anyone know how to resolve this, and effectively ‘unlock’ the feature to allow for the implementation of the FBW system?

Kind regards,

Llyr

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Andrius K
you need SQ6 Fly By Wire Upgrade on your ECU
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demlotcrew
Yes, your ECU needs the FBW upgrade to be applied. You can buy this from Cosworth.
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