DTA T8 -Davies Craig EWP control

Discuss which Sensors work best with these ECUs and share how you are using inputs and outputs
Lee_edwards
Posts: 6
Joined: Sun Jun 09, 2019 4:31 pm
ECU Model: S40 Pro

DTA T8 -Davies Craig EWP control

Post by Lee_edwards »

Hi all,
is anyone successfully a Davies Craig EWP via a SSR able to share their settings?

We started with the default / recommended 400hz with 10% duty then ramping up to 95% at chosen operating temp but when the engine mapper tested this by switching on the output with 400hz the duty cycle changes seemed to have no effect on the pump and it was running what seemed to be flat out across all (10 to 100%)

So he tried 100hz and then altered the duty cycle and you could easily tell the difference in just 5% increments.

So currently were at 100hz, 25% across the low / med temps for warm up then ramping up to 90% at 70 and 80 deg then 95% 85deg onwards with the fan activated at 75deg

However the issue i seem to be having is once warm and idling it cant maintain its own temp, it gets warm fairly quick then hits 75deg and it keeps creeping up slowly 1 by 1 (iv let it get to 94deg so far). (this is only once the engine is properly warm inc oil, on initial start up it will maintain 75deg for a while)

I'm fairly confident the Fan is fine and the radiator is a nice sized thick core

Any suggestions would be appreciated

Thanks
stevieturbo
Posts: 3578
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: DTA T8 -Davies Craig EWP control

Post by stevieturbo »

A lot of SSR's will not be happy at higher frequencies. Some even 100Hz will be too high.

Exactly what SSR are you using ?

And how are you determining nothing at the pump is changing ? Flow test ? pump current ? other ?
Alex DTA
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Joined: Fri Feb 28, 2014 1:03 pm
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79

Re: DTA T8 -Davies Craig EWP control

Post by Alex DTA »

400 Hz is a mistake in the document, it should read 50 Hz. I'll fix that now.
Lee_edwards
Posts: 6
Joined: Sun Jun 09, 2019 4:31 pm
ECU Model: S40 Pro

Re: DTA T8 -Davies Craig EWP control

Post by Lee_edwards »

stevieturbo wrote: Wed Dec 14, 2022 1:00 pm A lot of SSR's will not be happy at higher frequencies. Some even 100Hz will be too high.

Exactly what SSR are you using ?

And how are you determining nothing at the pump is changing ? Flow test ? pump current ? other ?
The SSR is a MGR - MGR-1 DD220D25

in respect to the pump changing this was just done by the sound of it, at 400hz there was no tone change when at 10% to 100% but like i mentioned when dropped to 100hz the different between 10% duty to 100% was night and day, and just a change in 5% could be heard (and seen by the brightness of LED on the SSR)
Lee_edwards
Posts: 6
Joined: Sun Jun 09, 2019 4:31 pm
ECU Model: S40 Pro

Re: DTA T8 -Davies Craig EWP control

Post by Lee_edwards »

Alex DTA wrote: Thu Dec 15, 2022 4:34 am 400 Hz is a mistake in the document, it should read 50 Hz. I'll fix that now.
Ah ok, will drop mine from 100hz to 50hz... is this likely to change the way/speed the pump operates? / possibly cure my issue would you think?

Thanks
Alex DTA
Posts: 1622
Joined: Fri Feb 28, 2014 1:03 pm
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79

Re: DTA T8 -Davies Craig EWP control

Post by Alex DTA »

Should do, yes.
stevieturbo
Posts: 3578
Joined: Tue Aug 02, 2011 12:08 pm
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Location: Norn Iron

Re: DTA T8 -Davies Craig EWP control

Post by stevieturbo »

Lee_edwards wrote: Thu Dec 15, 2022 5:37 am
The SSR is a MGR - MGR-1 DD220D25

in respect to the pump changing this was just done by the sound of it, at 400hz there was no tone change when at 10% to 100% but like i mentioned when dropped to 100hz the different between 10% duty to 100% was night and day, and just a change in 5% could be heard (and seen by the brightness of LED on the SSR)
That's full blown China, no tech specs at all.

I definitely would not be trying any sort of high frequency with it. Even 100Hz might be too much.

Also bare in mind a motor is an inductive load, and there could be potentially very high flyback voltages so will likely need a suitable diode across the motor.

I'd be wanting to see a scope of both voltages and current at the motor to ensure everything is happy....or not so happy before trying to actually use it for any time period so as to reduce chance of failure of either
katana
Posts: 455
Joined: Sun Jan 27, 2013 6:08 pm
ECU Model: S60 Pro
Firmware Version: 29

Re: DTA T8 -Davies Craig EWP control

Post by katana »

If the pump (when running flat out / 100%) can't hold the temp, i'd suggest it might be undersized? I'd have thought a pump should have a degree of headroom to cope with the ocassion when temps rise above 'normal'. Its like a HP fuel pump, they have extra capacity to allow a maximum duty cycle of 80 - 85% of the injectors with extra returned to the tank - bit obtuse reasoning but sort of makes sense to me LOL!
G3Lee
Posts: 9
Joined: Thu Dec 15, 2022 4:38 pm
ECU Model: S40 Pro
Firmware Version: 73.01

Re: DTA T8 -Davies Craig EWP control

Post by G3Lee »

stevieturbo wrote: Thu Dec 15, 2022 2:19 pm
Lee_edwards wrote: Thu Dec 15, 2022 5:37 am
The SSR is a MGR - MGR-1 DD220D25

in respect to the pump changing this was just done by the sound of it, at 400hz there was no tone change when at 10% to 100% but like i mentioned when dropped to 100hz the different between 10% duty to 100% was night and day, and just a change in 5% could be heard (and seen by the brightness of LED on the SSR)
That's full blown China, no tech specs at all.

I definitely would not be trying any sort of high frequency with it. Even 100Hz might be too much.

Also bare in mind a motor is an inductive load, and there could be potentially very high flyback voltages so will likely need a suitable diode across the motor.

I'd be wanting to see a scope of both voltages and current at the motor to ensure everything is happy....or not so happy before trying to actually use it for any time period so as to reduce chance of failure of either
Sorry iv had to create a new username as i cant access my account at home wierdly.

all of the above is over my head tbh, iv had the loom built for me i just gave the measurements and said what inputs and outputs i require
G3Lee
Posts: 9
Joined: Thu Dec 15, 2022 4:38 pm
ECU Model: S40 Pro
Firmware Version: 73.01

Re: DTA T8 -Davies Craig EWP control

Post by G3Lee »

katana wrote: Thu Dec 15, 2022 2:42 pm If the pump (when running flat out / 100%) can't hold the temp, i'd suggest it might be undersized? I'd have thought a pump should have a degree of headroom to cope with the ocassion when temps rise above 'normal'. Its like a HP fuel pump, they have extra capacity to allow a maximum duty cycle of 80 - 85% of the injectors with extra returned to the tank - bit obtuse reasoning but sort of makes sense to me LOL!
Yea i understand what you are saying. its a 115 model which is the one they use on the Rocketeer conversions with these v6 jag engines so its sizing should be right (well at least to keep its temp at idle)

iv done some testing tonight... EWP on 95% duty from 75deg and above, and fan to come in at 75deg.
once the engine is hot (baring in mind its very cold outside) the engine temp stabilised around 82/83deg but never came down the 75 to turn the fan off itself. i unplugged the fan to rise temp up to 90 ish then put the fan back on and it very very slowly crept down to around 83

i played with the EWP duty cycle, first of all increased to 100% above 75deg to see if it made any differences which is didn't, i also reduced it down to 70% and again no differences really which made me think i could be barking up the wrong tree and the EWP might not be at its limit / struggling and in fact it could be the fan even though it feels strong.

i also tried hooking the EWP and fan of individually to a 12v battery to rule out any power or ground issues on the car which again made no effect

also tried frequency at 50hz from 100hz no difference

going to try a new fan
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