Standalone

[barks944]

Ive been thinking about converting my car to a standalone injection system. I think with the right planning and know how theres some good improvements to be had for a good price. Ive been drawing up a list of inputs and outputs on the 944 and what additional I/O would be needed for standalone. Ive drawn up a spreadsheet and poured my knowledge on the subject into it. You can edit the spreadsheet to fill in some of the missing details or correct my mistakes.

http://spreadsheets.google.com/ccc?key=0AnlWST0MeZNodHBMa3dWeEpKWU9pUmR6aWVqT3Q3X0E&hl=en_GB

Ive also had a look at a couple of standalone systems that I think might be appropriate.

Link G4 (Storm/Extreme) - http://www.linkecu.com

EmeraldM3d - http://www.emeraldm3d.com/em_k3.html

Simtek DTA S series - http://www.simtekuk.co.uk/www.simtekuk.co.uk/info.php?p=9&cat=106224

I'd like to guage how many people would be interested in this and to get to the bottom of exactly what problems are in the way and how to overcome them.

 

[944 man]

Have you considered Simtek?

 

[barks944]

Thanks I'll take a look.

 

[944 man]

Id be interested to know whether Dave Wlaker has any experience with 944s too: as I was considering an Emerald after (previously) giving up on a MS.

Simon

 

[barks944]

I emailed him and he said he had "some success" converting his 924 turbo and had someone working on a 944. The ECU supports inductive sensors so I'm wondering if it couldnt be re-programmed to accept the standard crank sensors on the 944. This would certainly make life a lot easier. I'm sure it would be possible to do it's just wether he would be willing.

 

[944 man]

S1 931s dont have an ECU at all and S2s have a very simple ECU that doesnt have anything in common with our Motronic IIRC... Itd be appealing if he could guarantee a turn-key solution. Adding a trigger wheel to the front of the engine isnt a massive chore (and because ditching the Bosch AFM and moving to a MAP is desirable I wouldnt neccessarily expect all of the original sensors to work, althoug itd be reassuring to start with): the thing that puts me off is knowing that Id be ploughing my own furrow.

 

[barks944]

I agree, I would want some support from the ECU supplier especially considering with a propriety solution you cant change any of the internal code.

Adding a trigger wheel to the turbo might be an issue due to the number of pulleys, its pretty cramped around that area of the engine. And I dont see why the existing sensors can't be made to work, they certainly would be adequate if we dont want sequential injection and are happy keeping the distributor or switching to wasted spark.

I think in terms of standard sensors we could use the coolant sensor and the crank triggers. We would need to add a minimum of IAT, MAP and TPS. I think we could use the existing loom for these sensors. Other sensors can be added for additional functionality.

 

[barks944]

I hope Hartech starts making linered 3.0 litre blocks. A 3.0 litre block with a standalone EMS would really keep these cars going and would produce some pretty awesome results.

 

[333pg333]

I am ever waiting for my motor to be finished that has the LINK G4 Extreme. Have you been quoted prices Tom on one of these yet? I know that there was a good deal to be had, but you would have to buy the unit from the US. The advantage of this would be that you will have some base maps.

 

[barks944]

Its about £1200 I think. How is your build going? What sensors are you using? Did you fit a crank trigger?

 

[Indi9xx]

Going standalone is a nightmare... The biggest problem is Porsche take prototypes around the world to different environments for a reason. With stand alone, getting the car to run is one thing with a few technical hurdles to cross, getting it to run well at all throttle positions (or boost levels) and engine temps is another.. But the real pain is tuning it for unusual conditions, such as hot starts (of various cooling down periods) and freezing cold mornings for startup and super cold running.. All these things can turn a well running car into a kangerooing, non starting nightmare for some conditions, until you get out the laptop and alter some figures.

From experience, the biggest issues are getting a package to work, getting a good base map for basic running and then keeping a laptop in the car over the first year or so, so on that annoying time in a petrol station it refuses the hot start, you can bump the maps entries up and down to get it to catch (if it has not completely flooded at that point)

This is why for all cars except extreme tuned examples, we tend to use a standard ECU as the starting point and at one end of the scale of tuning, use off the shelf or custom made chips to provide a package, and at the other end of the scale use a MAF with a mappable ECU signal interceptor/manipulator to allow laptop tuning.

But for those who are contemplatingomeone is already working on a kit for standalone engine management for the 944.

The ECU is not a rubish off the shelf item, but the same item used in several high end super car models and by high profile motorsport teams.

Part of this persons plan as far as I know is to have it as a plug and play solution, plugging into the original harness via an adapter harness with a couple of extention looms and parts that elegantly bolt onto the engine to replace standard parts, and comming with a basic 944 generic map which will see you (in theory) up and running and in the ballpark from the word go.

So if your thinking of stand-alone, there is something on the way taylored for the 944 range, so you might be better off waiting.

 

[barks944]

Thanks for the info John. Sounds like it will be a good solution do you have any info on cost/timescales/features?

I was thinking that with modern ECU's things like cold start and to some extent tuning could be performed by the ECU. An algorithm to detect failed start and adjust enrichment automatically should be feasible. Some of the ECU's I was looking at and can auto tune using the feedback from wideband sensors, I'm not totally convinced of how effective this would be in practice but it should work if done properly.

 

[944 man]

In my experience, 'autotune' will get you in the ballpark (ideal if you dont have much of a base map / starting point), but it wont win the game for you...

 

[JamesO]

The biggest hurdle with standalone is the speed/ref sensors, they can be used as I have but I dont know about other ECU's.
This is a trigger wheel you can buy from trigger-wheels.com.
I decided not to use it as it means losing the power steering pulley. It is possible to fit the pulley with a washer but then the belt will run out of true and I can't see an easy way to move the pulley on the pump. Another solution but hard to do unless the engine is already out is fit a S2 flywheel as they have a more standalone friendly number of teeth, 60 rather than 130 on a lux or 132 on a turbo.

 

[barks944]

I could probably make something like this :

http://www.msdignition.com/Products/Accessories/Installation_Accessories/6301_-_LSx_Trigger_Converter-to-MSD_Ignition.aspx

To convert from the 944's native crank signal to a 60 tooth trigger wheel signal. That would be one option for producing appropriate trigger signals.