JamesG Posted December 3, 2007 Share Posted December 3, 2007 I went down to Mountune Race Engines in Essex today for some engine dyno training. I don't map engines for a living, but I write embedded software for motorsport ECUs, so it's useful to get a better feel for how people use the software I write. We spent the day setting up the maps and then mapping a Ford Zetec engine. The engine itself was all ready (apart from a couple of sneaky faults induced by my boss to test us!), so we concentrated on configuration of analogue inputs, engine configuration (number of cylinders, firing order etc..), crank/cam setup, and finally the fuel and ignition maps. It's surprising just how much setup is required before the engine will even start running. There's literally hundreds of maps (many of which I've written myself) and there's just so much that can be set incorrectly that will prevent the engine from running. Likewise, if something on the engine has a problem, you can spend ages thinking the ECU is at fault. In the afternoon we set up the base fuel map - the dyno allows you to dial in a maximum engine speed and it will put sufficient load on the engine (via a water brake) to hold it at that speed. At each engine speed breakpoint we stepped through the load breakpoints and checked the lambda reading. It's very quick just to add and subtract fuel in the correct location to get the right air/fuel ratio. Then we did some brief setup of the ignition map. The dyno displays the horsepower in KWatts and by increasing the advance, you can generally see the power increase up to a point. I meant to take some pictures on my phone, but completely forgot! One thing I was wondering, I know several people on this forum manage to map their Supras on the road. It sounds like it would be incredibly difficult to do in that situation. Do you have to do a lot of left-foot braking to stay at certain sites? Maybe it's easier if you are just making minor adjustment rather than mapping from scratch. Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 4, 2007 Share Posted December 4, 2007 Engine dynos are totally in a class of their own for nearly all mapping and general development work, IMO. To me this post of yours is very illuminating, please kep us updated on how you feel and get on with this Thanks. I agree, road mapping is a dngerous nightmare, as are inertia type rolling road, for mapping. You need to be ble to hold any load / RPM / boost level safely. Link to comment Share on other sites More sharing options...
Ryan.G Posted December 4, 2007 Share Posted December 4, 2007 Engine dynos are totally in a class of their own for nearly all mapping and general development work, IMO. To me this post of yours is very illuminating, please kep us updated on how you feel and get on with this Thanks. I agree, road mapping is a dngerous nightmare, as are inertia type rolling road, for mapping. You need to be ble to hold any load / RPM / boost level safely. I agree Engine dyno's are great yes espically for Normally aspirated engines but with Forced induction motors you cant just say hold 1.3bar at 5000rpm for a couple of minute while you trim the fuel and Ign like you would with an N/A. Load cell holding on a dyno dynamics or a Dastek is not as good as an engine dyno but still very good for most applications and no way a nightmare. Ryan. Link to comment Share on other sites More sharing options...
Digsy Posted December 4, 2007 Share Posted December 4, 2007 Engine dyno is the only way to go - if you have the luxury of having access to one. You mentioned fuel and spark. Did the engine you were working on have cam phasers or a variable intake system or any other gizmos? The more variables you add, the more of a nightmare mapping them becomes Link to comment Share on other sites More sharing options...
JamesG Posted December 4, 2007 Author Share Posted December 4, 2007 No, the engine had no variable valve timing. I think the turbo had been removed too to make it easier for us. It was mainly a training and usability exercise and we certainly weren't producing a finished map, but I was aware that there needs to be further tweaks to the fuel map when you adjust ignition timing, injection end angle, vvc etc.. It's satisfying to see the engine running nicely with my code in The ECU I work on is now used on many of the major race series around the world. It's even used on the Caparo T1. Probably the biggest bit of work I've done is a complete fly-by-wire throttle implementation - it can be set up to run almost any system within certain limits, and it has *lots* of error checking! Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 4, 2007 Share Posted December 4, 2007 There was a very interesting article in a recent Racecar Engineering issue about how Motec have worked hard to safely implement FBW in their latest software. I was amazed to what lengths makers go to error check, when I recall how frayed throttle cables used to make life interesting for drivers of late sixties and early seventies British cars I always think the Pectel software is more intuitive than the Motec stuff, to a novice like myself. You can use a mapping box with Pectel, can't you? I REALLY like the multi input mapping boxes from EFI Technology though, just wish I could afford their set up Link to comment Share on other sites More sharing options...
edge Posted December 4, 2007 Share Posted December 4, 2007 Ive heard nothing but good things from mountune. They build rally engines if remember rightly. A close friend of mine used to work for roush and they used them too. Infact is it the brentwood branch in the roush building as they had merged not so long ago. Link to comment Share on other sites More sharing options...
JamesG Posted December 4, 2007 Author Share Posted December 4, 2007 Yeah, I read that article recently. It should give you a pretty good idea of some of the issues I had to deal with. By mapping box, do you mean a box with dials for adjusting fuel and ignition? If so, we have something similar but I'm not sure it's in widespread use. Edge, I think Roush own Mountune. Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 4, 2007 Share Posted December 4, 2007 Yeah, I read that article recently. It should give you a pretty good idea of some of the issues I had to deal with. By mapping box, do you mean a box with dials for adjusting fuel and ignition? If so, we have something similar but I'm not sure it's in widespread use. Edge, I think Roush own Mountune. Yes, years ago Motec offered something similar, but no longer. I think it was to test the water and they deemed it not popular enough. DTA offer one, and think MBE, too. You set fuel and ignition at the current load sites by rotary dials, and then press the Input button to load to the ecu or map if offline. EFI Technology have up to six rotary dials, for boost, accel enrichment, blah blah, software configurable. NICE Link to comment Share on other sites More sharing options...
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