Gotta love modern technology.
After feasting on a McValue meal the other night, the Editor and I decided to set out into the darkness to tune the on-loan aftermarket EFI computer fitted to his car. Just a spur of the moment decision - no need to change into overalls or to bring along hand cleaner. We just plonked our BigMac-stuffed bums into the front seats and did all the 'hard' work from the comfort of well-bolstered seats.
The GT-R-matched APEXi adjustable ECU had taken literally two minutes to install in the passenger side footwell - perfect for us burger-biting slobs. After being plugged in, the new brain fired up the engine without hesitation and then started throwing its pre-mapped brainpower around. All it then needed was fine-tuning to suit the individual characteristics of this particular RB26DETT. Earlier that day we'd dropped into Allan Engineering - a business with a lot of experience in setting up modified RB-engines - and they'd kindly supplied us with some ball-park ignition timing figures. That way we had some maximums that we knew to be wary of exceeding, at least.
So time after time we drove the Skyline up and down the quiet main road; up and down, up and down, up and down, up and down - you get the picture. Different throttle positions, different speeds, different manifold pressures. A couple of times a car-load of the curious pulled alongside to have a sticky-beak as we kept eagle eyes on air/fuel mixtures, ignition timing, boost and rpm all while exchanging insightful comments on each. Speeds ranged from a dawdle to full-bore acceleration down the four lane road. Helluva weird way to spend a late Friday night, huh?!
Kicking off at the low-rpm and load scale we plugged in the data and gradually worked our way up to full throttle and max boost - that's the safe way. But it did take a couple of hours of entering and testing and revising. I soon 'became one' with the easy to use APEXi hand-controller - we became very good friends indeed. Just as well, because my fingers were very active... If (when?) I entered something that turned out not to be the best, a few pushes of the little clicky buttons eliminated the problem. Never before have I seen engine operating conditions so accurately and easily specified - this system totally kicked arse!
Midnight drew near and we were getting close to the right numbers - just a few more adjustments to be made. We hooked into a parking bay and I began to enter the new batch of figures, a process that takes a few minutes. As I did all of the work, Julian wound down his window and stared vacantly out into the night. After the right number of minutes, his turbo timer brain instructed his hand to turn off the ignition. Which it then did.
Ooops! The APEXi hand-controller's screen went blank as power was cut to the ECU. Gasps of horror came thick and fast. "Oh, God we've lost it all" I thought (along with a few other colourful phrases!), thinking of the last four hours of detailed work. But as Julian promptly returned the key to its former position, the screen lit up in its up-dated state - each of the individual figures had gone into the permanent memory! Phew.
Finally, we concentrated on the really light load settings. Like when the car is sitting at a constant 60km/h and you ease your foot down. We soon found that the timing and fuel that you run at these loads can make a radical difference to performance. It was about now that we also discovered where major car companies throw all their money - into just this sort of detailed product development! Setting sensitive light load and rpm maps was by far the most difficult of all the mapping - and sometimes changes were so small you had to convince yourself you weren't just imagining them.
The end result is remarkable. The car has unbeatable throttle response, goes bloody hard and is trimmed out for frugal highway cruising - all without having to get out of the seat (except for a toilet stop - mapping is so exciting!). Sure beats farting around with screwdrivers and a timing light, that's for sure!
On the subject of programmable EFI systems, it's amazing the number of people who swear one brand is head and shoulders above the others. "Oh, my mate tried Brand X on his turbo rotary and it used heaps of fuel - it was crap", or "My car uses Brand Y and it hauls better than when it had brand Z in it".
The fact is, it's the programmable component of programmable fuel injection that is really important. If yours hasn't set up properly, get the adjustments made so that it is - if the car runs badly, the workshop should simply change the system's maps! Granted, some brands have more load points etc than others, but with enough time on a dyno and the road, a damn-near perfect result should be achieved. Especially with the current brilliant generation of quality programmable systems - they're all extremely competent.
There's simply no excuses for a rough runner - if the right information isn't stored in the computer's memory, it's hardly the ECU manufacturer's fault! Sure, some of the first-generation programmable ECUs can be criticised for their crude operation, but if you're still using one of those then you're starting off well behind the 8-ball.
However, the top (and usually most expensive) brands will only show their superiority if the tuner knows exactly what they're doing. So a MoTeC system, for example, might drive like a dog if the tuner who mapped the ECU had felt the urge for an early lunch. That's the scenario where you've paid real money for superb management, but you get a poor result because there hasn't been enough good mapping carried out. You might as well have kept your 3-or-so grand in your pocket.
Recently we heard one guy's story. His highly modified aftermarket EFI car was running a bit rich, so he went off to a hi-po workshop for their expert guidance. Only problem was, the new company didn't deal in the quality engine management system that was already fitted to the guy's car. So did they send him back to where he'd had it first mapped? No. Did they get the software to allow the re-mapping of the system that was already fitted? No. What they did was convince him to splurge out another four thousand dollars on one of the systems which (surprise, surprise), they happened to sell! And the reason that the first ECU was no good? - "Oh, that brand always runs rich."
Ahhhh...
[A full review of the APEXi ECU will appear in AutoSpeed shortly - Ed]
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