Pete Boole wrote: ↑Tue Oct 10, 2023 21:55
I'm also considering using the Emerald ECU for my project - I'll be interested in how you get on with it. It's a good price and extras like a pigtail loom aren't ridiculously expensive. I spoke to them a while ago and they are hoping to include knock control later this year as well.
Pete
I've fitted Emerald ECUs to a number of cars over the years, the first being an M3D which was the predecessor to the K6.
The only criticism I have, and it applies to all aftermarket ECU vendors, is that I'm not terribly keen on their looms, hence I always make my own. The reason for my dislike is the type of cable that they use for analogue sensors which are susceptible to noise. Rather than traditional cable I always use Raychem Type 44 screened twisted pair/triple/quad with the all the screens tied down to a single star point.
Years ago, when I took my first car to Dave Walker at Emerald for mapping, he expressed some surprise at the techniques I had used, but then complimented me that mine was one of the very few kits cars that he had ever mapped which exhibited absolutely no signs of susceptibility to electrical noise. Praise indeed, so I've used the same principles ever since. Obviously in a car with a fibreglass body, the elimination of noise is even more important.
My dilemma at the moment is over the choice of throttle bodies and size: I understand that the existing Dellorto carbs are 45s, which I assume are fitted with 40mm choke tubes (can anyone confirm this, please?).
When converting to EFI there's obviously no point in fitting anything larger than this, so I shall probably buy 40mm throttle bodies, which will maintain a higher gas velocity at low throttle openings, than would 45mm bodies.
This coupled with the ECU's ability to finely control fuelling and ignition timing will result in far improved low down torque and responsiveness than a traditional carbs/dizzy set up.
There is a down side: when bolting 40mm bodies to an inlet manifold designed for 45mm carbs, there will be a 2.5mm 'step' at the carb/body interface. That may be enough to produce a pulsing air 'resonance' at one engine speed, but will be obvious as soon as we start to map it.
I can't decide whether to simply ignore the potential for this, or whether to build up the inside of the manifold with a bead of TIG, and then grind it back to perfectly match the new bodies.
The second dilemma is over the choice of manufacturer of bodies: my first ever set were home made, following an article in C&CC by the aforementioned Dave Walker, by machining down an old pair of Dellorto carbs, and filling all the superfluous holes I made a very acceptable set of bodies which I used for many years until I sold the engine complete with EFI set up.
Subsequently I used the de facto standard Jenvey throttle bodies, which are perfectly fine, but not cheap at £700 or so for a pair with linkage and fuel rail. Given that the design hasn't changed for 20 years I really think that Jenvey are kicking the behind out of the price, for they must surely have recovered the original tooling cost by now.
More recently I've seen reference to 'SherryBerg' which appear to be very similar (identical?) to the Jenvey offering, but obviously are made in China. By comparison, they retail at around £280, so I've a good mind to try them and see what the quality is like.
I'd be interested to hear whether anyone has experience of these...?
