ignition coils at high rpm

[millsn]

No particular application in mind, anyone out there with a modified K or similar? Just a thought but in these days of multi coil engines, is there any advantage of fitting a high revving engine with one coil per cylinder to improve spark availability?

[Peter T]

No, unless it is a very high revving 10,000 rpm plus or has exremely high combustion pressures.

Fitting individual coils to race engines allows individual cylinder trimming which is why they fit them.

 

 

R500 260 BHP Mango Madness CAR NO-37

[millsn]

What's individual cylinder trimming then?

[Peter T]

Something that race cars use. You do need a trick ECU like a pectel, it basically is mapping each cylinder for fuel and ignition requirements. Formula 1 stuff.

 

R500 260 BHP Mango Madness CAR NO-37

[dannylt]

Pretty sure many ECU's allow it these days, including the standard Emerald. Certainly for fuelling anyway. And I don't see why you need multiple oils to allow ignition trim.

[Peter T]

Er no the emerald does not have individual trimming, it only is on very high end ecu's costing £1K plus.

 

R500 260 BHP Mango Madness CAR NO-37

[dannylt]

I refer you to http://www.emeraldm3d.com/em_k3.html

 

Individual cylinder trims

 

The K3 ECU can now trim cylinders on an individual basis allowing simple calibration of unmatched injectors or fuel and ignition trims to suit individual cylinder efficiencies. Each cylinder can be trimmed with positive or negative gains.

[philwaters]

Not sure - I think it may have a half way house solution of applying an overall gain per cylinder, depends how you read the following:

The K3 ECU can now trim cylinders on an individual basis allowing simple calibration of unmatched injectors or fuel and ignition trims to suit individual cylinder efficiencies. Each cylinder can be trimmed with positive or negative gains.

See here - new K3

I'm waiting for mine to come back from being upgraded

 

Phil Waters

[dannylt]

Why is that half way? I got my K3 back a while ago, but I think they have a huge pile of them - they should have charged more for the upgrade

[Peter T]

*thumbup*Ok it does allow some trimming, clearly times have moved on, but it is nowhere near as detailed as the high end ECU's. This seems very good value. Thanks for bringing it to my attention.

 

R500 260 BHP Mango Madness CAR NO-37

[philwaters]

Well I though true cylinder mapping was where you have a map per injector and spark plug - then you just run effectively 4 maps at once (or 8 in F1 ).

If you are simply applying a gain for a cylinder then you are just adding a multiplier to a 'base' map which isn't going to give you the same level of control as an individual map. However, it will correct for a slightly different injector, etc.

 

Now, for the likes of us and our funny little cars, I doubt more than a couple of percent will even use the gain function as you'll need a AFR boss in each exhaust primary and a few days on a rolling road.

Might be talking a load of rubbish - until I see the K3 software I'm just trying to read into that statement. I know I won't be using it on my humble engine though

 

Phil Waters

[Peter T]

Yes it is not as good as the best, but it might allow some small adjustment. Pity it only loggs every 500RPM though.

 

R500 260 BHP Mango Madness CAR NO-37

[millsn]

My basic map still has work to do to finish it a year on! Lord knows what I'd do (or where I'd start) trying to map each cylinder!

[philwaters]

MOVABLE SPEED SITES

 

Emerald has always been proud of the speed capability of the system. Previously we had 32 speed sites at 500rpm intervals giving a total rpm span from Zero to 15,500rpm. The system has been bench tested on a simulated 36-1 trigger wheel to a staggering 44,000rpm - before it started to lose accuracy! We were confident that our 15,500rpm rev limit was no idle boast but to the best of our knowledge nobody has ever made use of it. Users were therefore asking for more speed sites over a lower speed range.

Consequently the K3 software package allows you to move the speed site position; which means you can shuffle the sites down the rpm range and have them anywhere you like. We wanted to give even the most demanding customer no cause for complaint so the resolution on site setting is one rpm (1 rpm). You can space them anywhere you like, even or uneven and all speed related events, like warm up tables, ignition sites, etc, move position to stay in alignment. This means you can move sites half way through mapping and carry on as if nothing had changed: practical as well as clever.

 

FLEXIBLE SETTINGS

Movable load sites

 

It’s the same story with load sites. Rather than having them fixed you can now move them to a resolution of one percent (1%) and with so many new throttle body designs coming onto the market this allows you to set up the maps for traditional butterfly bodies or roller barrels – whatever the design. Should you feel the need to experiment you can have different speed and load sites on each of the three available maps.

Load can also be read from a manifold air pressure sensor rather than throttle angle simply by changing the software configuration.

---

 

Sorry Peter 😬

 

 

Phil Waters

[dannylt]

Right - you could change the load sites etc. pre-K3 too - had to do it for my engine. And there is no technical difference between an adjustment per cylinder vs seperate maps - it's just operator convenience. Of course, given it's all wasted mapping time everytime you change something physical, it's hardly worth bothering with for us! But it's useful to do things with the middle hotter cylinders if it's borderline for safety.

[dannylt]

PS Just checked my old MBE 973 ECU, and that offers individual cylinder trims for ignition and fuelling too. At 1000rpm increments, though no idea if that's configurable - I know the load/rev sites are.

 

[AMMO]

Nothing wrong with conventional coils in my opinion. When we ran a Pectel T6 on the Superbike Suzukis we dumped the individual CDI coils and fitted conventional inductive double ended coils with HT leads as the Pectel could not run CDI. The bike still revved happily to over 15,000 rpm with 15:1 compression ratio.

 

On the Duratec you could run the individual coils but I still favour the conventional setup as there are bonnet clearance problems in Caterhams with the individual on-plug coils. If there were no clearance problems I would run whatever made the installation simpler as I don't think there is any difference at all. The gains from individual cylinder mapping are small and for the use we are putting engines to I think not neccessary.

 

I was running race bikes with individually mapped cylinders in the mid 90's. Worth having if you were chasing a tenth of a second a lap. For road use I think it is too much hassle.

 

 

AMMO

 

Edited by - AMMO on 28 Mar 2007 08:24:59

[oilyhands]

The Emerald had trims well before the K3 implementation, first used around 2 years ago on Steve Butt's engine which had unequal length trumpets and consequently changed VE for two of the cylinders.

 

Oily