Mappable ignition for KJet Mk2

I have an 85 KJet mk2 which is a TSR 1900 block with pack D head which is making 158bhp according to the graphs that came with it.

The ignition is currently the standard setup with the vacuum line on the dizzy blocked off, which i assume has been done as the car has a rather lumpy cam.

So in order to get the best out of it, I am looking into some sort of mappable ignition, I don't want to convert the car to full EFI, as I want to maintain a degree of originality.

So I was think of robbing my old car of the MS ecu and digging out a PB dizzy.

My questions are is it as straight forward as the old car was a CE2 car with the ignition module under the rain tray, this car is a CE1 and I haven't looked to see it it has the same module.

I can't for the life of me get my head around how i did it last time, but I'm think the reference must come from the hall sender in the dizzy, which is setup with the timing light?

Help guys it's been a while, and I can't seem to find any evidence of someone else converting a Kjet for ignition only.

 

Trigger wheel on he crank and just run the ignition side or maybe megajolt?

 

Thing is the blue car doesn't have a trigger wheel, and I have 2 Megasquirt ecus so if I can use one of them.

 

Fit one to the pulley

 

That's a bit embarrassing, I comment on that thread.

 

RJ do CE1 cars have the same ignition module and coil wiring?

 

I've just sent a distributor off to H&H to have it recalibrated to suit my Pirelli MK1 engine I've just built.

It's built for fast road, has an 1847 big bore, high compression bottom end on steel rods/KR cross drilled crank etc. with an ultra big valve G60 head, fully ported with arrow solid lifters and lash caps, but a reasonably soft (for me) kent GS2 290 degree cam, 40 dcoe's and the usual 4/1, big bore system etc. etc.

Its for a bit of fun and maybe some trips to shows etc. hence softer cam and smaller carbs.

However, as its for road driving as well as a bit of sport I wanted it quite tractable, hence the modified distributor.

The Guys at H&H said send the spec of the motor and they will re weight/modify the distributor to give an advance curve to match the engine spec. as well as ditching the vacuum advance kit.

Not sure how it will work, but as they were reworking it I took the advantage of using a later MK3 1800 distributor as it has an O ring machined in to the bore of the housing, so it shouldn't have that oil film around the distributor hole that the earlier ones get quite often.

Just fancied a sort of clockwork set up as JMR would say . Then was thinking it might be an idea for yours Alan, I'll let you know how mine works out. Quoted 50.00 + vat for the work, so seems ok.

 

Clockwork works!...

We sometimes re curve the distributor on the dyno if I've gone a bit overboard on the c.r relative to the cam, but theres no 'one size fits all' with them and they're still a one way street in regards to the curve.

On most though the std GTi distributor from a kjet car does a great job once set up...normally 26 to 32 degrees peak does the job...if you have a high c.r to the cam you'll be at the lower figure and a low c.r to the cam will see you at the higher figure....what it takes in the mid range around peak torque will decide what you can ultimately get away with.

I've found a basic balance with them now and run enough c.r to allow a decent amount of ignition...lots of c.r and less ignition isn't always the best way to go...but again it's dependant on the 'whole' spec...c.r, cam, cam timing, squish, fueling method, air & water temp etc.

 

You can get carbs, and breaker point/bob weighted dizzys to work and give reasonable performance that would have been acceptable in the early 90s.
However with programmable ignition, you can start to maintain combustion almost as good as a full on EFI car, providing the mixture control can meet LBT or economy set points for any load not just full load.

 

i never considered reworking the distributor, ill be interested to see how you get on tony.

i want to keep the engine bay looking period (so there will be no 20v, FSI's or VR's making an appearance) if i can keep the wiring down then the programmable ignition looks like a good option as i have all the bits already, even if i cant remember how i did it!! ill just have to take things off the blue car slowly and label them up as i go!!

 

My Megasqirt 1 is wired to take a signal from the KR dizzy hall sensor (I used a pull-up resistor).

I had it apart yesterday and diode 17 has a pull up resistor as well so I presume this is Spark Output to the Ignitor/ Ignition amp.

Megajolt may be the way forward, seems a waste using a Megasquirt just for spark output..

 

The thing is Keith I had the MS unit.

RJ now you have got me thinking...

 

I am not following your logic? Expand a bit.

You know better

If you are about period looks, then just build that without the modern performance enhancements.
If you want a performance jump, the you do it right the first time.

 

Sounds interesting!. Didn't realise you had 2 MS ecus.

To be fair the fuel delivery on K-jet wasn't that bad at all for me, drove very nicely.

 

As you should know from my postings on here, I know Alan quite well, having spent a lot of hours developing his 2.1 8v to run Megasquirt successfully, both on road and on dyno until we hit a wall for top end performance. Car felt stronger than a chipped ABF at lower revs and it is a shame we never really persevered to find the missing top end performance it should have had. My point is Alan is no fool to the benefits of an aftermarket and tuned SEM.
The 1.9 TSR 8v motor with '158bhp', even with a modern dyno will result in a healthy measurement over the 107-115bhp I have tested on stock 1.8 Kjet cars.
However any baseline has the added variability the engine may not be in the same '158bhp state of tune' post TSRs dyno plot.

I am not sure what control concern or engine performance limitation your idea attempts to over come, hence the reason I asked you to expand.

You are suggesting a lot of effort that no one has time to contribute (paid or volunteered) for very little gain to performance, when the current Kjet system seems very able to deliver to meet fuel flow demands ( at the time of the dyno plot) up to WOT.

 

Some interesting discussion. The reason for wanting to retain the kjet is for its period appearance, I haven't had a kjet car before so cannot comment on the way it delivers fuel or its efficiencies, the car isn't as thirsty as the old 2.1 and its more than the ~10% difference in capacity. I think can fit the PB distributor and wire up the MS unit and maintain the period look.

I don't want to mess with the look of the fuelling too much