Distributorless Ignition

[Brewster]

What's the best way to go distributorless? Preferably with some mapping function to tweak the curve to suit? I've read about MSD, but with mixed reviews.

Cheers.

[mycar]

MSD still requires a distributor but maybe with pertronix fitted instead of points.

Clewett Engineering offer electronic ignition options with matching crank triggers which do away with the distributor completely.

http://www.clewett.com/index.php?main_p ... ae9df0aef3

[Jonny Hart]

If you're still running a CDI, our CDI+ system will give you the mapping capability.

see www.classicretrofit.com -> products -> cdi+

[911hillclimber]

Having ummmed and ahhhred for years over this option, seems a lot of cost for very little gain unless you inject the engine as well.

Stand to be corrected.

[Brewster]

I struggle to understand how an XDi kit for our engines is $1300, plus shipping and tax when it lands (so £1300 effectively), and yet you can go distributorless on a Beetle or Mini or a couple of hundred quid. There has to be a better solution out there. It's not rocket science.

[Jonny Hart]

Having ummmed and ahhhred for years over this option, seems a lot of cost for very little gain unless you inject the engine as well.

Stand to be corrected.

More fuel plus more advance equals more power to a point ( and to the detriment of the built in safety factors of the manufacturer).

A lot of 911's (especially SCs) were timed very conservatively in the first place, give some more advance and some more fuel and there's a few more HP in there.

Now, you can all go out and twist your distributors another 5 degrees in advance and richen the mixture. Your car will perform better as you are bringing the advance in a bit sooner. Trouble is, you are moving the advance curve up and down rather than left and right so your car idles like a race car and is over advanced at higher RPM. The only way to move it left and right is 'recurve' the distributor weights/spring.

The electronic timing curve allows the curve to be exactly as you want and offers the ability to bring the advance back down again at high RPM. Weights/spring cannot do this as once they are thrown out, they stay out. This means that you can add advance in the mid range where you will really notice it and wash it off again at high RPM. Having another 10HP at 4000 RPM is 'worth' more than at 7000 RPM.

[MikeB]

Jonny

What's the performance difference between your product and the MSD ?

[yoda]

Would be good to see some before and after power curves as proof is, after all, in the pudding.

Thanks

[impmad2000]

If you want to get creative, looks at www.trigger-wheels.com . Mega jolt engine management uses the Ford EDIS module with a coil pack to give a fully programmable ignition, and crank timed, so rock steady. For a Ford v6 it's about £350. To adapt this to the 911, you need to mount the trigger wheel to the pulley wheel, and fit a VR sensor. And it's non-intrusive, just by swapping the ignition leads, it can be easy to switch back to conventional. Look at my Megasquirt conversion thread on how I made the pick-up bracket and trigger wheel.

[Brewster]

That looks like sound advice, Tim. I knew there must be a way of achieving it for reasonable money. It's amazing just how much mark up even aftermarket suppliers stick on just because it's Porsche.

[Jonny Hart]

Jonny

What's the performance difference between your product and the MSD ?

Performance is a big subject. Assuming you mean horsepower, any box that can be mapped in theory could match any other box. They are only tools to do a job after all. I haven't got back to back data against other products and being an engineer I won't speculate.

Other sorts of performance? Our system is specifically designed for the 911. It fits without modification and does not require swapping coils, leads or any other part. It will not fry coils or burn out rotor arms. Runs cool. 30,000 collective miles of testing.

Would be good to see some before and after power curves as proof is, after all, in the pudding.

Thanks

I posted this a while back, towards the bottom of the page:

viewtopic.php?f=1&t=53249&hilit=+retrofit

[Bruce M]

I have a small steel gear, a hall sensor IC and an old distributor. It some point they will become a "crank" trigger for efi.

[yoda]

Good results with the 2.7RS engine on the dyno. Most people would consider that pretty good value for +15 bhp.

[911hillclimber]

I once had all the parts for the ign without a distributor but you still need to map the lot and optimise it all, so you must add that cost to the parts.

I have spent a lot on r roads getting my carbs and ign to work, and in the end got more using a flow meter and colour tune!

To get just 10 or so BHP on an engine with 247 for £1000 falls short IMHO.

The technical side mind is certainly interesting and might be a winter project...

[MikeB]

The MSD 6AL Programmable can be yours for £400 landed in UK, so is the Classicretrofit unit at 1k+ VAT worth the extra?