Benefits of Mapped Ignition

[dtype38]

On my race car I've got a standard Lucas dizzy with bob weight advance. It also has vacuum advance but that's not connected cos I'm running on Webers. I've taken the points out and fitted an optical "chopper" and amplifier for a good quality spark. But recently I've been contemplating going to programmable ignition. I've found a nice little system which simply replaces my amplifier and (after disabling the bob weights) will allow me to directly programme the advance curve. After talking to the bods, they suggest also using a throttle potentiometer input, for more versatile control (although not a vacuum sensor because of fairly high vacuum pulse in the inlet tracts).

Soooo..... any idea what sort of benefit I might see, and more to the point, is it likely to be worth the £500 hardware plus rolling road setup costs?

[R59]

You'll see the benefits on the dyno. You'll also see scary amounts of advance in some places!! It's amazing what you can do with a fully mapped system.

The bottom line - driveability will improve, through an increase in mid-range power = grunt!

Will it be worth it - yes.

Rob.

[I Cooke]

Sorry, slightly off topic, but,,,,,,,,

1. Has anyone here had any experience with "Megasquirt"

2. If so, is it any good and can it be used with a Lambda sensor on a "closed loop" basis?

3. If you map to something like 0.91 will you pass an MOT or is this unrelated?


First post,,,,,, wahoo!

[greenamex2]

No difference to the top end, assuming your existing dizzy is set for max power.

As Rob said, it gives the opportunity to reduce the size of any 'holes' in the power curve, especially those on partial throttle if you have the throttle sensor fitted.

I originally had a dizzy and weber's on my Corolla. I went for a prrogrammable ECU that could cope with both ignition and fuel but only had the ignition at first. They got upto an extra 20BHP in various places in the midrange with it.

Subsequently fitting the fuel injection improved things further but not quite by the same magnitude.

Still, it was good enough to drive the car iton central London AND race at the weekends!

Having said that the Corolla engine is a touchy little git at the best of times so I wouldn't your Jag engine to benefit by the same percentages.

[dtype38]

Hello "I Cooke" and welcome to 10-10ths. Don't worry about being slightly off topic for the mo. I know its a bit intimidating starting a new thread for your first few posts. I've heard of a Megasquirt, am not familiar with them. If no one posts a reply, try starting a new thread called "Megasquirt - Info Please" Google might also help

Anyway, back to mapped ignition.... All sounds good to me I really just wanted to hear that people had found real benefits in practice rather than just what the sales blurb would have me believe.

Next question.... My only experience on rolling roads so far has been a few full power runs and a bit of fiddling with the advance and fueling to get the best compromise between torque and power outputs. Soooo..... what's involved in setting up a throttle potentiometer?

[greenamex2]

The same only, in theory, 16 times longer. In theory you would play with the ignition timing at each and every RPM (usually about 16) and throttle position (again, usually about 16) until you got the best power for each.

In reality, on a rolling road at least, this is impractical/impossible so a decent operator (don't even get me start on THAT subject) will check full throttle by changing the complete curve a couple of degrees between several runs, compare runs, program in the best at each point and then check out a few RPM and position sites to get an idea of what variations off full throttle are required. Of course he will also ask you if you have any problems when driving the car.

That the benefit with ECU's, you get great flexibility but CAN spend far more time setting things up.

Ideally you would have the engine set up on a proper engine dyno. I baulked at the extra grief in doing this for several years. When I had no choice it proved to be well worth it, you get a much better job and don't trash a pair of tyres.

[R59]

I really must get my dyno installed.

I concur with Denis, the setup on a rolling road is only as good and stable as the foot that's operating the throttle.

Rob.

[dtype38]

hmmmm..... so anyone know a decent engine dyno in east London?

I may consider it, but personally I prefer to hear it's reaction to gear changes and throttle blips (I've got quite big accelerator pumps fitted). I'm not sure that would be so easy on an engine dyno.

[R59]

Yes.

In the Ilford / Rainham area... Track & Road Powerformance - not far from the Dartford Xing, off the A13 -

I'm trying to remember.... Steve Greenald - 07774773824, tell him Rob Compton (Nova GSi with very very dodgy throttle bodies sent you).

He knows his stuff! When I was in there last, he was busy installing two dyno's, to complement the rollers.

Rob.

[dtype38]

Thanks for that. I think my team mate may have visited there once so I'll ask him. Either way it's not far from me so I'll pop in sometime soon and have a chat. See what's involved in doing the bare engine, that sort of thing. :-)

[graham bahr]

Originally Posted by racing59

The bottom line - driveability will improve, through an increase in mid-range power = grunt!

Will it be worth it - yes.

Rob.

oh yes you should get al the above, you might even be able to hang on to the power a bit longer to, as you can add more advance at the top end, after engine pass the peak torque speed they generally respond well to a bit more advance, but you cant do that with a dizzy without getting too much advance at lower speeds.

go for it, thers no down side to mapped ignition if you exclude cost, even then it can be cheaper than getting a dizzy rebuilt and set up properly to suit your inividule engine, no off the shelf item can ever be 100% right

[Tim Falce]

Originally Posted by racing59

Yes.

In the Ilford / Rainham area... Track & Road Powerformance - not far from the Dartford Xing, off the A13 -

I'm trying to remember.... Steve Greenald - 07774773824, tell him Rob Compton (Nova GSi with very very dodgy throttle bodies sent you).

He knows his stuff! When I was in there last, he was busy installing two dyno's, to complement the rollers.

Rob.

They are at Wennington, not far from the place you MOT'd your motorhome Ken.
Eric has used them a few times, I will let you know what he thinks of them.

[dtype38]

Originally Posted by graham bahr

go for it, thers no down side to mapped ignition if you exclude cost, even then it can be cheaper than getting a dizzy rebuilt and set up properly to suit your inividule engine, no off the shelf item can ever be 100% right

In my case its even worse than that. The dizzy I had exploded (screw fell between the bob weights) so I had to rebuild it using another shaft assembly. That one had the weight stops in a different postion so my timing was going up to 42deg adv at full load. I had to reset my static down from 14 to 8 to compensate. Which, come to think of it, may account for the big shift in my torque curve. Either way, it needs something doing with it

Oh, and thanks Tim.

[I Cooke]

For setting up a throttle pot. it needn't take 16 times longer, in fact barely twice as long if done by an experienced person. You only need to swing ignition and check fuelling at a few sites at each throttle opening (say every other site) and interpolate the rest of them. A quick look at the 3D map will highlight any "anomolies". Remember as well that you can't map all the way down to 0% throttle because the engine will stall and you can't map an unloaded engine on a dyno.

[Tim Wilkinson]

Originally Posted by racing59

Yes.

In the Ilford / Rainham area... Track & Road Powerformance - not far from the Dartford Xing, off the A13 -

I'm trying to remember.... Steve Greenald - 07774773824, tell him Rob Compton (Nova GSi with very very dodgy throttle bodies sent you).

He knows his stuff! When I was in there last, he was busy installing two dyno's, to complement the rollers.

Rob.

I've heard them be highly recommended too, friend of mine who races in CT swears by them. Sorted out a multitude of problems on his 205, they tend to give realistic figures rather than Max Power special 10bhp increase from a filter change type ones.

Again slightly OT, but does anyone have any experience of the MBE 906 ecu? Got a couple of them with my new engine, but have no idea what they control or who can re-map them if they need it.

[dtype38]

Originally Posted by teej

I've heard them be highly recommended too, friend of mine who races in CT swears by them. Sorted out a multitude of problems on his 205, they tend to give realistic figures rather than Max Power special 10bhp increase from a filter change type ones.

Thanks for that. Only problem I can see is that I've heard some places are the dogs danglies with a fuel injected, ecu controlled, hot hatch. Then you present them with an inline six with tripple webbers and a dizzy and they scratch their heads and say "what's that"

[graham bahr]

Originally Posted by dtype38

Thanks for that. Only problem I can see is that I've heard some places are the dogs danglies with a fuel injected, ecu controlled, hot hatch. Then you present them with an inline six with tripple webbers and a dizzy and they scratch their heads and say "what's that"

phone around and make sure you use someone who is familiar with the system your gonna use, ok that wont help if they have never seen a jag or webbers before but your be half way there.

can remember but have you already go your ecu?

[greenamex2]

Aldon's are still up on Weber and dizzy's. And the last time I was there they still had their distributor advance curve calibrating machine.

[AndyV]

I run my 4 clylinder Triumph Spitfire with a lucas dizzy, twin dellortos, Luminition ignition and have a Dastek Unichip piggyback mapped ignition module fitted.

The mapped ignition smoothed out the power curve, gaining power at all rev ranges upto the maximum where there was no gain. It was a godsend when fitted as I had a massive dip on power at about 3500-4500rpm and the mapping made it manageable.

I got the whole lot done on the rolling road in 2002 for a fixed price of £650 plus the fettling and fitting of a throttle pot.

So all benefits and no downsides, except for the fitting bill of course.

Cheers
Andy

[dtype38]

Denis, it was Aldon who did my fist dizzy and a very good job too. Worked great until I destroyed it, but now I'd like a little more control for when I change carbs/cams/compression etc.

Graham, Andy, I haven't actually got an ecu yet. I was thinking of using the Luminition ecu which replaces the basic amplifier on their Performance Ignition System. I'm very interested in what you have though Andy. It didn't occur to me there was anything that could be "piggy-backed" in that way, although I have heard of something like it now you jog my memory.

I just checked their website and the blurb doesn't seem to say much about programming them. Was the rolling road you went to one of their dealers? If you want to change anything, do you have to go back to them or do you have the programming software?

[graham bahr]

Originally Posted by dtype38

carbs/cams/compression etc.

Graham, Andy, I haven't actually got an ecu yet. ?

i would contact dave walker at emerald and have a chat about one of there ecu's, having used an emerald ecu for many years you could say i'm bias'd, but i would strongly look at one, not only is dave walker down to earth, and still charges the same that he did 6 years ago for rolling road time, he's well used to jag engines and webbers obviously preferrs throttle bodies for all there benifits, if you havn't bought your carbs yet i would look again at buying bodies, they are SO SO much better than carbs. he's probably not local to you being based near snett, but last time i poped in to see him he was mapping a car that had come all the way down from knockhill! and you cant be that far away!

[dtype38]

If you're talking about the Dave Walker that consulted for "Car and Car Conversions" for years then

Snett is a good couple of hours away from me trailering the car, so I might check out the Rainham one first as that's only 1/2 hour away. I have been using BHP at Byfleed who do lots of mini stuff and seem good with Webers. I've been very happy with them, so I'll have a chat with them as well before deciding.

As for the throttle bodies..... arrrrrgh, indecision threatens...... Nope! Mind is made up, I'm going with the Webers. If I wanted modern I'd buy a Radical

[graham bahr]

Originally Posted by dtype38

If you're talking about the Dave Walker that consulted for "Car and Car Conversions" for years then

Snett is a good couple of hours away from me trailering the car, so I might check out the Rainham one first as that's only 1/2 hour away. I have been using BHP at Byfleed who do lots of mini stuff and seem good with Webers. I've been very happy with them, so I'll have a chat with them as well before deciding.

As for the throttle bodies..... arrrrrgh, indecision threatens...... Nope! Mind is made up, I'm going with the Webers. If I wanted modern I'd buy a Radical

yes i am, i know he'd be a bit of a trek for you, mind you when his rollers were in brixton i used to have to leave home at 5.00 am to hopefully get to him for 9.30-10 even then i was late sometimes

[Tim Falce]

Originally Posted by dtype38

Snett is a good couple of hours away from me trailering the car, so I might check out the Rainham one first as that's only 1/2 hour away. I have been using BHP at Byfleed who do lots of mini stuff and seem good with Webers.

I would think Snet is quicker for you to get to than Byfleet and probably not more than 20 miles further when you use the M25 going to Surrey.

[AndyV]

Originally Posted by dtype38

I'm very interested in what you have though Andy. It didn't occur to me there was anything that could be "piggy-backed" in that way, although I have heard of something like it now you jog my memory.

I just checked their website and the blurb doesn't seem to say much about programming them. Was the rolling road you went to one of their dealers? If you want to change anything, do you have to go back to them or do you have the programming software?

OK a bit more explanation of my set-up. I have Luminition Performance Ignition System with an optical chopper in the dizzy, I'm not sure if the Luminition module qualifies as a ecu I think it is more of an amplifier like yours. There is certainly no advance or programmability function in the Luminition. The distributor is still used to provide the spark but vacuum advance is removed with the base pinned.

The unichip module interrupts the feed from the Luminition module to the dizzy and also takes signals from the coil and a throttle position sensor (mounted on the end of the carb throttle spindle). I belive the way it works is that the luminition module sends it's signal to spark which is interuppteted by the unichip which in turn takes the inputs from the luminition, coil and thottle sensor to identify from the map what the advance should be then sends the output to spark. (This may be overly simplified but electrionics are not my thing)

I do not have any programming software, my view is that any change in the ignition settings would effect the carb settings and as I do not have any expertise in how to set up carbs I leave well alone. After engine rebuilds I just take the car back to the rolling road and they check or re-set the mapping as required. It normally only needs a 2 hour session which is not much more than it took to twiddle the dizzy before I fitted the Unichip. All the tuner does is sit in the car with the laptop and run through each rev step adjusting the timing to get max performance all the way through the range (after sorting the carbs and fuelling of course).

With my time between rebuilds of 1-2 years the expense is manageable and when prevoisly skint I have just reconnected the ignition after a rebuild and ran without a re-tune and it has been fine.

The rolling road I use is Millway Sport in Andover and the tuner's name is Hedley, I think they are Unichip dealers. I do not believe their usual business is race cars, more in tuning fast Toyotas, but I have been very happy with their work (I was the Triumph race series champion last year).

My next development step is to remove the dizzy altogether and replace with a standard ecu, crank sensor and coil pack perhaps from some sort of ford. The unichip can then be re-programmed to suit this set-up so will keep costs down as I will not have to change the mapping hardware.

Cheers Andy