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Nodiz 3d engine mapping

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I have read somewhere (on the internet so it must be true :huh:) that most engine power on older engines is lost by worn distributor components and poor control of sparks through the rev range.


So as my chassis rebuild progresses and I start thinking about the engine rebuild and how to restore the 160BHP from the original engine; blueprinting seems expensive, reprofiled camshafts seem to be a big leap to a less refined engine idle, but better ignition timing seems to be the way to get best bang for buck. :2guns:


So this looked good and I'm convinced enough to have set my mind on this...

unless someone already has prior experience.


However the question I have is the choke... obviously the choke enriches the fuel/air mixture to make the car easier to start however would the same result be acheived by advancing the timing - (I read this somewhere too but I don't know why this might be true!)? This could be done on the 3D map and would mean I could dump the choke with the result that the car is easier to start?


So O.K. this is a really lazy question and I should research it more and it probably exposes my lack of understanding of the technicalities of the internal combustion engine but hey the only stupid question is the one that isn't asked. :no

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Richening the mixture helps starting by encouraging the fuel to evaporate.  When everything is cold, the fuel doesn't evaporate well.  Adding more fuel give more fuel vapour int the mixture.


Retard is often used for starting.  Over-advance can be a hindrance as it can lead to the engine kicking back.  The cranking speed is a lot less than the idle speed so the idle timing should be good.


To restore the power try regrinding the valve seats and setting the valve clearances properly.  Check the compressions and, like you say, check the ignition system is up to snuff.

S4 Elan, Elan +2S, Federal-spec, World Championship Edition S2 Esprit #42, S1 Elise, Excel SE


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Hi, I had a DTA S40 Pro ( ignition only fitted to my Excel SE 3 years ago.

The engine map, tuned on a rolling road who had experience of DTA, can be found on the DTA forum

The system uses a throttle position sensor (TPS) I.e. not a manifold air pressure (MAP) sensor.

I run standard cams and carbs.

I use the choke on cold mornings, and the DTA compensates for cold coolant and air. Starting is never a problem.

I would recommend you keeping the choke. If nothing else, you can simple leave it closed and never use it.

You can get a toothed wheel and sensor mount from LotusBits, who have installed a number of DTA systems on our cars.

Your choice of Nodiz appears to have a good set of features - I especially like the bluetooth link. Their history and some other forum feedback (Google 'nodiz reviews') have some 'interesting' observations.

The DTA option provides a good history of successful and reliable installations, a vibrant forum, and LotusBits can be a fall back incase anything doesn't work as you'd hope.

Installation, i.e. a clean power supply, earth, trigger wheel setup, wiring harness so that the toothed wheel signal is clean, tacho support etc can make the difference between a reliable system and one the works 'most of the time'.

As you might guess, I tend to err on the conservative side so absolute reliability is a high priority for me.

I'm extremely pleased with the DTA system, and a great fan of 3D mapped ignition.

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Did it release more power? The ease of starting is an attraction. My scimitar GTE was never a problem once I figured out the the choke had to be out and you had to pump the throttle 3 times blah blah blah... modern injection systems flatter us these days.


Releasing the power from the engine design is also appealing. I will be running with a standrad 5 speed elite gearbox and so can;t put too much extra power through it (unlike the getrag box).

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No more top end power, but then I didn't expect that as a properly setup distributor can be optimised for top end power.

However, low & mid range revs are much better. It is a more pleasant engine to drive everyday, especially around town. Lack of low end torque is a known issue with the Lotus 900 series and a mapped ignition seems to mitigate this problem.

As said above, starting is also much better.

A rolling road session lets you set the ignition advance for each throttle/rev configuration for best torque, which will be available over a small range of ignition settings. You can then back off the advance a bit, whilst maintaining the peak torque,  knowing you've got the best out of the engine without risking damage due to pre-ignition or other problems due to poor fuel, hot weather etc.

Also, if the rolling road guy knows the ECU and Dellorto carbs he'll be able to ensure the carbs are correctly tuned, and suggest alternate jets, if necessary. (My Excel SE has the idle jet increased from 55 to 58. Lotus used the 55 size to achive low emission goals, but it can cause a slight hesitation ~ 2,800 rpm unless everything is new and perfect. Moving up to the 58 size is a known fix by those who tune these engines, and removes this problem).

Not everyone agrees that a rolling road session is necessary. You can start with a base map, driven a bit, then modified the map, drive a bit more... etc

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There is a chap with megajolt on a 907 in a JH. He says it runs very well.


I have not heard of timing adjustments being used as an alternative to enrichment for starting, however if you are too greedy with your static timing on advance, your car won't start as too much advance doesn't help starting.


There are other alternatives. I am itching to hear from anyone who has used 123tune, although this retains the 'strib (albeit a nice new one on exchange with electronics inside) whereas some of the other alternatives go for coilpacks. You could argue that this is a good thing or a bad thing.

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Hear, Hear. on the rolling road. 


If you could get a before power curve for the engine and after power curve you would go a long way to understanding what you had and thus what you gained.  Also if you posted the before and after power curve printouts here on the forum everyone would cheer your name.


Also, you should keep the choke.  Cold engines need a richer mixture to start because the gas doesn't vaporize well in a cold engine.  You could start it by just judicious pumping of the accelerator pump, but with out a choke, you would be doing that pumping until the engine was warm.  Trust me the pumping method gets tired very quickly.



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I don't know about fitted but emerald do a generic efi kit  for around about £1700 inc   and   you will need a few extra bits.  Lotusbits recent quoted me £1300 plus vat for the DTA kit for mapped ignition BUT WITH the option to add efi at a later date. I think straight mapped without that option saves a few hundred.  Or there is the Aldon Amethyest for £180 that keeps the distributor.  You can add £80ish for a TPS or plug the vac advance straight into the amethyst.

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THe nodiz was £250ish but I guess tht would exclude the crankshaft sensor which would be a fairly cheap breakers special and the manifold alterations to get manifold pressure (my manifold has already been modded to provide vacuum fo rthe headlights it seems).


Personally I would like to do the rolling road before and after fitting but i'm want to get the engine bay resprayed and therefore the coil will go and be replaced by coil packs. The left over holes for coils etc mustn't spoil the paint job. I'm a long way from this problem though.

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  • 2 weeks later...

Re. 123 tune.   I've had one in my eclat for the past 18 months or so and it works faultlessly. Retail cost looks about £300.00. Which I think I've probably saved in fuel cost to date.  

Re. original looks, The distributor isn't a replica of the lucas, its slightly different, with a bosch cap. But its not visible, being hidden under the carbs. Other than that, there are no coil packs, crank sensors or boxes to change the looks.

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