DTA engine managment.
Turbo Mini Forums

Well actually I think DTA is more acurate...

The megajolt ignition map has a 10 x 10 grid.

The DTA can have up to 14x20.

Megajolt interpolates (or guesses) between the cells when you are not exactly in the middle of that cell. DTA does the same between cells but with more cells it doesnt have to guess as much as you can input more data. Making it more accurate and programmable. :)

Chris

Edited by 01smartc on 8th Mar, 2010.

Edited by jbelanger on 8th Mar, 2010.

http://www.jbperf.com/

Why do you need so many ignition sites in a map? Why make it complicated for yourself? after all, anything is going to be better than a dizzy.

Latest Vems thinking is a 16x14 fuel table, 12x12 ignition table and 10x10 lambda target table.

is it not a case of every little helps?

jbelanger you state that smart is trying to justify his dearer ecu, it looks the case that your trying to justifly your cheaper version aswell. evry 1 will surely have there prefurred makes and settings...

anyway can someone explain grids as i would love to know :)

im guessing a 10 x 10 grid means you have 100 different setting for different engine speeds and loads, am i thinking along the right rails here? if this is the case surely that means more settings will be better as you can optimise the ecu to different engine needs more?

please correct me if im wrong as im taking a wild stab at imagining what this means.

thanks. :)

Edited by Rick.SPI on 8th Mar, 2010.

In theory yes, the more cells you have and the more you can fine tune your engine timing for different speeds and loads. However, who actually goes to a dyno and loads the engine at all those loads and RPM and fine tunes the timing? No one unless they have an unlimited budget.

And even if you had the time and money to do so, you'd also need to adjust fueling to take advantage of all those timing adjustments and this is not going to be easy with a carb if even possible.

Finally, even if you did all this you'd probably end up with a table where you have some linear regions (or very close to it) which could be replaced by fewer points thereby making all the time and expense fruitless.

And I should add that I don't care what you or anyone else chooses because I have don't benefit in either case. I'm just trying to debunk a bunch of myths that are way too common on this subject. A big number of cells is a simple marketing tool for some because it's easy to assume that more is better and it's nice to brag about it. It's harder to explain and understand why it doesn't make any difference in 99%+ of the cases.

So go for the bling if you want :)

Jean

http://www.jbperf.com/

im not going for any yet. ive got to looks at the options hense the thread.

but i am saying he is justifying his ecu just as much as your justifying yours .

any more info is happily recieved... im learning a little haha :)

Edited by Rick.SPI on 8th Mar, 2010.

Ordered my dta s40 today :) mainly because it was highly recommended by my engine builder. Would be interested to know pro's and con's of different systems though.

2012 Avon class c 2nd place 13.8 @98mph

On 8th Mar, 2010 Rick.SPI said:
but i am saying he is justifying his ecu just as much as your justifying yours .

http://www.jbperf.com/

If there is ever a point that we are not going to agree on, then it is the choice of ECU.

Isn't table size more to do with resolution that accuracy anyway. As Jean says, no point in a big table if you do not need it.

How many rolling road operators work to less than 1 degree increments? My single experience of setting the ignition timing on the rolling road involved advancing the top line of the map by two degree increments and then backing it off two degrees when the last step did not make any more power!

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

I have spent a day on a rolling road tuing the injection on my mates Clan with megasquirt. Even with a 12x12 table there was way more sites than we could tune. I guess if you had a dyno and loads of time then gains could be made, but real world I would not like to start mapping any bigger than a 12x12 unless somebody was paying me. Maybe if I was a rolling road operator pushing DTA to my clients.....

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

I'd completely forgotten last night.....
I have it on my PC



..... Why ????

Because the hubby one one of wifey's friends has a DTA on his Lotus which wasn't running very well (to put it mildly) and last summer he found out what I was doing (with MS) so the Lotus ended up on my drive and the software on my PC.....

Personally I didn't like the software, but that's probably because I had become so used to Megatune/TunerStudio by then, but the functionallity seemed fine once you could find it.

The real issue though, wasn't the DTA itself, but the complete install.

It was total cowboy, plumbing, wiring, everything was a total mess and they hadn't even bothered with a MAP sensor, the fuelling maps were controlled by TPS only.

So my point is that it isn't just the choice of ECU, it's the quality of the whole package that counts, and this had been installed by one of the big Lotus tuning specialists.

Schrödinger's cat - so which one am I ???

Think thats where I might be biased ...

I have got my own rolling road to sit and do all the load sites! :) lol

Anyway I was just saying that although megajolt is very good for most applications (I cant see why anyone would want and more from a mini road engine ecu) It lacks the features I, and others require for race engines.

Things like launch control, shift cut, full traction control and realtime mapping

Chris

I doubt that any of the mainstream ECUs out there would disappoint. Being partly a software man myself I get a lot of people telling me systems are not intuative to use, but that is because complex systems are never fully intuative. Windows is not intuative, but we all KNOW how to use it. Sorry a bit OT.

I guess if I had more money I would go for an emerald, but as it it I am more than happy to enjoy the challenge of MS.

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

http://www.jbperf.com/

Edited by stevieturbo on 10th Mar, 2010.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

OK. well prices have put the DTA out now anyway haha.

price for the full lot in specialist components is around 400

price for megajolt is not yet found out.(any ideas on full kit prices?)

Thanks for the info, as you have stated it seems DTA is probably alot more than i need (at the moment ) considering the prices.

all this info is has been very valuable :)

Edited by Rick.SPI on 10th Mar, 2010.

Ignition map on that Rod is also a bit manky - far too rough should be more consistent and gradual

On 5th Sep, 2011 Vegard said:
I stand corrected. You should know

ah your in a completly different ball game then and guessing your runiing injection aswell?

Schrödinger's cat - so which one am I ???

doesnt the mjlt bouncing ball page update as you adjust it david ?

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

It does on my MS.

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

Apologies for my ignorance (and, incidentally for the apparent ignorance of my RR operator)Nic has now put me right on how to alter settings when running on the RR.

If and when I ever get the MJ up and running I will be able to use this information.