pa_sjo

Don't the Weber ECU's have a more accurate crank position trigger arrangement than Autronic?

Chip

iTrader: (3)

4 teeth instead of 2, but that really doesnt matter, getting updated twice per revolution (once per cycle) is plenty for the ecu to know where the crank is at all times, as it projects an exact value based upon the last known position and speed (as does the L8)

foreigneRS

it's not always exact if it's projected is it? but close enough

ECU Monitor Enthusiast

iTrader: (1)

The L8 weber ecu's have a 4 microsecond hardware timer and after software processing, this gives a resolution of 0.25 degrees on ignition timing @ 8800 rpm.

Dont know about the internals of the Autronic but I would have thought it would be better.

As an example, my own design ecu had a resolution of 0.042 degrees @10000 rpm
Good resolution but, it doesnt make much difference in the real world. !

Having said that, 0.25 degrees is a very small amount and most tuners tend to stick to the nearest whole degree most of the time when mapping or halves at critical points.

Also, while a crank is at a constant speed from your perception, in fact its actual RPM is fluctuating a small amount positive and negatively.
To keep the software stable, all ecu's will measure the rpm and average out the value in order to smooth out operation.
This smoothing inherently leads to loss of crank resolution anyway. !


Fuel map resolution size makes little difference too.
No matter how small the maximum values are, the interpolation between the 4 points in a map wil always be calculated at a significant numeric magnitude higher before pasing the final pulse width value to the fuel injector.
What does affect resolution is setting the mapping scaling to the right size of fuel injectors.

Hope this makes sense ...LOL

Chip

iTrader: (3)

Lol, NOTHING is exact, even measured values, its exact the degree of accuracy it needs to be though.

ECU Monitor Enthusiast

iTrader: (1)

Spot on

pa_sjo

That's all good and well, but my point still stands, Weber is 'more' accurate at measuring the crank position as it has twice as many pick up points on the trigger. Any smoothing/predictive algorithm will be relying on frequency of input to provide a 'more accurate' calculation

CossieRich

iTrader: (1)

Nope, L6 mate

ECU Monitor Enthusiast

iTrader: (1)

You are correct to a point BUT the L8 has a slower "look ahead timer" so needs twice as much samples.

I would think the autronic at least has over twice the "look ahead timer" clock speed so less samples are needed.

In other words, it pretty much cancels out when comparing these 2 set ups.

pa_sjo

That's fair enough My comment was really just a semi-educated provocation designed to demonstrate that the blindly-lead may not know as much as they think they do!

ECU Monitor Enthusiast

iTrader: (1)

Ah ok.

People forget that RS500 touring cars in 1986 were giving out 500+ BHP on a L1 or L6.

Just think how much more BHP they "could" have had if fitted with a modern ecu

Mark Shead

So what happens when you put a 36-1 or a 60-2 on the crank,
You can also use 4 lugs on the Autronic set up you just change the position of the lead one.

Mark

ECU Monitor Enthusiast

iTrader: (1)

Mark,

More teeth will increase the overal accuracy to a point but all samples from a complete resolution are added up to proved the same total value in any one RPM.
This is true no matter how many teeth there are, you get the same value. !

More teeth does allow decel and accel rpm fuel enrichment to be more accurate

True ecu resolution is defined by the bit (or word) size of the time processor master clock frequency and how the software takes advantage of it.

Hard to explain in laymans terms but even a high resolution clock will only have a big advantage when using large injectors and very small numbers in the fuel map.

Most tuners scale the map (by default) to the max range of available fuel pulse time.

For the record I am in no way dissing the Autronic but the L8, old it maybe but it can still hold its own these days.
Access to mapping the L8 is its biggest dissadvantage to the L8 but if someone else is doing the mapping ... that doesnt matter.

Mark Shead

Also check what lugs are removed when using a Autronic on the stock 4 lug pully,
Yes 0dg and 180dg which at this point the ecu has already fired and the 90dg and 270dg are the ones that tell the ecu where it is,
I guess Simon should be able to correctly tell us how important the lost lugs are,
I could easly change to 36-1 on them all, BTW Rods runs 2 lugs at 60dg lead angle.

Mark

Mark Shead

Simon beat me to it

Mark

james kiely

iTrader: (5)

Evening everybody
I can see this thread getting very technical and way above my understanding of the inner workings of ecus,thats not to say i dont find it interesting just a little over my head.
The car was bought as a project and i would like to put the best i can afford into the car,it just means the rebuild will take a little longer should the consensus of opinion be that autronic is the way forward.

dom123

iTrader: (1)

i would take your location as a bit of a guide are you near a good tunner that do good deals as the performance ecu will be more difficult to get up and running and may need calibrating to your standards a couple of times etc... i always run near the 400bhp mark so i think its just so easy to just order chips from msd put it in off you go.. have a quick and cheap check on a local dyno. and forget about it.

i know i could probly get 10more bhp from a live map but i cant be arsed to drive hundereds of miles to a tuner costing loads on fuel and pay my mates petrol to give me a lift there and back and the live map fuel and the live map cost.. i reacon probly Ł800 in total i would only be interested if i was running 450bhp+

sos just my opinion. Ł800 is alot of money.....

Turbosystems

iTrader: (5)

they ran bosh motronic 1.2 and zitec ecu's the webber ecu was for the 500 homologated road cars

space hoppers

oh dear did not no you would bite that hard si well you no its true anyway

GARETH T

very intresting read guys!

james kiely

iTrader: (5)

would there be a big difference in the cost of making up the loom,pectal style ?
cheers james

ECU Monitor Enthusiast

iTrader: (1)

I stand corrected Tony. I thought the Zitec only ended up on the RS200's

Those ECU's were not much different technicallly than a L1 anyway

Kelv

iTrader: (4)

ok dude, for some reason i thought you were



Thank you Simon, thats very polite of yourself and ill treasure your warming words after the day ive had.

But seriously mate, see PM - my comment wasnt aimed at you in the slightest

james kiely

iTrader: (5)

dom 123
to tell you the truth i am not aware of any good cossie tuners in the south of ireland ,so ulitmatley a quick trip to england would be on the cards.i really would like to have it mapped using the petrol i get locally as i dont fancy melting a piston.
cheers james

ECU Monitor Enthusiast

iTrader: (1)

Its true, an ecu was fitted but needed mapping which was never going to be done by me as I am not a mapper !
That is true also ... !!!

Turbosystems

iTrader: (5)

The road going rs 200 was on ford eec4 the evolution 620 bhp rs200 was on bosh
I agree these ecu's were thick but just goes to show that you don't need a clever advanced ecu to get big bhp

james kiely

iTrader: (5)

simon
would your l8 software be of use to me to keep an eye on important parameters

Turbosystems

iTrader: (5)

These modern ecu's are a bit like having an i phone when you actually just want to ring and order a pizza

james kiely

iTrader: (5)

tony
what is your favourite ecu,as a general all rounder?

ECU Monitor Enthusiast

iTrader: (1)

Yes mate it could.

Having said that, Autronics mapping software can also perfrom data monitoring and diagnostics.
I think they may even have there own dash type program too but not sure !

ECU Monitor Enthusiast

iTrader: (1)

Kelv,

I appologise 100% for my comments directed at yourself

Thanks for clarifying what you meant and taking the time to do so

I am a cock

Stu @ M Developments

iTrader: (12)

Candidate for quote of the year.

Turbosystems

iTrader: (5)

for a cosworth it has to be l8 and P8 as it came free with the cars
replacing ecu's means wiring looms and expense
If cost wasn't an issue it has to be the pectel T6 we also have motec ,life , autronics.
These ecu's are so easy to map compared with OE
Personally I like to pay more for quality and for things to be future proof

Kelv

iTrader: (4)

Simon - no worries atall

Turbosystems

iTrader: (5)

I have corrected the grammar and spelling now stu

Chip

iTrader: (3)

Its still wrong: "ring AN order"

Not that it matters.

james kiely

iTrader: (5)

tony
thats whats leaning me towards the autronic setup its pretty future proof.
i will have to have a loom made anyway as i didnt get one with the car,and fancy a new or good second hand braided loom just to eliminate any future wiring problems.
cheers james

Turbosystems

iTrader: (5)

Thanks EGG head I missed that one

james kiely

iTrader: (5)

lets have some more opinions peeps
cheers james

Jay,

iTrader: (4)

i agree tony but i have 1x6 and 2xl8s in the bin in my garage that have burnt tracks bodged quality repairs and for this reason i wouldnt put a webber ecu on my car let alone so called upgrade to a l8 and then spend a fortune on upgrades ,most webber stuff is over 20 years old and will only get more unreliable as time goes on