Astraoid

Hello all, I've just read through this thread and, as the owner of this car, felt I should fill in some of the gaps.

The engine is a stock XE with throttle bodies. Nothing clever. The car was booked in for an exhaust build and engine mapping with the added requirement of meeting SVA emission levels.
In total the car was at the 'tuners' for 15 days, which included 2 days for the exhaust to be built.
After the exhaust was built the tuner tried to start the car but it failed to fire up. I found the fault to be the wiring going into the ECU was bent over causing a loose connection. This fault was not identified or resolved by the tuner and I was not charged for it.

Once if was able to fire, it sounded 'wrong' and I said to the tuner the issue would be software related as the engine is completely stock. They disagreed and felt the problem was down to timing. This was simply not possible and despite being told the problem was to be found within the software they spent a few hours pulling cambelt covers off and hunting a timing problem that did not exist.

I spoke to Mark Shead who advised to add 32 to a specific flag. I advised the tuner to do so. Unfortunately they misinterpeted the instruction and changed the flag to 32 rather than add 32 to the existing number. This resulted in further delays - eventually resolved by the tuner contacting Mark Shead who corrected their mistake.

I visited the garage each day - most days the car remained untouched in the same loacation - which made my blood boil. There was absolutely no sense of urgency despite my SVA deadline being made known.

They announced no further work could be done as the car had an oil leak. I was aware that there could be one as I'd just installed a new oil pressure switch which I might not have tightened properly - they agreed to tighten this up for me.

Next they had to balance the throttle bodies - a fiddly little job that involved removal of the plenum chamber (containing the air temp sensor which was never replaced). I was there throughout this whole process and it took 30 - 45 minutes.

Finally, after 10 or so days they would be able to map the car...

Unfortunately not. I received a phone call advising it would be impossible to map my car as the map sensor was not pulling a sufficient vacuum to move the cursor around the table. They pointed out that most aftermarket ECU's use Throttle position but my Autronic was unable to do so...

Wrong. A call to Mark Shead confirmed that The SMC can be mapped using throttle position. So we should now be back in business.

15 days after this whole board meeting began and I eventually get a call telling me the car is ready to come home and that I'm £400 worse off.

My maths:
30 mins maybe 1 hour tightening up the oil pressure switch.
30 mins maybe 1 hour balancing the throttle bodies
1 hour (not) mapping my car and setting up emissions for SVA

In all fairness this was a 4 hour job maximum not an 8 hour job as billed IMO and I should have at least had a basic running car at the end of it. As it goes the car (when it eventually started) drove so poorly it was beyond belief.

It's been a long long time since I can honestly say I've been ripped off on something car related but this whole ordeal has left a really bad taste in my mouth. That said, this is something to put down to bad experience and I would not waste any time going legal. It's very unlikely I'll get any money back and it's a shame because up until this point I've always looked at this particular company as being a respectable family business.

The only reason I chose to use this company was because this was not supposed to be a maximum bhp map - I just wanted a simple reliable car with low emissions and so felt I'd save myself time travelling all the way up to Mark. The fact is I lost 14 days more than I'd have if the car was taken to Mark.

Mark Shead

Most people think its the main fuel table but infact it is just a trim table,
The Autronic is working in the back ground always adding fuel for boost/revs/tps, based on Comp ratio/injector size/cylinder size it will add a % of fuel for each increase rev/boost so infact you could have almost no load points in the Base VE table and you still get fuel increasing,
If you take a typical Evo 9 map the tickover it has the number 80 on tickover and at boost across the rpm range it has the number 80 and at part thottle it has the number 80 across 90%+ of the base VE table,
So you can see once you understand whats going on it is very easy to map the fuel table.

Mark

ECU Monitor Enthusiast

iTrader: (1)

Mark, I understand what you are getting at.... Sweet

Thats ok till you have sensor faults though.... !

rapidcossie

what does the 80 represent Mark?

Mark Shead

It has several limp home tables that work very well

Mark

Mark Shead

Effectivly 80% trim of the base VE table but most think it is just 80 on a fuel table but dont realy understand what it means.

Mark

Chip

iTrader: (3)

The VE table tells the Autronic how good the engine is at swallowing air in any given circumstance.
Mark can obviously describe the importance or not of this better than I can, but given the lack of MAP on neils car to reference, his relies on this table far more than on a turbo car, where you often end up with a fairly flat table as like Mark said in that situation it ends up as essentially not much more than a trim table.

What happens within the autronic, is it performs an equation to work out how much fuel to put in.

To do this, it looks at the engine size, then looks at the VE, then looks at the MAP (when used) it multiplies those together to work out the actual amount of air that has been consumed in that cycle.
Once it has the amount of air calculated it then looks at the AFR table to determine how much fuel it needs to add.
Once it knows how much fuel to add, it them looks at the injector size, and from that knows how long to open the injector to add that amount of fuel.


There are of course a few other sensors like airtemp which effect all this, but Ive just over simplified it to make it simple enough for anyone to understand.


Thats my ASSUMPTION on how it works anyway, based on what Ive seen of the system, I am however open to correction by mark if I have anything wrong there as Ive never seen the code within the ecu or talked to the person who wrote it, which is the only way to really know of course, im just doing my best to reverse engineer it from looking at the tables and how each one seems to effect the outcome etc.


*EDIT - Doh too slow, mark had already replied by the time I typed that, lol

Benni

Benni.

Benni

I take it the above place is where it was mapped?

Benni.

rapidcossie

So base VE changes depending on the engine and modifications?

Mapping is defo something I would like to understand more clearly but the more you look into it the more complicated it becomes

Chip

iTrader: (3)

Yes, a change in cam for example would be evident in this table, but not in any other table (correct me if im wrong mark!) so this table is the ONLY way that the ecu would know about that change of cam so is the only thing that would dicate that it now fuelled differently for that cam than the previous one.

rapidcossie

Cheers for that explination Chip.

So on a N/A car is essential for the ECu to know what happening but less so on a turbo car due to the fact that it can get similar info fromthe MAp sensor?

Chip

iTrader: (3)

Benni, those pictures were taken where it had the exhaust made up mate

Mark Shead

Yes your doing a good job explaining. Im off to bedso wil let you continue

Mark

Chip

iTrader: (3)

Its actually possible to use a MAP sensor on an N/A car as well but on neil's the issue with doing that is his current setup (which needs changing when we turbo it) doesnt allow for a good enough signal, so thats why (as he mentions) it had to be swapped over.

JTECH James

iTrader: (13)

i think i know where that is

Chip

iTrader: (3)

What the place that made his exhaust? Yes mate you probably do.

But anyway, if we could keep this topic about mapping and engines and general info rather than specific companies that would be better please

bigal1978

http://www.enginetuner.co.uk/q_and_a.htm ?

cosmo V6

he was on the house doctor prog (the one with the american woman) about two years back,

seem to remember he had married a thai bride and was looking to sell up and move

JTECH James

iTrader: (13)

they dont make exhausts....
he lives a stones throw from me, infact he is our closest neighbour.

if its who i think....

anyway nomatter.

Chip

iTrader: (3)

Its not a complete exhaust he had made, just some alterations, as detailed in the post copied in above:


but anyway......