Where can i learn how to map my own car.

[Evoluzione]

You need to find out precisely what is available for your specific application and report back with what you have found, someone will then be better placed to advise you.

Actual live remapping is very in depth and highly specialised, if you were to decide to do it as a hobby for the next few years then yes, crack on. For just a one off? Forget it. Take a look back earlier where I was asking what was what and that was just basic idling adjustment! See what you think you could do with filling in one of these from scratch:

[stevieturbo]

Lord said:

ah ok. I thought it would be modifiying the standard ECU in situ with a cable or patching kit of some sort. I think in my mind i imagined it was like uploading new firmware.

You havent even stated what car/ecu it is, so going to be impossible for anyone to tell you if there is something available for it.

And dont forget....in the wrong hands such abilities/freedoms to change can destroy an engine in seconds.

[anonymous-user]

Evoluzione said:

Max_Torque said:

There is no fundamental difference between what an NA engine experiences and that for a Turbo engine.

That's a very gross generalisation which is largely incorrect.

Max_Torque said:

All a turbo does is to increase the maximum possible intake manifold air density. it DOES NOT "blow air into the engine" in fact, quite the opposite (because exhaust back pressure is (except for a very very few odd cases) higher than boost pressure. As such, manifold volumetric efficiency is REDUCED by a turbo. However, that reduction in the engines ability to swallow air, is more than offset by the increased air charge density.

Yes I'm quite aware of how a basic engine works, but you are quite wrong about back pressure, with a modern turbo (especially a large one on a high performance engine) pressure ratios of 1:1 and better are easily and regularly are achievable.

Well, that's me told. I must have forgotten the last 25 years of OEM/WRC/F1 engine development i've done, silly me!

Perhaps you could explain the fundamental difference between a turbo engine and an NA one for me then?

[anonymous-user]

Evoluzione said:

That's a slightly strange looking map, or does the system not have pressure compensated fueling?


(you'd expect fuel mass per cycle at a constant throttle position to fall with increasing engine speed)

[PeterBurgess]

Maybe folk are looking at basic engine dyno and rolling road graphs in the wrong way. Most testing, especially rolling roads is to get the best from the engine and/or find out what is wrong. To get the graphs that Dave Baker and Evoluzione seem to want so they can see patterns in pulse tuning etc requires a different approach. This requires steady state power measurement. It would seem an Industry standard would be holding the engine at steady rpm full load to stabilise then allow five minutes between readings. This is repeated for each data point required so may well take a long time. Maybe Max-Torque could clarify?
Our SF901 is an endurance test model specifically built for long term testing as required for Industry Standard testing. It was used to test and develop the Lister V12 for the LeMans 24 hours racing and is more than capable of holding and heat exchanging that 600 bhp for in excess of 24 hours at full load. I would like to offer Evoluzione the opportunity to build an engine ( maybe best non turbo because of length of test etc) and run it on our dyno in 'usual' power test modes and the Industry standard 5 minute between readings test. This would take in the region of 3 hours for each test run, 3 runs for statistical compliance reasons.
We are moving nearer 'fire up' day and would envisage next springtime for power testing.
Now that is a good offer, we supply the testing, Evoluzione supply engine, fuel and oil and attend the sessions.

Peter

[Lord Pikey]

stevieturbo said:

You havent even stated what car/ecu it is, so going to be impossible for anyone to tell you if there is something available for it.

And dont forget....in the wrong hands such abilities/freedoms to change can destroy an engine in seconds.

Ah, sorry, i didnt realise it was that specific. Its a 2006 535d. Ill try and find out the ECU type later on.

[AW111]

Silent1 said:

Thanks chaps, that sounds like a good starting point, I think an aftermarket ecu might be a good idea as then as I move into other cars (of my own) I can take some knowledge with me.

One advantage of reprogramming a factory ECU is you get to keep all the corner mapping : below zero ambient, hot start, etc. and only change what you want to. A new ECU needs a base map from somewhere.

The main thing I see is time : if you only have a budget for an hour of dyno time, you will probably ask the tuner for max power. If you want all the transients and part-throttle mapping optimised as well, you will be paying for a lot more time.

[AW111]

Regarding the "dyno dip" - max has it right. It occurs when the dyno is in closed-loop speed mode, and the torque suddenly spikes to several times its off-boost value, and the control system takes a moment to catch up.
Unfortunately, I have seen a very similar dip when a wastegate or boost bleed valve "pops" open and there is a momentary drop in boost. As both occur at the same revs, monitoring the boost is necessary (as was mentioned above).

OT
You would be surprised at the number of people (never on PH ) who have a dyno graph but don't know if the power figure is as measured at the rollers, or estimated flywheel power, or why they are different.
I despair sometimes.

[stevieturbo]

Lord said:

Ah, sorry, i didnt realise it was that specific. Its a 2006 535d. Ill try and find out the ECU type later on.

You arent going to get anything cheap to allow you to tune that yourself.

[SuperchargedVR6]

AW111 said:

OT
You would be surprised at the number of people (never on PH ) who have a dyno graph but don't know if the power figure is as measured at the rollers, or estimated flywheel power, or why they are different.
I despair sometimes.

Having different measuring standards across the globe doesn't help matters! WHP has always seemed like the most sensible measurement to me, and obviously crank power from the OEMs who bench test their engines is useful, but BHP, KW & PS I've never had much time for.

[Evoluzione]

Max_Torque said:

Evoluzione said:

Max_Torque said:

There is no fundamental difference between what an NA engine experiences and that for a Turbo engine.

That's a very gross generalisation which is largely incorrect.

Max_Torque said:

All a turbo does is to increase the maximum possible intake manifold air density. it DOES NOT "blow air into the engine" in fact, quite the opposite (because exhaust back pressure is (except for a very very few odd cases) higher than boost pressure. As such, manifold volumetric efficiency is REDUCED by a turbo. However, that reduction in the engines ability to swallow air, is more than offset by the increased air charge density.

Yes I'm quite aware of how a basic engine works, but you are quite wrong about back pressure, with a modern turbo (especially a large one on a high performance engine) pressure ratios of 1:1 and better are easily and regularly are achievable.

Well, that's me told. I must have forgotten the last 25 years of OEM/WRC/F1 engine development i've done, silly me!

Perhaps you could explain the fundamental difference between a turbo engine and an NA one for me then?

I seem to remember you telling me that a turbo engine I built couldn't make anywhere near the power that it did.
You did this despite not having the faintest idea of the spec or size of the engine
With this fact in mind i'm declining getting into an argument with you as you are likely to argue black is white until the sun goes down and I don't have the time, nor the inclination for that.
I come on here for a bit of banter, to learn and to fill the gaps in my knowledge, maybe impart some knowledge too if I have any to contribute, not argue, but I notice you haven't challenged me rubbishing your incorrect comment about inlet/exhaust pressure ratio?

[Evoluzione]

AW111 said:

Regarding the "dyno dip" - max has it right. It occurs when the dyno is in closed-loop speed mode, and the torque suddenly spikes to several times its off-boost value, and the control system takes a moment to catch up.
Unfortunately, I have seen a very similar dip when a wastegate or boost bleed valve "pops" open and there is a momentary drop in boost. As both occur at the same revs, monitoring the boost is necessary (as was mentioned above).

Does an engine dyno have the same issue? I pulled out a dyno sheet from one earlier and noted the same dip.

[SuperchargedVR6]

Engine mapping / tuning has always created differences of opinion. At the end of the day, burning fuel in a cylinder isn't rocket science and if the owner is happy with the end results, who is anyone to question it? There are only 2 extremes of engine tuning. It either doesn't run at all, or it blows up. A lot of engines can run sub-optimally perfectly fine (limp mode in the case of OEMs) with crude parameters and guess work. That may not satisfy those who do it for a living, but for project cars it's a good way to learn.

[Evoluzione]

PeterBurgess said:

Maybe folk are looking at basic engine dyno and rolling road graphs in the wrong way. Most testing, especially rolling roads is to get the best from the engine and/or find out what is wrong. To get the graphs that Dave Baker and Evoluzione seem to want so they can see patterns in pulse tuning etc requires a different approach. This requires steady state power measurement. It would seem an Industry standard would be holding the engine at steady rpm full load to stabilise then allow five minutes between readings. This is repeated for each data point required so may well take a long time. Maybe Max-Torque could clarify?
Our SF901 is an endurance test model specifically built for long term testing as required for Industry Standard testing. It was used to test and develop the Lister V12 for the LeMans 24 hours racing and is more than capable of holding and heat exchanging that 600 bhp for in excess of 24 hours at full load. I would like to offer Evoluzione the opportunity to build an engine ( maybe best non turbo because of length of test etc) and run it on our dyno in 'usual' power test modes and the Industry standard 5 minute between readings test. This would take in the region of 3 hours for each test run, 3 runs for statistical compliance reasons.
We are moving nearer 'fire up' day and would envisage next springtime for power testing.
Now that is a good offer, we supply the testing, Evoluzione supply engine, fuel and oil and attend the sessions.

Peter

They are a tuning tool and not much more.
My comment to you earlier needs backing up; if you offer all the graphs and data you have to a customer then you can do no more, but they will always want and flash around the smoothed version. It's like head porting, an inlet port straight from the grinder will flow as well as one that has been further polished or smoothed, but you can't go giving a customer ports which have a carbide burr finish on them, even though you know they are as good if not better than the smoothed or polished ones which come after.

Thanks for your offer, it interests me greatly, however if you are to employ your caveat of 'non turbo' I can't take you up on it. If you could do turbo then yes please, if it requires the addition of some funds let me know. I have no need for N/A knowledge as I don't do many and am more concerned with turbo engines. Programs which calculate intake and exhaust size from a variety of specifications for N/A are very accurate and readily available, any man on the street with an iota of sense can spec a reasonably successful basic N/A engine.
I do have many things i'd love to try if time and money allowed (sadly it doesn't). I think that given we move in such different circles and have no competition between us a meeting of minds and theories would be a great way to spend some time, i'd follow it up with a report for fellow PHers to read if I thought there was any interest.
PM me and let me know what you think, I can knock up an engine or two over Winter and you aren't far South from me. What about mapping the engines? I don't have a clue hence me joining in this thread!

[Evoluzione]

SuperchargedVR6 said:

There are only 2 extremes of engine tuning. It either doesn't run at all, or it blows up.

True. If you could have a signature, that would be it; made me laugh

[anonymous-user]

Evoluzione said:

I seem to remember you telling me that a turbo engine I built couldn't make anywhere near the power that it did.
You did this despite not having the faintest idea of the spec or size of the engine
With this fact in mind i'm declining getting into an argument with you as you are likely to argue black is white until the sun goes down and I don't have the time, nor the inclination for that.
I come on here for a bit of banter, to learn and to fill the gaps in my knowledge, maybe impart some knowledge too if I have any to contribute, not argue, but I notice you haven't challenged me rubbishing your incorrect comment about inlet/exhaust pressure ratio?

Sorry, i don't remember that original discussion! But i bet you never actually posted "proof" of the engine performance is it making "silly power" (ie, statistically valid data from an in calibration, certified/traceable engine dyno) ;-)


Regarding the engines pressure ratio: Tell me how a turbo can make more intake pressure than back pressure? (it actually can, but it takes a very specific set of quite unusual enthalpy circumstances to do so) For 99.99% of turbo engines, the turbocharger reduces volumetric flow.............

[Evoluzione]

Max_Torque said:

Evoluzione said:

That's a slightly strange looking map, or does the system not have pressure compensated fueling?


(you'd expect fuel mass per cycle at a constant throttle position to fall with increasing engine speed)

I'm afraid you're asking the wrong person! I don't remember where it came from, but do know the manufacturers ECU it's from, it isn't one of my maps, but same ECU I use.

[SuperchargedVR6]

Evoluzione said:

SuperchargedVR6 said:

There are only 2 extremes of engine tuning. It either doesn't run at all, or it blows up.

True. If you could have a signature, that would be it; made me laugh

It's true though Fossil fuel engines are not binary in nature so there is no such thing as the 'correct way' to tune an engine, unless of course a specific operating target has to be met, which generally only falls into the OEM arena. In the aftermarket and DIY, the requirements are far less stringent.

The guys who do it for a living, quoting dozens of different acronyms etc, kudos to them, that's a whole different level but I don't need to understand all that in order to get a bit of fuel and air to push a piston down it's hole.

[PeterBurgess]

What we were offering was power testing a 'sorted' engine to show the power delivery, this would take two or three days for fitting and testing with no time for tuning. I will see what is what with regard to running a 500 bhp turbo over a long period and keeping the intercooler cool etc.

As you can see from the raw data I posted all meaningful graphs have been subject to smoothing and interpolation. We think a power graph at 100 rpm intervals with time to stabilise will show a pretty smooth curve on an engine dyno. The rolling road graphs are subject to all sorts of interfernce from transmission, dyno, pau modulation etc etc.

Peter

[AW111]

Evoluzione said:

Does an engine dyno have the same issue? I pulled out a dyno sheet from one earlier and noted the same dip.

Short answer : yes, but it may be too small to notice.

Any closed-loop control system is trying to hold the target value, in this case speed, to a particular value. If the speed is over the target, it applies more load to slow it down; if the speed is under the target, it reduces load to let the system speed up.
In both cases, it is reacting to a deviation from the target.
If the response is too great, the system will hunt, or oscillate; if the response is not large enough, the system will overshoot and be slow to respond.

Here's the trouble : you can tune a control system for best response for a certain range of inputs. A chassis dyno may have to cope with anything from a 50 hp city car, to a 750 hp turbo monster. As operators just want to put the car on the dyno and start work (and a lot of "tuners" have little if any technical nous), any dyno control system is a compromise.

We found out years ago that asking operators to select "tiny / average / huge" power settings, or do a "calibration run" first got massive resistance : "it should just work". It does, but a control system with that range of power inputs (and driveline inertias) will always be less than perfect.


A major difference between OEM and aftermarket tuning is that OEM's trust their engines, and will happily run them flat out on the dyno for hours or days, while many owners of modified cars seem to think that the engine will self-destruct if held at full throttle at constant speed, or the run takes more than 10 seconds. I assume they never drive uphill...