In tuning, what are standard conditions?

Posted on August 16th, 2016 in Driving Emotion,Economy,Engine Management,Honda,testing by Julian Edgar

It’s been cold hereabouts, and I have been doing some more on-road tuning of my MoTeC-equipped, turbo Honda Insight.

(But before I get to the subject of this column, a point on the DIY tuning of programmable engine management. In short, it’s the best fun-for-$ expenditure you can ever make on a car.

Why? Because after you’ve bought and fitted a system, you’ve just gained a pastime you can do for literally ever. There is always – always! – a tuning change you can make that will cause the car drive fractionally better in a given situation, or to develop slightly more power, or to use a little less fuel.

In short, buy programmable management and you’ll never need another hobby or leisure activity!)

So anyway, this time I had the car on 98RON and there was an ambient temp of 5 – 10 degrees C.

Over the last two years I’d have tuned the ignition timing maps on this car for literally hundreds of hours. That might seem to indicate that I’m rather slow at it, but in fact more accurately reflects the statements above about gains always being able to be made – and also the fact that the little Honda is very sensitive to ignition timing variations.

As an example of the latter, it’s one of the very few cars that I know of that requires some negative timing figures if it is to avoid detonation. That’s especially the case at low revs and when only one intake valve per cylinder is working (ie VTEC is off), so giving very high combustion chamber swirl.

I do the on-road tuning of the ignition timing using a microphone temporarily mounted in the engine bay (clipping it to the throttle cable works well). This microphone feeds a small amplifier and I listen on headphones. With this system I can not only clearly hear detonation, but I can also hear the harsher edge the engine develops just before detonation.

In addition to the headphones – and the laptop on the passenger seat – I also have another trick up my sleeve. A dashboard-mounted knob allows instant variation in ignition timing of plus/minus 10 degrees.

So I drive along (lots and lots of empty country roads around here), listening to the engine through the amplified headphones. I might be at 2000 rpm, full throttle in 4th gear, the engine just coming onto boost and lugging hard up a hill. VTEC is switched on. (So that the engine will readily accept boost pressure, I have the engine switch to two-valves-per-cylinder operation from 1750 rpm upwards at full throttle. The engine doesn’t like it so much if only one-valve operation is occurring as it comes onto boost – in this non-VTEC mode, I have heard turbo compressor surge.)

Anyway, in these conditions, where change is occurring relatively slowly, I manually advance the timing with the dash knob and listen carefully. If the car clearly goes harder (almost always) and there’s no sign of detonation (or its precursor sounds), I pull over and add some timing at that spot overall ignition timing map. Then repeat the process….

Now you know why it takes me so long!

Anyway, finally to the point of this column.

As with all programmable management systems, the M400 has a base timing map (it uses RPM and MAP axes) and then a series of correction maps. These corrections include coolant temperature and intake air temp. Because, as I’ve said, the Honda is very sensitive to timing variations, I use all these correction maps.

Let’s take a look at intake air temp – and how I influence it.

I regulate intake air temp by using a water/air intercooler and variable pump speed. If the intake air temp is below 35 degrees C, the pump stays off. Depending also on throttle position, as the intake air temp rises above that figure, pump speed increases. Together with the effect of the thermal mass of water within the heat exchanger, the upshot is that in nearly all conditions of ambient temperature and boost, the intake air temp stays within the range of 20 – 50 degrees C.

Initially, I’d intended to aim at an intake air temp of around 45 degrees C (the higher temp better for fuel atomisation and so fuel economy), but I found that to avoid detonation, timing had to be retarded at this intake air temp. I then reconfigured the water/air intercooler pump map (ie I turned the pump on earlier) to aim at an intake air temp of around 35 degrees C.

So, all well and good. On this basis, the main ignition timing map would be configured optimally for 35 degrees C, and the intake air temp correction map would knock off timing as the temp rose above this.

Hmm, but what about when it is very cold, like it has been over the last few days? I’ve seen intake air temps lower than I’d ever planned – around 25 degrees. The intercooler water pump is off, but the air entering the turbo is so cold that even with spurts of boost, the water within the intercooler heat exchanger is staying at less than 35 degrees.

And in these conditions I’ve been hearing precursor sounds of detonation through my headphones.

Is it because the density of air (and so cylinder filling charge) is greater, resulting in higher combustion pressures? That is, the greater mass of air (more likelihood of detonation) is more than offsetting the colder air (less likelihood of detonation)? And so do I pull back timing at lower intake air temps (ie less than 35 degrees C) as well as at higher intake air temps (above 35 degrees C)?

And do I therefore accept that, in the real world, the engine will probably never be running the timing as specified in the main chart – after all, while intake air temp might occasionally be at 35 degrees C, stopped at traffic lights in might be 40 degrees, and down a long country road hill it might be 30 degrees – and so on…

And how do I correctly tune this intake air temp correction map? After all, to do it accurately I’d need road test ambient temps that range from -10 degrees C to plus 50 degrees C.

And, thinking about that, I have in fact tuned at the high intake air temps. Early in the tuning process, in the middle of summer and with an ambient of about 35 degrees C, I can remember doing repeated 0 – 160 km/h runs, flat out and working the little car as hard as I dared. I was tuning the high temp ignition timing correction chart (and also revising how much boost gets pulled out in these conditions – another variable!).

Looking out the window as I type this early on a Sunday morning, it’s frosty and foggy, about 0 degrees C. I should, I think, get away from this desk and hit the road for some tuning…

It’s a process that will literally never be finished.


My year

Posted on December 7th, 2014 in Aerodynamics,AutoSpeed,Driving Emotion,Economy,electric,Honda,Hybrid Power,Intercooling,Opinion by Julian Edgar

Well, it’s nearly the end of the year, and I have been reflecting on my busy car modification 12 months.

All the modifications I have done have been to my little Honda Insight.

Fitting a turbo, water/air intercooler and making and fitting a new airbox. Installing a MoTeC M400 ECU, and then doing all the engine mapping on the road. Fitting a MoTeC CDL3 dash, and then upgrading to an ADL3 dash.

It’s been a huge amount of fun turning the all-alloy, two-seater Honda hybrid into a fuel-efficient turbo with about 70 per cent more power than standard from its 1 litre, 3-cylinder engine.

None of these mods was cheap, but all gave the results I’d been hoping for.

And in the last few weeks I have been playing with the suspension. And, so far, this has been cheap! I calculated the required specs for new springs front and back, sourced them at near zero cost, then installed them. That step was very successful, so then I fitted a new rear antiroll bar – this time, for a cost of less than fifty bucks.

The car is absolutely transformed in both ride and handling – and I am yet to fit the new dampers, which at the time of writing, are on their way from the US.

Sitting in the corner is the next Insight modification – a Tritium Wavesculptor200 high voltage electric motor controller. It will be used to run the Honda’s standard 10kW electric motor, although not always at only 10kW. Given the nature of electric motors, I should be able to over-rate it for short periods, gaining perhaps 20kW for huge short-term torque.

I plan on controlling the Wavescluptor200 using outputs from the MoTeC ADL3 dash. The dash – really, a digital control system that happens to have a display – has a full range of programmable maths functions and can use 3D look-up tables.

The new high voltage battery pack and battery monitoring system? I am yet to decide on these things.

I don’t know if I will achieve my final aim of 0-100 km/h in the Sixes and fuel economy in the high Twos (litres/100km), but the challenge is enormously exciting and rewarding.

In the meantime, we’re off to the United States for five weeks. We’ll be concentrating on the eastern side of the country, and have on our itinerary a long list of technical and automotive sights – and sites. We hope to next year bring you a series in AutoSpeed that describes some of what we see.

Finally, I also published another three books this year – if you are interested, search on Amazon under my name.

Have a safe and happy Christmas and New Year, and remember: for fun and challenge, nothing beats modifying your car!

Picking gauges

Posted on April 2nd, 2014 in Economy,Honda,Hybrid Power,testing by Julian Edgar

It’s not often that you get a clean slate in terms of designing an instrument panel.

With my Honda Insight project, where the standard instrument panel is being ditched and replaced with (primarily) a MoTeC CDL3 digital dash, to some extent the type of display becomes obvious – it’ll be dominated by the MoTeC unit.

But what about the factory-fitted warning lights – things like ABS, EPS (electric power steering) and airbag malfunction indicators? And how will high beam, low beam and the action of the indicators be shown? And will there be data that I will want to be able to see but the MoTeC dash won’t easily show?

Despite the dash not likely to be installed for many months, I’ve been mulling over these ideas.

At this stage – and things may well change – this is what I am thinking I’ll need:

Warning lights for:

 – high beam

 – low beam

 – left indicator

 – right indicator

 – EPS

 – ABS

 – airbag

 – handbrake / braking system fail


Small backlit numerical LCDs for:

 – high voltage battery voltage

 – electric motor current flow


MoTeC dash display of:

 – engine rpm

 – coolant temp

 – fuel level

 – road speed

 – manifold pressure

 – intake air temp

 – gear

 – oil pressure

 – oil temperature

 – turbo exhaust back-pressure

 – water/air intercooler pump drive voltage

 – 12V battery voltage

Some of these MoTeC-displayed parameters (eg intake air temp and rpm) will be communicated via the CAN bus from the M400 ECU.

One parameter (selected gear) will be internally calculated in the dash, while other parameters (like oil temp and pressure) will require dedicated sensors.

Note that the MoTec dash allows different data to be displayed depending on the mode selected – so not all of these things will be available all at once!

On the list above there are a couple of unusual ones.

I want to be able to see turbo exhaust back-pressure because, in order to provide low rpm torque, the turbo that is being used is small. However, if as a result of its small size, the exhaust back-pressure is overly high, then fuel economy will suffer. It’ll be good to be able to see this figure.

So why show the water/air intercooler pump drive voltage? The pump will be varied in speed by the ECU. This is needed because I want to control the intake air temp, rather than just keep it as low as possible. For much of the time, I would expect that the pump will be operating at less than full speed. Displaying pump drive voltage will allow me to see at what speed the pump is being driven. Not only will this be interesting in itself, it will also allow me to assess how effective the control strategies are that are being used to operate the pump.

As I said, all still a long way off, but I need to start sourcing bits and installing sensors right now.

Heavy cars

Posted on August 22nd, 2012 in Driving Emotion,Honda,Materials by Julian Edgar

My Honda Legend is the heaviest car I have ever owned. As a fan of light cars, the Honda’s mass is not something that fills me with joy – but as described elsewhere, it was my best choice based on a variety of factors.

So does it feel unwieldy – even lumpy? No it doesn’t. Particularly because of the yawing ability of its all-wheel drive system, it turns-in readily and feels poised and amenable to directional change.

Driving the car, especially over bumpy roads, you can feel its favourably high mass / unsprung mass ratio: the body tends to float over the bumps rather than drop into them, and there’s never the feeling of the car being ‘shaken by the wheels’ that occurs in vehicles with a low sprung / unsprung mass relationship.

So is it all sweetness and light – the 1855-odd kg doesn’t matter?


The Legend, despite its big brakes, is a car that requires clear effort to slow. Part of that effort can be seen in how quickly it blackens its front rims – even in gentle driving.

It also cannot get away from the disadvantages of its mass in fuel consumption. Particularly noticeable in open-road undulating terrain, the fuel burn when hauling its lard-arse up hills is high.

However, with lots of kg, a low Cd and relatively small frontal area, the Legend is a car that will roll a long way. Time and time again in the first month of ownership I have found myself committing that cardinal driver sin of going straight from the accelerator to the brake, rather than getting off the power sufficiently early that there can be a roll-down time in between.

I think it’s a good car… but I think it would be a better one at (say) 200kg lighter. That would have required all-alloy construction, something that another Honda I own (a first gen Insight) already has. (The – much smaller – Insight has a mass of just 827kg!) An all-alloy Legend I would guess at around 1600kg – still no light-weight, but more appropriate for its size and equipment level. I wonder why Honda didn’t do this? In the Australian market (at least) the car was underpriced compared to its Euro and Japanese opposition, so you’d have thought they could have worn the extra cost.

But whichever way you analyse it, the disadvantages of high car mass well outweigh(!) the advantages.

New DIY Electric Car Opportunities

Posted on January 22nd, 2009 in Driving Emotion,Electric vehicles,Honda,Hybrid Power,Opinion,Toyota by Julian Edgar

People who have been into modified cars here in Australia have for decades known of the incredible bargains that can be had from Japanese-importing wreckers.

Because of the speed with which Japanese drivers discard near-new cars, the drivelines – or even complete front halves of cars – can be bought amazingly cheaply. Engines and gearboxes boasting late model technology, for less than the cost of having an old clunker rebuilt. It’s simple – buy a locally-delivered car and then install a new Japanese-import driveline having much greater performance. Over the years I’ve done this twice – and both times got a tremendous car for the money.

And now there’s a whole new and exciting Japanese-import field opening up.

Because Japanese manufacturers have led the world in the creation of hybrid petrol/electric cars – the first was built over 10 years ago – and because many were sold locally in Japan, hybrid car parts can now be sourced out of Japan at the same ridiculously low prices.

$2 for an improved suspension…

Posted on December 11th, 2008 in Driving Emotion,Honda,Opinion,Suspension by Julian Edgar

The topic of bump stops does not attract much interest. But especially in cars with lowered suspension, and in light-weight cars, bump stops form an important part of the springing system.

A bump stop is the (usually) rubber buffer that is compressed as the suspension reaches full bump. (Some cars also have full droop buffers as well.)

Traditionally, bump stops were impacted only rarely, but more and more often in current cars, the suspension is designed in such a way that the bump stops are frequently contacted.

Let’s look at light weight cars first.

In a light weight car, the variations in possible loads make up a greater proportion of the overall vehicle mass. This means that, to avoid bottoming-out, the suspension must be set up more stiffly to cope with the potential load variation.

Or – and here’s the key point – the bump stops can be designed to be increasing rate (but still relatively progressive) springs that are brought into operation when the car is carrying full loads over bumps. That way, the spring rate of the suspension during ‘normal’ load carrying can be set much softer, giving a better ride.

Cost vs benefit of car modifications

Posted on November 25th, 2008 in Aerodynamics,Driving Emotion,Economy,Honda,Opinion by Julian Edgar

When modifying cars, everyone conducts some sort of cost/benefit analysis.

That might be as informal as weighing-up the likely cost of the modification against the guessed benefit, or it might be a more detailed analysis.

A friend of mine, Paul, has a rule of thumb that goes like this:

Back in 1998, on naturally aspirated cars, he budgeted $100 per kilowatt for a power improvement. Any more than that and he thought the value poor; any better than that and – well, he thought that was pretty good.

That $/kW ratio was for mods like intake, exhaust and chip.

The best and worst elements in new car design…

Posted on September 30th, 2008 in Handling,Honda,Opinion by Julian Edgar

It never rains but it pours.

After not testing any new cars for a while, this week is the fourth in a row in which I have had new Honda vehicles. The Hondas – Accord, Jazz and two Accord Euros of different specs – have all been interesting cars.

They’ve been interesting because each of the designs has had some major positives – and some major negatives.

The 3.5 litre V6 in the Accord is simply a magic engine – powerful, free-revving, fuel-efficient with its cylinder shut-down technology, and with a glorious sound as it heads for high revs.

But the steering of the car is amongst the worse I have ever experienced in a new car, and the dry road grip is simply terrible.

Coming hybrids

Posted on June 25th, 2008 in Economy,Honda,Hybrid Power,Toyota by Julian Edgar

…from the most successful hybrid car makers in the world –

The current Prius technology is a decade old – so expect a big jump in new models.

Honda, despite always having far better petrol engines in their low-cost hybrids than Toyota, have been left well behind by Toyota – so expect an even bigger jump!

Interesting times ahead.

Your Favourite Car Maker

Posted on May 8th, 2008 in Driving Emotion,Ford,Honda,Makes & Models,Mitsubishi,Opinion,Toyota by Julian Edgar

The other day, on learning that I am an automotive journalist, someone asked me what is my favourite make of car.

I must admit the question rather stumped me. It did so for two reasons: firstly, I can’t see how any impartial automotive journalist could ever admit to having a favourite amongst car brands, and secondly, I am not even sure how anyone can logically have a favourite car maker.

I’ve owned cars made by Alfa Romeo, Audi, Austin, BMW, Daihatsu, Holden, Honda, Rover, Saab, Subaru, Toyota – and many others. I’ve driven cars ranging from Rolls Royce to Porsche to Ferrari. I’ve also driven many Mazdas, Mitsubishis, Volkswagens – and so on.

And really, despite brands developing their images based on specific advertised criteria, I have to say that the idea that certain brands have certain attributes is largely a myth.