Two engineering autobiographies

Posted on September 22nd, 2015 in automotive history,Engine Management,Turbocharging by Julian Edgar

I have recently been reading some engineering autobiographies relating to the early years of piston and jet engine development.

The first, The Ricardo Story: the Autobiography of Sir Harry Ricardo, Pioneer of Engine Research, is the story of the early years of life of a man who, working outside of the major automotive and aircraft engine manufacturers, made a huge contribution to the development of piston engines.

The autobiography, which covers the period between about 1900 and 1930, is especially interesting in the technical area of fuel octane and detonation. In fact, Harry Ricardo invented the concept of fuel octane rating – the resistance that a fuel has to detonation. In those days, what made a fuel effective was not much understood – to the degree that Shell was burning off, as waste, high octane fuels! Why? Because the measured specific gravity of these fuels didn’t match what was then regarded as the requirement for internal combustion engines…

Ricardo was able to physically observe detonation occurring, using windows into the combustion chamber and a moving shutter. He was the first to realise the positive implications of high-swirl combustion chambers, the first to use water injection (unfortunately not much covered in the book), and the first to build an experimental variable compression engine.

The book is written in a flowing, readable style and – for those interested in the technical aspects of his career – doesn’t get bogged-down in personal life meanderings. It’s probably best a book for those who already know something about those early days of motoring (and aircraft – the engine technology was not much different) and want to see more into a world when so much was unknown.

Another book that I have been reading is Engine Revolutions: the Autobiography of Max Bentele. As I write this, I am part way through the book – and what a fascinating treatise it is.

Bentele, a German, started his working career in the late 1930s on turbochargers. Turbos? Yes, the world’s first. He then went on to German jet engines – along with the UK’s Frank Whittle designs, again the world’s first – before the world of German engineers came crashing down in 1945 with the end of WWII.

He then migrated to the UK and then the US, working in the latter country on – among other engines – the Wankel rotary engine. It’s now not so much remembered, but US industry was very serious about the rotary engine and did much development on this design.

As I say, I am currently only part way through this book – but it is already enthralling. The non-English native language of Bentele shows a little in his prose; at times it is a bit stilted and the text more uneasily mixes the personal and professional. On the plus side, the technical detail is very high and these aspects are also well explained.

Harry Ricardo was born in 1885 and died in 1974, while Max Bentele was born in 1909 and died in 2006. Ricardo’s name lives on in the engineering consulting company that he began, but Bentele’s name is much less well known.

Two fascinating books.

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Tuning programmable management on the road

Posted on September 23rd, 2014 in Driving Emotion,Electric vehicles,Engine Management,Hybrid Power,testing,Turbocharging by Julian Edgar

Never have I had such fun when playing with a car! So what am I excited about?

Tuning programmable management on the road.

Regular readers will be aware of our Honda Insight series. As you’d expect, the publication of the articles in that series lags well behind where I am actually up to with the car. (I don’t want to run into a problem and have a big gap in the middle of the series, so it’s best from a publishing perspective that I take this approach.)

So I am around three months ahead of the series in what I am actually doing – so explaining my recent tuning of the MoTeC M400.

In the last month I’ve been tuning crank and start, fuel, ignition, idle speed control, turbo boost, exhaust gas recirculation, acceleration enrichment, wide-band closed loop feedback and lots of others.

All has been done in my shed, driveway or on the road.

It has been an immense learning curve – I’ve never before tuned a programmable management system – with some problems to overcome along the way.

But what I have found so rewarding is the degree of control that you can have over how the car drives. Tuning an interceptor (that I have previously done) or making minor tweaks to factory ECU inputs and outputs allows you to do lots of things, but tuning programmable management allows you to do so much more. (The same would also apply to factory ECUs where the software has been cracked – not the case with the Insight.)

Having so much control means that you can stuff things up absolutely mightily. I am not talking about blowing the engine (though that of course isn’t difficult with wrong timing or fuel figures) but how the car can be made to drive so badly, so easily.

Or, more positively, you can tweak and tweak and tweak until you achieve things that appear initially impossible.

The Insight is running without its hybrid electric assist at this stage, so the bottom-end torque normally provided by the electric motor is missing. With just a 1 litre engine, very high gearing (especially in first and second) and 4800 rpm peak torque, getting the car tractable around town has been no mean feat.

That’s especially the case when no ‘start-up’ map exists for this car – the MoTeC has had to be programmed literally from scratch.

The excitement of activating and then mapping exhaust gas recirc that boosted part-throttle low-rpm torque to a major degree was sensational; getting acceleration fuel enrichment sorted so the turbo boosts much more quickly after a throttle movement was fun; mapping the control of the water/air intercooler pump so that the pump works only when needed was intriguing; and designing the boost table in three dimensions to give exactly the boost behaviour I want was exciting.

I can now see better why a friend of mine years ago talked about driving to work each day, laptop on the passenger seat and making tuning tweaks at every set of traffic lights! With literally thousands of data points able to changed, and often interacting with each other in the driving, getting the perfect tune could be a lifetime pursuit.

But in the mean time, it’s a helluva lot of fun.

Bits from all around the world

Posted on August 16th, 2014 in Materials,Opinion,Suspension,Technologies,Turbocharging by Julian Edgar

I’ve written before about the enormous range of automotive parts now available through eBay, but until I have been working on my little Honda, I’d never realised how well developed such a part-sourcing network it now is.

As I write this morning, I am watching the tracking on my DHL express package that contains the stainless steel gasket set for my turbo. The package, in the last three days, has been through five countries. It started off in Latvia, went then to Lithuania before reaching Germany. Then it travelled to Heathrow airport in London, before arriving (this morning at 2.20 am) in Sydney. Out in country New South Wales, I reckon I’ll get it in the next few days.

And the exhaust gaskets are not alone in having travelled far.

My Bosch fuel pressure regulator came from the US, the fuel rail adaptor from the UK. Also from the UK came carbon fibre sheet for making a new dash panel, and replacement ignition coils. Other stuff direct from the US has included oil temperature and pressure sensors, the boost control solenoid and a water/air intercooler pump.

From China there has been a host of parts – the front-mount radiator for the water/air intercooling system, fittings, hose clamps, hose joiners and rubber grommets. On its way now from China are a thermocouple adaptor board, a weld-on bung for the thermocouple, and the thermocouple itself.

And of course I have bought plenty of parts locally.

With the fast availability of parts, cheaper than ever before, from all around the world, there’s never been a better time to be modifying cars…

Wrecking yards are better than ever!

Posted on August 8th, 2014 in Engine Management,Materials,Opinion,Suspension,Turbocharging by Julian Edgar

I’ve always loved going to car wreckers, looking at the bits and pieces available so cheaply and wondering how I can integrate them into my car.

I started visiting wreckers when I had my first car – a 1973 Honda Z. That was way back in the early Eighties. I remember looking through the field of dismembered wrecks, finding dash parts from Honda Civics that I could shoehorn into the Z. I even integrated the high beam flash stalk from a Datsun 260Z into the little Honda.

Time passed, and I was then looking at wreckers importing Japanese engines and transmissions…. That led to a turbo 660cc 3-cylinder engine going into my Daihatsu Handi, and later an RB20DET turbo six going into a C210 Skyline.

I have been musing over this because in the last month I’ve been spending a lot of time back in wrecking yards.

I’m lucky enough to have discovered a wrecker of the old school, one that lets you wander around the yard of cars, spanner and pliers in hand, able to take off whatever parts you want and then take them to the front counter to have them priced.

But the big difference now is this: with modern hi-tech cars having been around for literally decades, the sheer variety of the parts that you can buy is amazing.

Need an idle speed control valve (as I did the other day)? Well, at this yard you can chose between Bosch (three types), Nissan, Toyota, Holden, Ford, Mazda – basically, every car in the yard has an idle speed control valve!

After half an hour of browsing, I walked out with a Bosch idle speed control valve from a BMW, complete with plug and a short section of loom. Cost? AUD$33.

Need a factory bracket on which to mount a GM MAP sensor? Sure – look under the bonnets of not only GM cars but also Daewoos. Cost? In this case, I was charged nothing!

Want some direct fire ignition coils? Would you like those coil-on-plug or remote-mounted? After a long look, I decided instead to go brand new with some Bosch coils – but the browse through the yard showed some very interesting approaches.

Need some 19mm hoses, preformed with bends to plumb a turbo blow-off valve? An hour later I walked out with no less than nine of them – all different lengths and bend radii. Cost? AUD$11. Oh yes, and that also included a rubber mount for the idle speed control valve that I’d forgotten to get earlier!

If you’ve not been to a wrecking yard for a long time, find a good one and have a long look around. You might be as surprised as I was.

 

Water/air intercooling

Posted on July 1st, 2014 in Intercooling,testing,Turbocharging by Julian Edgar

We will be covering in a later issue of AutoSpeed what I am about to write about – so this is just a quick heads-up.

If you are developing a custom water/air intercooling system, here are some critical questions for you.

1. How can you bleed all air out of the system? Nearly all commercially available aftermarket water/air heat exchangers don’t have bleed fittings. If you are mounting these heat exchangers conventionally, eg horizontally, about one-third of the internal volume will stay full of air – not water!

2. How are you measuring pump flow? If your answer is to pull off a hose and direct it into a bucket, then almost certainly the amount you measure will not be correct. Why? Because pumps will often work differently when they are part of a closed system versus an open system.

3. Finally, is the pump flowing effectively – or is it cavitating? Of the three pumps I tried in my system, only one was effective in circulating water without any apparent cavitation.

Looking around the web at pics of custom water/air intercooling systems, I’d guess that many (most?) of these systems are operating below par because of these issues.

 

Turning over a new leaf

Posted on March 14th, 2014 in Intercooling,tools,Turbocharging by Julian Edgar

Over the last few weeks I have been working on my little Honda Insight. I’ve been installing a turbo, water/air intercooler system and a new airbox, the latter fabricated from scratch.

It’s a complex job in that there’s not much space – especially when I am deliberating oversizing everything (but the turbo) to improve volumetric efficiency.

I am also doing things in a significantly different way to the approach I’ve used previously.

So what’s different then?

Specifically, I am being very careful that each newly-placed nut or bolt can be easily accessed by a tool. This means that instead of just looking at aspects like strength, weight and functionality, I am adding another criterion – can I get a spanner (easily) on that bolt?

It might seem a kinda obvious thing to do but I must admit I have never much done this in the past. In fact, I remember working on my little Daihatsu Handi turbo, way back around 20 years ago. The water/air intercooler I first installed on that car was so tight for space that the nuts had to be placed on bolts using long-handled, long-nose pliers. Yes, both long-nose and long-handled!

It was like performing surgery.

I got so jack of it that in the end I removed that intercooler heat exchanger and fitted another that sat on top of the engine rocker cover, in clear view – and with clear access.

The trickiest job so far on the Honda has also involved a water/air heat exchanger core, the one that sits on a fabricated steel frame bolted to the top of the gearbox, next to the engine.

The intercooler bolts to the frame via three rubber mounts. I need to (1) gain access to the frame’s mounts to bolt it to the gearbox, and then (2) gain access to both ends of the rubber feet, and (3) gain access to the bolts that hold little (extra) brackets to the intercooler core itself.

So far I am JUST successful: the rear bolts for the intercooler rubber mounts, positioned partly under the windscreen in the deeply indented firewall, can be accessed by using a short 12mm spanner – not a ratchet spanner as it looks may be needed, but a conventional spanner. The other fasteners are all easily accessible.

Another tricky job were the mounts for the airbox. A long cylindrical design mounted at an angle to the horizontal, it also sits on the gearbox. By manipulating the bracket design until it was all ‘just so’, I am able to access all three mounting bolts using a long extension on my small socket set.

Importantly, making a design that allowed access to these points was almost the first step in the process – I didn’t position the airbox solely for plumbing access to the turbo. Had I done this, the bolts holding the airbox in position would have been ‘blind’, and furthermore, would have needed tiny hands to even get to them.

And I have to say, positioning the fasteners for good access has made it so much easier to work on the car. That’s especially noticeable when some items, like the airbox, have been on and off perhaps 50 times while the intercooler water hoses have been routed and then fastened into place, and then the intercooler-to-throttle-body tube has been fabricated (twice!).

So for me no more the bad habits of the past: now everything I install has to be easy to work on, no matter how small the space into which it must fit.

Optimising turbo boost control for performance and fuel economy

Posted on December 4th, 2008 in Driving Emotion,Economy,Turbocharging by Julian Edgar

The more you think about turbo boost control, the more implications there are for any given system.

Let’s just refer to a traditional wastegate system.

(That’s where there’s a bypass passage – the wastegate – around the turbine. Open the wastegate and exhaust can bypass the turbine, slowing turbo speed and so dropping boost pressure. Remember – the less open the wastegate, the higher the boost pressure.)

In this discussion it doesn’t matter if it’s an electronically controlled system or a simple pneumatic system.

Let’s say that boost pressure is sensed from the compressor outlet of the turbo. If the maximum desired boost is 10 psi, the maximum outlet pressure of the compressor will also be 10 psi.

But the situation changes if the boost pressure is sensed from the intake manifold. If 10 psi is again desired, the boost pressure at the manifold will be 10 psi, but the boost pressure being developed by the turbo will need to be higher.

Taming throttles

Posted on November 11th, 2008 in Engine Management,Mitsubishi,Opinion,Turbocharging by Julian Edgar

A while ago in a reply to another blog post, I wrote about the current Lancer Evolution that:

 

“The Evo should use far improved throttle mapping where blade angle is mapped against foot position and the calculated instantaneous tractive effort value. It should also use a smaller turbo. ”

 

At least one reader was so excited by this notion that he wished to “quietly roll up into a foetal position and rock back and forth on the floor”. However, leaving aside bizarre responses, it’s a concept sure to interest some.

 

I won’t discuss the ‘smaller turbo’ bit because most of you will have a good understanding of this idea. But what about the throttle mapping?

 

In electronic throttle cars, the relationship between the accelerator pedal position and the throttle blade opening no longer needs to be linear. In a linear system, the throttle blade would be half open at 50 per cent accelerator pedal travel, three-quarters open at 75 per cent accelerator pedal travel, and so on.

The disappointing Lancer Evo X

Posted on October 8th, 2008 in Driving Emotion,Mitsubishi,Opinion,Turbocharging by Julian Edgar

Look, I am sorry to say so, but I just don’t think the Lancer Evo X lives up to its hype.

In fact, as a driver’s car, I don’t think it even lives up to the (immense) promise that drives of previous Evos would lead you to expect.

There are four separate problems.

Firstly, the engine drives like an old-fashioned turbo. That is, despite the hoopla about variable valve timing, super lightweight turbo assembly and all the rest, the engine is slow to come on boost.

In fact, the engine really only gets going at just under 3000 rpm – say, 2800. Redline is 7000 rpm so that gives you just over 4000 rpm of powerband. Not terrible, but certainly nothing special.

Monitoring Factory-Fitted Oxygen Sensors

Posted on September 16th, 2008 in AutoSpeed,Economy,Engine Management,Hybrid Power,testing,Turbocharging by Julian Edgar

This week we have the first in a two-part series, one that I am very pleased with.

The series is on how to use cheap and simple electronic kits to monitor the output of the oxygen sensor.

The first story I did on this, way back in the mid 1990s, resulted in the development of the ‘Mixture Meter’ kit – thousands have since been sold.

Now we both re-introduce the narrow band sensor display, updating the story to additionally discuss what many people want from such a display (and that’s improving fuel economy) and also, in Part 2, look at how a similarly cheap and easy-to-build display can be used with wideband sensors.

The latter is especially significant: while there are plenty of aftermarket air/fuel ratio meters that use wideband sensors, we’ve never seen a description of how to tap into the standard wideband sensor fitted to many of today’s cars.