This week we discuss getting into the software of electronic throttle and stability control systems, and the Lachlan suggests the common mistakes that he sees being made in car modifications.
One of the things that has surprised me is that in the last five years or so, there hasn't been any software modification of systems other than engine management. It seems to me that you could achieve enormous gains in driveability and effective on-road performance - not necessarily on the dyno but on the road - if you started modifying software in areas like electronic throttle control. Why aren't people going into electronic throttle control software and modifying it to give a more sporty characteristic, which could have great advantages in driveability?
I don't know about other companies, but the only one that I have looked at in detail was the BMW M5, and it was substantially good to start with. Certainly in terms of electronic throttle control systems, we've had limited access to it here in Australia. But throttle control and gearshift control are vital points to improving how the vehicle drives on the road. [But] these are items which are often difficult to convey to customers through advertising in a magazine. We can't say that if we shift the throttle control or the gearbox change points that the car makes any more power.
It doesn't.
However, the car may drive substantially better on the road in terms of its throttle response and overall acceleration to suit a certain market. I mean, if the car is a large heavy vehicle and we make it respond more like a sports car, then although the vehicle has made absolutely no more power, it will drive substantially better. This is difficult to convey through general marketing - perhaps again it comes down to the integrity of the modifier. If we say that it's good just as the manufacturer produced it, then leave it alone.
So you'd feel quite positive if someone came to you with an Alfa 166 - which has got abysmal throttle response from its electronic throttle - and said, "Can you make the throttle work a bit more as I would expect of it in a sporty car?"
Indeed. The first question is, 'are we able to access the software?' because I haven't done any research at all on the current series of Alfas. But if we are able to do so, I'd have no difficulty at all in modifying the software to do throttle control. I'd have to have a look at its emissions implications, but certainly outside of the ADR 37/01 or the Euro [emissions] requirements, we should be able to make it respond much better - if I'm able to access the software.
I am also surprised that no-one has gone into car control systems like Vehicle Stability Control. Why haven't people changed certain software factors so that the car can get more out of line before the Stability Control comes into operation?
I suspect two reasons. One would be that the degree of difficulty in accessing the software may be beyond the average modifier's level.
The second may well be litigation issues, in that vehicle stability affects how the vehicle will enter a spin or the point at which control will be lost. These will have litigation ramifications which I certainly haven't looked into any detail at this point. Nor have I modified the software what you are describing.
A simpler version of that same question - traction control. I could see a situation where someone says, "Look, I still want traction control - it saved me on a greasy road - but I'd like it to come on a bit later". That would seem to have less litigation issues - do you see an opening for work in that area?
I guess that it's certainly feasible. At the moment where we've headed people is to say, "Look, we've got an aftermarket traction control system which is designed specifically for sports feel and sports response, and will allow you to drive the car with a result that may be considerably quicker than the original traction control system while still giving the ability to retard the engine's torque when the vehicle is about to spear into a profound oversteer".
I haven't looked in detail at the standard traction control systems.
What about more recent Holden systems, which you would know reasonably well. They've got traction control built-in as part of their ECU operation.
Yes they have. Again I concede that I haven't looked at modifying their software; I have done work in adding our traction control systems to it. Their software - as I am sure you're aware - tends to pounce, and tends to rip the torque out of the engine extremely fast, choking and killing the engine response and the vehicle's response on the road. Certainly it will bring it back into line and keep the vehicle - for want of a better description - under control, but it leaves the feeling of just having the engine strangled as you're driving.
With respect, your traction control system is extraordinarily expensive. If I have a car which already has traction control, it would take a lot of convincing for me to say, "Well, disconnect the factory system and put on your very expensive aftermarket system." Your specialty is in modifying factory software - it seems that would be a far better way of doing it.
It's entirely feasible. The hard part would be finding sufficient customers who are saying that they need their factory traction control system modified - to make it a viable exercise for us.
Let's change topic to the broader modification scene that you see a lot of. What do you think are the most common mistakes that people make in modifying late-ish model cars?
Perhaps going for the simple fix. They see an airflow meter - from my perspective a complex scientific measuring instrument - and they decide that the total air/fuel ratio up high in the engine rpm is too rich. So they say, "If we just knock a few screens out and polish the inside of the airflow meter that'll make it leaner up high and we'll have derived the response that we want".
This to me seems like taking an axe to an engine management system. The results gained up high may be leaner than they originally were, but the finesse and the control of the engine management on the way through has also been hacked to death. It may lose all of its ability to make fine adjustments to the fuel mixtures or the ignition timing - both responds to that amount of air - by losing the accuracy of the measuring tool.
Couldn't a car company engineer say exactly the same thing about the software modifications that you make? There are typically hundreds and hundreds of variables in factory engine management software - and you're accessing perhaps only eight or ten of those variables when you make changes.
Certainly they could say that. But when the two primary inputs into an engine management system are the amount of air that the engine is consuming and the engine rpm itself, if you're modifying the tool which measures how much air goes into the engine this seems to be an extremely dangerous application. If I'm modifying the original software (which takes all of this information in and commands a certain result out), then I am doing what the manufacturer originally does. Perhaps I am doing it to a different set of parameters because I am working in the aftermarket industry, but I am doing with their tools what the original software calibration engineers at the factory were actually doing.
What are some of the other things that you see as common mistakes?
Unnecessarily changing the exhaust system if the exhaust system actually isn't a flow restriction, or the air intake system if it isn't a flow restriction. Or, worse still, modifying the air intake system and providing a less dense air mixture to the engine. If you're drawing-in hot air from under the bonnet, the likelihood is of generating a worse condition - even though you've got a freer flowing airfilter system - than having the original air which was drawn from outside of the car in a cool airstream. These are the sort of modifications that I see that can be detrimental. If they're done the right way - if there's sufficient improvement in the air density and the airflow - both in the exhaust and the intake system, then certainly they'll be a torque and a power response.
How would you like to see testing done of that? Obviously you cannot look at an exhaust and say that it is restrictive or free-flowing...
Unfortunately, it's very difficult. You've got dyno results that you can use to measure the power and you can remove sections of the exhaust and substitute other sections, and this should give you a reasonable indication of the improvement in airflow - if there's going to be one. You can check intake system flow if you remove a certain component of the intake system - again on the dyno. If the engine improves its power output then there's certainly a restriction of the airflow into the system. However, the only way to accurately measure your temperatures is to put temperature probes into the intake and measure it on the road, back-to-back with the modified filter.
What about camshafts changes on modern engines? Do you think that they are largely successful or unsuccessful - or is that too broad a brush to be painting?
It's far too broad a brush to paint. There are applications where the appropriate amount of research is done by camshaft engineers and engine management modifiers to actually test certain camshafts in various applications and derive the appropriate response. We have camshaft packages that we happy are a combination of gaining an improved torque and power output and not modifying the low-end response of the vehicle too much.
However, I regularly see camshafts which are just inappropriate for the modification that the customer was actually wanting out of the vehicle. They may have lost far too much torque at the bottom end or generated a cantankerous result out of the engine.
So in sequence of modifications, your recommendations on a typical naturally aspirated modern engine would be along the lines of looking at the exhaust, looking at the intake, and making changes as required. Then engine management?
Yes, usually then engine management, because you're going to try to put the appropriate level of ignition timing and fuel mixtures with those modifications. If the modifications have been successful and there's a change in the amount of air that entered or exited the engine, then engine management modifications are appropriately going to be the next step. If the customer's next step after that is going to be cylinder head modification or a camshaft, then again they'll need to look at engine management after those modifications have been done.
Next week: New software for the Gen III/LS1 Holden engine revealed!
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