Request - any sample data with lambda

[pentoman]

Hello users/staff,

A friend has asked about logging lambda values and is thinking about getting a race-technology device to do so. Presumably a DL1 is the simplest way to do this but is there a cheaper option? Presently they don't want the other features of the DL1 but do find them interesting.

Secondly please can I have any files you have which contain lambda readings in order to show him the capabilities? Any sample data will do but if they're a few laps long then that would help. If they're of a car on mechanical injection - even better!

My email is anything@pentoman.com

thanks

[faraday]

Would you call a carburettor "Mechanical injection"


PS that email doesn't seem to work

[Turby]

I think that http://www.innovatemotorsports.com/products/lm1.php would be more suitable.

[pentoman]

Would you call a carburettor "Mechanical injection"


PS that email doesn't seem to work

Hmm... oh. Weird. OK well just go with -edit- which is where it ends up anyway.

Thanks!

I'm not sure if a carb is mechanical injection. I grew up in the 80s, anything without an 'i' on its badge is undesirable!!!

Thanks for the link Turby, it may be more suitable, I'll give the bloke the options so he can choose.

[tristancliffe]

I'd have thought that anything WITH an 'i' in the 80s would have been undesirable with the dodgy and restrictive metering of the time. A nice set of carbs would almost certainly unleash some power, without hurting economy (much) or driveability.

But I suppose it does depend slightly on the specific application. Injection only became desirable, in my opinion, in the early 90s for manufacturers, and late 90s for aftermarket 'on a budget' setups.

[RTUSA]

I've emailed some race data with lambda from my Mk1 VW Scirocco, which is "sort of" mechanical injection- Bosch CIS.

And btw, this worked very nicely for early emissions days. I never had a street Scirocco but did/do have an A1 GTI, very good driveability and economy. Has not needed (knock on wood!) any fuel system repairs in 25 years!

As far as logging, the DL1 + lambda sensor may be overkill for pure lambda logging, but a dedicated lambda logger won't do a lot else as time goes on. Speed / track position info is handy if there are any intermittant issues.

[Turby]

As far as logging, the DL1 + lambda sensor may be overkill for pure lambda logging, but a dedicated lambda logger won't do anything else as time goes on.

I believe the LM-1 mentioned above can record up to 5 other analogue inputs (0-5 volts) and the latest LM-2 can record up to 32 analogue inputs.

[pentoman]

Thankyou very much for the emails, great response here. The very long one I will reply to in due course! I'm not sure what injection is on the car the sensor will be fitted to.

I like cars with an 'i' on the badge, ('e' in the case of my road/track car)because they manage acceptable fuel consumption for the performance, as I understand it which is important for a poor young chap like myself . This discussion of mechanical injection is interesting because my road/track car is a Merc 190E 2.5-16 (the cosworth engined one) which runs Bosch CIS. It's actually CIS-E with electronic adjustment of fuel pressure instead of a warm up regulator. Yes there's that 'toilet lid' thing in the intake which changes fuel flow, but in addition the electronics adjust the fuel pressure to further change fuel flow based on engine temperature, intake air temperature, engine load etc. Frankly I find this injection reliable but a pain in the butt. If something is wrong you don't know if it's because of the electronics, the mechanical parts, or an air leak or a combination!

At the moment the car has a problem where initial throttle response is very soft, so it feels like it's turbocharged (it's not) and as if it's losing boost each time you let off the throttle. Not very pleasant and I can't track it down . Any opinions on this greatfully received! I've fiddled for days, months, years!

By comparison my little Peugeot 206 is dead simple with a computer connection and a load of detailed engine values it gives you as the engine is running. yay for technology.

[faraday]

While it is hard to imagine the mechanical "toilet lid" part of the K-Jetronic CIS system working well during high 'g' manouvres and having a generally long service life, it was obviously well enough engineered to satisfy many "sporting" customers.
In Porsche and BMW land, Kugelfischer mechanical systems made superior performance possible, but even the renowned German engineering did little to give long or satisfactory service. I believe that regular service for simple cleaning and fastidiously clean fuel, air and oil would keep the system performing well for over a hundred thousand miles, but most owners would not oblige.
The simpler Lucas system was worse for road car use, but was chosen for many serious Continental and even some Oriental racing engines as well as the expected British examples. Bosch took over Kugelfisher's injection business mid-70s and could provide more precisely tuned mechanical systems than Lucas. Electronic systems were well accepted in road cars long before the pure racing industry perceived a need for greater sophistication.
Three facts underlie this.
1) IC engine output changes very slowly over quite a broad A/F range
2) The possible failure paths increase with the number of components in a system, so these additional components have to have greater reliability for the system as a whole to not lose reliability.
3) Performance gains were possible with superior fuel atomisation from high pressure mechanical systems. Even today, most production EFI systems are low pressure and prepare fuel less well than a carburettor. Of course, poor manifolding can undo the carburettor's good work.
The reduced aerodynamic clutter in the induction tracts speaks for itself.
Although the weight of fuel is always significant in high performance racing machines, reliability risks could be avoided until fuel consumption regulations were introduced.
The need for more detailed and tighter control was also pushed by special fuel brews, rising RPM and advantages found controlling fuel temperature.

Tight, closed-loop control was needed in production cars far sooner for catalyst operation. Even before complex integrated circuits, microprocessors and digital control significantly increased reliability and reduced costs, a simple electro-mechanical system like K-Jetronic was probably cheaper to manufacture than a complex carburettor. Thus, while emissions were the original bogey, in mass-production high-tech actually helped profits, when the technology was mastered.

However, I sympathise with Pento's Jetronic drivability issues. Most examples I drove (never on the track, and did not include VW) felt like the throttle was connected with a soft rubber band. Notwithstanding, the contemporary Japanese carburettor cars were worse with tardy dashpots and air-control valves. Nevertheless, I find many recent 'Drive-by-Wire' systems are little better.
As Tristan appreciates, all quite easily fixed with a DCOE (or IDA) choke per cylinder, but not exactly cheap these days. Tuned well, they will be almost as economical as a similarly well tuned EFI system, unless the engine is wild. In that case, you would need to spend a fortune mapping a complex EFI sytem to be superior anyway. After-market injection is probably cheaper in the long run, especially if you want to tune it yourself. Make it like the Pug.
Manufacturers have very little interest in making their cars perform like new at ten years. Most of the desirable and affordable RWD cars for club racing/track cars are over fifteen. It is unfortunate that RWD is becoming more exclusive/expensive or historic.
If I hadn't written mine off, it would be thirty-five
Now I have a family, I think a lower powered but newer FWD might one-day be affordable and an interesting project.

As Turby states, there are sophisticated and affordable logging A/F meters available. If you have RPM and throttle position logged as well, you have the basics to do some serious fine tuning, but Nb 1) above.
All academic, of course, unless you have a tunable system.

In a turbo-car, or an atmo unit that is making a lot more power than the original, induction air temperature becomes more significant. Reducing and controlling it is necessary to find and maintain performance. As power-to-weight rises, more installation variables must be considered part of the tunable system. Just changing the fueling on the basis of an A/F reading can send you 'round the twist.
This is a good reason why a logger like the DL1 is perhaps better value than an A/F logger, because we produce a speed, position and lap number reference that is much easier to interpret than a time based record, even if it includes wheelspeed as well as RPM.

After this epistle, the simple summary should be made:
It's very much 'horses-for-courses'

[TheOtherEric]

I use an Innovate LC-1 with my DL1 and it works great. I won't bother emailing you data, because it is exactly what you'd expect it to be.

If all you want is AFR, the DL1 is overkill obviously.