I'm leading the tech/rules team for my series and we have rules that use max rpm and max boost in a formula to class weight/power (no dynos).
The competition is not fierce (4-5 in each class fighting for the points, and 10-15 more grabbing a point or two during the season) so we want to keep it decently simple.

The plan is to be able to plug in a logger of any car in the lineup to log the actual rpms and boost used during the session and then make a readout in parc fermé afterwards.
I've been looking at options ranging from the EagleTree V4 to DL1 but the option I think of now is a LM2 combined with a decent MAP sensor.

The setup in each car would be a connection with 12V, ground, rpm and a small hose for MAP.

Would a LM2 with a suitable MAP sensor be rugged enough option to quickly mount to a car or would there be better options?
The LM2 seems to be a tough enough solution to me, and it's not that expensive.
Or are there options that could even be battery powered where you log on a SD-card and then just read it in your laptop.
We only need rpm and pressure over time (with resolution good enough to spot the difference between max used and spikes).

Oh, just for kicks, here's the formula
Power= 14.5*((Volume (L) – 1.1)*0.92+1.1)*((Maxrpm (Krpm) – 6.9)*0.79+6.9)*(1 + 0.60 * Maxboost (bar))
Do I need to say it's empirical (and 2valve, carbs etc have other factors)

 

Can you just not take a datalog with the DIYPNP while out on track and then use that? Just set your redline at whatever is the highest rpm you are allowed to run, and your overboost protection at the most boost you you are allowed to run.

 

You didnt read the question did you?

Dann

 

What about a msI? Self powered, you could throw it in the car and hook up map and rpm signal. Youd have to specify that all cars have a readable rpm signal, and an available map hose barb. Plus it might be more expensive than your lm2 option, which I honestly didnt look at.

You might have issues throwing it between cars and easily picking up different rpm signals. Most timIng lights use an induction clamp offf the #1 spark plug wire, would that work? Dunno if you want that on your valve cover while racing though.

 

I missed the part about wanting to move it from car to car.

 

And that the cars range from Triumph TR2 with dual 50 Weber Volvo engine to Caterham with Blackbird engine. and some Audi TTs, Miatas on stock or modified power etc etc.

12V, ground, rpm and a hose for MAP is all i can imagine doable, easily added to a car in under a minute, easily removed and analyzed within minutes.
All cars have some kind of Tacho, or can be forced to have, but the signal can of course be of very different quality.

 

How many of these boxes do you need? One per car?

If only a small number are needed, I'd think that an MS3 (on the 3.0 board and without MS3X) would actually be ideal for this, given the ability to log to SD cards without a laptop. You could configure it to accept both an optoisolated coil(-) signal and a logic-level RPM signal on the comparator input and install an external switch to select between them. Just set up the software as though it were driving a distributor (one pulse per ignition event) and do the math to compute actual RPM from the logs. Should work for anything that isn't an odd-fire engine, regardless of what type of ignition system it has.

 

I believe he wants one or two units capable of going between all the cars.

 

One unit to start with, just the existence of a way to make controls is usually enough to improve compliance a lot.

Reading up a bit more on the LM2, it seems to be a good start, if I don't want to add a soldering job to the mix.
I have no problem to build/support it for my benefit, but this would need to be a bit more rugged and possible to handle for others too (warranty when it breaks is nice).
Running the LM2 off a battery pack would make life even easier (since loosing power will kill the logging session).

But then the DL32 cost about the same, and includes the MAP...

If I add things up a base MS3 would cost about the same in just parts. If you have some spare 3.0 broads etc it would be cheaper of course.

IF (big if, too many things started, too few delivered) I get this done and working I'll let you know.
A working solution would probably be interesting for others with limited resources (manpower especially).