Race Technology

How do I determine the scaling for my 4 cylinder Toyota 2ZZGE engine ?
The RPM seems to be too high by about 25%

What is the value of the "Ignition Pulses Per Revolution" field in Data/Vehicle Options/RPM-tab?

I would expect a value of 2 would be correct for your engine. (4 cylinder, 4 stroke). The ignition normaly fires twice for each revolution of the engine.

What does the RPM trace look like? Is it smooth, or does it have noise in the signal?

What is the value of the smoothing in Data/Variable Manager/External Inputs/RPM? Try changing that to a smaller value to see how smooth/noisey the RPM trace really is.

The Elise uses the same engine and the "Ignition Pulses per Rev" in the Car Options dialog should be .5 (as well as for the Dash1 and VOB).

Thanks I am now Registered as 007FSR as I cannot log in as Fraser will.

Have tried it at 2 and seems to work and shall now try it at .5 to see if any difference.

I now understand I should also set the lower limit to say 500 RPM and the upper to say 9,000 as the Toyota2zz revs to 8,500 in standard form. The default is I understand 8,000RPM.

What does the smoothing setting do?

Smoothing stops the signal from being erratic. I use around 0.5 second smoothing. Use slightly less if you run a lightweight flywheel.

A setting of .5 ignition pulses per revolution would be correct if you were picking up the signal from a single spark plug wire (or a coil on plug setup). If you are using a coil/distributor and using the coil input then you would use the value of 2. So, both values could be used for a 4-stoke 4-cylinder engine.

I also have problems.

Use the tach Out from an MSD 6A and the signal looks perfect, no problems with noise or anything but it reads too high.
I also have an Autometer tach Pro Comp 2 Ultralight connected and it reads correctly, verified with speed vs. gearing calculations.

~6700rpm reads 8000 on the DL1.

Any thoughts or ideas what might cause this. Doesn't matter if the tach is connected or not and the signal trace is crystal clear.

Mats:

Some of the early "Mk2" (single black connector, serial port on rear) DL1s had a firmware bug causing RPM to read high.

Please send me an email confirming your type of DL1 and I'll email back a firmware update.

aseim@race-technology.com

Hi,

I run my system normally on a Triumph TR4 with good results.

I now moved the equipment to my TR8 with V8 engine and I get funny RMP readings.
https://www.youtube.com/watch?v=-cXyGUUazAw

I connected the DL1 to the MSD 6a box to get a clean 12V square wave signal with a 20% duty cycle.

What can cause this to have 42000rpm?

Cheers
Chris

Have you checked the settings for the number of pulses per engine revolution? Depending on the settings on the ECU and in the software that could give odd results. I assume there is a tacho output from the MSD box?

Martin

I have set the number of pulses to 4 per revolution.

This is the MSD manual.
http://www.msdignition.com/uploadedFile ... ctions.pdf

It shows the tach output to which the DL1 is connected with.

Cheers
Chris

Problem is solved:

I mixed up polarity on the DL1 connector.
12+ from ignition went to the ground and vice versa.

Now connectors are sitting correct and revs are shown as they should

Thanks for all the input!

Cheers
Chris

Now it is working correctly:

https://www.youtube.com/watch?v=1stg7HYcMs4