Hey all,

How do tuners know what frequency should use for det? Does it vary between 2L, 2.5L, forged etc?

 

If you need it to set a knock analyser, use this:

http://www.phormula.co.uk/KnockCalculator.aspx

JohnD

 

Thanks for that...just need to find out my piston ODs now...

 

Yes it varies between piston size, the larger the piston, the lower the frequency, now what engine do you have?

Tony

 

2.5L with forged pistions, CP pistons if memory serves

 

Hmm, interesting, did calculation on 99mm pistons (actual size 99.5 but calculator wont take .5) and came out at 5.8 khz. ECU has 5.68 or 5.9 Khz as setting, best to go with 5.9? If put 100 in, should then be 5.7...

 

Have you a visual display of knock detection? Knocklink, KS3 etc will listen and display noise either side of the set frequency but det will be a sudden and sharp rise in value.
The KS3 calculator gives 6.2 khz for the 2 litre piston (92mm) so you would set device to 6 khz (0.5khz increments)

JohnD

 

I have a simple knock link LED item that uses existing sensor but I will get something like KS3 early next year just to be safe. I've gone for 5.68 as that's nearest 99.5 mm pistons.

Thanks all

 

How do you set/reset the frequencuy on a KnockLink? Mine just has a simple potentiometer for sensitivity.

 

The Knocklink was a bit of a "one size fits all" device. No external frequency tuning just a gain adjustment.
One advantage it has over the KS3 other than the big "knock" LED was that it was continuous, unlike the KS3 which needs to be re-set once the alarm is triggered. The KS3 does however, give more information.

JohnD