Merlins Ralliart and EvoX TUNING GUIDE Version K.pdf - EvoScan

MERLINS RALLIART & EVOLUTION-X TUNING GUIDEThere are four main presentations of knock that you may encounter:1. Knock that appears to be random/non-repeatable and less than 3.This type of knock you can usually ignore. It typically means your spark map is agood match for the fuel/boost/modifications that you are currently running.2. Knock at part throttle, starting at less than 3500rpm.This type of knock can be caused by many factors, many of which are effectively“False Knock”, though each will require a specific remedy.2.1 Low octane fuel, the knock is real, get the correct octane fuel and tune as perWOT knock tuning.2.2 Noisy engine/driveline components:Valve-lash adjusters - These can and should be replaced if they are the problem.Use electronic DET-CANS to diagnose the problem.Plumbing rattles - Intercooler, exhaust or whatever. This is the knock sensorpicking up loud engine noise and will require fixing the mechanical fault These canbe somewhat harder to find sometimes. Use electronic DET-CANS to help diagnosethe problem.Forged pistons and piston slap - Some combinations cause a problem, others don’t.This is a tough one, short of changing the pistons, it is better to fix with the ECU,see the FALSE KNOCK section. Note that you can hear piston slap with goodelectronic DET-CANS.Balance shafts removed - Affects some cars, not others. Fix via the ECU, see theFALSE KNOCK section.Clutch rattle - Some twin-plate clutches have been reported as causing a problemand can be difficult to diagnose. Use electronic DET-CANS to help diagnose theproblem. Fix via the ECU, see the FALSE KNOCK section.REV: 0.K merlin@three.com.au Page 51 of 134