xpro

iTrader: (2)

Tuned for 25psi my car still knocks for some reason,i tried using race fuel and knock is still there.Theres nothing loose underneath that would trigger the noise,checked everything.Also there is very bad knock on lift off,could Dumpvalve maybe cause the knock on lift off?
i have leanspool enabled at the mo,but with leanspool disabled car still knocks the same,but it just runs about half point richer.


I attached my log if someone can please review it for me,i can also email my map if anyone wants to look at it.

Sharkbite2000

iTrader: (21)

did you drain out the regular gas completely ?

dudical26

iTrader: (17)

First of the knock counts are pretty small and are not effecting you octane count so they are really not that bad at all.

What kind of gas are you on (octane rating)
You fuel is pretty rich, you really should never see the number 10.XX on race gas.
Personally I would keep it at 11.5 or leaner. I know too much fuel can definitely cause knock.

Also those logs are ok, but really not the cleanest for tunning. In some places you have 23psi before even going full throttle, and then the pull is only 500rpm long.

xpro

iTrader: (2)

i used 105ron with little bit of 99ron left in the tank.

Sharkbite2000

iTrader: (21)

I guess you see where It came from

jcsbanks

All seems to be part throttle or lift off.

I attach my timing map for 9 FQ340 on 99 RON with Walbro, 3" exhaust, airbox mod running similar boost (except I hold 25 PSI to 6000 RPM). Tested over a year in all driving conditions - see how savage I had to be with intermediate load timing. I've used just enough retard to get rid of all predictable, repeatable knock. Occasionally I get a knock count a little higher, dropping off an octane number of 100 happens briefly about once very few months (I log continually on Pocket PC), but the conditions are not repeatable, or the odd lift off count of 7 or 8 very occasionally, but again not predictably.

The sudden ramp up in timing with weird mixtures on lift off (from the remainder of what's in the inlet manifold and whatever fuel the injectors add to it) probably creates an odd combustion event during the actual lift off. It does seem to be timing responsive. It may well not do any harm at all, but I got rid of it because I could.

skold

iTrader: (6)

i had same issues i had a bad rod bearing.

JohnBradley

iTrader: (30)

Clutch springs in a bad clutch will cause phantom knock. Like has already been pointed out its lift off/shift knock and a loud BOV will set it off. I saw 24 counts with an HKS the other day.

xpro

iTrader: (2)

you trying to scare me

i will work with my timing to see if that helps.Im definately suspecting my aps BOV for lift off knocks.

i will try your timing jbs, mine acctually looks all over the place.

thanks lads

matt55

iTrader: (12)

+1
me tooooo , only in 4th i was getting 5-7 counts of knock even after straight 110 oct .

bigpzz

iTrader: (2)

are you sure it has the right octane rating

fastrob691

iTrader: (9)

I have APS BOV and no more lift knock than with stock BOV.

xpro

iTrader: (2)

what boost are you running?

i think you right there,i adjusted my timing abit,so lift off knock is gone,but still getting few knocks on wot after 5rpm

taenaive

iTrader: (20)

It looks like your overly rich condition is causing the knock.