Knocking

[Guest B34ST GTR]

Hey all,

Just had my power Fc D-jetro and Profec B elec boost controller fitted yesterday!! :laughing-smiley-014:

Hyper Drive in malaga did the job and did it pronto aswell.

Pre Fc/boost cont. Dyno was 279 hp

after FC/Boost cont. Dyno was 309 at 1.0 bar boost

pretty decent gain i thought?

However the tuner told me to keep an eye on the fc's knock reading as a mid to low 30's reading is the norm, however a knock reading of 50 is near detonation therefore call me!

i went on a two hour car cruze from carpark to car park and was getting a pretty consisent 32-36 but i did get a 41-43 at one stage.

Does anyone have any idea what this situation is good/norm/bad? before i call the boys at hyperdrive today i just wanted some other feedback.

thanks

[R31Nismoid]

no more than 25-30 is acceptable if you ask me, and thats it

Much more than that and the tuner really needs to take a look at the tune and fix up a few places

[scarface]

mine is between 5 and 15, if it ever goes into 20 i back off, u should take it back for a re-tune or take it to a better tuner

[v_s_p_e_c]

readings around 15-20 are just road noise. I somehow hit 108 once in fourth with a lot of load very scary moment but has not done it since

[fEkuaR]

readings around 15-20 are just road noise. I somehow hit 108 once in fourth with a lot of load very scary moment but has not done it since

ummmm no... 15-20 is not road noise. Its knock. On the highway my car sits on 1 - 2 knock consistantly.

[erwin_skyline]

i think any thing less then 60 is all good.

[moonus]

ummmm no... 15-20 is not road noise. Its knock

but i thought that 15-20 knock figure was mainly attributed to road noise

[crack]

at what revs and load is it knocking?

[Guest B34ST GTR]

at what revs and load is it knocking?

Most of the high readings are not from hard runs.....i get 30-35 readings at full boost at 8000rpm yet just cruising at low speeds i seem to get the 35-45's

not getting any worse so far so not to worried at the mo...

[djr81]

Well I get a reading anywhere from 0 to 120 when the clutch plates rattle on start up!!!

Don't get too paranoid or read too much into PFC knock readings. As a rule they are not very repeatable - what may give you 10 on one particular day will spit out a 20 with a different batch of fuel on another day.

Having said that a consistant mid thirties is pushing it. Probably best to plug in your lap top & hoover out a degree or two of ignition advance on some of the load cells. If you don't have a lap top you will need a mate & a video camera....

[fEkuaR]

but i thought that 15-20 knock figure was mainly attributed to road noise

bit late on my reply i realise...

I dont see anything over 1 - 2 knock while driving. And full throttle generally dont see anything over 8. So i deffinately wouldnt jump into a car that is continually sitting on 15 and assume that that all is fine.

[R31 Gagz]

Hey All,

I've got a power fc but no hand controller (getting one soon though), so I cant check this setting. I've been told the check engine warning light in my dash detects the same thing - detonation. Does anyone know what relative value it comes on at, like 20-30??

Cheers!

Gagz

[VB-]

its 60 from memory, but even that is waaayyyyyyy conservative

[a20089]

Knock must be related to "road noise" in some way. I normally get 5-13 knock for all onroad action, however when driving over some rough dirt roads I had knock up to 23.

[R31 Gagz]

its 60 from memory, but even that is waaayyyyyyy conservative

Thanks, thats good to know.....if thats conservative, then the rest of the guys are worrying about nothing when they are reading 30s.

Cheers!

[Guest B34ST GTR]

i have had people telling me anything over 15 is a problem, getting me all worried, but i have spoken to many people on the topic now and have found that anything under 50 is fairly normal provided it is only a peak figure and not consistantly sitting on 40's.

Whenever i get a high figure like 40-45 i refresh (by pressing right arrow on hand held) immediately and it has always returned down to a norm of 5-15..

high readings i have found, are a combination of, a bit of load, maybe a bump in the road or an overly aggressive stab on the throttle or a rough shift.....but definately not a direct result of giving it a bit at full boost.

thats my thoughts anyway - correct me if im wrong.

[BAMR33]

Mine never spikes that high. You should get your tuner to look at it as 45 is not acceptable. Under load up a hill accelerating full throttle at high rpm the highest mine reads is 18 but I have water injection .

[fEkuaR]

Thanks, thats good to know.....if thats conservative, then the rest of the guys are worrying about nothing when they are reading 30s.

Cheers!

Thats what i call selective listening. One person out of a large group of people tell you what you want to hear so you believe it? 60 knock is not conservative at all. And anything over 30 is heading for disaster.

Edited August 6, 2007 by fEkuaR

[Thunderbolt]

I think it is easier to forget the numbers all together and look at the bar. If the bar is large and not moving around, then it is more likely to be knock than if it is spiking etc.

Also don't forget the old fashioned way of measuring knock and that is to listen for it.

[2rismo]

What a waste of a thread. Read djr81's post and be done with it.