Rb26 Safe Knock Levels

[R33-RB26DETT]

Just got my PowerFC installed and I have been monitoring my engine knock.

Normally it is between 12 and 37.

The other day it was pretty hot during the day at it went up to 67.

Is this something to be worried about, or is it pretty normal?

Edited June 28, 2009 by R33-RB26DETT

[James_03]

http://paulr33.skylinesaustralia.com/docs/...powerfc-faq.htm

[benro2]

I used to get crazy high readings on my PowerFC (this is on a Supra TT BTW) but nothing ever happened to my engine. I thought that surely there must be *something* wrong to be getting knock readings of 120+ (sometimes, but always only on WOT). So I got it retuned by a PowerFC guru, and now it's even worse I've seen figures over 150, *however* this is the important part: I have never seen the Check Engine light illuminate.

I'm not sure what light it illuminates with the GTR but I assume they've wired it up to something! A lot of people in the Supra forums didn't seem to realise that the PowerFC *will* retard ignition automatically when it detects excessive knock, in tandem with illuminating the Check Engine light (or whatever it is in the GTR). I have also confirmed this with my tuner.

I have never witnessed any decrease in power on WOT either. I usually floor it then view the max readings on the hand controller straight after, and even after those figures of 150+, I have *never* seen the Check Engine light illuminate and have never felt any reduction in power, not to mention, I can't hear any knocking!! Although, with a decently loud exhaust and at 6000+rpm, you may not anyway

Bottom line: I don't think there's much you can do with abnormally high knock readings with a PowerFC. I think all you need to do is look for the Check Engine light, listen out for knock, and make sure you're not feeling a reduction in power. If you don't get any of this, just forget that you saw the high reading and be on your way I had some problem accepting this but the reality is, I've been giving it WOT for nearly 2 years and there are no signs of engine damage!

[maximajim]

I'm not sure what light it illuminates with the GTR but I assume they've wired it up to something! A lot of people in the Supra forums didn't seem to realise that the PowerFC *will* retard ignition automatically when it detects excessive knock, in tandem with illuminating the Check Engine light (or whatever it is in the GTR). I have also confirmed this with my tuner.

Since when does the pfc retard knock? There are no settings for knock retard in fc edit.

[snozzle]

knock sensors are known to be dodgy and fail, id definently look into buying a new one if you wanna be sure, im pretty sure standard ecu's retard the timing wen there is knock detected, otherwise why would u have one? however im not sure about the power fc, id assume it would if the stock ecu does tho

[limpus]

I used to get crazy high readings on my PowerFC (this is on a Supra TT BTW) but nothing ever happened to my engine. I thought that surely there must be *something* wrong to be getting knock readings of 120+ (sometimes, but always only on WOT). So I got it retuned by a PowerFC guru, and now it's even worse I've seen figures over 150, *however* this is the important part: I have never seen the Check Engine light illuminate.

I'm not sure what light it illuminates with the GTR but I assume they've wired it up to something! A lot of people in the Supra forums didn't seem to realise that the PowerFC *will* retard ignition automatically when it detects excessive knock, in tandem with illuminating the Check Engine light (or whatever it is in the GTR). I have also confirmed this with my tuner.

I have never witnessed any decrease in power on WOT either. I usually floor it then view the max readings on the hand controller straight after, and even after those figures of 150+, I have *never* seen the Check Engine light illuminate and have never felt any reduction in power, not to mention, I can't hear any knocking!! Although, with a decently loud exhaust and at 6000+rpm, you may not anyway

Bottom line: I don't think there's much you can do with abnormally high knock readings with a PowerFC. I think all you need to do is look for the Check Engine light, listen out for knock, and make sure you're not feeling a reduction in power. If you don't get any of this, just forget that you saw the high reading and be on your way I had some problem accepting this but the reality is, I've been giving it WOT for nearly 2 years and there are no signs of engine damage!

Interesting...i've got a supra too which runs a PFC and i can get abnormally high knock readings too...especially if i hit the limiter by mistake...and my engine check light does not come on as well...i am pretty sure that the PFC does not retard timing though...

[Johnny]

I tried a little test the other day to see whether it was road/engine noise and/or faulty knock sensor:

run on the freeway when no1 is around then push the clutch in and reset the controller to get a reading with no engine load; ive found that on smooth roads there is still 8-10knock and on harsh/bumpy roads i can get as high as 10-18knock.

i guess this would work for a faulty knock sensor too ie if you get 50knock when coasting.

[Beer Baron]

I used to get crazy high readings on my PowerFC (this is on a Supra TT BTW) but nothing ever happened to my engine. I thought that surely there must be *something* wrong to be getting knock readings of 120+ (sometimes, but always only on WOT). So I got it retuned by a PowerFC guru, and now it's even worse I've seen figures over 150, *however* this is the important part: I have never seen the Check Engine light illuminate.

I'm not sure what light it illuminates with the GTR but I assume they've wired it up to something! A lot of people in the Supra forums didn't seem to realise that the PowerFC *will* retard ignition automatically when it detects excessive knock, in tandem with illuminating the Check Engine light (or whatever it is in the GTR). I have also confirmed this with my tuner.

I have never witnessed any decrease in power on WOT either. I usually floor it then view the max readings on the hand controller straight after, and even after those figures of 150+, I have *never* seen the Check Engine light illuminate and have never felt any reduction in power, not to mention, I can't hear any knocking!! Although, with a decently loud exhaust and at 6000+rpm, you may not anyway

Bottom line: I don't think there's much you can do with abnormally high knock readings with a PowerFC. I think all you need to do is look for the Check Engine light, listen out for knock, and make sure you're not feeling a reduction in power. If you don't get any of this, just forget that you saw the high reading and be on your way I had some problem accepting this but the reality is, I've been giving it WOT for nearly 2 years and there are no signs of engine damage!

your tuner is flat out lying or just does not know what he's talking about. Power FC DOES NOT RETARD IGNITION ON DETECTING ENGINE KNOCK. I hear this myth all the time. the factory ecu certainly can do it, but power fc does not which is why a good tune is important.

it is possible your high knock readings are being caused by a faulty knock sensor. but if it was real knock do not think the power FC will save you by reducing timing. cause it most definitely wont.

[Guilt-Toy]

SEARCH!!!

http://www.skylinesaustralia.com/forums/Kn...ml&hl=knock

all explained here.