Any way to datalog knock?

[goofynick6]

Well I think I'm going to go with the E-Manage to tune my car in the near future, and I'm going to get the ignition harness to adjust timing. However, timing is one of those things that is not so easy to adjust as a/f via a wideband. The only way I know of to tune with knock is to buy something like KnockLink which has l.e.d.'s that blink when different levels of knock occur, however, there's no way with KnockLink to datalog at what rpms it occurs, etc.

When hitting 6000rpms it's hard to watch blinking led's and do anything else. So, I was curious if anyone knew of a way to datalog knock so the timing could be tuned properly.

Thanks,Nick

[Yellow4g63]

a chezzy way is to watch your EGT gauge. If it starts to climb really fast while under boost your prob getting knock and the computer is pulling timming out. . . Well thats how it was on my DSM I have no idea about the RB's yet.

[goofynick6]

I'm thinking the best way is to datalog the timing thru the emanage, and then see if it gets retarded at all, and then work from there. Maybe?

Nick

[wga240]

Well if you get the Profec E-01 or E-01 to go along with it, you can buy the optional external signal harness and should be able to hook that up to the kncok sensor output to datalog knock.

[goofynick6]

Hmm, so that's a maybe? Not sure how that'll work since knock signals are not easy to read voltages usually.

Nick

[DSMs_Suck]

most times knock is a very hard thing to log... Most ecus have complicated algorithms built in that filter te knock signal to come up with a good knock value...

Many times it depends on voltage, RPM, frequency, etc...

[Imissmyturbo]

Can't the SAFC II datalog knock?

[goofynick6]

Can't the SAFC II datalog knock?

It can detect it, don't know if it datalogs (don't think so)

I've also heard Nissan knock sensors aren't the best?

Nick

[Wulfgang]

I agree with the EGT idea. You can get a lot of information from a good EGT gauge that can be used to tune your timing, and it will be a lot more reliable than using a knock sensor.

But regardless of the method, you'll need to first get a baseline (EGT or knock reading) so that you know where the knock starts. The additional advantage of EGT is that it can be read at any rpm, whereas the knock sensors become dead weight at high rpm.

If you are interested, Texas Instruments makes specialized knock sensing digital signal processors. They have a bunch of knock sensing information available at the website, for example: http://focus.ti.com/docs/apps/...a039. It just goes to show you how complex it is to even get a reliable knock signal.

So EGT is the way to go for the home tuner, IMHO.