Hi guys,

Recently I just went up to do a dyno tune.

What I have noticed...

For example:
On the either the mitsulogger or the evoscan, it shows knockcounts of 4 to 8.
Whereas with the Knock gadget hooked up to the ride, it didnt show any traces of knock noise.

I am able to push the limit of the tune til i hear the knock noise from the dyno knock gadget and reduce it down by a percentage.

Power and torque is great.

But the question is:
1) Which information should i follow?
- go by the mitsu or evoscan way or the knock detector that is hooked up to car?
2) With the mitsulogger and evoscan, the octane level/flag went down from 255 to 240 correlating with the knockcounts register with the logger but the knock dyno gadget doesnt show any. I also didnt see any retard of timing.

I should follow which info?

Please advise ecuflash gurus out there....

 

Follow the Mitsu sensor. If its showing knock its pulling timing and hurting performance. If you don't believe it to be real knock then find out where the knock noise is coming from and fix it. You need to play nice with the OEM knock sensor.

 

+1

 

for clarification, what you see on the loggers is what the car ecu is seeing. mitsulogger and evoscan and others are just reporting information, they don't generate it, (except to calc load).
the knock sensor that comes with the car is more likely to be correctly reporting knock than a third party unit. In your case the knock was severe enough to reduce octane, that is pretty significant. If you think your timing is way out of whack when tuned to the ecu's knock sum, then I would suggest a visit to the shop* to verify that there isn't a loose wire, or such misleading your stock sensor.

*not the shop that used the third party unit.

 

thanks for the advice guys...

No harm visiting the dyno operator again to reconfirm the suggested thoughts..

Will update you guys again the following day..

Anymore inputs on this topic is highly appreciated..keep them pouring in...

cheers mates!

 

according to jscbanks he used some det cans and evoscan to measure knock and he says that knock passing the 18knocksums is where some slight det could be heard through the det cans but all in all is better to tune to 0-3 KS safty is first.
i had my car tune with an xede and some off the shelf maps from the vishnu sit and i drove my car for 12,000miles with their tunes and when i bought my evoscan and ecuflash my surprise was that my car on 3erd gear pulls had knock sums of up to 15 passing the 6000rpms and my car i have made compression test to the engine and its still a healthy engine my car was riding the knock sensor but thank God the ecu is so good at correcting knock and saving up your engine.

 

Throw the knock gadget in the garbage with the rest of your narrowband AFR gauges and undercar neons.

 

You can hear knock sums much less than 18 with det cans if it is on lift off because the ECU doesn't correct it.

Under full throttle the ECU is quite good at keeping it all quiet, but I shoot for 0-3 knock sum because this is how you get the highest possible average timing by cooperating with the ECU. If you have say a knock sum of 5 you'll be retarding about 2 degrees, yet 1 degree off the timing map would have kept it all quiet and you might end up running 1 degree more.

 

Yeah, I remember that and you had a destroyed spark plug because of these poor maps. IIRC, Shiv does not log knock sum when tuning. If JCSBanks is correct, (and most of the time he is), then Shiv could not hear the 15 conuts of knock when creating those OTS maps. I knew these maps were dangerous and that is why I only tested one of them once and that was it.

Could you PM me that e-mail from Dustin regarding KS that you sent to me once? I seem to have lost it.

Thanks

 

I don't know that you couldn't hear a sudden 15 under full throttle because I've never triggered it, but I did conclude I could not hear any detonation when the knock sum was tuned to the 0-3 range and this gave the maximum timing.

 

hi nj your right thanks God the ecu pulls timing when needed cause if not my engine would have exploded something else that helped me was that i was using 93oct with a 91oct map for the xede and thanks to you for helping me and teaching me how to tweak the xede maps
i checked my emails but i most of erased it dustin told that knock sums where floor noise and that 15knock sums was fine. iam know very unhappy with vishnu they answered all my emails but never gave me a solution to my problem, nj did, not them,know i dont use the xede its still hooked up with all its tables zero'd out cause no one wants to buy it and i didnt feel capable of tuning my own stock ecu so now mellontuning has been tuning my car and all i can say is that according to DLL my car has gained more power using his flash and the car is a blast to drive and its more smooth and its able to run more timing in comparison to the xede.
somewhere in this forum Al from dynoflash and sean ivey said that no one knows how much of knock sums will blow an engine why dont they say to people then how much?


jcsbanks in a pm you told me that 15knock sums you could hear slight dets but nothing meaningfull and this gave me peace mind.
i regret so much that i drove the shoot out of my car with such a poor tuning with the xede i hope nothing has damaged in my engine i did a compression test and all cylinders came fine,if it wouldnt have been for the stock ecu controling knock i would be with a destroyed engine.

know to anyone out there what are the damages i made to my engine using a bad tune? i check compresion and it is fine anything else i should check?
thanks a lot.

 

Different motors will sustain damage at different knock sums. The biggest difference being the amount of power the motor makes. The more power the less you can detonate before hurting something all things being equal. Stock EVO's can detonate something horrible and run fine for years. Modified 500whp pump gas cars can be damaged extremely quickly, even with factory knock control, when things go sour for just a little bit. In all cases though its best to play nice with the knock sensor and learn to be good friends with it. Even low levels of detonation will slowly pound the rod bearings over the years and extend the clearances to and past the service point.

 

A big part of the problem here is most people have no clue what the knock #s mean, is 15 high or low? Is it dangerous? What impact does it have on the engine long and short term.
Without this type of information, it is hard for some people who are only starting and are only tuning one simple combination to determine what it is they are shooting for, also some tuners have a different approach where they let the car run on the knock control.
Experience is a huge part of the tuning equation.

Ask yourself, "how much knock would it take to push a stock rod through the block?"


Sean
__________________

Nevertheless, base on your assumptions, most people would think that it’s safer to keep your “knock #s” low (to zero); since there is some correlation between high knock #s and a blown engine….wouldn’t you say?
Offline

this is a quote from sean ivey

 

so what knock sum do you need to push a piston out cause iam worried that in a past my car had a crap tune with 15knock sums and 12,000miles driving it like this an racing it all the time?????

 

something i forgot to add that when using the xede and its maps which had 15KS i could never hear nothing with my ear i come from a bmw m3 which you could clearly hear it knocking when it was under load and 91crap oct.but my evo i could never hear nothing but all in all iam so happy with my new ecuflash tune in the next couple days i will ditch out my xede and sell it if iam lucky.