Is there any way to minimize the Tip-in (Burst) Knock on the 98's. I have tried reducing timing in the sections where KR is detected and still getting KR.

 

Your tip in knock retard is caused by something else. Are your O2s crashing when you stomp it? Do you get knock retard when you are doing normal tip-in (maybe below 20 degrees on the TPS)? You may need to change when you PE kicks in I guess. I have seen some posts on this in the past...

 

The O2 sensors are new and are not crashing. Sometimes it does and sometime is doesn't.

 

You should check and see if your exhaust is hitting somewhere. That would do it too. Maybe bad motor mounts too. Look for something loose.

 

I have heard that increasing the ve table in the areas that you're getting kr can help. Maybe it's worth a shot?

 

This is true IF he is getting real detonation due to a lean mixture. If it is false (exhaust banging) then adding more fuel wont help anything

 

Exactly. My false is probably caused by some weird engine harmonics because it always happens at the same RPM regardless of how much timing I pull, or fuel I throw at it. Stupid 98s. But if it is tip-in it could be something banging as your engine shifts position under your initial push of the pedal.

 

Curious - Have you upgraded your 98 KR sensors?

joel

 

ive got the exact same problem. I replaced the KR sensors with 2002 sensors and it still does it. I can count on it 3100 rpms and it will do it. If i mash it at 3500 it pulls like a raped ape. If i mash it at 2500 it pulls to 3100 dies then climbs again...any guesses??

 

You might try rolling into it instead. A big torque
jerk may bring things into interference and hit the
knock threshold. Then, too, the air surge is not
tracked well by the MAF and you depend on the
speed density tune being semi-right to suppress
any pinging. O2 voltages dipping on rising throttle
or rising MAP indicate your SD tune is too lean for
power on throttle transients. A throttle event that
lasts for more than one logger-tick might let you
see if your O2s are staying low (even if not "crashing"
anything below 0.8 has a pretty good chance of
pinging at higher MAPs).

Other internal engine rattles, valvetrain, etc. can also
be knock detect triggers, but valvegear should be a
knock blip at the same RPM regardless of load. If you
do a (say) half-throttle run-up and still see something
funny at 3100RPM (KR blip, though it might not feel
like much with the higher part-throttle advance),
you would have to consider this possibility more
seriously.

 

No...I haven't upgraded my knock sensor yet...I just hate the idea of pulling the intake without putting something better on for all my time and effort...

 

I have tried easing into it...same thing. 3100 KR comes in hard then backs out. I have a rather noisy valve train (i think it is anyways) but i dont think it could be that bad. Any guesses on how to tune it out?

 

If your valvetrain is noisy (but you're sure it's
intact, not noisy like all your roller bearings are
now in the oil pan) then you probably do want
to desensitize the knock sensors. Either getting
the new versions, or I guess some folks have
used Teflon pipe tape to muffle things a bit as
far as the sensor hears? In some tuners you can
play with sensitivity params I think. In HPTuners
I see a table that lets you set max KR by RPM,
so you could "mask" certain RPM ranges that way
(though this table only limits KR while in PE mode).

But I think you should dig a little deeper on the
mechanical noise sources just for peace of mind.

 

I did that in my current tune, eliminated the knock retard at specific RPMs in PE mode. I haven't logged anything yet to see if it worked though. I figure if it is real knock it will just show up at a higher RPM than I am used to seeing it at. Or my engine will blow up. Either way it doesn't matter, I'll just buy a 6.0 liter short block.

 

Another User,

I dont mean to jack your thread but im having the same problem so im trying to get answers too

Im sure my valvetrain is intact. I replaced my stock rockers with YT's torqued them to spec and used lock-tite. As far as the sensors go i did put 2 wraps of teflon on the threads but it didnt seem to help. I have a feeling its in the tune for some reason. I use Edit but i dont want to "overall" desensitize my KR because i use N20 as well and really like the KR feature Is there a way to just pull it from that specific RPM? thanks

-bernie