knk st

[MACADO1]

My 2011 Charger R/T with a Trinity T1000 and revG. I get some short term knock about 2 to 3 deg. at the shift points. This is running with a 91 tune, CAI, with or without 5% fuel added. Is this normal?

[mikel]

thats not uncommon...

[MACADO1]

Is there anything I should do to get rid of it, like a CMR? Or should I worry about it?

[mastuning]

i have seen up to 7 on stock, your absolutely fine with those counts.

[dtru1222]

Try running 93 on the 91 tune if you are really worried about it.

Agree with the others that 2-3 ST is nothing to worry about, but if you have an auto you can try running it in manual shift mode to see if it reduces it.

My Challenger RT would get up to 5.5 ST in auto mode, but in manual mode it only gets up to 1.

[mastuning]

in most auto transmission equipped cars, there is torque management that is used via spark to reduce power. this is on many other platforms.

[dtru1222]

in most auto transmission equipped cars, there is torque management that is used via spark to reduce power. this is on many other platforms.

Interesting, I didnt know spark was used to implement torque management.

Thats going to rattle around in my brain for the next few days...

[gdragich]

i have seen up to 7 on stock, your absolutely fine with those counts.

I wouldn't want 7* on anything of mine. The 2-3* should be pretty intermitant and not a consistent thing. Start with a catchcan on there

[Mike_Levy]

i have seen up to 7 on stock, your absolutely fine with those counts.

I wouldn't want 7* on anything of mine. The 2-3* should be pretty intermitant and not a consistent thing. Start with a catchcan on there

Agreed. Any more than 2 or 3 degrees on the shifts is too much. Any knock retard when not shifting is too much IMO. Catch can is a MUST. And then NOS Race Formula Booster can be used to see if its real knock or false. 4WD/AWD vehicles tend to have false knock. Performance killer, but not much you can really do about it short of isolating every drivetrain and suspension part.

[dtru1222]

You think NOS octane booster is the best bet? Lot of people recommending Aces and even strait acetone.

[Mike_Levy]

NOS is by far the best. Its proven to reduce KR by 3-4 degrees on the Hemi. It also love the NitroMethane shot. Makes the exhaust sound wicked.

AcesIV is not a proven product. I have yet to see a consistent reduction in KR from it. All I've seen are outlandish claims with no substance. In addition, it contains cleaners, which are known to actually cause KR, not reduce it.

Acetone I've never used, but I have used Toluene. Used to mix up my own gas blends with it back in the early 2000's. Problem with it is that it takes a large amount to make a small difference. And its not cheap stuff, so it gets really pricey.

[dtru1222]

Im going to give it a try to see if my knock is real. I read that it claims 7 full points but in a knock test it raised it by 2, which should still make a difference in KR.

[vjo90rs8]

For reference I ran my 2012 Charger R/T at the track (stock 89 octane tune) with 91 octane to get an idea of what the short term knock retard looks like. I datalogged two passes and had 3.5* kr above 5k RPM (first pass right after driving 80 miles to the track) and 2.5* kr above 5k RPM (second pass after the car cooled down for about an hour).

[Mike_Levy]

Go +5 on the fuel at the top rpm range and that will go away if the gas is decent.

[MACADO1]

I got a email tune from Johan. Now, I have no knock. No long term, no short term, none......