Diablosport Forums

Could somebody explain the different types of knock retard? LT, ST, Fuel? Which ones should I be watching?

Thanks

LT and ST are the ones to keep an eye on.

I'm running the 87 tune (2011 hemi ram) and seeing knock on the low end. Usually it's under light acceleration and under 2k rpms, LT knock retard goes to ~6, sometimes ST goes to 10-12. This can be induced by setting the cruise at highway speeds, 60-70 mph and 1500-2000 rpms. On flat highway, there's no knock, but hit a long gradual incline and the knock comes one. Still the throttle is less than 25%. If I mash the gas or downshift to get the rpms up, the knock goes away. I even filled up with 93 at my last fill-up to see if it was an octane issue and I'm still seeing the same knock. Does this indicate I need to add fuel on the low end?

I also tow a 21' boat with my truck every week, though I haven't pulled it since I've had the trinity, but i can only expect that the knock would probably get worse while towing if I don't address it, right?

Thanks


Neal

Here's an example of the knock i'm talking about. Barely on the gas, increase throttle from 10% to 25% as I start up a sloping hill, not even enough to make it shift out of overdrive. As the throttle comes on, LTKR goes to 6. More throttle, goes away. If i hold it there, it subsides as I crest the hill and the load on the engine is reduced. Add fuel? How much?

Not making it downshift is why its knocking. You're lugging the motor. When its under load is when it will knock, not when its running freely.

It's not like I'm holding it back from shifting. I'd think if it was really lugging, it would downshift. And I'm in MS.......not like I'm pulling up mountains or steep grades to induce that knock. My biggest concern is that it will be amplified when I tow.

Thats just the way Mopar programs their transmissions. My Jeep used to do the same thing. Theres not enough pedal pressure to make it downshift, so it just lugs in a higher gear.

Mike_Levy wrote:Thats just the way Mopar programs their transmissions. My Jeep used to do the same thing. Theres not enough pedal pressure to make it downshift, so it just lugs in a higher gear.

That is why I run in tow/haul mode about 75% of the time on my RAM.
It then downshifts with much less pedal pressure.
Gas mileage is only slightly affected unless you stay on it all the time (like I do).
I have an 11 RAM 1500 R/T (4:10 gears) and still manage between 14-15 mpg per tank with 50/50 mix City/Hwy driving.

Mine's going back to stock and I'm going to test out the 30 day money back guarantee if they don't get this fixed soon. I can't even set the cruise on the interstate. At the lightest throttle application, it'll ping to the point of being audible occassionally. The power is great when I put my foot on the floor, but the rest of the power band is crap.