Installed tune on 2012 srt8, car is slower help!!!

[SRTGR8T]

Ok, I adjusted the spark as instructed, did another 10 minute ride and now the knk fuel is at 4 and the knk st is at 4 and the knk lt is at 0, most of the movements were in between 3700 rpm and 4600 rpm with half as many from 4900 rpm to 5400 rpm, but the heaviest 4.0 read was at 4500 rpm and had a 3.5 read at 5100 rpm, the knk st gauge pretty much moves every time I lay on the peddle a lot of .5, 1.0 and 1.5 in the 3500 rpm range, what should I do now?

[Mike_Levy]

Okay at least we got the long term down to 0. That was the important part. Not sure how to get rid of the short term when you get on the pedal. I have the exact same thing on my Denali. It hits when you get on and then when you get off. Lets see what the guys that do work at DS have to say.

[SRTGR8T]

Do they even respond? Do I have to notify them that I have a question?

[Mike_Levy]

They'll respond eventually. They fit in the forums when they aren't on the phones.

[SRTGR8T]

Thanks mike I'll wait for diablo to respond, I just reinstalled the stock tune and I'm getting similar reading for knk st and kr fuel, this car is only 3 months old with about 6500 miles on it, is it normal or do you think the cai and throttle body is causing it?

[Mike_Levy]

Hemi's always knock somewhat. I haven't looked at the 6.4 yet, but with the older motors they used to get oil in the intake manifold due to the PCV system. If the 6.4 has the same problem, then a catch can might help. Oil won't combust or compress, so when it gets in the manifold and eventually into the cylinders, it just sits there, effectively raising the compression, causing preignition. If no more is added, it will eventually burn off and the knock will go away. Agin, not sure if thats whats happening with the 392.

[SRTGR8T]

Any particular catch can? Also what's the reason for the 180 thermostat that people are swapping out for, what benefits does this have?

[Mike_Levy]

Not sure whats out there for the 392. I always used Billet Technology cans on my 6.1s. The thermostat lowers the coolant and engine temperatures. The Hemi also likes to heat soak. When they get hot, performance goes downhill in a hurry. The 180 stat and lowering the fan temps keeps the engine cooler and the performance up

[mikel]

the Diablo Catch can

[Mike_Levy]

Do you have an answer for the rest of his knock problems Mike?

[SRTGR8T]

I guess the only time they respond is when they try to sell you one of their products!! Lol, it's just business you know...

[mikel]

if you are getting knock, try adding fuel in the affected rpm range until it clears up.

[Mike_Levy]

We tried that already. And I had him pull timing. LT is gone, but he still has a fair amount of ST.

[SRTGR8T]

How much fuel is too much?

[mikel]

How much fuel is too much?

no such thing

and adding fuel will not kill power like pulling timing will...