I own a 2004 Ram 1500 quad cab and i just installed a flowmaster series 40 and a mopar(K&N????) high flow replacement air filter. My problem is when i hit 45 mph my rpm's go down, you cant hear the flowmaster anymore, and it gains speed very, very slowly and it continues til about 60 mph,then it takes off and its back to normal. It did this before the flowmaster installation but now its more noticable. Is there a problem or is this "flat spot" suppose to happen??? Any info would be appreciated, Thanks.

 

nope, once you get to 45mph it can slip into overdrive, it will continue in overdrive unless you give it enough gas to down shift, you develop more horsepower at higher rpms (especially with an aftermarket muffler) and thats why when you get past that you hear the exhuast again and get more power...the reason your exhuast goes silent is simply because you are at low rpms

 

I have sorta the same problem. There is one onramp i have to hit at 15 mph...its a very tight turn...but then you have very little space to get up to speed b4 you run out of lane and slam into the damn railing.

So i hit the ramp and make my turn at around 10 to 15 mph...and then i have to floor it!!!!! When it hits about 40 mph...its like my truck has been smoking for the last 20 years and has to take a couple deep breaths....then i hit about 50 mph..and zoom...she is off again. I'm not to sure what it is....was kinda wondering if its the Diff. clutch..since it kicks in at 30 mph i think.

I am a little curious to see what else it may be.

 

The same thing happens to me. I found that you need to press the gas just a hair more to accelerate (ex. if your going from 30-60), but if your only going to about 45 or 50....it drops off and boggs until you really press on the gas. This is so far the only complaint I have. It must be their attempt to save us some gas.

 

I am having the same problem. I have had my truck for about two weeks now. I have just started to drive spiritidley. It feels like you hit a speed governer, it just falls flat.