I was on my way home the other day and I was like hey I wonder what this thing will do. So, I opened it up and hit about 90 in a 1/2 mile stretch. When I hit 85 my acceleration decreased dramatically. And at 90 that was all I could do[]. Another guy I know has a '97 5.9 too. The only differences is his is a sport, quad cab. I've been with him when he has hit 115 with no problem. I have a dual flowmaster exhaust so my top end should be increased, right? I was just wonderin if I'm governed and that is what is slowing my acceleration when I hit 85 or if there is some other problem. Thanks

 

Yes you have a speed limiter, it should get better than 90 though. Possible fuel restriction, they have been known to have fuel pump problems in the past.