Speed limit?
 

Hey guys I got a new 08 Chevy Silverado with a 5.3L in it.
I have a problem, it wont go past 91 MPH? WHY?!? Lol I was cruising down the freeway and decided to see what it can do....but I was surprised it stopped at 91mph. Any reason for this?

Re: Speed limit?
 

Speed limits (usually via fuel cutoff) are in place to not exceed (a) the ratings on tires, (b) propshaft critical speed or (c) driveline resonances that were deemed to be harmful, whichever is lower.

Is your truck 4wd? Some combinations of tire, gear ratio and the addition of the 4wd t case drive those resonances down into a range that could limit top speed.

K

Re: Speed limit?
 

It is a 2wd 1/2ton. I thought I might have done something wrong when I lowered it. Haha I mean I honestly doubt it but it had worried me.

Re: Speed limit?
 

You mean it ran out of steam, or did it feel like it was being artificially speed limited? (it will "buck" a bit when it hits fuel cutoff).

I didn't even think about the former, because one of the typical speed cut offs is 92 mph (I figured that must be what you had).

K

Re: Speed limit?
 

Its like it goes into neutral? it doesnt rev high or slow down. I am not to sure how to explain it? Maybe make a short film of it.

Re: Speed limit?
 

That can be easily tuned out. These trucks have a reputation for throwing the driveshafts at high speed though and it's not pretty so be careful.

Re: Speed limit?
 

Oh really? I see, Well thank you. I appreciate the help guys.