Talking 99-04 Lightnings, bone stock.

My dad has a 03 that has been modded and professionally tuned, and at 100MPH he says it stops accelerating and kind of sputters?

I know my old 03 SCrew would do that at 100, but surely the Lightnings should not have the same governor!?!?

Thanks.

 

Nope, no computer controlled governor, just aerodynamics.

If his truck is doing what you say, sounds like it is running out of fuel. Something in the fuel system needs upgrading.

 

On a stock Lightning, the computer is set to limit speed at 142 mph (as I seem to recall). This is a limit imposed by the tires. It shuts the fuel pump down. A tune usually eliminates this limit. Hard throttle acceleration also cuts out every other plug to save the tranny.

Jim

 

I believe there is an rpm limiter on the stock Lightning. Usually this limitation is removed when the engine is tuned on a dyno.

 

fixed it for you

 

Interesting because I still have a Lightning brochure laying around and I think it said top speed was 147mph.

 

The only thing keeping these trucks from going faster is it's shape. lol

The computer can be set to stop the truck from exceeding a set speed by a tuner. My first chip had a valet mode on it to keep the truck from doing more than 35 mph.

 

Check the fuel filter .

 

No speed limiter on the Lightning. Sounds like a fueling issue to me too.