Has anyone had any luck increasing their rev limit with an SCT X3? Several attempts to increase or remove mine have been unsuccessful. In 4 low 1st gear at WOT it bounces off the limiter at about 5,200, which is actually below the stock limit. Is there something in the stock computer that overrides the custom tune setting?

 

I've never done it myself, I don't need/want to go above 5200 RPM. Matter of fact, I thought that the stock limit is 5200 actually.

The PCM has an input that reads the 4x4LOW signal. It's possible that it reduces the rev limit when your in 4LOW.

Maybe Mike will come along and speak to this.

 

I guess no one else on here has pushed one of these beyond stock? I do sled pulling with mine and shifting probably isn't a good idea.

 

well @ 5200 RPM your well past the peak torque of the engine anyway....

 

There are two rpm limiter adjustments in the tuner. One limits rpm in park/neutral the other limits rpm in drive. Bumping up the rpm limiter in park/neutral will not change anything when you are in drive.

FYI I would not go over 5300 rpm with the stock rods there is reason it was limited like that from the factory.

 

Uh ya what everybody said. Mine at wot shifts at no greater than 5k. Kinda playing hot potato with a grenade on that one

 

Sled pulling is mostly about momentum. I won't get far if I chug down the track at 3K RPM.

All limiters have been adjusted up. We've even tried shutting them off completely.

Has anyone on here actually broken a rod, or is that just more of the "I read it on the internet" so it must be true?

It seems there are few out there that have actually tried to push the NA performance of the 6.8 beyond very basic stuff.

 

Sled pulling is mostly about momentum. I won't get very far if I chug down the track at 3K RPM.

All limiters have been adjusted up. We've even tried shutting them off completely.

Has anyone on here actually broken a rod, or is that just more of the "I read it on the internet" so it must be true?

It seems there are few out there that have actually tried to push the NA performance of the 6.8 beyond very basic stuff.

 

5,200 is stock limit, Mike @ 5Star has posted that before. With a 2 valve, I seriously doubt the thing could breathe at anything over that. What other mods does the truck have, and what gearing in the axles?

 

CAI, Headers, dual exhaust w/X crossover, & the SCT with a custom tune. 3.73 gears & running 315/75/16 tires to drop the RPM's, which has not helped enough. It will spin to 6K or more, but only if eased into the throttle. At WOT it hits the limiter hard at 5,200. On a stock tune it would go to 5,400 but the power level is down.

 

Try running 265s n let it hit 2nd gear. Or a tighter converter to get more wheel speed with the same rpm. I don't think sheer rpm from the engine is your answer here.

I would call SCT n see whats up with it if you can 'feather' 6k but matting it only nets 5,200.