Occasionally when I accelerate (floor it) to get from a driveway to the frontage road to the freeway, it feels as if the engine hits the rev limiter. The last time, it appeared the tach needle was around 5k.

From the other electronically controlled cars I've driven, the transmission has never let me even hit the rev limiter...

Or is my transmission screwed up? I don't have any kind of modifications to improve shift response, so perhaps the delay between shifts allows the engine to rev in between gears?

Thanks,
Mike

------------------
Model: '99 F150 Lariat Supercab 4x4 SS Mechs: 5.4L, 3.73 Diff (9.75" LSD Rear, 8.8" Front)
ORP: Skid Plates, LT265/70R17 GY Wrang. AT/S
Group III towing: HD Electrical/Cooling, GVWR 6500# (Extra leaf spring).
Stuff: Step Bars, 4W Disc ABS, K&N filter, 0W-30 Series 2k Amsoil @ 8200 miles, Herculiner
Stock Items That Differ Across F150s: Steel Driveshaft, Oil filter bolted to engine w/ drip guard, 4R70W transmission.

 

What did the truck feel like when you hit the rev limiter?

------------------
2001 F-150XLT SuperCab, Silver, 4X4, AOD, 5.4L, 3.55LS, 17in Rubber, Sport Package, Bedliner, Sliding Rear Window and A partridge in a pear tree...

 

Almost as if I had hit a bump. It happens mainly when I press the pedal down hard enough to feel it bend a little.

 

Mike,

I did hit my revlimiter on my F150. I am sure that I was way past the 5k mark. The truck at the rev limit started to "surge". Not surge past the rev that I was at, instead it dropped say 500 rpm then surged back up to the limit.

I think it may be controlled by the ignition system and it retards the timing until a "safe" rpm is achieved. I do know that there is a fuel cutoff rev limit (usually 250 rpm past the the red line.) I do not know what the "redline" on the engines are.

I have seen SOHC engines (4 cyl.) that can hit 6500+ in the rev area. I know that my F-150 leaves 1st around 5000 (will check on the way home) with the throttle wide open, second gear is around 5500. Does the fact that I have 5.4 liters moving in that engine, even though it is SOHC, limit the rev to 5500 or could it be something in the drivetrain? I do know that air delivery to the engine is an issue at the higher rpm, maybe that's it.

Any Info?

------------------
2001 F-150XLT SuperCab, Silver, 4X4, AOD, 5.4L, 3.55LS, 17in Rubber, Sport Package, Bedliner, Sliding Rear Window and A partridge in a pear tree...

 

The reason these 5.4's don't rev as high as traditional 'car' engines is due to the long stroke, 4.17 inches compared to a more traditional 3.55 inches. The long stroke gives us the monster torque that we know and love.

If you have two engines with equal displacement but different strokes (that brings back the 80's), the piston speed of the longer stroked engine will be much faster at any given rpm. The connecting arm and pistons can only go so fast before coming to their mechanical limits. It's the same reason why diesels only rev to about 3000, monster torque but lower horsepower because HP = torque x rpm / 5252.

 

Mike,

Ahhhh...Thanks for the info. I double checked my RPM's on they way home, I shift at 5000 on first-second and second-third shifts.

------------------
2001 F-150XLT SuperCab, Silver, 4X4, AOD, 5.4L, 3.55LS, 17in Rubber, Sport Package, Bedliner, Sliding Rear Window and A partridge in a pear tree...