Raptor Top Speed Update

[RLTW]

what kind of runway would you estimate it took you to get up to that speed?

 

[SterlingE55]

Well the issue is not the gearing so much as it is like pushing a brick through the air lol.. Between 60 and 75 I lose 2.5 mpg..

Haha not denying that but the size and weight of the truck are fixed variables. Gearing on the other hand can change. I run the truck around 75-85 most of the time on the highway which is 2200-2400 rpm. It doesn't need to be that high. There's enough torque at 2000 to keep it moving at 80. I doubt that much of a change would hurt it offroad vs the mpg advantage. How much of a change in rpm did you see with 37's at highway speeds?

 

[Boss Hoss]

what kind of runway would you estimate it took you to get up to that speed?

That is a tough one because I started at around 90... Maybe 3 miles at the most..

---------- Post added at 10:26 AM ---------- Previous post was at 10:14 AM ----------

Haha not denying that but the size and weight of the truck are fixed variables. Gearing on the other hand can change. I run the truck around 75-85 most of the time on the highway which is 2200-2400 rpm. It doesn't need to be that high. There's enough torque at 2000 to keep it moving at 80. I doubt that much of a change would hurt it offroad vs the mpg advantage. How much of a change in rpm did you see with 37's at highway speeds?

I do not remember the rpm change been too long. All of my trucks have been lifted and run big tires. Most over the last 30 years have been oil burners that were highly modified... It is the aerodynamics period. When you lift them it makes bad aerodynamics even worse esp leveling the truck like I have.. Really makes it a flying brick lol..

 

[WyoStorm]

Nice!

So the driveshaft is rated at 110 mph but you can hammer it off-road at up to 100 mph? Yet, a short drive at 120-130 mph on pavement is worse?

 

[Squatting Dog]

Nice!

So the driveshaft is rated at 110 mph but you can hammer it off-road at up to 100 mph? Yet, a short drive at 120-130 mph on pavement is worse?

Rotational harmonics... Offroad you will not be as likely to sustain 120 mph without slowing down. Unlike on highway (private road, closed course) you would be more likely to reach those speeds and maintain it. Setting up the harmonics to finally destroy the driveshaft. And like my previous post a slight imbalance at those sustained rotational speeds will destroy the driveshaft.

-Greg (aka squatting dog)

 

[Mogo]

The wind is such a killer for MPG's in these trucks. I get a full MPG less driving out to Midland than I do in town. It's annoying. Makes me wonder if a light weight 37 would be worth the ratio change. Had a 5.0l Screw rental last week in Midland and at 80 it barely hit 2000rpm and it got 16mpg in the wind. Haha it was painful to drive though. Really makes you appreciate the Raptor. But seriously we need a 7th gear.

On my trip to Texas two weeks ago, we had headwinds coming out of the south and southwest for basically the entire trip. I got better MPG in the Colorado mountains (16.5) than I did from Dalhart all the way to San Antonio (14). It was incredibly frustrating. And of course on the same route back we had winds come out of the west and slight northwest. The big uphill climb from almost sea level where we were hunting to 6000ft in Raton, New Mexico probably didn't help either. I managed about 14.3 on the return leg, doing my best to safely draft anybody else that wanted to run at 85 MPH.

I actually think that I get better MPG in the mountains because of the long descents from the high passes. When you're coasting for 20 or 30 miles at a time, the fuel shutoff/cylinder deactivation really shines. And you've got more than enough power to keep up with traffic on the uphill climbs without maxing out your revs. I'm able to make the trip from the western slope of Colorado over to Denver at 21-22 MPG in my 5.4L FX4.

 

[WyoStorm]

Rotational harmonics... Offroad you will not be as likely to sustain 120 mph without slowing down. Unlike on highway (private road, closed course) you would be more likely to reach those speeds and maintain it. Setting up the harmonics to finally destroy the driveshaft. And like my previous post a slight imbalance at those sustained rotational speeds will destroy the driveshaft.

-Greg (aka squatting dog)

Just trying to understand. Is it strictly a speed issue then? Since the Raptor is marketed as an off-road machine capable of speeds up to 100 mph, I would think the driveline issue shouldn't be a problem at that speed. I know all about "regular" 4 wheeling but trying to learn all I can but the upcoming Raptor world of off-roading.

 

[Squatting Dog]

Just trying to understand. Is it strictly a speed issue then? Since the Raptor is marketed as an off-road machine capable of speeds up to 100 mph, I would think the driveline issue shouldn't be a problem at that speed. I know all about "regular" 4 wheeling but trying to learn all I can but the upcoming Raptor world of off-roading.

Completely understand. Here is how I was explained what is happening.. In order to do the 100mph off road and take the deep plunges and max extension of traveling offroad at higher speed. The designers had to beef up the components which adds more rotational mass.. The added mass is not a mass most speeds. But once you get at higher sustained rotational speed the driveshaft starts oscillating. It can only handle this strain for so long before it destroys itself.
If max it lighter to handle the higher speeds it could not handle the offroad shocks.. So the designers chose strength over high speed..

-Greg (aka squatting dog)

 

[WyoStorm]

That makes sense. Thanks for explaining that!

 

[J-train]

I personally think you guys are way overthinking the drive shaft issue. I would not be afraid running it up to those speeds for a short distance, but why? I definately did not buy my truck for 100mph+ plus speeds on the highway and could care less about MPG's