Hi all, I have a question: My truck FX4 Super Crew 2007 with rear stabilizer bar, shock Bilsteins on all 4 corners, 315/70R17 tires, was traveling on a highway yesterday alone and accelerate up to 125 mph, caught my attention that at 120 -125 stepping my truck starts with a wobble very large, very likely to lose control. They believe that can cause it? , The size of the rubbers? I have been with the intention of installing a Watts Linkage or a KW V3 shocks, but now, with this experience I have no idea which way correcto.Todos my bushings and ball joints are in perfect condition

 

Are your tires rated to go remotely near that fast?

 

No, and I'm aware of it so that only reach 125 MPH for a few seconds, but as I have planned to invest money in suspension and rubber safe me to make this decision. As mentioned, the stretch of motorway was alone, and sometimes need to perform tests to identify weaknesses.

 

As much as you're not gonna like this, just don't go that fast. It's like the kid that says "hey doc, it hurts when I do this" and the doctor answers with "then stop doing that!" If you have no problems from 0 to 120 mph, the truck is doing what it should. 34.6" tires don't like to go that fast. I have 33's on my truck and I wouldn't feel safe driving that fast. If your truck was lowered and more like a car, I'd see why you'd want to go fast. But with how high yours is off the ground, I think 125 mph is about as fast as the vehicle can go and is stressing its limits. Remember that a 2007 Mustang GT can only do 152 mph under perfect conditions.

And I'm the last guy to be telling you to slow down, believe me!

 

It's a truck, not a race car, try to be a little responsible...

 

Ok, sorry I raised the issue in this way, so far I have only received advice which I appreciate it greatly, but I must clarify that I do not walk on the roads traveling like crazy breaking all the rules and standards of speed and driving. I usually travel with top speed of 70 MPH, and clarify the beginning, I wanted to experience the 125 MPH and notice a wobble of the bodywork. I have as a project to improve the suspension of my truck, not to go 125 MPH but because I like to feel in control of handling, braking, etc.. In this specific point is that I want to concentrate on the rest, I am fully aware of this and not my daily walk, in fact, is the first time exceeded 90 MPH, but still argue that if one wants to improve something must try. . Thank you all for your concern and good advice.

 

So the sheet metal is wobbling/flexing at that speed or the truck itself is shaking? I don't think you're being irresponsible, I just think 125 is about as fast as the truck can go, even if you supercharged it. I think that's as much as the shape, frame, and height can handle. I love going into triple digits when I'm in cars, I just don't think the trucks can handle it. Good luck improving the suspension and everything though, not trying to keep you from doing what you want to do!

 

Shoot with my 35's mine starts to get wobbly over 80. I can only assume its because the tires, suspension, etc aren't made to go that fast...

You can upgrade all you want, but your still gonna hit that point the truck doesn't like.

 

It is a truk not a race car. I guess the next thread will be about how you blew up your motor..lol

 

Actually I pegged mine at 130MPH a few times the tune then limits the truck so I don't run out of fuel pump. My truck is lowered though with high performance street tires on it. No shakes at all.

My guess is tires. Off road tires usually suck at freeway speeds let alone 125mph. Driveshaft could be it too but I would put money on the tires being out of balance at that speed.

 

Well I agree with YOUR truck being completely different and being able to handle that speed. Certainly not his high 4wd for all the reasons we've stated haha

 

Thanks Ironsin, I think there is the problem, in my future project this tires 20 "KW V3 self adjusting shocks, that way would not return to have this problem. Again I say, not to travel at this speed constantly but, suspension increases security improved in both straight and curved like, especially under braking. RED13 the friend informed him that, our supercharged truck at 125 mph are spinning, I think, 4000 rpm, the problem here is the provision gasoline, but our fuel feeding systems are designed for this purpose, and also IRONSIN said the speed limit to avoid damaging the engine. Apart from that, I have 3 ROWS radiator, additional coolers for the transmission oil, the improvements in engine and supercharger intercooler. Several additional mods, my breaking point is the suspension.

 

10-4 I agree that this could more then likely be it. I've had all kinds of camaros and stangs well over 100 and when I noticed any shake it always came back to the wheels. Check weights,and tread design. Anything that is all season or off road tire is not the best option. Also any dents to the rims will cause it as well mud or other foreign material stuck to the rim. Anything that messes with the balance of the rim in any way. Another thing to consider is using Hub centric rims so you never have to use weights to balance the wheel. I have a feeling your higher line car mfg. would use them.

Also if your interested in spirited runs you might want to also consider a turbo or centrifugal set up.

 

f150 are limited to 90-95mph stock...there's a reason for that.

I limit mine at 115 with the edge and it's plenty enough.
even lowered 3/5 with rear sway bar. I don't really want to go over 110 :|
it's just funny to accelerate against a stock one and continu accelerating while they hit the limiter...lol

 

Yes, I agree with you, my exhaust system has a muscular sound, guttural, and accelerating feels great but will always trucks, there is much inertia in them anyway, at 70-80 MPH will feel very comfortable the manage and, if you have supercharger, the passing is a unique experience.