Stopping rear end sway under hard acceleration

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Xlr8tin

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I have a 2014 with a whipple supercharger I need help figuring out a way to stop the rear swaying. Whenever I accelerate hard the rear sways to an almost fish tale and when you are already going 100+ it is scarey.

I replaced the shocks last year, back to stock, and I installed deaver springs in the rear. I need a solution to fix this issue without sacrificing off road mobility. How did Ram fix this problem on the TRX?
 

2020FordRaptor

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Ram had million dollar engineers developing it. Ford didn't engineer the Raptor to handle that mich power because they didn't have to.
 

FordTechOne

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This “problem” never existed on the TRX. It was engineered for its power output from the start, just like the Gen 3 Raptor and Raptor R. They’re modern trucks with much more robust chassis, 5 link rear suspensions, and adaptive shocks. The TRX even has a pinion angle to prevent deflection under load.

In the case of your G1, you can’t have stability at 100MPH and maintain off road capability at the same time. For your own safety and the livelihood of everyone else, stop driving it like it’s a sports car. Because that’s about as far as you can get from one.
 
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Xlr8tin

Xlr8tin

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Thanks for stating the obvious. No shit they made em that way...but it's only money....And those shit trucks more robust than these ....you almost had me. I almost thought you had an idea of what you were talking about
 

FordTechOne

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Thanks for stating the obvious. No shit they made em that way...but it's only money....And those shit trucks more robust than these ....you almost had me. I almost thought you had an idea of what you were talking about
Umm did you forget what you posted?

How did Ram fix this problem on the TRX?

And if you think your 15 year old truck is more robust than a brand new TRX or Raptor, you’re really a lost cause.
 

smurfslayer

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There are common issues between Jen Juan and Jen Too. very softly sprung, leaf spring rear suspension. Your truck is amplifying the problem even past Jen Too levels - remember stock Jen Too torque is way higher than stock Jen Juan.

@FordTechOne is right - the TRX had a lot of investment spent in handling the kind of power -and weight of the truck, whereas you are modifying a platform designed for a naturally aspirated truck at 400+ crank HP. It’s way overwhelmed.

Best guess. You need slightly stiffer springs, traction bars and probably revalved shocks. The traction bars can go on right away, but, you need to decide if you’re going to lift the truck or not FIRST. IMO, what makes the Rap good is its low center of gravity for an off road truck.

Traction bars will do a few things.
1) pretty much eliminate axle hop.
2) eliminate axle wrap; the tendency of the axle to torque down, grab, twist the axle in one direction because of the force applied on one side, release, repeat.
3) positively locate the axle in a single plane as the suspension articulates.

Even with Deavers, your leafs and shocks are probably well overpowered.

I have a Jen Too, but it’s very, very easy to cause a LOT of rear suspension drama in the dirt or sand or even the street in 2hi. If you ever watched the chase scene in Bullitt, that’s a good demonstration of leaf spring suspension being overwhelmed. That’s what’s happening.

I looked hard at traction bars but went with the KHC torque arm. It’s a night and day difference. When I took off at full throttle before the T/A in 2Hi, it was a thumping, fishtailing, lack of control. the same launch on the same pavement and the same sand was completely different. On pavement there was at least a 95% reduction in steering wheel correction. The truck tracked straight and introduced no unexpected drama into the launch. In the sand I have a lot more predictability than before.

At least in theory, the traction bars should be superior in axle location. I think SVC and Rogue were making them.

good luck!
 

MTF

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I agree with Smurfslayer on tractions bars, an absolute necessity.
Go with RPG traction bars they are the best!!!!!

Now, I see you said you replaced the rear shocks, what about the fronts???
What happens with the Raptor at high speed is the front lifts up do to air getting under neath and throwing off the ride geometry.
Lowering tire pressure helped a lot.
Your wheel alignment needs to be spot on as well.
And, I found the Hellwig rear swaybar and upgraded "stock length" rear shackles for the leaf springs to be a game changer with changing lanes at speed.

Hellwig REAR SWAY BAR FORD 10-14 F150 RAPTOR 4WD.......Part Number: 7724
And the collar locks for the bar!!!



 
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MTF

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This “problem” never existed on the TRX. It was engineered for its power output from the start, just like the Gen 3 Raptor and Raptor R. They’re modern trucks with much more robust chassis, 5 link rear suspensions, and adaptive shocks. The TRX even has a pinion angle to prevent deflection under load.

In the case of your G1, you can’t have stability at 100MPH and maintain off road capability at the same time. For your own safety and the livelihood of everyone else, stop driving it like it’s a sports car. Because that’s about as far as you can get from one.
You still make me laugh with your Gen1 comments, LOL
It's a good thing the first Raptor R that is a 2010 1/2 Gen 1, won third place in its class at Baja 1000, as a stock setup!!!!
 
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Xlr8tin

Xlr8tin

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I agree with Smurfslayer on tractions bars, an absolute necessity.
Go with RPG traction bars they are the best!!!!!

Now, I see you said you replaced the rear shocks, what about the fronts???
What happens with the Raptor at high speed is the front lifts up do to air getting under neath and throwing off the ride geometry.
Lowering tire pressure helped a lot.
Your wheel alignment needs to be spot on as well.
And, I found the Hellwig rear swaybar and upgraded "stock length" rear shackles for the leaf springs to be a game changer with changing lanes at speed.

Hellwig REAR SWAY BAR FORD 10-14 F150 RAPTOR 4WD.......Part Number: 7724
And the collar locks for the bar!!!



Yes I replaced front and rear shocks. I bought caltrac traction bars but the suspension travel was bad so I took them off. Since then I replaced leaf springs with deavers +2.

Should I put them back on with new deavers? Will shackles and rear sway bar fix my issue? I lowered the tire pressure all around to 40psi but no change. I'll try a little lower and see. I've had them at 44 and so far it's the same amount of sway.
 

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