4wd launch with cranked torsion bars

[danzick]

so, I know that a heavy boosted 4WD launch with cranked up torsion bars usually ends up being a disaster. What could I do to leave my truck in the leveled position and still be able to do boosted launches? I dont really want to jump out of my truck at a stop light with a ratchet and crank them down.

 

[BlackHillsHD]

Buy a really nice set of CV's.

 

[Cknight199]

odds are, a part will fail. Most people that don't want to lower their truck, will add a 2-4" lift then lower the lift so the CV's are flat. A lot of sled pullers run a 4" lift and do this.

Not only is it bad on your CV's. but your tie rods and all the steering components are being torqued with much more leverage when your CV's aren't flat.

 

[danzick]

Hm..... I'm really not into the lift thing at all. I would lower it if I didn't need good ground clearance for what I use my truck for. Anyone have pictures of a lowered 4 inch lift?

 

[Hot COCOAL]

Hm..... I'm really not into the lift thing at all. I would lower it if I didn't need good ground clearance for what I use my truck for. Anyone have pictures of a lowered 4 inch lift?

Here's a couple pics of my truck with a Cognito 4" NTB lift. The T-bar bolts are removed so the front is pretty much as low as possible. In the rear, I've removed the overload leafs and added a Deaver 2" mini pac. The tires are 285/75/18 (34.8") on 18"x10" wheels.

Not the best pics, but the only ones I have of it with the lift "lowered"
Also, this was right after I took it off jack stands after sitting on them for 2mo and it sits a little lower now that it's settled out a bit. The bottom pic represents the stance/rake pretty well, it was taken a few days and about 400mi after the truck was off the jack stands

 

[danzick]

thanks for the pictures. I guess its not super tall, but your wheel wells look pretty full with basically 35's. It would probably look funny with my 305/55 20s.

 

[MACKIN]

Do you have tie-rod sleeves?

 

[danzick]

Yes.

 

[Chevy1925]

there is nothing you can do with a cranked front end to get it to launch as well as a decranked front end even if you had all the best parts in the world on the front end.

1. these trucks have nasty bumpsteer (toe change through out suspension travel) and the worse of it occurs close to the end of the suspension travel. this will cause toe in on launch

2. the angle the tie rods are at amplify upward leverage on the steering centerlink causing parts to flex. while the centerlink/pitman arm/idler arm might barely move/flex, it adds to toe in.

those two things coming together add to a horrible launch, hopping and broken parts.

 

[DmaxRvRrat]

HOT COCOAL, I love the stance and was thinking about de-cranking my 4" lift down also. I have a question about the torsion bolts though.

My torsion bolts are cranked unevenly on my pickup and have seen this on other pickups from factory also. Is this to create a different pre-load on the bars for weight distribution? Does taking the bolts out make it ride uneven while hitting bumps, etc?

 

[danzick]

So my closes option would be a lowered 4 inch lift.

 

[Chevy1925]

HOT COCOAL, I love the stance and was thinking about de-cranking my 4" lift down also. I have a question about the torsion bolts though.

My torsion bolts are cranked unevenly on my pickup and have seen this on other pickups from factory also. Is this to create a different pre-load on the bars for weight distribution? Does taking the bolts out make it ride uneven while hitting bumps, etc?

supposably its to counter act the added weight of a driver and fuel tank on the driver side. personally, ive never seen it make a difference. my truck had the same amount of preload in each coilover and it sits level with me in it and full tank or without me in and 1/4 tank.

So my closes option would be a lowered 4 inch lift.

yes, absolutely

 

[Hot COCOAL]

thanks for the pictures. I guess its not super tall, but your wheel wells look pretty full with basically 35's. It would probably look funny with my 305/55 20s.

You're welcome
No it's not a tall lift at all, I was pretty against lifting my truck too...
But like you I needed the extra clearance and I wanted the highest load range for my tires...I ran this tire size with the truck leveled, but the ride was pretty bad and it was REALLY bad on the front end parts. The first boosted launch I did with an upgraded turbo snapped the drivers side CV!

I know it looks fairly "beefy" but as it sits now, with the front lowered and the rear overload leaf removed with the 35's, it's only about 1" taller than it was before the lift.

IIRC, a 305/55/20 is a 34.4" tire???
I don't think that tire size would look bad at all with a lowered down 4" lift, and you shouldn't have any issues with rubbing. I rub a tiny bit at full lock in either direction, but I'm running a fairly aggressive offset and a pretty tall tire.

HOT COCOAL, I love the stance and was thinking about de-cranking my 4" lift down also. I have a question about the torsion bolts though.

My torsion bolts are cranked unevenly on my pickup and have seen this on other pickups from factory also. Is this to create a different pre-load on the bars for weight distribution? Does taking the bolts out make it ride uneven while hitting bumps, etc?

See below response to James' post for my thoughts on the t-bar bolts having different settings...
Nope, removing/adjusting the bolts only affects pre-load/ride comfort, ride height and the angles/ability of the IFS components... But as such, changing the adjustment either up or down will affect the set of adjustments for your steering alignment and technically you should have an alignment done if you're making a drastic change to the T-bar bolts...
I haven't needed to, and actually cuz I lowered mine my camber and toe settings are in a much more ready position to accommodate for boosted launches

supposably its to counter act the added weight of a driver and fuel tank on the driver side. personally, ive never seen it make a difference. my truck had the same amount of preload in each coilover and it sits level with me in it and full tank or without me in and 1/4 tank.

I've heard that too James.
I've also heard a couple other theories...
Like, the t-bar adjustment is different side to side to accommodate for a variance in fender to ground height left to right
And
The t-bars are adjusted to different heights to counter the effects of road crown...cuz most areas (especially around here) pave the roadways with the center being a high point and taper off to the sides to allow water to run off...

I've also heard it's like that to counter "torque steer" from the engine torquing/twisting the chassis under load/acceleration

 

[Chevy1925]

I've heard that too James.
I've also heard a couple other theories...
Like, the t-bar adjustment is different side to side to accommodate for a variance in fender to ground height left to right
And
The t-bars are adjusted to different heights to counter the effects of road crown...cuz most areas (especially around here) pave the roadways with the center being a high point and taper off to the sides to allow water to run off...

I've also heard it's like that to counter "torque steer" from the engine torquing/twisting the chassis under load/acceleration

i honestly think its just crappy torsion bars. they are not exactly all the same spring rate and it seems over time, some dont hold tension as well as others.

 

[danzick]

You're welcome
No it's not a tall lift at all, I was pretty against lifting my truck too...
But like you I needed the extra clearance and I wanted the highest load range for my tires...I ran this tire size with the truck leveled, but the ride was pretty bad and it was REALLY bad on the front end parts. The first boosted launch I did with an upgraded turbo snapped the drivers side CV!

I know it looks fairly "beefy" but as it sits now, with the front lowered and the rear overload leaf removed with the 35's, it's only about 1" taller than it was before the lift.

IIRC, a 305/55/20 is a 34.4" tire???
I don't think that tire size would look bad at all with a lowered down 4" lift, and you shouldn't have any issues with rubbing. I rub a tiny bit at full lock in either direction, but I'm running a fairly aggressive offset and a pretty tall tire.

my tires are only a 33x12.5. Id like to see a picture of a lowered 4 inch lift and some 305/55 20s.

 

[Big Chris]

There are several pictures of trucks with that tire size and a 4" lift in the 4" lift kit help thread.:thumb:

 

[danzick]

link to that?

 

[lutzjk913]

Can you post a pic of your cv angles?

Mine is leveled and I raxe it aome but I don't launch it too hard. It gets hairy if if i do.

 

[danzick]

with the truck sitting on a level concrete pad.

 

[TheBac]

^ Wouldn't be too wise to do any boosted launches with those CVs like that.