Handling info

10secTy

10secTy

Sy-Ty builder and Tuner
Looking for some info on setting up my truck for going in circles. I have a rear bar of unknown origin coil over front suspention and stock front bar. Should I be looking at the larger front bar from Bell tech? Tires will be Invo 275/40/18 and 325/30/19

Do these truck tend to under steer? Any info on size of rear bars?

Thanks

Nolan
 
JSM

JSM

Active member
Re: Handling info

They understeer badly, or push. Define going in circles?

I would not suggest a larger front bar, but a larger rear bar.

http://en.wikipedia.org/wiki/Sway_bar said:
The other function of anti-roll bars is to tune the handling balance of a car. Understeer or oversteer behavior can be tuned out by changing the proportion of the total roll stiffness that comes from the front and rear axles. Increasing the proportion of roll stiffness at the front will increase the proportion of the total load transfer that the front axle reacts and decrease the proportion that the rear axle reacts. This will cause the outer front wheel to run at a comparatively higher slip angle, and the outer rear wheel to run at a comparatively lower slip angle, which is an understeer effect. Increasing the proportion of roll stiffness at the rear axle will have the opposite effect and decrease understeer.
Click to expand...
 
95xtreme

95xtreme

New member
Re: Handling info

What do you have for rear suspension currently? Basically what shocks, springs drop blocks?
 
95xtreme

95xtreme

New member
Re: Handling info

A few things that are easy upgrades that you may or may not already have included.

- Quicker ratio steering box (zq8 or otherwise)
- Solid tie rod sleeves
- Like Jeff said the biggest rear bar you can find

Personally if it were me I would ditch the flex a forms and swap to a triangulated four link. And swap to a fuel cell or typhoon/blazer tank behind the rear end.
From the days of auto-crossing my awd s10, I found by running the smaller front sway bar it acted like a band-aid against understeer or "pushing". The truck did not stay as flat but allowed the outer front tire to load up more and hook better. One thing to keep in mind though the truck still had torsion bars installed instead of coilovers.

Do you still have stock arms up front or tube arms, if so which ones? And are you lowered much? This is also a common misconception that you want the truck as low as possible for the center of gravity. But there does reach a point where your ball-joint and steering angles are compromised. When very low on these trucks the bumpsteer increases and the balljoints tend to bind. The other issue then comes into the cv shafts starting bind as well which is not only bad on them but will slow down that wheel with increased resistance. Also sorry if I am rambling it is finals week.
 
10secTy

10secTy

Sy-Ty builder and Tuner
Re: Handling info

I have the ZQ8 box and solid tie rod sleeves. I will measure the bar I have.

Who else sells a rear bar now? Bell tech does not list anything.

I have the JS control arms. Which truck should I get the smaller front bar off of?
4cly 4x4 truck? I have 600lbs springs right now on the front. They are very stiff should I be ordering some softer springs to play with?

Nolan




95xtreme said:
A few things that are easy upgrades that you may or may not already have included.

- Quicker ratio steering box (zq8 or otherwise)
- Solid tie rod sleeves
- Like Jeff said the biggest rear bar you can find

Personally if it were me I would ditch the flex a forms and swap to a triangulated four link. And swap to a fuel cell or typhoon/blazer tank behind the rear end.
From the days of auto-crossing my awd s10, I found by running the smaller front sway bar it acted like a band-aid against understeer or "pushing". The truck did not stay as flat but allowed the outer front tire to load up more and hook better. One thing to keep in mind though the truck still had torsion bars installed instead of coilovers.

Do you still have stock arms up front or tube arms, if so which ones? And are you lowered much? This is also a common misconception that you want the truck as low as possible for the center of gravity. But there does reach a point where your ball-joint and steering angles are compromised. When very low on these trucks the bumpsteer increases and the balljoints tend to bind. The other issue then comes into the cv shafts starting bind as well which is not only bad on them but will slow down that wheel with increased resistance. Also sorry if I am rambling it is finals week.
Click to expand...
 
vortecfiero

vortecfiero

New member
Re: Handling info

something else to try that is really simple

lots of the courses are set up for smaller cars and getting the back end to rotate sooner
or transition sooner pays off big time

i start off with about 40 psi in the rear tires... it allows you to slightly slide the rear end
around, and move on to the next cone marker.

on road courses id put about 38psi in all 4 corners to aid with turn in.

some guys set up with a little toe out but i never liked it... too darty
 
95xtreme

95xtreme

New member
Re: Handling info

10secTy said:
I have the ZQ8 box and solid tie rod sleeves. I will measure the bar I have.

Who else sells a rear bar now? Bell tech does not list anything.

I have the JS control arms. Which truck should I get the smaller front bar off of?
4cly 4x4 truck? I have 600lbs springs right now on the front. They are very stiff should I be ordering some softer springs to play with?

Nolan
Click to expand...

Well the JS arms are the best I have seen thus far, since the ball joint angles have been corrected. I thought you could still get the belltech bars through summit, maybe even Mike lee? As I have seen him post GP's on them before.

I also run 600lbs springs and they are very stiff, I have heard that 550's ride great but am not sure what that will do to the handling. Can you weight the front and rear of your truck at all?

As for trying the smaller bar, they came on 4x4 pick up's and 2dr blazers for sure. Best way to check would be to take a caliper out there, and check them before removing. Also you will need new sway bar bushings at that point.

The other big thing as well is play with your shock adjustments. I have a friend here who works for QA1, we took his truck out one night and just by playing with the valving of the shocks, it took the truck from riding like a Cadillac to riding like it was on rails.
 
10secTy

10secTy

Sy-Ty builder and Tuner
Re: Handling info

Rear bar is 1" now the search for a larger bar.

I will measure the stock front bar and keep a eye out for a stocker 4x4 bar.

Once I get the motor in the truck I will scale it. It is a LS7 so I should loose some weight off the front compared to the 4.3 with all the turbo stuff.

Nolan
 
95xtreme

95xtreme

New member
Re: Handling info

10secTy said:
Rear bar is 1" now the search for a larger bar.

I will measure the stock front bar and keep a eye out for a stocker 4x4 bar.

Once I get the motor in the truck I will scale it. It is a LS7 so I should loose some weight off the front compared to the 4.3 with all the turbo stuff.

Nolan
Click to expand...

That's a good plan, if you know the front and rear weight can more appropriately figure out what spring rate to run.

On a side note are you keeping it a dry sump ls7?
 
10secTy

10secTy

Sy-Ty builder and Tuner
Re: Handling info

That is yet to be determined. i just got RPM's motor mounts and will start mock up.

The ARE LS7 dry sump pan looks like it might fit. Or we might mod the stocker or I might just go wet sump. so have not decided yet.

Oh I ended up getting 19 x 10's for the front with nitto NT05 285/35/19 and 19 x 12 with 335/30/19. Today I measured the stock rear sway bar on a 07 yukon and its 1" so that bar I have is quite beefy. But I guess I will find out if its beefy enough.

Nolan


95xtreme said:
That's a good plan, if you know the front and rear weight can more appropriately figure out what spring rate to run.

On a side note are you keeping it a dry sump ls7?
Click to expand...
 
10secTy

10secTy

Sy-Ty builder and Tuner
Re: Handling info

Do you think I should be looking for a 1 1/4 bell tech typhoon rear bar?

Nolan
 
95xtreme

95xtreme

New member
Re: Handling info

10secTy said:
Do you think I should be looking for a 1 1/4 bell tech typhoon rear bar?

Nolan
Click to expand...

Where is your gas tank located?
If it is in stock syclone location it will not work. If there is not anything there all you will have to do is fab up a couple end link mounts.
 
10secTy

10secTy

Sy-Ty builder and Tuner
Re: Handling info

I might put a fuel cell in the bed so mounting is not a issue. Or you could turn it around possibly?

Nolan
 
rentedmule

rentedmule

wanna-be
Re: Handling info

I don't know what the geometry is like on the 4wd chassis but the camber curve on the 2wd is bad. You can run tall balljoints and shorter upper control arms on 2wds to help correct it and raise the roll center but tire wear is still horrible on the outside of the fronts. In about 25 runs I basically destroyed the tires I bought from Mark a while back.

I run 42-44 psi front and 32-35 rear with C5 ZO6 wheels/tires to help with the understeer and rear traction issues. The alignment has lots of negative camber and close to zero toe to help with turn in. Adjustable shocks helped too - I'm running HAL stocker stars. It's nice to be able to dial them back for normal driving.

When the guys did the auto-x at Nats last year the body roll looked pretty bad from the sidelines - I don't think I would sacrifice the larger front SB. Is the front bar 33mm? If not, the later model 4wds came with one and that's as big as they get. ES makes poly bushings for it and fabbing endlinks with heim joints is pretty easy from what I've read.

There's a few guys building 4wds on protourings10.com but I think most are members here as well.
 
95xtreme

95xtreme

New member
Re: Handling info

10secTy said:
I might put a fuel cell in the bed so mounting is not a issue. Or you could turn it around possibly?

Nolan
Click to expand...

Putting the fuel cell in the bed towards the back is a good plan for weight distribution, although if you mounted it under the bed behind the axle it would get all that weight lower to the ground.

Otherwise yes, you can mount the ty style bar rearward since you are making mounts anyway. Although I am not sure what the current rear bar you have now is?
 
Last edited:
You must log in or register to reply here.
Top