4wd launching w/ cognito 4-6" lift kit

[jonathancasey19]

I've had this cognito 4-6" lift kit on for two years and did my first 4wd launch other night for the girlfriend. Used to have t-bars up and 35's so never bothered. Now, switched back to stock tires, t-bars backed out full & no rear blocks. Also have cognito hd tierods, brace kit and t-case brace. I was not impressed with the launch at all. Kinda scared the hell out of me how sloppy it felt & pulling hard right. First launch was at 1800 rpm and second was at 2100. You could feel a pop.....CV-angles are flawless but the truck felt like it had so much flex in the front. Is this from the longer bilstein shocks? Has anyone else had any issues launching with a lift kit? I made over a dozen passes b4 the lift kit and I'm hesitant to do it again. Lastly, I don't have traction bars and from guys that installed them with lifted trucks seem to praise the investment. Wondering how much they will help?

Thanks

 

[McRat]

You have to be really careful with boosted launches and lift kits. Lots of guys have folded their front ends.

At a minimum, make sure you are running a straight (solid) centerlink and tierod sleeves.

 

[sparepartsracing]

i have 2" lift keys maxed out t-bars ....really bad cv-angles, sleeves, solid center link and my truck launches great at 2200rpm on 33x13/50 on 20x10's :roflmao:

 

[RENODMAX]

I've had this cognito 4-6" lift kit on for two years and did my first 4wd launch other night for the girlfriend. Used to have t-bars up and 35's so never bothered. Now, switched back to stock tires, t-bars backed out full & no rear blocks. Also have cognito hd tierods, brace kit and t-case brace. I was not impressed with the launch at all. Kinda scared the hell out of me how sloppy it felt & pulling hard right. First launch was at 1800 rpm and second was at 2100. You could feel a pop.....CV-angles are flawless but the truck felt like it had so much flex in the front. Is this from the longer bilstein shocks? Has anyone else had any issues launching with a lift kit? I made over a dozen passes b4 the lift kit and I'm hesitant to do it again. Lastly, I don't have traction bars and from guys that installed them with lifted trucks seem to praise the investment. Wondering how much they will help?

Thanks

By lifting a truck you basically put a giant fulcrum in the front end. I personally have a lifted truck, and knew that only decided to lift it after I felt my racing days (for this truck ) were over. I agree on the centerlink and tierods, however I have not seen any benefit in the braces. They break regularly, and I lost turning radius with them. This is all of course my opinion. However I don't feel that a tall vehicle is ever a good idea for racing just based on general principle (unless its a badass old gasser but you have to be a nut to drive one anyway).

 

[ecc_33]

although I have the TC lift, I aslo have the SD center link and tie rod sleeves, My truck looks just as good coming off the line than anyother stock lifted truck. NEVER had mine toe in from boosted launches or pulling

 

[GeorgiaDuramax]

I've done a few soft launches for test with my 6" Fabtech. Haven't had a really probelm, but I wasn't pushing it either. I have to agree on the sleeves and centerlink, but I would think that the HD tie rods would be better than sleeves.

 

[Chevy1925]

I've had this cognito 4-6" lift kit on for two years and did my first 4wd launch other night for the girlfriend. Used to have t-bars up and 35's so never bothered. Now, switched back to stock tires, t-bars backed out full & no rear blocks. Also have cognito hd tierods, brace kit and t-case brace. I was not impressed with the launch at all. Kinda scared the hell out of me how sloppy it felt & pulling hard right. First launch was at 1800 rpm and second was at 2100. You could feel a pop.....CV-angles are flawless but the truck felt like it had so much flex in the front. Is this from the longer bilstein shocks? Has anyone else had any issues launching with a lift kit? I made over a dozen passes b4 the lift kit and I'm hesitant to do it again. Lastly, I don't have traction bars and from guys that installed them with lifted trucks seem to praise the investment. Wondering how much they will help?

Thanks

pull your braces off and do the old test to see if you idler/pitman arm are good. In my personal experience, the braces never really worked for me. at most i got 10k out of my idler/pitman arm with the braces on, 5k with no braces and now have 45k with the EXAXT kit with 0 movement in my idler/pitman arm. im pretty damn hard on my truck

Ive yet to try out my traction bars at the track but drivin around town i notice a big difference. surprising how much axle wrap you get and is un-noticed till you put traction bars on

 

[GeorgiaDuramax]

Ive yet to try out my traction bars at the track but drivin around town i notice a big difference. surprising how much axle wrap you get and is un-noticed till you put traction bars on

x2.

 

[RENODMAX]

pull your braces off and do the old test to see if you idler/pitman arm are good. In my personal experience, the braces never really worked for me. at most i got 10k out of my idler/pitman arm with the braces on, 5k with no braces and now have 45k with the EXAXT kit with 0 movement in my idler/pitman arm. im pretty damn hard on my truck

Ive yet to try out my traction bars at the track but drivin around town i notice a big difference. surprising how much axle wrap you get and is un-noticed till you put traction bars on

The braces do suck. He said he took the blocks out though so his rear suspension should act relatively stock. I wonder how much of a difference the one piece TC kit makes.

 

[JD Dave]

I have the same lift as you with 4 " deavers. With my stock wheels on my truck launches straight and true. At the track with a PPE Hot +2 it went 13.1 @101 MPH. I havn't been back since I did the rest of the stuff to my truck. I know the straight centre link made a big diff pulling but I didn't have it when I went to the track. I had traction bars though.

 

[jonathancasey19]

pull your braces off and do the old test to see if you idler/pitman arm are good. In my personal experience, the braces never really worked for me. at most i got 10k out of my idler/pitman arm with the braces on, 5k with no braces and now have 45k with the EXAXT kit with 0 movement in my idler/pitman arm. im pretty damn hard on my truck

Ive yet to try out my traction bars at the track but drivin around town i notice a big difference. surprising how much axle wrap you get and is un-noticed till you put traction bars on

So you are saying with the brace kit installed, that it is actually restricting me from the ability to jack up a tire and test if pitman/idler are in fact worn out? I've replaced both three times since 07'. Alignment is dead on. Tires wear perfect & no toe issues. Sounds like a centerlink is the way to go. Only reason I never switched was because I didn't want a terrible turning radius in a DD.

I still think one of my major issues is the longer Bilstein shocks with the lift kit. There is a new spindle which puts the t-bar in a higher location but the upper control arm remains in the factory location. Technically, if the torsion bar bolts are backed all the way out and the truck sits like it is cranked yet everything is perfectly aligned, then a longer shock for up front is not needed? I know this because since I backed the bolts out, my shocks are bottoming out on every speed bump, hole etc.... When I launched the truck, the decompression of the shocks was insane. I've never had my front end raise that high. I guess I'd need something with more damping.

 

[calabria69]

Ive yet to try out my traction bars at the track but drivin around town i notice a big difference. surprising how much axle wrap you get and is un-noticed till you put traction bars on[/QUOTE]

x3....i launch as hard as i need to depending on the track and no issues at all, i have the brace and sleeves.....

 

[Chevy1925]

So you are saying with the brace kit installed, that it is actually restricting me from the ability to jack up a tire and test if pitman/idler are in fact worn out? I've replaced both three times since 07'. Alignment is dead on. Tires wear perfect & no toe issues. Sounds like a centerlink is the way to go. Only reason I never switched was because I didn't want a terrible turning radius in a DD.

I still think one of my major issues is the longer Bilstein shocks with the lift kit. There is a new spindle which puts the t-bar in a higher location but the upper control arm remains in the factory location. Technically, if the torsion bar bolts are backed all the way out and the truck sits like it is cranked yet everything is perfectly aligned, then a longer shock for up front is not needed? I know this because since I backed the bolts out, my shocks are bottoming out on every speed bump, hole etc.... When I launched the truck, the decompression of the shocks was insane. I've never had my front end raise that high. I guess I'd need something with more damping.

Well its the best way to check them. the braces can give enough strenght that when you go to turn one tire by hand you see no movement but when you drive it and 4wd launch it, it flexes the braces and the cause wear and rotation of the drag link. My drag link is a straight link but i do not get excessive tire wear or bumpsteer due to its design. the inner tie rod sits behind the drag link instead of on the side so you dont put excessive angle on the tie rods giving you the bad tire wear or bumpsteer.

Your second paragraph is confusing. Cognito doesnt make a spindle that moves the t-bars up, no lift kit does. they make a bracket that bolts onto the LCA that puts the torsion bar up higher buts its not related to the spindle. i also dont under stand how you can have a truck sit like its cranked with the torsion bars fully relaxed?? when you say decompression do you mean the truck lifts very quickly under load in the front?

 

[jonathancasey19]

Well its the best way to check them. the braces can give enough strenght that when you go to turn one tire by hand you see no movement but when you drive it and 4wd launch it, it flexes the braces and the cause wear and rotation of the drag link. My drag link is a straight link but i do not get excessive tire wear or bumpsteer due to its design. the inner tie rod sits behind the drag link instead of on the side so you dont put excessive angle on the tie rods giving you the bad tire wear or bumpsteer.

Your second paragraph is confusing. Cognito doesnt make a spindle that moves the t-bars up, no lift kit does. they make a bracket that bolts onto the LCA that puts the torsion bar up higher buts its not related to the spindle. i also dont under stand how you can have a truck sit like its cranked with the torsion bars fully relaxed?? when you say decompression do you mean the truck lifts very quickly under load in the front?

Sorry I didn't mean spindle. You are correct with the lower bracket. With the torsion bars fully relaxed, the truck appears like it is stock (no lift) with t-bars maxed out. All angles are completely flat.

 

[jonathancasey19]

Here:

 

[Chevy1925]

Sorry I didn't mean spindle. You are correct with the lower bracket. With the torsion bars fully relaxed, the truck appears like it is stock (no lift) with t-bars maxed out. All angles are completely flat.

got ya. It really looks like your bracket is bottoming out on the frame before the shock is bottoming out. that bracket is really close but that boot on the shock is hiding how much shaft you have left in your shock. Bilsteins are not a shock ment for drag racing, the rebound is very fast so your front end will raise quickly under accel. QA1s have an adjsutable rebound that you can play with for a track or DD.

Id really make sure everything in your steering is in tip top shape before changing anything out. Ive spent lots and lots of time and money on our front steering figuring out what works and what doesnt and under what conditions things work best. im now down to plating the frame on the idler support side and possibly giving up the ball joint tie rods for heims (though i dont like to go that route for a DD). I dont even wanna go back and add up what ive put into my front end testing different ideas/theorys. it makes me cring

 

[hondarider552]

Crazy Steve has that same lift and pulls mid 1.7 60's, might wanna talk to him about it.

 

[SHOTZY]

I've done at least 20-30 launches at 15-20 psi of boost with my lift. Never broke anything. However, I think I've been very lucky! Be careful.

 

[rcr1978]

I've have a 6" Fabtech that absolutely would not do a boosted launch over 5psi it jerked back and forth bad. I let it down for a camp trailor to basically a little less than a 4" lift, I have 2" blocks in the rear and the front is as low as it can go the adjuster bolts for the torsion bars just barely run in enough to lift the key off the adjuster bracket. My CV's are level and I have P&A braces with tie rod sleeves, It's been a while since I've done any boosted launches but I remember leaving at 16-18 psi with no troubles I can't remember the RPM. It does pretty good leaves strait no jerking or any real things that make me scared shitless like before. I have bilsteins and I think mine lifted a little also, no traction bars but I need them bad.

Chevy1925, what do you mean about the relaxed torsion bars?

 

[Chevy1925]

I've have a 6" Fabtech that absolutely would not do a boosted launch over 5psi it jerked back and forth bad. I let it down for a camp trailor to basically a little less than a 4" lift, I have 2" blocks in the rear and the front is as low as it can go the adjuster bolts for the torsion bars just barely run in enough to lift the key off the adjuster bracket. My CV's are level and I have P&A braces with tie rod sleeves, It's been a while since I've done any boosted launches but I remember leaving at 16-18 psi with no troubles I can't remember the RPM. It does pretty good leaves strait no jerking or any real things that make me scared shitless like before. I have bilsteins and I think mine lifted a little also, no traction bars but I need them bad.

Chevy1925, what do you mean about the relaxed torsion bars?

bascially what you said above.