Torsion Keys Vs. Cranking The Bars

[karlairey]

Can anyone explain what is difference between cranking torsion bars vs. adding torsion keys. Is there a notable benefit to using keys?

[Sugarphreak]

It is the exact same concept... the only difference is that only Keys allow you to crank them even more.



I put keys in mine, but there was actually tons of room to continue cranking it down with the OEM keys.



I think the only real benifit I get from them is the GM guys don't look for aftermarket ones (they look identical to the OEM keys) so the key position as it is now looks totally stock.



I have heard of dealers giving a hard time to anybody who cranks the bars (as it changes the CV angle and technically could cause pre-mature wear).. but they have not said a thing to me about it yet.

[Khamul]

There was a string regarding this ealruer in the year so you may want to look back and see if you can find it as there was some really good information in there.



Basically it is always best to use new Keys and from I have been told, the Suspension max Keys are the best ones to install. Reason for this - it does not add any further tension to the torsion bars at all whereas cranking them certainly does. How it doesn't.... I must admit I am unsure but I know for a fact - the Suspension max Keys I put in did not add any stiffness to the ride and still allows the front wheels to travel freely same as factory ride...



I cranked the bars on my H3 and then changed later to keys and I noticed a substantial difference. Cranking the bars, my front end was very stiff.... when I cranked them back and put in the keys.... Normal ride which is important...



But, I did like a bit more stiffness so I did do about a half turn on the bars after the new keys were put in, but to add a bit of stiffness.

[whitehumh2]

Ok, there is ZERO difference in ride quality whether you use keys or crank the bars. The big advantage of torsion keys is that you will have more range of adjustment whereas the other way once the bolts are maxed out well you have no more adjustment. I have actually kept the stock keys and upgraded my torsion bars. Instead of the factory 6715lbs rating I now run 7215lbs bars, this gave me way more lift and load carrying capacity. Also it is important to note that new longer lower shock brackets should be used to ensure that you get maximum wheel travel!



Hope this helps!



Kev

[Khamul]

[quote name='Polar Bear' date='06 September 2010 - 06:35 PM' timestamp='1283819715' post='20748']

Ok, there is ZERO difference in ride quality whether you use keys or crank the bars. The big advantage of torsion keys is that you will have more range of adjustment whereas the other way once the bolts are maxed out well you have no more adjustment. I have actually kept the stock keys and upgraded my torsion bars. Instead of the factory 6715lbs rating I now run 7215lbs bars, this gave me way more lift and load carrying capacity. Also it is important to note that new longer lower shock brackets should be used to ensure that you get maximum wheel travel!



Hope this helps!



Kev

[/quote]



Hate to be the one that argues.... but I will say without a doubt that with the suspension max keys.... substantial difference in ride compared to cranking the bars. I know you're a tech but I've done it all. Cranking the bars which I did on my 3 made it ALOT stiffer...



Maybe I'm blindly listening to the sales hype..... but I i swear there is a difference...



Kev - what did you do in the rear (or did you do anything?) for lift?

[karlairey]

[quote name='Polar Bear' date='06 September 2010 - 06:35 PM' timestamp='1283819715' post='20748']

Also it is important to note that new longer lower shock brackets should be used to ensure that you get maximum wheel travel!

Hope this helps!

Kev

[/quote]



Kev...please help me understand wht that bit means. I am guessing 'travel' as in up nad down right? So with longer lower shock brackets i would get less bumpity bump yah?

[karlairey]

[quote name='Sugarphreak' date='06 September 2010 - 01:49 PM' timestamp='1283802542' post='20740']

I have heard of dealers giving a hard time to anybody who cranks the bars (as it changes the CV angle and technically could cause pre-mature wear).. but they have not said a thing to me about it yet.

[/quote]



How to address this good point made by Sugarphreak. I am not so worried about what dealers think, but have been told by my tech to undo the bars back if not to spec then close (I think I have 2" raise from) so I stop having front end issues and a proper lift is needed. I know he wants that business but at the same time, looking at the angle of the CV shafts and where ball joints connect, it seems to make sense. If I lower to 1" to save wear up front, is there any other lift options besides 4-6" lift kit?

[Sugarphreak]

The way torsion keys work is they pre-load the torsion bar by twisting them... the bar basically stores that twisting energy in them replaces the spring. Imagine you have a straw from McDonalds and you twist it... when you let go it has a natural tendency to snap back towards it's original shape. Same concept, only with metal and a lot more energy.



The only thing keys do is change the angle of the lever... by doing that it allows you to twist the bar more than you normally could with an OEM Key. This of course does not matter at all as the OEM keys (at least on the H3) already have a lot of space to twist the bar.... let me elaborate further on that;



Even though you can twist the bar more with aftermarket keys... if you overtwist the bar, sure it will lift the front end a lot... but at the same time it will put so much energy into the bar that when you hit a bump the truck will want to hop side to side and behave like an old stage coach wagon. This is why you can only do about a 2" lift max (again H3 specific example) despite whatever key you run.



There is no difference between putting 500ft/lbs of energy into a torsion bar with one key or another... that energy is what gives you the lift and ride feel, this has nothing to do with the keys actually.

Also it is important to note that new longer lower shock brackets should be used to ensure that you get maximum wheel travel!

There is a lot of debate about this, the theory behind it is it allows your shocks to operate in a more optimal range to match the new ride height which extends the life of the damper and also increases the ride quality... but there is 2 negative sides; firstly it also allows your suspension to drop further than it normally would in certain situations (bumps, drops, dips, ect) which could allow the CV joint to be put under considerable stress. Secondly when you hit a big bump... the shock will bottom out before it hits your bump stop. This will kill your shock really fast. If you do go with this option you need to extend your bump stops!



My own philosophy is that 1-2" typically has little affect on your shock operation, this applies to running spring kits in cars too, if you run a 3" drop you usually kill your shocks in about one to two years... on the other hand a performance spring kit with a 1" drop has a negligible affect on your dampers. You still get at least 80% of the life and 100% of the performance out of the damper. With trucks you have a lot more travel and bigger dampers, by almost a factor of 2... so a 1-2" change in ride height should be OK, plus the torsion bar loading alone will still keep the suspension within the designed operation range at all times.



Karl in regards to your last question



I would actually agree with your mechanic, I think you will see pre-mature wear on your CV joints if you keep the 2" lift with just the torsion keys. What I don't know is how much reduced life would result. My feeling is dropping it down an inch would take a lot of stress off of the angle... one thing to note is make sure whenever you adjust the load on the torsion bar to change the height you get a wheel alignment afterward.



The problem is anytime you want to do a lift you change the geometry... as soon as you get out of the ride tolerance range of the vehicle (which is usually just an inch or so) without addressing the angles of the CV or drive shafts you end up with vibrations and early wear issues.



As an example; I did a 3" lift in my Jeep a number of years back... to do it properly I dropped the transfer case by 1.5" to keep everything within that 1-2" tolerance... everybody I know that did a 3-4" lift without doing that had drivelines that would vibrate so bad they would eventually shake themselves apart.

[Khamul]

Agreed... In the end I think it will come down to preferance.



Plus another factor is everyone having an opinion as well, so always take everything with a grain of salt. I was told a simple 2 inch lift shouldn't add any strain on the front end components but really common sense says that there will be some. Driving patterns will also come into play. It's nice to know that as long as you have a 35 mm socket, you can remove a drive shaft on the trail and the Hummer will still be able to run.



I would have liked to have gone with a 4" lift kit but my kids have a hard enough time getting in with just a 2" so that was another big factor for me. Cost is another one as lift kits for these babies aint cheap! And then you have to balance against home driving and trail driving.



I really find that the simple 2" lift adds the ground clearance needed for a better trail ride, and I can still go through a car wash! I can't park underground in Chinook centre though as I'm too tall!

[Sugarphreak]

^^ I tried to get a 35mm socket at P.A. .... all they have is 34mm and 36mm <img src='http://www.canadianhummerclub.com/forum ... #>/dry.gif' class='bbc_emoticon' alt='<_<' />