I have searched and read hundreds of posts. But, I have yet to read and authoritative answer to the question I have.

Does a (properly designed) replacement tubular k-member and a-arms increase the handling performance of our cars? Does it change the drivability, at all?

I understand that the weight savings may give you an extra tenth in the quarter mile. I also understand that it opens up more room and looks better. But I'm mainly concerned with handling.

Note: I added the "properly designed" notation to my question because I understand that some of the current k-members that are available are supposedly inadequate. I don't want a debate over a specific brand or model. I'm interested only in a 'theoretical' properly designed product.

 

In theory, yes. Lighter suspension parts that provide the same geometry and strength will produce better handling.

In practice, not noticeable. Spend your money elsewhere.

Si.

 

The K-member could make a difference as far as front/rear weight distribution, definately something that should be considered if you are looking for neutral 50/50 distribution. Over 50 pounds lighter than stock. Combine that with other weight saving mods in the front and you're on the way to a neutral balance. The A-arms weigh around the same from what I've read, just supposedly stronger. I have no experience with either, I'm still running stock everything. But when I eventually swap in the next motor I'm gonna seriously consider these mods.

 

I was doing a FULL ground up build and decided to do all these mods. All I can say is that is makes doing custom stuff and fitting of other things a SNAP. I dropped Hooker long tubes in and installed them on my motor all by myslef in less than 15 minutes. Hell I could have done it on the phone. There is just so much damn room. Much easier to run custom fuel lines/brake lines/ wiring.....everything. looks great and supposedly strong, but who knows. I know guys lifting off the frontend with these running low 10s. Should be ok.

parts look great too. Every part of my suspention is now powdercoated or at least painted red. One i get rid of my UMI tubular trailing arms (black) and get some red spohn ones then I will be all set. I wanna put mirrors next to the car at shows.

Anyways, the parts do weigh a LOT less than stock, I almsot didn't even care, I just really wanted clearance. I think my roll bars and N20 bottle help even out the weight of the Aluminum headed SBC and all tubular stuff. But who knows. Oh well good luck

Later

-Dennis

 

just FYI (i dont want to start a debate here...) the stock Kmember itself doesnt weigh 50lbs.



fadetoblack:
no. nothing noticeable. however a weaker one could allow for more deflection..... but i have no way of measuring that... its just a theory.

no. ive driven several cars with them, and they all drive the same before and after... once they're aligned.... and problems fixed.
without going off topic into it, some aftermarket Kmembers have sucky spring perches, and some of their a-arms have sticking problems.

now, i DO change my driving habits with one... slamming a stock K member into railroad tracks sucks... but you're not worried about it surviving.
slamming my Kmember into ANYTHING would royally suck, and id have to pull over, check it out, ect.... so i drive more carefully now... no big deal since ive been driving lowered cars for a few years now.. i pay attention to that kind of stuff anyway.. but i wouldnt go flying around dukes of hazzard style.. lol

 

If I remeber correctly my stock K-member stripped of everything after powder coating weighted 38lbs. It looks heavier than it really is. I am however going to be using a tubular K-member for clearance...............jt

 

i noticed you could feel the bumps a lot more with the tubular k-member.

Justin

 

with the same engine, or with the LS1 vs with the SBC??

because the LS1 weighs soo much less, it has the effect of making your front springs seem stiffer...
so if you're talking about the engine swap before vs after... you cant really make a accurate comparison.

 

EDE is a piece of sh*t
Ban me asswipe if you don't like my helpful post.
You are only antogonising me to cause trouble

I plan to have alot of fun around here durring the holidays

Merry fu*ken X-mas

 

This is true but i have read, and was told my bruce before i bought the k-member that it would stiffin up the chassis a lot more and would make the ride a little harsher. But your right i can't make a accurate assumption becuase i did the k-member swap and coil overs after the swap. But i can tell you that when i hit bumps sounds like my car just blew up.


Justin

 

I could have sworn I saw advertised weight savings between 50 and 75 pounds, maybe I'm drinking too much egg nog. Or maybe that was with some custom rack steering I didnt notice. Sorry to spread mis-information. Can we verify the stock one is only 38 pounds? I had planned to do this mod specifically for weight savings, if its not gonna save much then I'm gonna save my money.

 

i had a pa k member on a 83 and it was around 25 pounds in weight savings. if you drive it everyday i do not recomend one. i did drive mine about everyday and it made me sooo nervous when i saw a pot hole. but bot did i have so much more room with it, it was great.the inner tie rods did hit the cross member(had to put them in front of the center link). until someone makes a GREAT tubular k member, i am sticking to the stock one.

 

I weighed a stock one.

It was 45 lbs.

It was not clean, full of road grime dirt etc.

I have a clean one that I can weigh, but it will only be lighter.

I dont think there is an advcantage other than clearence issues.

The stock one could not be any stronger than it is now without adding weight.

GM did a good job on this piece.

 

Give me a day or two and i will get you the exact weight. The 38Lb was me holding the K-Member and stepping onto a bathroom scale. I have a digital scale that I use for shipping now so it will be exact on the weight. Its bare and powder coated so i just have to unbolt it. Needs to come out anyway to make way for the tubular one............jt

 

Thanks guys!

 

I'm a dork, weighed everything, and here's the data from when I swapped them out on my 84:

Stock k-member: 44.52 lbs
Stock bolts: 1.16 lbs
Triangle brackets
that get removed: 3.94lbs

Total: 49.62lbs

PA k-member: 22.74lbs
New bolts (shorter): 0.80lbs

Total: 23.54lbs


NET LOSS: 26.08lbs

 

that sounds about right, i never weighed mine but i guessed it was between 40-50 lbs. I had no problem picking it up and moving it around. As for daily driving the tubular one, i have no problem with mine. Put on almost 15k miles since i put it in this summer and thats driving around in detroit where the roads just plain out suck.

Justin

 

One thing that has not been introduced her yet is the fact that one could relocate the A arm conecting points if designing a K member from scratch.
When we lower our cars the geometry is changed for the worse. Changing the A arm connection points would have an effect similar to using drop spindles. As far as I know there are no drop spindles nor is there a K member that relocates A arm currently available. Belltech are you listening?

 

i'll concur with the 26 lbs. i did both k-member and a-arms. weighed myself holding each and subtracted the difference. roughly 27 lbs. this was pa racing's member and arms. and the overall looks and added clearance really sold me on getting one!

 

Thanks for verifying that guys. If the weight savings are that minimal then I'm gonna stick to the stock stuff.

As for the drop spindles, a little bird told me that something might happen in the beginning of '06, possibly a product ready by mid '06. Look for the post by Kevin.