What's up guys, I'm a newbie trying to learn a little more about suspension and chasis upgrades and I'm having a hard time getting a thorough response on LT1tech.com. Does anybody have a BMR tubular K-member? I am considering installing one once I do an engine swap and I keep hearing horror stories about them colapsing under road racing stresses. I know that they offer reduced frontend weight and better accesability in the engine bay. But are they actually stronger? The car is going to be a daily driver only most likely, but I'm not going to rule out the possibility of me roadracing on occasion and I DON'T want it to fail on me. Any opinions are apprecialted!

 

is it stronger than stock? In a word, no. No K member is stronger in all aspects than the stock. Never heard of a stocker failing...

You can run them, as many do, just be sure and check it out from time to time..

 

I have a bmr k-member on my daily driver and it broke at the welds on the cross bar that ties both a-arm mounts together. The weld just separated.

The reason it failed was because they didn't weld the whole length of the joint. They spot welded it. So when this happened it threw my alignment way off because the lower a-arm was able to move out towards the fender a little. I took it into my uncle's shop and we used a long puller to get everything back where it was supposed to be and welded it back together.

I havent had a problem with it since. I have also heard that BMR changed their design and this k-member is older so this might not be a problem anymore.

 

Is there any other particular spot that they are prone to breaking? I could just weld in some tubular steel or angle iron and stiffen things up.

 

in the cross bar area.

dont need angle iron, but weld a tube in there to trianglulate the bar if you'd feel safer.

do a search , there are TONs of threads dealing with this.

 

I'd keep the stock one for street use and expecially track/autocross use. If it fails at 125 mph in a corner and I wind up in a wall (destroying the car or worse), I won't be thinking about the 30 lbs I saved....

Just my thoughts.

 

I read the F-body suspension write-up at http://robmeadway.com/fbodysuspguide.html
It seems that aftermarket K-members are primarily built for drag racers looking to save a few extra pounds. It would be nice to have better engine bay acess though. I'll just put up with that heavy LT1 frontend. Thanks guys, good website!

 

For raod racing apps, your goal to lighten the front end is a good one. But look at a bigger picture ... shoot for something closer to 50/50 front to rear weight distribution.

Taking 25lbs off the front will certainly help that. But, relocating your battery to the rear will also get you closer to the 50/50 weight distribution.

You can the look at ways to get the 25lbs off in other places. The net affect will be the same and you have no worries about a K-member failure

 

Or for a couple of 100 dollars more, you can consider a raceweight carbon fibre hood from VFN or other manufacturers to shave around ~25lbs. off the front end. Tubular K-members may be cheap to purchase, but it will be a major PITA to install, and if needed, to uninstall. If and when a tubular K-member deforms and/or breaks, you've got major troubles ahead.

 

I highly recommend not buying an aftermarket K member for street use.

 

screw the K-member, gotcha. Thanks guys

 

thanx for helping me decide also.. was looking at getting one for the weight savings but after hearing of others breaking them and now this post, ill forget about that part. Now i have to think of other parts that are lighter than stock..

 

Yes, at least for what is offered on the market at the current time. If any of the aftermarket sponsors can take this note to heart, then they might be able to engineer one that can exceed the capabilities of the OEM version, e.g. stronger, lighter, and probably allow better clearance for header and oil pan.

Another plus would be that it wouldn't break the bank, but in most cases the first three aspects mentioned above are a definite requirement for street, AX, and/or RR.

No need to really criticise, but why purchase something that is supposed to be a "bolt-on", then have to modify it later, or spend money on a design that isn't strong enough to begin with, then spend more money on options that make it stronger but add weight at the same time? In both of these cases, it seems that you will eventually end up with negligible weight savings, and worse, the K-member is already difficult to install for obvious reasons.