I have a question for those with tubular K members in their f-bodies. I'm about to drop a iron block 408 in my car and I want to offset the weight with a tubular k member as well as tubular control arms up front.

What I'm running into though is people keep telling me not to run the tubular k member on the street for a couple of different reasons. One guy says the ride will suffer. That one I'm kinda iffy on because I think his car just rode rough because of the coilovers.

The one that concerns me is another guy said that the tubular k members have a tendency to crack during street use. Has anybody ever had this problem? Help me out here before I get started on this. Thanks

I plan on going all UMI parts BTW

 

free bump for the rooster. 40 views and no answer

 

I've had mine on since..............................'04? Earlier? I haven't had a problem with it. The ride may have suffered from it, but I have pretty much every piece from the BMR catalog, so I can't put any blame on it specifically. It hasn't cracked yet either, at least as far as I know. I've had my iron block 408 in for about a year now as well, and that's driving it every day over some pothole filled roads back home, and a nasty washboard section of the highway here in Houston.

I hope that helps.
Adam

 

I have one and no problems yet. I wish I would have done it years ago. UMI has a good one. I went with the Spohnn one. I liked how the stock steerring rack mounted and the brake line mounts to it.

 

ive got the spohn k-member/a-arms and i drive it all the time i felt it rode better with the tubular k-member/a-arms

 

Any extra noises from running the tubular K-member and A-arms with rod ends when on the street?

 

I got one of the first run BMR K-Members installed back in 2001 and one of the welds on lower passenger side broke upon hitting a pothole in '08. I called BMR immediately and they were great to work with in getting me set up with a current model and its MUCH beefier than the 1st. I street drive my car and road race it at Road America and the car goes repeatedly from 150+ mph to low speeds while tracking. Oh yeah....... with it, 1 hour plug and wire changes kick ***.

 

I didn't notice any more road noise from the arms or K mem. Gotta love the ease of maint. with the K mem.

 

Ride comfort does not suffer, you may feel the front end
a bit more "floppy" as no aftermarket K is as stiff / stout
as the factory double-layer pig.

I know a thing or two about busted K-members. There
are more, and less stout ones. Bottom line is this - if it's
not shipped with a street-duty warranty, it's a "race part".
And this one is one of the more involved installs, all told.
So you had better pick the right one especially if curb
surfing is a hobby of yours.

I wouldn't go with tubular A arms myself, the stockers
are tough and the tubulars, not much lighter in some
cases. And is lighter really your friend when the going
gets tough?

 

Thanks for considering the UMI K-member

We have designed our K-member to withstand the stress of a street car, drag racer and pro touring machine. We are very confident with our set up and proud to report to failures of this item. We also offer a 2 year replacement warranty on the item in case a instance would arise.

We designed our K-member with a dual tube center section offering more support than any other competitors item. This design reinforces critical areas that are exposed to stress, we also heavily gusset the rear A-Arm mount to prevent failure. The gusset design is similar to what GM used on there convertible K-member. Another small and unnoticed feature to the UMI k-member is we have lowered the center tube to protect the oil pan. Many other designs leave the oil pan exposed and open for damage. We lowered the rear tube just enough to help prevent damage and offer extra protection.

I think you would be very happy with the design and fitment of the UMI k-member and I would have no worries with your new 408 set up. The K-member won't effect your ride quality but aftermarket A-Arms may stiffen the front suspension up since you are eliminating rubber bushings.

Let me know if I can help anymore. Thanks!
Ryan

 

Awesome guys, thanks for the help. I'll definitely be getting the mild steel UMI K member then.

So I take it that the control arms aren't worth it then? How much weight savings are they, and how much do they help the performance or handling of the car? Also, I was told last time I had my car aligned that I should get a caster or camber kit to help get the alignment completely right because the car is lowered, so would the tubular control arms maybe have that adjustment?

Thanks

 

sweet

 

I drive my car on the street and love it.. And I would only use UMI products on my car.. Once you get them you will understand and never go back to anything else lol

 

The A-Arm kit will save you 8lbs more, the weight savings is from the lower A-Arms more than anything, uppers don't save weight. Depending on what the vehicle is being used for the A-Arms can be beneficial. Weight is one, additional alignment is another and also a less friction item. For a drag race application the rod ends work as a low friction bushing allowing the suspension to travel faster with minimum deflection.

With the K-member and/or A-Arms you will be able to receive the correct caster and camber from the vehicle.

SSHAWK- Thanks for the kind words

Ryan

 

All you have to do is read the posts above if you question streetability. Thanks msgZ28 andHeat Seeker WS6 for your input. We have over 2000 of them on the street, something no other manufacturer can claim, and have been building them for over 12 years now. In this time frame there have been less than 5 isolated incidents (that were reported to us) of cracks developing around the front box area (a high load point). 6 years ago the K-member had a complete re-design, eliminating the box and integrating the A-arm mounts into the upright tubes. There have been no failures since and I can promise you there are many more BMR K-members out there than any other brand....just saying

 

I'm guessing I'm one of the 5. When I hit that big pothole, it was as HARD hit at 50+ mph. A car moved out from in front of me and had no chance of avoiding it. And the damage was in the front box area. Prior to that, the k-member survived an accident involving a telephone pole's guidewire.
The new ones very beefy and not a single worry about pounding on the car at Road America or the street.


this was the broken one...

 

I should say breaking a K is not the end of the world
(if it doesn't happen at speed or under "challenging"
circumstances). Mine broke for good backing into my
driveway, though in retrospect it had been pulling the
weld apart slowly for weeks judging by the steering
feel.

Couple evenings of cobbling, better (if uglier) than
new, and alignment even came back. Maybe 5lb of
steel and 20 bucks (I hoard scrap) all told. You can
find the thread if you look.