Need feedback/reviews from those that have changed there K member from stock read the older threads in here mostly arguing about it being a pointless gain and negative feedback about build quality and fitment for various vendors. From what i gathered the UMI roadrace version is the one to get that is the strongest theres a vid on YT of the weight difference from stock to standard UMI, and its only 16lbs keep in mind the roadrace version has more braces so it will be even less than that. Only plan on doing the K member atm as the engine is out and redoing the bay as i can always do the arms later when engine and bay is done as the arms are only another 6lbs total left and right.

Want to know if as a driver can you tell the difference when the tubular member is in specifically the UMI one if theres any flex, creaks, or any other noticeable driving differences between it and stock as the only thing talked about on here is that its not a worthy mod cost/labor to gains and not anything specific about the actual product

Car is not a daily only gets driven on weekends sometimes gets long trips 100 miles in a day set up for street/drag will be using stock arms engine mounts and springs

 

The stock GM k member is way stronger than the aftermarket k members, you can jack the front of your car up from the stock k member. I would not try that with an aftermarket k member. With that said I went with the UMI k member, control arms and weight jacks for a number of reasons:
The UMI stuff is well engineered and built,
It provide easier access to the bottom side of your engine and clearance for headers
i ended to modify the cross bars for my LT5 oil pan, much easier to do than the stock k member
it does drop some weight
The UMI k member did not change any ride characteristics IMO
Weight jacks are the only way to go to dial in your ride height and much easier to install

 

Lol i have a 4000 lb bbc turbo car and jack car up on kmember just fine. Thats nonsense

havent noticed any difference over stock. I had the umi road race setup and the pa racing very light one and both have been good.

 

I have this Heidts Kmember in my car. Its a pretty stout piece. Got one after seeing one of Hawks Motorsports feature vehicles having one. Ive driven on it 19k miles all street driving and its great.

 

My BMR k-member will fold like a taco if try to lift from the center. First one actually did.

Most tubular K-members are meant for drag racers that don't experience cornering loads. All they want is weight reduction and extra clearance to package speed goodies. It's a good kind of weight reduction for drag racing because it helps weight transfer to rear tires.

It is not a good kind of weight reduction for road racing. You want a very low center of gravity, and removing that weight only raises the center of gravity. And most tubular K-members are too weak and flimsy for hard cornering. The only good reason to change the k-member for road racing is if you want some kind of geometry change or need more oil pan clearance or something like that. Heidts is the only K-member that has a geometry change by adding 3° anti-dive into the A-arm mounts.

For reference, Detroit Speed has a road racing 3rd gen and they could have done anything they want and they chose to keep the stock k-member.

If you just want it because you want it.... well, that's okay too and you don't need to justify it to anybody.

 

I knew those existed but this is the first time I've seen one on this forum. I'm super interested! Got more pictures? How's oil pan clearance? Does it accept stock A-arms?

 

which one do you have on the car now umi or PA?

 

PA racing as i needed room for bbc headers and no engine mounts for engine plate. Also no spring perches for coil overs

im honestly shocked to hear a kmember folding while jacking car up. Where else are you supposed to jack the car up at? If the design cant handle it, its a crap design.

pa racing one seems as small/thin as you would like to see and my car with bbc is not light but even that tube holds. I was nervous but its been in the air more than it has been running it seems lol so its strong enough

 

I stand corrected on the UMI tubular k member. I reached out to UMI's tech dept today and they stated that you can use the center bars of their k member as a jack point.

 

My BMR is a flimsy noodle. Only reason it's still in my car is because I'm too lazy to redo my trans mount. Everything fits because my car was built around it. Makes it hard to move away from it.

 

where are the spring perches? or are you using coil overs? can you jack the car from this? how does the anti dive work?

 

I have a RaceCraft k-member
I use the centre to jack the car up, with no problems
https://www.thirdgen.org/forums/susp...t-kmember.html

I cruise the car on Sundays and don't see a difference in driving, but lost alot of weight doing it though

 

I got this kmember in 2016 from heidts while attending the thirdgen expo. If i remember correctly silverstreak had this kmember at the time. Oil pan clearance is great but you still need to raise the motor up to remove the oil pan. The spring perches were not visible in the box but they are there as I am running just regular factory style springs. Im running Spohn A-Arms because I already owned them at the time. This is the only photo I have at the moment but can take some when i put my car in the garage. Before QwkTrip mentioned it I was actually not familiar with the term Anti Dive.

 

Thanks for the picture. Do you know if the LS AC compressor clears? I think you're using stock 3rd gen compressor with a high mount bracket. Not sure if you tested LS style compressor on LS brackets?

 

I have not test fit it, but the way things are going with these R4 compressors it may be happening.

 

the anti dive is built into the a arm angle they are pitched back a few degrees, did you weigh yours before install? I was told its 32 lbs