propaintball96

Hey guys,

Ive been doing a ton of research on the UMI Road Race K-Member and the Racecraft 4130 Road Race K-Member. I was hoping someone here had a little experience/input on which I should buy...

The UMI definitely looks more beefy with a couple more support bars and gussets but it made of Mild Steel. This K-member is 629.99

http://umiperformance.com/catalog/in...roducts_id=732

The Roadrace is made of 4130 Chromoly which is much stronger but looks like it has less gussets and support bars. This K-member is 649.99

http://www.racecraft.com/index.php?m...oducts_id=1254

Both of these I have heard good things about. Does anyone here have any input? Any help is very appreciated!

Thank you

SlickTrackGod

Between both those choices?
1) stock kmember. Paint it. Nothing wrong with it.
2) umi. The have good fabrication skills. But way spend money on a part with no added benefit unless you want to lighten the nose for drag launch.
3 )
4).....
...
...
19743) Racecraft/ paracing etc... their stuff is known to break from poor fab & engineering skills.

If you actually did a lot of research on here you would have read and known this. ; )

Save the money and buyother more Iimportant parts from umi. Stock is best.

propaintball96

Stock K-Member is huge ugly piece of junk...may be strong but ugly. really really ugly. All of my research has shown everyone on TGO loving their Racecraft k-member...

Thanks for your input

//<86TA>\\

iTrader: (14)

What are the plans for the car?

The k member would be the last piece to change unless it needed for clearance reasons. None of the aftermarket pieces are strong or as strong as the stock piece.

572_Rat

I have the Racecraft Road race K member, if you do a search on my post your will read the horror story I had to go through to get it. But the fitment and the quality of work was excellent, I have had zero problems with it.

With UMI I bought there new A-arms and had a lot of problems with fitment, spring pocket was put in to high so I had to cut coils, had to cut end links because they were mounted to high, and had to cut the bushing because they were cut to wide. But the product was nice in appearance.

I realized with these after market products, it is really a 50/50 chance on what you buy will work right out of the box.

Nice thing about having the tubular k member, I would have never been able to get that BBC in there with my headers with that factory k-member

propaintball96

Well my headers are a pain in the *** to get in without lifting the motor a few inches...but this is not why I am doing it. I'm doing purely for astetics. The stock k member is a huge ugly pile of crap and its not going to go with the rest of the suspension build I'm doing.

propaintball96

I actually read your thread several times. I was very disappointed in the customer service you mentioned throughout your thread...but I did figure over the past few years they have made their manufacturing process better....but also like you said, the quality once it finally worked was amazing so that's what I am trying to figure out...should I risk the racecraft kmember or go with the umi and have weaker steel but a much more well known and represented company that will most likely have it right the first time?

572_Rat

Racecraft is a well know company, just very poor customer service. But you can see either company can produce problems. Racecraft at least did something about the problem, I contacted umi about my problems and they did nothing about it.
If I was buying another k member I would buy another Racecraft, i do like the k member after I got the proper one

UMI Performance

I'm very sorry you had trouble. We have honestly had no fitment trouble with the k-member or a-arms. We have been making the a-arms the same for years, spring bucket in same location and have not revised them. We also run the same a-arm on G-Body cars with same height and no issues. The k-member has not been revised since first design as well.

So again I am sorry you had trouble. We were probably mind boggled since this isn't a common issue. We really receive no complaints.

As for mild steel, the tensile and yield strength is lower than 4130 yes. But keep in mind most companies when using 4130 steel use thinner wall to cut weight. Thinner wall 4130 can have close strength characteristics to heavier wall mild steel. 4130 requires TIG welding and has to cool properly, so companies making this item from 4130 need to use extra caution. We have never used 4130 on a k-member and don't plan on it as of now. Our k-member is unique as it is more fabricated flat steel than tubular.

Using a 4130 k-member I don't think is going to gain you any strength but maybe a pound or two of weight savings. But this is hard to compare on different brands.

anesthes

iTrader: (12)

I have the same issue. When I'm cruising down the highway at 75mph with my x-ray vision turned on and I see a car with a stock ugly k-member I just get stick to my stomach.

-- Joe

anesthes

iTrader: (12)

These are the clowns that sell $500 spindles, and tell you that they are not for road racing OR street use. When they fall apart Racecraft says "You must have driven on the street!".

-- Joe

articwhiteZ

iTrader: (56)

I just installed a UMI K Member..had another brand.. (sphon) dont even ask..I will say the UMI fell into place.. no wheel set back..you can use any tie rods ..every thing is like it should be... eng fit..finnish...my cars a drag car show car..cruiser..and a 1 owner....me..

The customer service was outstanding..with anything I asked...

SlickTrackGod

As you have now read, Racecraft has had issues with some serious life and death matter when dealing with fabricating components.

Racecraft used to also be affiliated with PA Racing. These guys were firends or employees of one another or something like that. Search REDRAIF and A-arm and you'll read about welds failing and the poor fabrication. I would not trrust these guys with mild steel, never the less chrome molly which is much more dangerous to fabricate with because it has to be normalized after welding or will be brittle. All it takes is one thing to impact that Kmember ONCE and create a little bit of consmetic damage that can and will progress into failure. that big ugly Kmember is big and ugly so it has mass to hold up to accidental impact of crap on public roads.

I'm not telling you what to buy, I am merely warning you about trusting costomers that bolt on a product and live in a perfect world. Of course they are going to say the $600+ piece of powdercoated metal they bought makes them happy when they look at it. How many of them have hit something on the road with it yet?

You're welcome.

propaintball96

You must not open your hood very often...

propaintball96

I am starting to lean more towards the UMI member... I like the fact they are a well known company and I called yesterday and had someone immediately pick up and tell me all about their k-members.

Plus...it sounds like SlickTrackGod wont be very happy if I buy a Racecraft ;D

Thank you for your help

anesthes

iTrader: (12)

Sure I do. (I just can't see the k-member)

-- Joe

anesthes

iTrader: (12)

I ripped the cobra rack right off my PA racing k-member

When I switched back to box steering, the tie-rod sleeve sawed a hole right through the k-member on the test drive.

-- Joe

propaintball96

Hmm....try turning the x-ray vision off. You'll see that ugly thing right away! ;D

articwhiteZ

iTrader: (56)

If you do go with UMI make sure they give you free shipping...order with them....as you can always use summit..and get the free shipping.....

gmancamp

I ordered my UMI K-member and a-arm kit directly from UMI last and look forward to receiving it as the customer service was great to deal with.

articwhiteZ

iTrader: (56)

did they give you free shipping?

gmancamp

Yeah caught the Labor Day sale, free shipping and 10% off. K-member came yesterday it looks awesome. Waiting on the a-arms to come in now.

articwhiteZ

iTrader: (56)

I got lucky and was able to sell off my Sphon K Member. for the cost of the UMI K member. and got the free shipping as well...

propaintball96

Why go with UMI instead of through summit?

Just wondering?

articwhiteZ

iTrader: (56)

i like summit..i do.. but sometimes the guys taking the orders get it wrong.
by 1 part number is all it takes to set you back 2 weeks..

by dealing with UMI your self. ya cut out the 3rd guy. and ya cut out the time it takes to fax a order in from the 3rd guy..

you can save your self a day or two. going strait to the maker..

gmancamp

I bought the k-member / a-arm combo and got an awesome deal buying directly from UMI and the customer service was superb.

572_Rat

Understand before I get started, I am not defending Racecraft, it still pisses me off what they did to me. My point is all these companies have their issues. UMI had that problem with that torque that broke off at transmission mount. That also was a live a death issue, can you imagine that catching the ground a 60 mph. I also have the Racecraft spindles, mine were not cracked, but it brought them to the shop that did by back half and had them reinforce them, same place I had to take my UMI arms to have them modifier to fit.
All these companies are playing with our lives, so far I have not found one better than another. Just be careful and check the parts you buy before you just put them on you cars.

SlickTrackGod

You just made my point- If you read my first post on here I suggested to leave the stock Kmember. I do not play with my life when it comes to pieces that can fail upon accidental impacts of objects on the road. I don't care how beefy they can make it, it needs to be as heavy and beefy as the OEM one.

SlickTrackGod

I'll also add that I know my opinion is just that, and everyone here has one, But most here do not deal with things like this like I do on a weekly basis on my professional race car team. I see a lot of stuff bend and break with impact. Sometimes with another car, and sometimes just plain ol fatigue. Some things need to bend and not break, whereas if things are not bendable they can snap and kill someone. A Kmember is a serious piece of metal undee the structure of the front suspension and chassis. One good rock or object on the road could put the entire front suspension into chaos at speed.

Just my two cents- but a very experienced two cents.

SlickTrackGod

...and here is a good read to educate anyone interested as to why 4130 is dangerous to use when fabricating structure pieces like this. I can promise Racecraft is not going through all this heat treating and tempering process. mild steel is by far the safest way to go if you are still debating using an aftermarket Kmember. It will bend but not break (as long as someone competent has done the welding. 4130 can brittle break regardless from a big impact. 4130 LCA's? it is difficult to take a hard hit on them, but a Kmember? God help anyone that does.

http://www.netwelding.com/heat_treated_4130.htm

articwhiteZ

iTrader: (56)

With any aftermarket part things can fail...even factory parts can fail...build them fast make them light.and anything can fail...keep an eye on things as you should. Should help with longevity.
not keeping an eye on things. is how things can go wrong.. the only broken A arm i have seen pics of. the crack/fail 10 years ago..it. was not in a weld..but in the tube it's self. and you could see the rust from it cracking long before it broke..if a PM would have been done on the car/parts..like you should.. it would have been spotted..(should have been)
but with guys/gals just bolting on parts and forgetting...this stuff will take place.. blame who ya will but the end user needs to keep an eye on things..
and when it's spotted the maker needs to stand up and take care of it!

we are not talking a life time Guarantee.. but a year should be good. most dont even do that...
all have that thanks for buying there parts letter with the parts..and on the same page they have the same use at your own risk letter...lol covers them if it fails the day or anytime it fails.. but remember..racing sports can kill....go fig

customblackbird

iTrader: (15)

I just purchased the moly race craft k-member. Moly is stronger than more flexible than mild steel. Moly is used in the aerospace industry and nothing flexes more than airplane structures. I also got it cheaper than the UMI steel road race so it was a no brainer. Only fault with moly is it breaks when it fails compared to mild steel where it bends more and deforms.

SlickTrackGod

. Never mind. Im staying out of this

anesthes

iTrader: (12)

When welding 4130 if you are not going to heat treat you use er70s2 rod. If you are going to heat treat you use 4130 rod. If you use 4130 rod without heat treat you will get stress cracks.

http://www.netwelding.com/Welding%204130.htm

Even an *idiot should be able to get this right, by simply walking into the local welding supply and saying "I'm welding this material, what rods do I use".


-- Joe

*Does not apply in California (I.e: http://www.marinij.com/marinnews/ci_...-centers-pay-1)

customblackbird

iTrader: (15)

I'm not sure what I contradicted myself with. Moly is stronger than mild steel, therefore can be used at thinner wall thickness for reduced weight but at the same strength as mild steel. Its only fall back is that it doesn't bend/deform before it fails, but it will flex more than mild steel. Push moly past its flexing and it will snap vs mild steel which will flex and then break, mild steel will keep bending and distort.

I can tell you the main reason why more ppl don't run moly on the street is all the hype about it being more "brittle" and the price stand point, who wants to spend 20-40% more for a product of the same strength but 20% less weight on a street car? Also you should be able to TIG weld to add anything to moly where as mild steel you can be as sloppy as you want with a MIG.

I can TIG and MIG but prefer TIG if possible.

customblackbird

iTrader: (15)

Yes and thanks Joe, another guy on another forum brought that to my attention. Since I use the 70s2 for just about all my steel welding it shouldn't be a problem. I thought about just welding it to the spring perch (center area and let the outsides overhang) or weld a bucket on the WG frame plate and then weld the bucket to the outside edge of the spring perch on the moly member (short welds to keep it in place since it can't push through and not taking the full load). Not sure yet and it might be easier to just run coil overs.