Sam Strano

iTrader: (41)

I don't know if I'd use the term stress riser in this case. But tubes are very, very strong. I can't imagine they'd make race car chassis out of it if boxed tubing was better.

2FAST4U

This has been talked about to death. By much smarter and better people than me. And the answer is this...
Box is better is some designs and tube is better in other. For the most part tube is used in chassis building because it is easyer to bend. The only time I would pick box over tube is SFC or maybe frame from scratch<--- only to save from having to use way more tubes for suport. Note all thing the same.

In fact it got so heated in other forums people started tested and even posting videos.

I have Boxed and say many people should do the same. However I would do tube now due to my CM cage. Save weight and all.

So no cage 2pt SFC boxed. Cage tubed SFC. Or 3pt tubed

2FAST4U

Oh and you are right but that is the mother of all loaded questions. As the tested that where done needed. Set measured load and the same steel. answer box won. i can't remember the numbers but same metal same test boxed holds 100's lbs more. Some people put down two blocks on the floor and set a 10ft. tube from one to the other and jumped on the center. LOTS of flex. Then with boxed with little to no flex. But hard to say if the guy used the very same thickness metal and the same metal.

exodus

iTrader: (15)

curious on this issue myself

allmotor

Only you would ******* try to hijack a thread that has nothing to do with shocks and springs and try to sell your products.

Back to RELEVANCE


Take lower control arms for example. The tubular ones are somewhat lighter than the boxed design. However, the boxed are stronger. They resist torsional(twisting) forces much better than tubular designs. This torsional fatigue is taken into consideration when building earthquake-proof structures, i.e. buildings. Along with having a polymer base rather than concrete, many of the buildings are designed in a cylindrical fashion. This allows the forces to transfer through the building, while the building absorbs much of the energy so that it would not collapse like a normally constructed building. This is just an example, there are several types/designs of these buildings.

Adam2001WS6

iTrader: (1)

I'm somewhat confused by your example. Are you advocating use of boxed or tubular?

allmotor

The example with the buildings is stating that because the tubular structure absorbs more energy by flexing/twisting, mixed with a polymer base, it is able to withstand an earthquake. a rectangular building with a standard concrete base will not flex, and the energy transferred throughout the structure will cause failure (i.e. windows shattering, building crumbling, etc) because it is being rocked/shaken apart.

Also, compare concrete and polymer bases to spherical bearing/poly bushing options on parts. The spherical bearings TRANSFER the energy through the suspension rather than the bushings which ABSORB some of the energy.

I'm saying the boxed are more rigid and allow for more energy transfer (to the ground). How much more energy transferred is minuscule and depends on other factors such as bushings/bearings, etc. They are stronger though, and will not flex as easily as the tubular. However it would take a great amount of force to bend or twist either one a significant amount, so you'd be fine with either unless you're making huge power. Even then you'd more than likely be fine with tubular, although if enough stress is applied many many times on several extremely hard launches, the tubular could and would be warped before the boxed. Bottom line is it takes more force to warp a boxed arm than a tubular, either bending or torsionally.

The boxed design is also stronger because of how the bushings are in the arm. tubular design would break more easily, as the loads are exerted at the ends of the arms. The boxed designs encompass the entire bushing rather than welding a bushing on the end of a tube..

Someone needs to make a poly/rod and/or rod/rod BOXED control arm for F-bodys......

Adam2001WS6

iTrader: (1)

Is the myth of clearence relevent in this case? I'm planning to have the lowering springs and shocks installed and I have read that tubular is suggested for the clearence. I would much rather go with Boxed SFCs, however, I don't want to waste my money if they are going to have to just be replaced...

Sam Strano

iTrader: (41)

I pay for the privledge. It's called being a site sponsor. I'm sure if you think I'm out of bounds you could report me to a moderator and let them figure it out. In no way was I pushy, just mentioned to the man we had a package that would save him a few bucks if he bought two parts he was already thiniking of in a CSP setup.

My screen name isn't something like "Strano Performance Parts Sales". I offer tech (as I have tried to here), but if Adam thinks I've been pushy he's welcome to let me know. I answered him, not you allmotor.

Sam Strano

iTrader: (41)

Tubulars do fit better as they tend to be smaller. If you pick a set that fits tightly it won't be an issue. The UMI's tuck extremely tightly to the floorpan in tubular. And if you prefer boxed for some reason, they also sell those--unlike some that offer only one of the other type.

2FAST4U

ALLMOTOR

Thank you for the makeing my point. And when I was at 550rwhp and 620rwtq and had a 17x10 and 17x11 wheels I distroyed lots of parts. Like swaybar mounts, Arms, Torque arms. The key words are all things the same box is better. There are designs that tube is more than good. And for many people on the board they will never know the differance. I like my boxed also b/c it gives me a jacking spot anywhere on the side of the car so at mid door if I jack it up both tires lift.

Oh and I have seen tube broken 6" away from a weld. Not saying box would be better but boxed also fails in a much safer way. And shows signs of failing.

allmotor

You are correct 2Fast4U. Even though I deem them useful/helpful posts, someone else did not like my 2 previous posts and I was unfortunately warned for language, regardless of content of the message.


IMHO:
You will be fine with lowering your car on boxed SFC's. With a lowered car, you're going to have to pay more attention while youre driving to maneuver around obstables i.e. bumps, potholes, sharp inclines, etc. so you dont catch anything on your car. That is regardless of what SFC's you have. The boxed design is stronger, plus gives you more places to jack the car on. If I were you, I would do some research before jumping the gun. BMR has boxed and tubular SFC's. Check out BMR's site, www.bmrfabrication.com. they are also a sponsor on this site, and offer a wide variety of all suspension components for all applications/needs/wants.
Check out all of the suspension manufacturers sites and compare all of them. Keep in mind that it is hard to judge quality by a picture on a computer. I'm sure there are many other options that are *decent* and that others aren't the *worst* out there either. There are plenty of happy customers of many different companies on this site. Yes, I have BMR suspension on my car. I could not be any happier. I would not change them for any other piece. That's me. I'm sure you will be happy with whatever company you decide to go with.

Adam2001WS6

iTrader: (1)

How well do the UMI Boxed SFCs fit underneath a T/A? Lowered? Perhaps you have some pics that I have not found?

allmotor

I could take some pictures for you later tonight if you'd like.. I have an SS lowered on coilovers w/ tubular sfc's

Sam Strano

iTrader: (41)

Bear in mind you are talking about a piece of 2" square tubing. That means they hang just over 2" lower than the floorpan where they mount. ALL SFC's will "hang lower" by a touch. The tubulars are better able to tuck as the diameter and shape allow them to better match the shape of the floorpan, and they are 1.75" tubing.

It's largely a moot point. I can tell you without doubt the UMI's (any of them) tuck as well as any, and better than most. And fwiw, header collectors and y-pipes hang lower. That's where you should be worried about dragging.

Adam2001WS6

iTrader: (1)

That woould be great if you could. I've seen a few pics of tubular and boxed installed, but anymore couldn't hurt to check out. Thanks.

Big Bird WS6

iTrader: (9)

i have UMI 3 point. had bmr on last car. and hochkis on car before. i love my UMI. it sits so close to body. best on market. do three point tube

Adam2001WS6

iTrader: (1)

Are there any problems with the 3 points (p.s. i've only seen UMI offer 3 points in tubular) and headers/exhaust? I'm also thinking of relocating the T/A mount to the tunnel and not the tailshaft (i still need to do more research on this)... might this pose a problem?

I'm going to be doing everything in stanges, as my budget allows, but I would like to plan as many things as possible in advance so that they work in concert, not against each other in the long run as i add more parts to the car.

I need to win the lottery!

UMI Performance

iTrader: (77)

Our boxed SFC's hang approximately 3/8" below the pinch weld under the vehicles door.. on a Trans Am model like you have the ground effects are going to hide them and they won't be seen from the side at all!

if I can help anymore please ask and I will be glad too. Thank you!

Ryan

Sam Strano

iTrader: (41)

Don't we all?

The SFC's will not interfere with any sort of normal exhaust system. Relocating the TA on a UMI bracket won't either, as the TA runs where the stock one does and the bracket is different tranny crossmember that sits in the same place as the OEM unit.

It's only wise to make sure your parts fit with future mods and needs, and encourage folks to think long term every day.

Both Ryan and I are available to help you with the decisions and parts. Because I sell the biggest variety of parts under the car, I am always looking for conflicts and want to use the best combination available for whatever the particular goals are.