bigSS

Ok, i'm going to purchase a set of BMR tubular SFCs (weld on). I have a frame hoist, and a welder. I'm planning on having a buddy weld it on for me. Does the suspension need to be unloaded or loaded when he installs them? Any other tips (like perhaps making sure the car is level)?

DARK AGE 53

The suspesion needs to be loaded, I know you probably don't want to hear this but get the bolt on type. Great deal from these guys on them www.spectaclesolutions.com

horist

yup needs to be loaded... Personally I dont like the boltons.. they're more money than weldons and in the end you usually have to weld the bolt ons anyways.

Silver99Z

At first my BMR's were welded in front (have to be) and bolted, TIGHT, in rear, but there was a clicking noise because the connectors were moving slightly on the bolts. Welded the rear and everything's okay. Bolts are good for connecting but don't make for rigidity which is what the connectors are for in the first place.

prockbp

if you think about the point of a subframe connector, it just doesn't make sense to use bolt-on subframe connectors

the bolt-on joint will slip and flex before the subframe connector will... that's not a good situation

DARK AGE 53

I have always found it hard to convince guys that the bolt-on SFC are the way to go, but look at the Spectacle or SLP SFC. There double diamond, the rear uses the LCA bolt plus plus another bolt, the front uses two bolts to hold it to the body as well as two bolts more that hold it to the center of the car.

If you want to use the weld-on type why would you want to use there tubular SFC, tubular SFC aren't as strong as there square ones also remember the SFC is only as strong as the weld.

Like I've always said it's your car and $$$ so do what you think is best.

prockbp

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by DARK AGE 53:
<strong>the front uses two bolts to hold it to the body</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">that's exactly the problem.. the front subframe can easily twist on that joint... it's the most crutial point since that's where most the weight is

how do you know that tubular steel isn't as strong as the rectangular steel? polygons are not the strongest shape out there, triangles are stronger.. hyperboles are the strongest.. circles are shaped more like hyperboles

i have boxed SFC's.. they bend easily

horist

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by DARK AGE 53:
<strong>I have always found it hard to convince guys that the bolt-on SFC are the way to go, but look at the Spectacle or SLP SFC. There double diamond, the rear uses the LCA bolt plus plus another bolt, the front uses two bolts to hold it to the body as well as two bolts more that hold it to the center of the car.

If you want to use the weld-on type why would you want to use there tubular SFC, tubular SFC aren't as strong as there square ones also remember the SFC is only as strong as the weld.

Like I've always said it's your car and $$$ so do what you think is best.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">But weld doesn't flex... and if it does it's most likely broke or braking....

In the end the cost is about the same or cheaper to get weld on vs bolt on (weld on are cheaper but you need to have someone weld)

That's great that there are four bolts but it still leaves room for flex...

DARK AGE 53

[/QUOTE]that's exactly the problem.. the front subframe can easily twist on that joint... it's the most crutial point since that's where most the weight is

how do you know that tubular steel isn't as strong as the rectangular steel? [/QB][/QUOTE]

It dosen't matter if you use the weld or bolt on kind there's going to be some flex, the part of the SFC that's welded to the body is quite a flimsy piece compared to the rest of the SFC.

If you look on BMR web site they even will tell you to use the boxed SFC if you're looking for strength, but hey maybe they don't know what there talking about.

ss01gtw

I've got the bolt-ons and have had no problems! True, I don't do alot of racing with the SS but, I still give it a real good workout. I think for the amount of work involed with weld-ons, bolt-ons were the way to go for me. I haven't had any loose bolts, (loctite works just fine), and there's a huge improvement in handling! Just .02 cents.

<small>[ June 27, 2002, 01:49 PM: Message edited by: ss01gtw ]</small>

prockbp

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"><strong>but hey maybe they don't know what there talking about.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">you got that right, taking advice from BMR is probably the biggest mistake i have made so far

the weld on my SFC's makes a HUGE joint compared to the joint that two bolts make....

quote from the Global West website:
Using subframe connectors for high performance street and racing applications has been done for a long time. It is no secret that tying the car together with subframes not only stiffens the chassis but improves vehicle response. Global West has been building subframe connectors for 20 years. Over this period of time we have come to certain conclusions.

1. Subframes that attach to unibody chassis like the Camaro/ Firebird must be welded.
2. Subframes on unibody chassis must extend to the strongest point fore and aft for obtaining the best results.
3. Round tube subframes, yield stronger torsional resistance then square, per given weight..
4. Subframes should have large mounting areas to distribute the loads.
5. If you are serious about street performance,or you drive a convertible / T top, subframes are required.

http://www.globalwest.net/camaro93.htm

<small>[ June 27, 2002, 06:27 PM: Message edited by: prockbp ]</small>

Fulton 1

iTrader: (9)

Tube is more efficient at resisting torsion than box. That doesn't mean that a box section can't be stronger, it will just be heavier for any given amount of torsional rigidity.

Dope

iTrader: (2)

Let's see, what are race cars made out of? Tubular steel framework or boxed steel?

Dope

FAST LS1

iTrader: (2)

I have the BMR tubular welded in SFC's. I too read that the Boxed were "stronger" than the tubular. But like everyone has said they aren't as torsionally rigid for the same given wieght as tubular. The tubular one's have huge tubing, yet only weigh 15-16lbs. Boxed are much heavier, but may provide the same rigidity, just at a weight penalty.

My take is that BMR just says that so they can still sell the boxed ones, since the tubular one's haven't even been out for a year.

mitchntx

iTrader: (14)

One of the subtle advantages of boxed over tubular is that the boxed can be used as a jacking point.

I place my jack under the door on the sub and lift both wheels NASCAR style.

Been doing it for 3 years now.

WEASEL

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by mitchntx:
<strong>One of the subtle advantages of boxed over tubular is that the boxed can be used as a jacking point.

I place my jack under the door on the sub and lift both wheels NASCAR style.

Been doing it for 3 years now.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Nope, no advantage there. I jack my car up by the Global West SFCs all the time.

Both wheels, huh? <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

mitchntx

iTrader: (14)

I tried doing this on a friends tubular type and I was afraid that I was either gonna bend or collpse the tubing or the jack was gonna slip off.

94bird

One of the biggest reasons I can't go with boxed is the ground clearance is less than the tubular style. I've lowered my front 2" with GC coilovers and I can't get a normal floor jack under the front end anymore. I jack up the rear end of the car and then use a bottle jack to get the front end up. It's a pain but that's what it takes to get good negative camber in the front and be legal for ESP.

If I got boxed subframe connectors I would imagine I'd have to drive the car up on some wood planks to get it high enough off the ground that I could slide a jack under there. That would be just one more thing to bring to an autocross. Ugh.

Red2000SS

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by mitchntx:
<strong>I tried doing this on a friends tubular type and I was afraid that I was either gonna bend or collpse the tubing or the jack was gonna slip off.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I have to agree with Weasel, the Global West tubular SFC's are the very stout, they are 2" diameter 1/8' thickness tubing. I jack my car up all the time by them lifting the whole side of the car.

I never worry about them slipping off, my floor jack fits nicely. Then again I NEVER get under a car supported only by a jack. Always use jackstands and / or ramps.

Trans Am 2 N V

Just get Kenny Brown SFC They bolt to the tunnel brace and to the LCA and the rest welds, you weld every part were the SFC touches the car