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Weld on vs Bolt on SFCs

Old Oct 31, 2003 | 12:53 AM
  #1  
Black01_Z's Avatar
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Weld on vs Bolt on SFCs

Any advantage to getting weld ons. Do they do a better job of stiffening the body than just bolt ons.
Old Oct 31, 2003 | 06:31 AM
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I've heard weld-ons are a little stronger but it depends on what sfc's you buy. I went with SLP bolt-ons because they are top-rated and I can remove them to make my firehawk stock again. Someone said I should also weld my bolt-ons too, no way. Kenny Brown's double diamonds are rated high too. If you're on a budget just get the weld-on BMR one for $100.
Old Oct 31, 2003 | 08:13 AM
  #3  
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If you autocross your car check how this will affect your class standings. I got a big lecture from a bunch of SCCA guys on how they are a huge improvement in the handling of the car and thats why they place cars with those up in SM/SP classes. Basically they are full of crap... but that doesnt change the rules. I would imagine the weld on units are more stiff, if all other things are equal.
Old Oct 31, 2003 | 10:17 AM
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bolts loosen and give way over time.. the bolt holes get stretched on the frame and the SFC's nolonger do what they were intended to do and they make noise ontop of that... (after and IF this happens..)

id just do weld-on from the get-go.

/tek.
Old Oct 31, 2003 | 10:40 AM
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DARK AGE 53's Avatar
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Originally posted by tekker
bolts loosen and give way over time.. the bolt holes get stretched on the frame and the SFC's nolonger do what they were intended to do and they make noise ontop of that... (after and IF this happens..)
I need to tell my friend his SLP bolt-on's aren't any good,. We installed them three years ago and they now have well over 25K miles on them, while his car was on my lift a few months ago we checked the SFC's and there as good as the day we installed them. I have ( not many miles on them ) bolt-ons as well as another friend of our's and we wouldn't want anything else. JMO

Al
Old Oct 31, 2003 | 01:23 PM
  #6  
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FWI, there is no such thing as weld-on subframe connectors for my car... there are 3 different brands, I have the ones from Tom's Racing which is a huge autocrossing company. I figure if they think it's OK to use bolt-ons exclusively, then they're OK for me.

I have a total of about 12 different bracing pieces all over my chassis... they're all bolt-on, and nothing has even begun to come loose yet!

I guess you can weld-on and bolt-on SFCs... but I just don't like that idea because if they ever need to come off or if the weld ever fails, you might be left with a chassis that isn't quite right. Even the slightest change to the density or shape of a unibody structure's frame can make a major difference in a bad way.
Old Oct 31, 2003 | 03:55 PM
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Originally posted by Threxx
FWI, there is no such thing as weld-on subframe connectors for my car... there are 3 different brands, I have the ones from Tom's Racing which is a huge autocrossing company. I figure if they think it's OK to use bolt-ons exclusively, then they're OK for me.

I have a total of about 12 different bracing pieces all over my chassis... they're all bolt-on, and nothing has even begun to come loose yet!

I guess you can weld-on and bolt-on SFCs... but I just don't like that idea because if they ever need to come off or if the weld ever fails, you might be left with a chassis that isn't quite right. Even the slightest change to the density or shape of a unibody structure's frame can make a major difference in a bad way.
On Camaro's, typical "weld-on" SFC's go alongside the edges of the car, tucked up inside the unibody frame, they are not in the way of anything at all. Other SFC types such as double diamond SFC's may cause some problems, highly unlikely though, access to the tranny & driveshaft is still no problem. LG Motorsports weld-on SFC's have bolt on v-braces which can be unbolted for easy access to the tranny, driveshaft, etc.

There is no reason to remove SFC's on Camaros whatsoever. I don't know about your car though.
Old Oct 31, 2003 | 04:10 PM
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I'd have to agree w/you guys about the bolts ons being just as good. Some good torque and you can break a weld easier than a bolt. If you use high grade bolts and tighten them down to spec you should have no loosening. Think about it, your whole suspension system is held together w/bolts and they don't loosen.
Old Oct 31, 2003 | 08:36 PM
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Originally posted by Carlos93Z
On Camaro's, typical "weld-on" SFC's go alongside the edges of the car, tucked up inside the unibody frame, they are not in the way of anything at all. Other SFC types such as double diamond SFC's may cause some problems, highly unlikely though, access to the tranny & driveshaft is still no problem. LG Motorsports weld-on SFC's have bolt on v-braces which can be unbolted for easy access to the tranny, driveshaft, etc.

There is no reason to remove SFC's on Camaros whatsoever. I don't know about your car though.
Most of the pieces wouldn't get in the way of anything, but there are two many lower chassis braces that would definitely get in the way of a couple things... especially the tranny.
Old Nov 2, 2003 | 05:17 PM
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just installed the SLP bolt ons today!!

picked em up at slp day along with a STB. as long as ya use some locktite and tighten the bolts down good they should stay nice and tight. and as far as them being in the way.... full access to everything under car without removal.

only thing is ya gotta grind the 2 lips (one on each side)on rear frame where the single SFC bolt lines up or it wont fit right.my buddy's grinder came in real handy!

i was getting weld ins but a bunch of fbody guys told me id be better off with the bolt ons for an everyday driver and mild mods. the weld ins are for serious race applications from what i hear.
Old Nov 2, 2003 | 06:36 PM
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mmmm locktite.. tasty.

/tek.
Old Nov 2, 2003 | 06:43 PM
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Originally posted by Greed4Speed
I'd have to agree w/you guys about the bolts ons being just as good. Some good torque and you can break a weld easier than a bolt. If you use high grade bolts and tighten them down to spec you should have no loosening. Think about it, your whole suspension system is held together w/bolts and they don't loosen.
There are many suspension parts held together by bolts, but they're parts that flex. Some cars out there, like Threxx's, don't need weld on ones, because their frame's already pretty decent. You've gotta understand that with our cars, we've got Unibody frames.

And who cares if most of our pieces come bolted together stock, does that mean it's the best? Hardly. Our cars are put together pretty poorly from the get-go, not to mention all the flex they have WITHOUT SFC's. If you think the stock suspension is fine bolted together, why not keep it stock then?

Weld-ons ARE better in our case because our cars flex ALOT. As far as I know, Tom's Racing only works with foreign cars, correct? The little cars that are FAR more rigid than the factory than ours. That's why that company only sells bolt-on, because they have no need for weld-on, and the body doesn't flex enough for it to widen the holes where the bolts go.

Like I already stated, our cars flex like crazy. Everyone knows that SFC's, bolt-on or weld-in, make a DRAMATIC difference. That goes to show how much our cars need them. So here we have two ideas: our cars flex A LOT, and we all know our cars are pretty damn heavy compared to most cars (most are at least 3500 with us in them) A car that flexes and is BIG will have a lot of force twisting the frame, which is definately enough to start bending stuff that wasn't designed to be there from the factory.

I don't know if I porved anything in here or not, I just kinda went-off, and I apologize, but bottom line is that our cars need weld-ins. If you must, get bolt-ons then reinforce them with welds.
Old Nov 2, 2003 | 07:28 PM
  #13  
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Originally posted by RS Dragster
our cars flex ALOT.
Werd, dey's be flexin' ah night long .
Old Nov 3, 2003 | 09:37 PM
  #14  
tekker's Avatar
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well it does appear dragster pretty much summed this one up..

ownij.

DD weld-ons for mememe!

/tek.
Old Nov 3, 2003 | 10:14 PM
  #15  
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The truth is bolt-on SFC's are just as good as weld-on SFC's if they are installed propery and tightly. They do need to be checked occasionally. I went with BMR boxed only because they were cheaper and lighter than the SLP Bolt-ins. Cost me $75 to have them welded in. Didnt feel much of a difference though
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