Welding SFC's
03-23-2009, 07:23 PM
#1
1st Gear Member
Thread Starter
Join Date: Dec 2007
Location: Sacramento
Posts: 76
Welding SFC's
Im installing my MM full length sfc's tomorrow and was wondering if you guys stitch weld them in rather that running full beads. The instructions mention something about doing it on the front subframes but are pretty unclear. Thanks.
03-23-2009, 08:27 PM
#5
4th Gear Member
Join Date: Apr 2007
Location: DeRidder, Louisiana
Posts: 1,184
You can start out by putting some heavy tack welds all around. Then finish them by welding up all area of subframe connector that touches the subframe. You will want a full bead around the whole area, no stitching. Mine are fully welded also.
03-23-2009, 09:37 PM
#6
1st Gear Member
Thread Starter
Join Date: Dec 2007
Location: Sacramento
Posts: 76
The car hasn't been on the dyno, but with a good tune im looking from hopefully around 300rwhp and high 12's. But back to the sfc's. One of my dads vendors he works with is a welder by trade and was saying they should be stitch welded in because a full seam could create a weak point where the material like the frame would crack next to the weld. He also said a stitch can be just as if not stronger than a seam. Im kind of torn cause there going in tommorow with some help so i dont know. Anyone else?
03-24-2009, 08:57 AM
#8
M.A.D. Motorsports
Join Date: Jul 2006
Location: Indiana
Posts: 8,014
Stitch welding can be just as strong but full seams are better IMO. The gaps between the welds leave an area that can bend if enough torque is applied or the stitch spacing isn't done correctly. Just get them fully welded at any point where the sfc touches the frame and body.
03-24-2009, 12:37 PM
#10
5th Gear Member
Join Date: Nov 2008
Location: SC
Posts: 2,401
Leave a half inch gap between every 2 inch weld. Fully welded makes the metal around the weld brittle. The gaps give it better strength because it has two differant hardness levels of steel. You end up with a spot that isn't pure brittle so there is some stretch. Now that said I doubt you ever to to the point where this becomes a factor unless you have the hoops reaching for the stars and landing hard. Full welds are better left for roll cages where you have exact thickness of mild steel or full chassis cars.