Jump to content
HybridZ

Bad Dog rails installed


Recommended Posts

PICT0163.jpg

PICT0160.jpg

PICT0161.sized.jpg

PICT0162.jpg

 

my floorpans and rails were arced, so there was no good way to straighten them out to make the baddog rails fit... so instead, the car was dropped on the baddog rail to make the rail arc... and welded in.

 

also, here's a quick update of my exhaust while i'm at it

 

PICT0157.jpg

PICT0159.jpg

Link to comment
Share on other sites

Looks great, I think I might get a set for my car. Anybody know if the 240z rails baddog sells will fit over the 280z factory rails. It looks like the 280z rails they sell dont tie into the rear subframe?

Yes, the 240 rails should fit over the stockers. The 280 rails are stock replacements, what we're looking at here is the subframe connectors, not just stock replacements. I don't know if they make a 280 subframe connector.

 

Alex, it looks like a nice install, but the one issue I have is the full seam weld. It would actually be stronger if it were stitched in. Regardless, I'm sure it will be fine for your purposes and it looks like you found a shop that does good work.

Link to comment
Share on other sites

Alex, it looks like a nice install, but the one issue I have is the full seam weld. It would actually be stronger if it were stitched in. Regardless, I'm sure it will be fine for your purposes and it looks like you found a shop that does good work.

 

This seems counter intuitive to me. Why is this true? I do not doubt the fact, just hoping for an explanation.

 

Regards,

Justin

Link to comment
Share on other sites

There are others with more knowledge who can probably answer this better than I can, but here's what I've been told. The area immediately surrounding a weld gets very hot and becomes more brittle. As an experiment you can try welding two pieces of sheet metal together then bend them until they break. It won't break at the weld, it will break around it. When you seam weld a long part like this you end up with a brittle section all the way down the seam. If you stitch weld you end up with no one long seam that is brittle.

Link to comment
Share on other sites

when you seam/stitch weld, you leave some play room for chassis flex that is necessary. Think of it this way... if you fully welded every frame component on a car, and took it to a track, you'd have cracks all over the place despite the car being very stiff.

 

jon's right about seam welding, and I should've asked the shop to stitch weld it, but as he said, it won't cause problems for me because my car won't be track only balls out racing every weekend. It won't see that much stress

Link to comment
Share on other sites

Stitch or skip welding is mainly used to reduce heat input, warpage, cost, and time. A properly done full length weld will be stronger the a properly done stitch weld but its way overkill for a sheet metal structure. If done improperly it can lead to cracking as Jon mentioned above. The cost in time and consumables does not make up for the strength increase gained by doing a full weld.

Link to comment
Share on other sites

Stitch or skip welding is mainly used to reduce heat input, warpage, cost, and time. A properly done full length weld will be stronger the a properly done stitch weld but its way overkill for a sheet metal structure. If done improperly it can lead to cracking as Jon mentioned above. The cost in time and consumables does not make up for the strength increase gained by doing a full weld.

 

Interesting. I have baddogs sitting in my garage waiting to be installed. So how long should each stitch be at what intervals? Please excuse my ignorance, I'm not a welder so I will have a buddy do this for me. Or would plug welding them be better?

Link to comment
Share on other sites

When I installed my frame rails from Bad Dogs I used the stitch method, but also welded them up full on the outside and most of the way on the inside. I stitched welded because the metal was getting to hot and was warping if you went more than 2 inches at a time ... so I went back and forth from frame rail to frame rail to allow the metal time to settle between welds. I only stitch welded the inside cause I was having a hell of a time getting under my car on my jack stands. I just used some a boat load of silicon to seal up the frame rails and later went over it all in Por-15 then Herculiner Bed Liner ... the bottom of my car is quite rust proof now.

 

Also, be sure to jack up the car on the frame rail to make sure it is settled well. if you just weld it up free hanging with someone holding it and then raise the car on a lift it will warp the metal.

 

Here is a question to you all. The original frame rails had a hole in them, I presume to allow water to drain out. The Bad Dog ones don't have this? Would this be a good thing to add or just leave it be?

Link to comment
Share on other sites

When I installed my frame rails from Bad Dogs I used the stitch method, but also welded them up full on the outside and most of the way on the inside. I stitched welded because the metal was getting to hot and was warping if you went more than 2 inches at a time ... so I went back and forth from frame rail to frame rail to allow the metal time to settle between welds. I only stitch welded the inside cause I was having a hell of a time getting under my car on my jack stands. I just used some a boat load of silicon to seal up the frame rails and later went over it all in Por-15 then Herculiner Bed Liner ... the bottom of my car is quite rust proof now.

 

Also, be sure to jack up the car on the frame rail to make sure it is settled well. if you just weld it up free hanging with someone holding it and then raise the car on a lift it will warp the metal.

 

Here is a question to you all. The original frame rails had a hole in them, I presume to allow water to drain out. The Bad Dog ones don't have this? Would this be a good thing to add or just leave it be?

I put holes in mine. I'm also going to use those holes to spray Zero Rust in there to seal them from the elements. If you look none of the frame rails on a Z is watertight, so I think trying to make the SFCs watertight isn't really necessary or practical.

Link to comment
Share on other sites

.

 

Also, be sure to jack up the car on the frame rail to make sure it is settled well. if you just weld it up free hanging with someone holding it and then raise the car on a lift it will warp the metal.

 

I don't understand what you are saying here.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...