DB1 Manual seat belt conversion

aiight, have read most of the posts regarding this, and yea i know i can’t do this myself but i got plenty of welders available. for simplicity tho… if i could somehow come up on the B-billar (cut it out from a CDM/JDM sedan) then all the guess work would be taken out of it.

then for installation… the same size piece would need to be cut out of my vehicle, and then have the replacement piece welded in. this would already have the structural integrity around bolts/nuts that is stock with the cdm’s/jdm’s. and as long as its a certified welder (that knows what he’s doing)… it shouldn’t have any issue right?

opinions and/or feedback will be useful, cuz i’m thinking about buying the seat belts and having an importer or somebody with access to one cut out the b-pillar parts from both sides.

i just cut the inside of the b piller out of a civic 89 i think an had it weld in an it works just fine an is safe as i have kids with me

Make sure you pull on the seatbelt once its done, to check if it can sand some force. I thought about doing the same thing, but trusting a weld to save my life is kinda ifffy

Jeff, that seems like a bad idea for 2 main reasons.

  1. It’s a hell of a lot more work than the standard way of installing manual belts.
  2. By cutting out and re-welding in new b-pillars you’re probably doing more structural damage than you are reinforcement (assuming you’re not ADDING bracing from a roll cage or something of that sort).

There is nothing difficult about the welding required to install manual belts on a USDM car.

There is nothing dangerous about welding in manual belts on a USDM car (assuming you have a competent welder/fabricator do the install). These mounting points you create will be as strong or STRONGER than the stock mounting locations.

Creating a good solid mounting point for the belts is a piece of cake. When done properly that bolt isn’t going anywhere. However if you’re talking about cutting out serious structural components of your unibody and trying to fit new ones in… who knows what could go wrong or how you might change how the unibody would react to an accident. People seem to get scared when dealing with seat belt mounting bolts for this stuff. Yet bolting an aftermarket harness to stock locations or adding a roll cage and harness bar doesn’t even raise an eyebrow. I think that from a safety standpoint, either method would probably be OK if done right, but one is a lot more work - unnecessary work. [EDIT - oops, forgot this is regarding a 4dr]

I just re-read the post and replies… Now I’m questioning my initial interpretation. Did you mean you were going to cut out the entire b-pillar and replace it? Or just try to cut out the inner portion where the nut is welded in place?

If the former, then see my above post.

If the later, then… yeah, you could do that. But again, why? That is essentially exactly what you’re doing when you do it the normal way. The stock piece is essentially a plate with a bolt on it. To do it the normal way you’re going to take a plate and weld a nut to it… same exact thing. Except chances are you’ll be using more weld and thicker plate than stock.

The ONLY reason I can see for trying to use a stock piece and weld it in place would be for cosmetic reasons. If you want it to look as stock as possible. But if you’re going for that look, then you’re actually going to make a weaker setup. If you cut a piece out and weld a new one in so that it looks exactly stock then you’re welding the end of sheet metal to the end of another piece of sheet metal. This is one of the weakest ways to weld something together. If you use a plate and nut like is standard practice then you will overlap the plate and the stock sheetmetal. This allows for greater surface area of weld and creates a much stronger weld.

In regard to scooby’s comment… your whole car is held together by welds, so are bridges and buildings. You’re trusting your life to welds all day long every day - they can be trusted. I don’t consider myself an expert welder or fabricator. But welding isn’t rocket science. I did a large chunk of the welding for the cage we installed in our race car as well as all sorts of other supports and things we fabbed. True we didn’t roll the car or get in any serious high speed accidents. But we did get into MANY MANY “contact” incidents with other cars and the car held together perfectly. The only part that failed was the front bumper we fabbed (all metal to protect the front end and radiator). And even then the weld did not fail, the metal around the weld ripped apart before the weld itself was compromised. Welds are plenty strong when done right. And doing them right doesn’t take a genious.

End rant.

yea my bad colin. was just thinking of the inner portion of the B-pillar.

i get what you’re saying now tho about the overlapping a plate with the nut and making it stronger. normally i’d just make do with the whole thing and leave the auto seatbelts, but upon working on my car a lot more recently… i slammed my head into the retracted buckle thing (YOU ALL KNOW WHAT I’M TALKING ABOUT) like about 4 times with lots of force. totally my fault.

and regarding the welding, tons of ppl say its easy n stuff, (even a few girls) but the only thing is i have never had the chance to actually weld. we’re building a school drag car n stuff and put in a 8 pt roll cage and i wanted to at least try n weld in the support plates n stuff but unfortunately the “higher ups” in the automotive dept wanted a certified welder to do it all. so yeah.

thx a lot for everybody’s input and stuff.

I think it’s great you’re wanting to swap to manual belts, it’s a great modification and I encourage you to continue to research and hopefully you can do the swap - I know you’ll be stoked when it’s done.

And don’t get me wrong, I’m not saying you should let just anyone do this welding for you. It does take skill, but mainly experience. I wouldn’t suggest you attempt your first welds on something like a seatbelt setup or a roll cage. But I would suggest you take the opportunity to try and have whoever you find to do the welding show you a little thing or two. Have them explain to you some of the basics and let you try your hand at welding on some scrap that 's laying around.

You should spend your first attempts welding using scrap and then move onto some small basic projects - preferably things that wont’ matter if they fail, yet will be tested so that you get to see the outcome and evaluate your welds.

[QUOTE=Colin;2018961]I think it’s great you’re wanting to swap to manual belts, it’s a great modification and I encourage you to continue to research and hopefully you can do the swap - I know you’ll be stoked when it’s done.

And don’t get me wrong, I’m not saying you should let just anyone do this welding for you. It does take skill, but mainly experience. I wouldn’t suggest you attempt your first welds on something like a seatbelt setup or a roll cage. But I would suggest you take the opportunity to try and have whoever you find to do the welding show you a little thing or two. Have them explain to you some of the basics and let you try your hand at welding on some scrap that 's laying around.

You should spend your first attempts welding using scrap and then move onto some small basic projects - preferably things that wont’ matter if they fail, yet will be tested so that you get to see the outcome and evaluate your welds.[/QUOTE]

sweet thanks a lot man. i talked to my old boss/instructor that is an auto body instructor. he does really great work, and he said he’d show me how to weld a bunch of 2"x4" plates and see how i do. so i’m coming along. i’m also workin on my soldering. been burning the wire a bit lately. just gotta get it all down to where it all comes naturally.

Hardest part about welding something like a cage or seatbelts into a car is dealing with the difference in metal thicknesses. Typically the unibody material is going to be thin (gets most of it’s strength by having layers, complex curves…) and the metal you’re welding in will be thicker. This makes it very easy to burn through the stock sheet metal.

Oh, and be careful when welding to anything that has undercoating or sound damping on the other side. Keep a fire extinguisher and a wet towel around. That stuff catches on fire pretty easily.

[QUOTE=Colin;2019793]Hardest part about welding something like a cage or seatbelts into a car is dealing with the difference in metal thicknesses. Typically the unibody material is going to be thin (gets most of it’s strength by having layers, complex curves…) and the metal you’re welding in will be thicker. This makes it very easy to burn through the stock sheet metal.

Oh, and be careful when welding to anything that has undercoating or sound damping on the other side. Keep a fire extinguisher and a wet towel around. That stuff catches on fire pretty easily.[/QUOTE]

yea i had that issue when i was using a plasma cutter to cut up a shell… the undercoating caught on fire. was fun… but it smelled horrible.