How to notch the frame

[patmckinneyracing]

I want to notch the frame rails and am looking at only doing it only in the rear fender wells to run larger tires and rims.

What I want to know is how much of the frame can you take out? What are the safety issues of doing this? What is a good step by step procedure to follow along with the whole "cutting out a section and welding in another section" ?

I was thinking of only cutting out a section up until the center weld of the frame and stopping there. It should take out roughly 3/4 to an inch. Thanks for the input

 

[username]

someone on here had a link posted that came off of maliburacing that was really good.Try searching that site.

 

[Qdub24]

Here's on old one from the ECR/KOTS forum:
Pt.1 http://www.kingofthestreetgarage.com/fo ... t&p=809422
Pt.2 http://www.kingofthestreetgarage.com/fo ... t&p=809435

 

[Mudweizer]

http://www.montecarloss.com/community/u ... ber=639067

 

[Mudweizer]

http://www.maxchevy.com/tech/2008/iii_8-frame-1.html

 

[Qdub24]

http://www.maxchevy.com/tech/2008/iii_8-frame-1.html

I've been looking for that forever. Thanks a ton.

 

[patmckinneyracing]

Maybe this is just me, but after looking at all of the write ups on this, why not weld in the crossmember first? This will, in a way, prevent or minimize the frame from actually warping. At least this is the way I'm thinking.

Any input?

 

[FE3X CLONE]

In my opinion, you should at least tie the rear frame rails together at the bumper shock mounts with a tube steel bar. This way you will know where the frame rails should be when your done.

On my frame, we kept my rear frame brace in place (bolted to the bumper shock mounts on the frame horns) as well as tack welded a thicker steel tube on top of the frame to try and keep it from moving.

However, my frame rails will still spread apart without the rear brace installed. I actually have to take a ratchet strap, wrap it around the frame horns and pull them together to be able to get my rear brace back on. So the frame did move a little but it's not a huge deal since the only thing the rear frame rails are doing is providing a place for the body to mount to.

Other than that I pretty much went through the same steps as they did in the above write up at www.maxchevy.com. Really the only thing I did different was I reused the piece of frame that I cut out instead of making a pattern and using a new piece of metal.

The only "issues" I've heard about with notching the frame rails is on powerful cars with slicks launching and buckling the rear 1/4 panels a bit. But this is on cars well into the low 11's/high 10's.

 

[patmckinneyracing]

Funny you posted FE3X Clone, I was just about to read your thread on this topic.

I don't ever plan on my malibu dipping to those low times in the quarter. Would you say that putting in a thick pipe near the rear frame horns AND another where the frame was notched be unnecessary? These braces will be there permanently in my case for added rigidity.

I will be using a MIG welder which creates more heat, which is why I was asking about bracing before actually cutting or welding. How far of a notch would you consider safe? I only plan on taking it to the frame seam and stopping there. Would this be a safe spot?

The other thing I was going to ask about was re-using the cut piece of the frame instead of doing a template as you mentioned.

 

[FE3X CLONE]

Would you say that putting in a thick pipe near the rear frame horns AND another where the frame was notched be unnecessary? These braces will be there permanently in my case for added rigidity.

That's pretty much what I did on mine. I have a 2"x2"x.125" square tube that runs from frame rail to frame rail. I actually cut out a pocket for it between where the spring cup in the frame is and the upper shock mount then welded it in.

You can see it somewhat in this pic:

I ended up removing the center metal piece I welded from that bar to the frame because it ended up interferring with my rear end.
Of course my watts link is also helping to strengthen the frame rails as well.

How far of a notch would you consider safe? I only plan on taking it to the frame seam and stopping there. Would this be a safe spot?

That's essentially where I stopped with mine.

The other thing I was going to ask about was re-using the cut piece of the frame instead of doing a template as you mentioned.

Yeah, I've read where some guys say it's not strong enough and that you should use a thicker piece of metal but I don't think it will be a big problem.