As we move into the next stage of the Mini-tub process on Project Grandma, our focus turned to the frame rails. Clearly with the larger 295/65 M/T Drag Radial tires we would need to create more room in the wheel wells between the frame rail and quarter panel. The stock skinny tires fit in the factory designed wheel wells very comfortably, but those stock tires don’t offer any traction! So we picked out the largest footprint Drag Radial tire we could find that we could make fit into our re-designed wheel well. Our pick of the litter was the Mickey Thompson P295-65-15 ET Street Radials mounted on Billet Specialties Street Lite Rims.
Mike started by cutting the sheet metal kick up behind the rear passenger seats. We found an easy to mark surface about 8 inches up from the floor board and a perfect cut-ready marked seam just below the rear speaker deck. Cutting this section of sheet metal out of the way opened up the top of the frame rails so that we could cut the rails unabated and without interference.
We cut the sheet metal behind the rear passenger seat at the bottom along our marked line to allow access to the top of the frame rails. There is a seam in the sheet metal, just a little higher up, but cutting along that seam would not give us the full working area that we needed to cut the frame rails and add some support bars later. This will allow us to work the frame rails, cut out the stock upper spring buckets, and then run roll cage bars to the back of the upper control arms mounting locations.
The top cut was made just below the speaker deck and the entire section of sheet metal was removed. Cutting it at the seams makes for a straight line cut and is easier to weld back in.
Now we had a clear path for cutting the parameter frame rails without too much interference from other panels. While Mike continued to cut away sheet metal so that we would have unlimited access to the frame rails, I took the tires and rims to one of the local tire stores for mounting and balancing. We needed to have the real deal ready to go so that we could mock up the tire placement in the wheel wells. Ultimately, this would tell us how much frame we needed to cut.
Billet Specialties Street Lite Rims. These were a little wider than the tire shop was used to seeing.
Getting the Mickey Thompson ET Street Radials ready for mounting. They almost needed two guys to lift these tires up and over the rims for mounting.
Once the wheels were mounted and back at the shop, the real work began in earnest. By this time, we had the frame rails completely exposed and Mike had already found the center line of the wheel well. You'll notice in the picture below that there are four "sharpee" lines marked on the frame rail. A forward line, which is where the leading edge of the tire would rest. The axle tube location in the wheel well is marked by the two middle lines, and the aft line indicates the rear edge of where the tire needed clearance.
Our precision marked cut lines that indicates where we needed to make the initial notch cuts. The two black lines in the center are indicative of where the axle tube would be located.
We knew that we would be using a coil over spring/shock set up, so our next step was to remove the upper spring perch that attaches to the top of the frame rail. Now that the we had the working room, these came out without a problem using nothing more than our trusty sawzall.
Now you see it and......
Now you don't.
With the removal of the spring perches on both sides, nothing was preventing us from starting our frame cuts. In the picture below, our master fabricator Mike, starts to make the initial cuts into the frame rail using the fabricator's best friend; a sawzall.
With the initial cuts being made to the depth that we wanted, we could start cutting the frame rail from front to rear lengthwise. Knowing that we would have to weld plate metal over the section that was cut out, we decided to cut the frame rail outer section off with a 1/8 inch lip so that we could weld that part onto the frame rail once the center section was removed. Removing the center section of the frame rail (roughly an inch and half) would provide the clearance for the wheel that we needed. Using the outer section as a cap would make the notching job look "stock-like".
Follow along this sequence of photos to get the idea of how we cut the frame rails:
We started by using a cut off wheel and die grinder to open the frame rail for our sawzall. Using the sawzall, we were able to follow a marked line down the length of the frame rail.
Once the lengthwise cuts intersected with the cuts that we made earlier, the frame rail cap came off in a nice single piece for later reuse.
We then cut the frame rail center section out, making them a little "skinnier" for the actual clearance part of the proceedure.
With a little test fitting and some grinding, the cap that we had made previously was made ready for use.
Once our fabricator had the cap where it fit tightly inside the frame rail, it was tack welded into place.
In the photo below, you can see how much of the frame rail was removed even with the cap in place.
Now was the time for the true test. We fit the tire into the wheel well to see if it would clear and sit in the wheel well fully. Sadly, we didn't cut the rail quite narrow enough, and we couldn't tuck the tire completely inside the well, even with removing the lip. We'll need to come back after the holidays and finish this job 100%!
After our test fit, it was evident that we needed to take a bit more off of the frame rail.
A look at the inside of the wheel well where the tire is rubbing on the frame rail.
By this point we had hit the wall on a full day's work. We decided to close the shop for the day and tackle the clearance issue on a fresh new day.
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