DSE Mini Tub Install Question

[FireSale]

Hi. I’m working on the install of a set of Detroit Speed Mini Tubs on the 68 Mustang coupe I plan on running in SS GT. I have a question for anyone who has done this before. I’ve measured and market the frame rails for the insert cuts and was planning on doing both of the rails before moving to the inside of the car to do the tubs themselves. The steps on the instruction video show finishing all of one side of the car, frame rail and tubs, before moving to the other side. It seems to me that it would leave the car more stable to seal up both the frame mods as soon as possible, then worry about the wheel tubs.

What do you think?

For those of you who have offered advice and encouragement on this project, I ditched the Mexican block in favor of a Ford Racing BOSS 302 with Crower rods and an Eagle crank. The rods are legal, and the crank is the best I could do given that the one on the NHRA list hasn’t been manufactured in 9 years…

Dale

[gbur]

Originally Posted by FireSail

Hi. I’m working on the install of a set of Detroit Speed Mini Tubs on the 68 Mustang coupe I plan on running in SS GT. I have a question for anyone who has done this before. I’ve measured and market the frame rails for the insert cuts and was planning on doing both of the rails before moving to the inside of the car to do the tubs themselves. The steps on the instruction video show finishing all of one side of the car, frame rail and tubs, before moving to the other side. It seems to me that it would leave the car more stable to seal up both the frame mods as soon as possible, then worry about the wheel tubs.

What do you think?

For those of you who have offered advice and encouragement on this project, I ditched the Mexican block in favor of a Ford Racing BOSS 302 with Crower rods and an Eagle crank. The rods are legal, and the crank is the best I could do given that the one on the NHRA list hasn’t been manufactured in 9 years…

Dale

reinforce rails by tac welding several strips so they stay located, before cutting ,measure x10, one cut

[FireSale]

Originally Posted by gbur

reinforce rails by tac welding several strips so they stay located, before cutting ,measure x10, one cut

That was a thought I had. I have a couple of spare lengths of 2X2 to tack to the back or bottom side of the cut area to hold everything in place for the surgery. I've seen temporary X braces used, too, but I don't have enough room for that. I have a Total Control sub frame connector and frame brace system installed and the unit keeps the frame quite stiff.

Dale

[MAURICE BLENDHEIM]

Dale…Assuming you have no rear suspension or fuel tank in the car. Block the car up on the pinch seams of the rocker sills near front leaf spring mount using wooden blocks. Also support the body at the rear shackle area. Make sure the body is level front and rear, also check to make sure doors open and close normally and trunk is aligned and the gaps are where you want them before any cutting. By using wooden blocks there is less of a chance the body will move around when cutting, the body must remain level. You can do both sides before tub removal. I done it with the tubs removed also, but braced the floor between the tubs to the area between trunk opening and package tray with flat bar. Measure and measure again otherwise you will be patching things up. Tack weld everything on both sides before finish welding takes place. The rule book says "The bottom of the frame rails can't be higher than the stock floor height", this is something that you should think about. What are you using for rear suspension? I hope this helps…Maurice.

[FireSale]

Originally Posted by MAURICE BLENDHEIM

Dale…Assuming you have no rear suspension or fuel tank in the car. Block the car up on the pinch seams of the rocker sills near front leaf spring mount using wooden blocks. Also support the body at the rear shackle area. Make sure the body is level front and rear, also check to make sure doors open and close normally and trunk is aligned and the gaps are where you want them before any cutting. By using wooden blocks there is less of a chance the body will move around when cutting, the body must remain level. You can do both sides before tub removal. I done it with the tubs removed also, but braced the floor between the tubs to the area between trunk opening and package tray with flat bar. Measure and measure again otherwise you will be patching things up. Tack weld everything on both sides before finish welding takes place. The rule book says "The bottom of the frame rails can't be higher than the stock floor height", this is something that you should think about. What are you using for rear suspension? I hope this helps…Maurice.

Thanks. Currently the car is up on 4 six ton each jack stands. I can get another set to support the rear shackle area tomorrow. that was a concern I had. It's not quite level but I can fix that before I cut anything. The car has ChassisWorks sub frame connectors and the stands are placed at the front and back ends of each side. It feels stable.

One door has been removed but the other is still on and moves freely.

The fuel tank and complete rear end is out of the car as is the engine and trans, so the weight is about as far down as I can get it.

The Detroit Speed mini tub kit is similar to the one offered by ChassisWorks/Total Control for the pre 1970 Mustang. It replaces a section of the frame rail with a piece that is the same height as stock but jogs in to make the frame parallel behind the rear tires, so the floor remains unchanged.

Currently, I have no rear end or axle. Just a budget. A shipment from MoneyMaker should come Tuesday with Cal traks, Calvert's split mono springs and a hanger kit from Alex D. at MMR.

Thanks for the help and input.

Dale

[MAURICE BLENDHEIM]

Dale… Level and support are the most important factors. The rockers on a unibody car are structural members that connect the front to the rear and support (platform) the 1/4 panels ahead of the rear wheel opening into the door jamb. The inner and outer wheel housings also are structural, assisting with support to the rear half of the body. Unless the frame connectors are tied into the rockers, the rear subframe your about to remove is partially supporting the weight of the body. The supporting of the rear of the car as far back as you can is vital. I would also suggest mounting and lining up the other door, before you start cutting make sure the doors are latched closed. After you have done your tacking make sure your doors open and close normally as well as the trunk lid, then finish weld. Utilizing your cars integral members properly can save you some unnecessary tubing. Are your plans for a 29.5x11.5 x15 tire? Good Luck…Maurice.

[Dion Hildebrandt]

Originally Posted by MAURICE BLENDHEIM

Dale… Level and support are the most important factors. The rockers on a unibody car are structural members that connect the front to the rear and support (platform) the 1/4 panels ahead of the rear wheel opening into the door jamb. The inner and outer wheel housings also are structural, assisting with support to the rear half of the body. Unless the frame connectors are tied into the rockers, the rear subframe your about to remove is partially supporting the weight of the body. The supporting of the rear of the car as far back as you can is vital. I would also suggest mounting and lining up the other door, before you start cutting make sure the doors are latched closed. After you have done your tacking make sure your doors open and close normally as well as the trunk lid, then finish weld. Utilizing your cars integral members properly can save you some unnecessary tubing. Are your plans for a 29.5x11.5 x15 tire? Good Luck…Maurice.

Also when it comes time to weld...DO NOT BE IN A HURRY!! At my shop I have had to have more than a few projects similar to yours put up on the frame machine because there was not enough time allowed for cool down between welds. They all would have been quicker for my shop to do them from the start (and cheaper) if this advice was followed. A fellow body technician friend had his nova "banana" doing this exact modification with the minitubs. He fired up the welder and didn't stop till it was done.....and then installed floor pots and started doing frame straightening.

That being said as long as all the panels (doors, trunk, even fenders and hood ) are lined up properly and the car is supported properly (the rocker pinch weld is best as described earlier) there should be no movement of the car.

Take your time, pay attention to the details, and you should have no problems. Your thoughts and concerns about structure are well founded, and if you plan out this project properly you will be rewarded for it

[MAURICE BLENDHEIM]

Dale…Exactly as Dion mentioned, take your time when finish welding starts. Prepare all surfaces to clean bare metal. I generally start from the centre of the wheel opening. Don't be afraid to add another series of tacks between your originals. Then stitch weld, moving from side to side till complete, this way you will allow heat to dissipate as you make progress. You would be amazed how much something can move with such a small amount of weld. "Your attention to detail in the construction will yield the best starting line results". MB.

[FireSale]

Maurice and Dion, thanks for your time.

I'll look at the rockers today and move the supports over. That will take the stress off the frame from the weight of the car shell. Getting the passenger door off was a pain - the bolts are part rivet part bolt. It's off because there's some body damage to the right front fender that catches on the door when it opens. I will probably replace the fender rather than try to take a race car to the body shop.

As for the welding, I just replaced my 110 with a Miller 211 and plan on doing a lot of practice on scrap before I ever touch the car with it. I'm retired and time is something I have plenty of.

Here is a link to an install of the DSE mini tubs if you want to see what's involved.

Thanks again,

Dale