SN95 Dash Frame Reinforcement

[SlowSVT]

Just completed another step in my build which was rather unexpected but it's something most people never considered (including me) and actually makes a lot of sense from some perspectives and not much from others (mainly the effort required but as you probably already know I'm pretty tenacious).

What started me down this path was ruining my dash pad in a welding accident so I bought one from a fellow SVTP member and got burned :nonono:

http://www.svtperformance.com/forum...fellow-STVP-member-que4dog&highlight=dash+pad

After seeing the dash assembly had been damaged (I think he smushed it parking a car in the garage the frame was bent and the dash pad mounting bosses were broken off) I removed the pad from the frame and noted how flimsy the frame was (it wiggled like Jello).

One thing that drives me crazy is having a beautiful car that has been carefully built and is a joy to drive only to have a dash that rattles worse than a gypsy bandwagon at every bump! When new they are pretty quiet but will loosen-up overtime carrying all that weight so I decided to add gussets to reinforce the frame and am extremely pleased with the outcome. Here is the finished results:

Before & After (that quedog's frame in the foreground which is now destine for the dumpster)

The difference in stiffness is astounding! Wiggle the factory frame at one end and it quickly oscillates from side to side at the other end. The whole frame readily twists in your hands. No such movement in the welded frame the only thing you feel is a low frequency vib when you set it down on concrete and it doesn't budge trying to twist it. It's welded mainly with .040 thk. chromyl sheet which is fairly thin and light I estimate I added about 3 lbs to the frame which are pretty light to begin with (I'll weigh both frames and post the results).

Lots of pre-fit for clearance checks before welding up the frame. Cardboard patterns were used to create the gussets, helps having a bend brake as well.

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This is something I would not recommend doing unless you have patients and time there is 8 hours of straight welding work alone here. A lot of thought went into the design and placement of the gussets. Long term I expect the dash on this car to be even quieter then when new :rockon:

 

[SVT_Troy]

Looks good, I suspect your car will provide an entirely different driving experience from the rest of ours. I wonder what yours will weigh after everything is said and done.

Besides improved crash worthiness is the dash frame providing any rigidity to the chassis? I'm assuming it may but if Ford left it so flimsy I can't imagine it providing much if any.

 

[SlowSVT]

Troy, I don't expect this dash frame to stiffen the chassis in any discernible way, its mainly there to keep the dash tight and quiet hopefully for the life of the car. I'll use lots of neoprene padding and HD fasteners when I assemble the dash to minimize any noise from rubbing or rattling. As for crashworthiness I don't think this will make much difference in most situations. While it's a lot stiffer I don't think it will take much to collapse it over the stock frame.

I did a "before" & "after" weigh measurement:

Stock Dash Frame = 24 lbs

Modified Dash Frame = 28 lbs

I have a few more gussets I want welded on these frame then I will zinc primer it then paint it silver which will make it easier to see if you need to work under the dash (I use to design Telco equipment and a minimum light reflectivity was a requirement to make it easier to see when it was being servicing, no black boxes!). The unpainted frame from the factory rust just looking at it even here in So. Cal, very little corrosion resistance.

 

[Givens]

Wow clean work but it seems a little over kill but I'm sure it will achieve a rattle free experience.

I had to pull over the other day on the side of the highway in my f250 to find what was rattling in the back. Rattles drive me crazy just not sure I would take it that far.

 

[SlowSVT]

Wow clean work but it seems a little over kill but I'm sure it will achieve a rattle free experience.

I had to pull over the other day on the side of the highway in my f250 to find what was rattling in the back. Rattles drive me crazy just not sure I would take it that far.

"overkill" is not the term I would use if the goal is to quiet the dash ......... more like a "necessity". After seeing how flimsy the factory dash frame was I said there was no way I'm putting it back in the car like that, not this one!

Here is a shake test between both

[video]http://vid81.photobucket.com/albums/j215/SlowSVT/SN95%20Dash%20Frame%20Shake%20Test%20OEM_zps05yc0c at.mp4[/video]

[video]http://vid81.photobucket.com/albums/j215/SlowSVT/SN95%20Dash%20Frame%20Shake%20Test%20reinforced_zp sezl2tuq6.mp4[/video]

 

[Givens]

Necessary I like that, looks like you achieved your goal from the video

What are you doing with the car that you have it that stripped down?

 

[oldmodman]

I think the only way to take anymore rattles out of your car would be to cast it in concrete.

I have been following your IRS reinforcing thread too and am sold on what you have accomplished. I am getting a spare complete IRS and already have Bruce's kit but now I think I might take a stab at doing what you have done.

Since it's a spare I can fiddle as long as I want and still have the car to drive until it's done.

I remember a thread on another forum (now defunct) in which a guy got a body in white and he spent six months removing all the seam sealer. Then welded the entire body where it had previously only been tacked or spot welded.

Then he gusseted nearly everything. He weighed the car before and after all the work and after it only weighed 60 pounds more. He said he pulled about 50 pounds of seam sealer out of it so he actually had 110 pounds of gussets and weld rod into it.

I may have my numbers wrong on the weights since it has been ten years.

Anyway. I can't wait to hear your opinion about the handling with al;l the IRS mods in place.

And here is some interesting news about halfshafts. In this months MM&FF it was revealed that G-Force is making the new "racing" halfshafts for Ford Performance in the 2015 Mustang parts catalog so I just had to contact them to see if they would be making any for the 03/04 Cobras. And they said they would likely be doing so. But didn't have any timeline. they are so tied up making parts for the 2015.

 

[SlowSVT]

I think the only way to take anymore rattles out of your car would be to cast it in concrete.

I have been following your IRS reinforcing thread too and am sold on what you have accomplished. I am getting a spare complete IRS and already have Bruce's kit but now I think I might take a stab at doing what you have done.

Since it's a spare I can fiddle as long as I want and still have the car to drive until it's done.

I remember a thread on another forum (now defunct) in which a guy got a body in white and he spent six months removing all the seam sealer. Then welded the entire body where it had previously only been tacked or spot welded.

Then he gusseted nearly everything. He weighed the car before and after all the work and after it only weighed 60 pounds more. He said he pulled about 50 pounds of seam sealer out of it so he actually had 110 pounds of gussets and weld rod into it.

I may have my numbers wrong on the weights since it has been ten years.

Anyway. I can't wait to hear your opinion about the handling with al;l the IRS mods in place.

And here is some interesting news about halfshafts. In this months MM&FF it was revealed that G-Force is making the new "racing" halfshafts for Ford Performance in the 2015 Mustang parts catalog so I just had to contact them to see if they would be making any for the 03/04 Cobras. And they said they would likely be doing so. But didn't have any timeline. they are so tied up making parts for the 2015.

As you can surmise there's a bit more to this story to tell and the best one is yet to come and it gunna happen soon!

This kind of work is always a "give & take" adding weigh which you are contently trying to combat at the same time. The end result is I removed weight in one place and moved it somewhere else which in my case has the CG been moved "down' and "back" right where you need it. I think in the end my car will weigh close to the stock weigh perhaps a little more but the balance will be much better.

I scraped off every ounce of body sealer and dynamat the factory applied to this chassis as it's not needed or wanted in this car. I'd say about 10-25 lbs of the stuff. A few guys lined their entire interior with dynamt which I found horrifying.

Modifying the IRS to stiffen the backhalf (which the IRS sub-frame is basically and mini-backhalved chassis) won't make a lot of sense unless you address the rest of the chassis .............. that's where the big "rub" comes in. Once you start looking at the sheet metal unit construction of the SN95 it starts to get a little scary, it's not much as as a fox though now I know why they are so light.

 

[oldmodman]

Your sure are right about a light car being weaker. Everytime you strengthen one thing it dumps the load into something else. Which then has to be strengthened too.

I am starting to worry about the point on the shell where the tops of the coil over shocks attach and transfer all their load. So I am going to be reinforcing those areas now.

And that will be about another ten pounds of steel and weld. But every time I look at that thin sheet metal holding up the entire weight of the car I can imagine the shell metal starting to tear along the spot weld lines.

I'd love to see your "frame" strengthening methods. I finally just decided to put in the entire Stiffler's system and put up with the extra weight. I know that a better method would be taking relatively thin sheet metal and bending

it into a secondary frame with longer moments to prevent flexing. It would be lighter but I just don't have that much time, or the space to do it.

 

[SlowSVT]

Reinforcing the shock towers won't add 10 lbs more like 5. Include beefing up the fender aprons will get you to 10 lbs.

I don't want to get into the chassis here, It will overwhelm the original intent of the thread.

We can make arrangements for you to come see the car but you might want to take a Xanax before you arrive :-D