My version of a inner fender support/front subframe stiffener

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ardentindustries

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Hey all,
Its a well known fact that the front of our cars SUCK when it comes to rigidity and structural integrity. This becomes a much bigger problem when you start cutting corners as one can imagine.
I have had this idea for awhile now, and finally was able to bend up a piece today. The rear mounts to the front of the subframe connector, while the front mounts to the outside of the front subframe rail. Of course, in the mount areas, a plate would be welded first, and then the tube to the plate.
This is about as tight to the factory body structure as can be, so hopefully it doesnt get in the way of bigger tires. It would definitely be okay with stock size tires. This, together with subframe connectors(coming soon...), and I think you are about as close to a full tube frame as you can be without actually have a tube frame...if that makes sense.
For install, a hole would need to be drilled in the vertical sheetmetal panel behind the wheel opening, and a portion of the factory "gusset" for the shock mount needs to be removed. Both take less than 10 minutes per side.
This is just an idea...looking for input. Just thought Id throw it out there. It'll take some fabrication work, but Im not a fan of bolt on stuff. Let me know what you think. Thanks.


Its dark here now, so nevermind the "flash" pictures.

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small block car that would wrk great. not sure about a big block car with fenderwell headers. but you could probably move the bar that is up against the firewall forward maybe closer to the shock and rear mount for the upper arm.
 
I think its a waste of time messing with this shock mount! The weight of the car is soley on the k-frame, torsion bars and their mounts. It would be much easier to cut a piece of 3/16 plate and box the shock mount in and gusset the top portion. As long as you leave the radiator support attached to the front of the frame rail there will be NO twist in it. The frame rails are High Strength Steel. If you go welding on it you will end up destroying its strength! I know its a crude drawing but you get the idea! Weld up the sides and plug weld along the frame rail to keep the heat down. Leave enough room to access the camber bolt nuts.
Then add the factory braces from the firewall to the inner fender apron.

To many folks believe that the "SHOCK MOUNT" is a part of the structure! All it does is is support the shock during jounce and rebound! Thats it!
 

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Here's what bothers me about all the different ways that has been done..
Not one has cut away and reshaped the upper shock mount to smooth away some of the dang hump so there's more usable space in the engine bay.

When someone does take a support from the front of the frame rail like pictured above, take the other end right straight back to the A pillar, put a shock mount on it and delete the factory shock mount, I'll buy it.
It wouldn't hurt my feelinds if the top of the shock wasn't visible in the engine bay. I suppose a shorter shock might be required.
 
This idea was not to be used as a "coilover mount". I know I can say that until Im blue in the face but its the truth. This idea came about when I lowered the car down on jackstands, which were places on the TBar crossmember. When the weight was on the stands, the front clip continued dropping...and dropping...and dropping. Think of what holds the front of these cars together...simply sheetmetal.
High strength steel??? I'd say as strong as normal cold rolled steel is. Nothing special. By the way, your drawing gets your point across but you can add all the plate you want...in the end, the sheetmetal is still what is hold the load. Something like Tori did that bolts through the frame is the best idea for the coilover mount I think.
Think of this as simply a chassis stiffener. I have my doubts of coilovers anyways...after talking to a good friend about things, its easy to see coilovers are not the "answer to all" solution.
RedFish...in my opinion, the idea of good aftermarket products is that you dont have to cut up the car too badly. If you have a nicely painted car, the last thing you want to do is cut up the inner fender with a cutoff wheel. PM me and let me know what you want, and I'll bend them up for you if you're seriously wanting one.
Since these pictures, I have been adviced to go out towards the fender, behind the shock mount area. After going towards the fender, then follow the firewall down to the lower area. I'll get some more tubing and see what I can come up with.
Thanks guys.
 
curleysracecars said:
When the weight was on the stands, the front clip continued dropping...and dropping...and dropping. Think of what holds the front of these cars together...simply sheetmetal.
ahhhhhh....could it be the reason the car continues to drop is because when you move the jackstands further back...not only does it change the pivot point...but greatly increases the load/weight in front of those jackstands....

think about this...if what you say is true...you would see a GIANT gap forming somewhere....but I bet if you watch or measure your rear bumper height...its coming further off the ground

of course...just my take, I've never had any professional lessons

BTW...stay tuned..I'm about to unveil my new stealth upper shock tower support.....for street application front coilovers
Click to expand...
Click to expand...
 
Thanks Denny. I do understand what you mean, and realize this was part of the problem. On another note...if anyone wants to argue that the front of these subframe cars do not flex, they are out of their mind.
Anxious to see your coilover mount. Eventually maybe we can put together a collage of everyones ideas...yet there are always a band wagon of haters to every design introduced? :) Again, this is not intended to be an upper coilover mount, so I am not including myself in this collage. :)

I think it'd be wise for people to sit down and look at the idea of coilovers on these cars...its not the cure all for everything as alot of people seem to think. Just food for thought.

Im not bitter by any means, and honestly appreciate your input Denny. Carry on...hopefully someday we can put all ideas together for one killer part???
 
no issues with me at all...with anyone....I hope
just good ol' spitballin here

interestly the Hemi Demon I work on from time to time is a Calif car...so NO rust...NO frame connectors....But,the Demon has over 250,000 miles on it and I can hold up the front with one jackstand....hows that for flex?

so ...sorry, but I dissagree with you on the need to add more stiffining to them. I realize the drag racers...with a set of sticky rear meats TWISTING the car time after time after time with awesome wheelies and holeshots...requires some help...but not your weekend warrior/ grocery /coffee getter. in my opinion, adding all that weight...just slows ya down.

I strongly agree with your coilover statement....as I have said in the past...#1 reason for coilovers/rack conversions...I luv the extra room you get without the torsion bars and that big ol' steering box

I have read most of your posts and highly respect your opinions....you are a very knowedeable builder/racer...I just disagree on this one little one

Mopar to ya'
Denny

oh yeah...as far as being out of my mind...thats not the first I've heard that...just say'n (ooops)
 
I agree a grocery getter doesnt need anything. But anyone who drives there car even semi-aggresively could benefit from some chassis stiffening correct? If not, are you saying other companies(XV especially), have a bogus product line not needed for anything that is less of a racecar(drag or corner carver)???
I just fail to understand how some real structure, like round tubing, could be no more beneficial than some formed 16 gauge sheetmetal. Were all car guys, so you cant say we always putt these cars around town...

No hard feelings at all here either...this is how people learn...discussions are great! Unfortunately most times people cant take criticism and/or talk about things they have no idea about.
 
I just think about ALL the $hit we put our hot rods thru in their day...1969 to about 1976

we beat the snot out of em almost every night...and I'm not talking pure stockers...WE were all cammed up/ good compression (milled heads/115 octane gas(Sunoco260)/headers/4;56 gear at a minimum...even some of us ran slicks

none of us tied our cars together...And never had an issue other than my buddies 440/4speed Satellite's dome light would flicker ONLY if he pulled a 5500 rpm holeshot with his 12" slicks on after fryin to get them sticky

so...in my opinion...most of the stuff I see is strictly marketing....build it/ they but it
just adds weight.......weight slows ya down. But if you think it needs it...go for it!

ever see/read about the "Wire Car"?
 
Interesting concept Denny. Never heard of the "wire car"...link me to some reading if there is any. I agree the cars have been through hell and back...question remains whether we can better them or not. Sure they didnt break, crack or come apart while getting beat on...but were the moving around or flexing?
IMO, the best option is an underhood brace tieing the firewall, core support and fenders together...triangulating them. This is a tough job because of lack of good mounting positions, as well as a bunch of different under hood combinations you'll encounter.
 
the "'wire car" is an ultra lite Duster Don Carlton was building.....shortly before the ill handleing short wheelbase cars they began using to compete in Pro Stock.

I'll have Bro John post you some links tomorrow....getting late here in the east
 
just found a thread on here....go to General Discussions...there is a link in one of the posts...about the third or fourth one
 
Don't need jack stands or anything to see it flex. Take he fenders/front bumper off, attach a chain to the bumper mounts and lift with a engine hoist. Popped a good portion of the old seam sealer off.
 
poor ol' girl must be gettin a little tired, eh???
 
Nope. Car was a rust free CA car that was sitting for 14 years or so.....
 
if they flex that much...these things would not be still around...

I'm just not seeing it...sorry
 
Well I sure as hell aint making it up......for what it is worth it did not flex when I lifted it with the fenders ON....
 
calm down there ......

Sorry my friend...
but I still do not buy it...unless the car is a rusted out POS...

but don't worry.....it will not be the first time (or last) I was wrong
 
want me to send my wife over to sit in place of the motor?....then there WILL BE flex...just say'n
 
There's definitely flex in the front end, there's no doubt about that. The frames on these cars are nothing more than formed 14 gauge sheet metal, so yeah, there's flex.Twist is probably a bigger issue than plain vertical flex, but its still there.

As far as "high strength steel", that's a joke right? Literally, the frames of these cars are made out of 14 gauge sheet metal. It's doubled up in a few places (near the bumper mounts), but thats it. It's just mild steel sheetmetal, there's absolutely nothing "high strength" about it. Welding to it will have no dire consequences, no carbon migration, heat quench issues, etc.

As far as the inner fender support goes, I like the look of it and how it conforms to the body panels. That said, I think its too much tubing and not enough contact points with the original frame. The length of the tubing will allow it to flex as well, and without more tie-ins with the original structure it may deflect more than you think. I'm not saying that it wouldn't help, but I think inner fender braces like the ones XV sells would actually help more (firewall to upper shock support only). Its a short piece of tubing, so less flex in it, and it makes a decent box out of the shock mount and fire wall to stiffen the frame below. Of course, you still need to box the upper shock mount to make it work well.

When you think about stiffening chassis, you have to think about making "boxes". With a connector running from the upper shock mount to the firewall, you're not just adding the brace, but also a moment arm- the vertical distance from the upper shock mount and the frame and the firewall and the frame. That parallel link makes a box that significantly strengthens the frame rail's bending moment. The long tube that you've made still attaches low on the frame, so, you're not getting additional strength from the boxing of the framerail, just the additional strength of the tubing itself. Now, if you used a plate to weld it into the frame structure where it passes through that lower hole,and tied it into the firewall at the top of the bend with an additional section of tube and anchor plate, you'd have a pretty strong brace.
 
HemiDenny said:
calm down there ......

Sorry my friend...
but I still do not buy it...unless the car is a rusted out POS...

but don't worry.....it will not be the first time (or last) I was wrong
Click to expand...
Completely calm, just know what I observed when I went to lift the car off of the jack stands without the fenders. Glad to know that you think a few pieces of sheet metal are that stout.....
 
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