Fair enough. Boxing the frame probably does nothing for most of the people interested, but my thoughts on making it better without any particular requirements in mind would be minimizing fatigue and potential cracks/other failures. We know that the factory welds are often poor and sometimes missing in places, and boxing would certainly help to remedy those issues as well as aid the handling and ride characteristics like you mentioned.
To most people some upgrades aren't necessary until you hit a certain power level but I like to mess with things and "make them better", and with these particular frames I almost see the mod as making them sufficient considering they're hot garbage to begin with. I absolutely agree that boxing it "just because" is unwise, I doubt I'll ever reach a point where it's necessary, and I've never boxed a frame. But I'm sure interested in the subject.
reinforce the shoe box....then put the lid on it
"Sir, we decided to remove our frame kit from the market"....."Why?''......81Cutlass on the gbody forum says it doesn't do anything"....."Does he have any experience in frame strengthening?"....."Well, no"......"Then why would anyone listen to what he has to say?''....."Well, he has some assumptions........
"Sir, we decided to remove our frame kit from the market"....."Why?''......81Cutlass on the gbody forum says it doesn't do anything"....."Does he have any experience in frame strengthening?"....."Well, no"......"Then why would anyone listen to what he has to say?''....."Well, he has some assumptions........
Chassis flex, mostly.
One common problem on G bodies from what I’ve read is B pillar cracks. That’s caused by the large door opening on the body, combined with that opening being right above a flimsy section of C channel frame. That twisting is why the GNX’s had that beefy rear seat brace in the back with around half the power you’re pushing.
It’s really noticeable on high horsepower-hard launching cars, turbo cars not so much especially if they’re launching soft.
The flimsy, thinner, and less braced (than previous generations) frame combined with a thinner flimsier body gives the car the strength of a wet noodle. Boxing the frame remedies the strength to a large degree by helping the frame resist the twist.
For me, it’s the combination of twisty mountain roads and the prospect of a “universal” car for the first couple years that make me want to brace it as much as possible. Going from drag to autocross to road course/spirited driving is too much to ask of a stock frame.
WyoGN, not sure why you're singling out '81cutlass. Unless someone actually calculated the numbers everything is speculation. He's merely the guy calling out how effective boxing is or likely isn't. Me?? I'd do chassis bracing over boxing if I wanted to eliminate the probability of chassis flex so I don't think he's wrong @ all. If you know better let's see the proof.
My logic says something that ties the rails together (where the front & rear rails kick-out under the passenger compartment) & then also ties the rails together side to side @ the sections where the frame turns to C-channel would be beneficial. That in addition to the standard front rails to X-member brace, a rear shock tower brace, & a rear bumper brace should help a stock chassis.
My logic says something that ties the rails together (where the front & rear rails kick-out under the passenger compartment) & then also ties the rails together side to side @ the sections where the frame turns to C-channel would be beneficial. That in addition to the standard front rails to X-member brace, a rear shock tower brace, & a rear bumper brace should help a stock chassis.
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funny you ask for proof.....where's his? yea, I apologize for making fun....he seems adamant to not do it, is all. Standing on a frame and see it flex and standing on the frame after it's boxed is very good indication of the effectiveness of stiffening the frame through the helwig kit. I agree there's more to do like shock tower brace and rear bumper brace. I think there's someone showing jacking the car and 3 wheels come off the ground after the install.
you can cross brace and create a grid under the car if you like. There's another frame kit that does just that. Like I said I'm doing this to a chevelle abody that el caminos and convertibles came from the factory with....maybe the GM engineers are wrong, but I would guess it does "something" ......I haven't seen any performance aftermarket frames that are c channel, but I haven't look either....again to each his own
you can cross brace and create a grid under the car if you like. There's another frame kit that does just that. Like I said I'm doing this to a chevelle abody that el caminos and convertibles came from the factory with....maybe the GM engineers are wrong, but I would guess it does "something" ......I haven't seen any performance aftermarket frames that are c channel, but I haven't look either....again to each his own
My question isn't if strengthening the frame is/isn't worth it, I agree boxing the frame can be helpful, I question if the hellwig boxing kit is achieving the results people want.
The product doesn't have to work, it just has to sell. Is it confirmation bias by people that spent the time welding it in saying yeah it worked, or am I biased against it because I just don't see it doing much, possibly.
My concern is that boxing the frame (in the way I see the hellwig kit is welded in) isn't strengthening the frame (in my eyes) in a plane where you want.
The failure people see from B pillars or whatever cracking is torsional, the chassis can twist from the front axle centerline relative to the rear axle centerline. The 'weakness' in the frame is (in my eyes) mostly in the front and rear crossmembers allowing the long pieces of the frame to twist relative t each other. The boxing kit is making the long runs of the frame stronger, sure. Let's assume they are PERFRECTLY straight and never bend. If you have 2 really strong frame members connected together with wet noodles, the frame pieces are still going to bend relative to each other.
Boxing the frame makes the frame stronger in lateral loads, like side impacts, or vertical loads, like if you are dukes of hazard jumping the car.
But, in a frame torsional case (turning a corner with a lot of load on one side of the car or launching hard), or a frame planar bending case (say you hit the brakes hard and one tire locks up and the other doesn't) where I see people wanting more strength, you still rely a lot on the front and rear crossmembers to hold the long runs of the frame square relative to each other.
I do believe a kit like this does increase the frame rigidity. It's putting structural reinforcement off the frame surface and making a more effective geometric/force stiffening shape.
Maybe I just expect that if I take the time to weld in weight that it provides significant improvement. Does welding the boxing kit in do something, sure. Is it 5-25% better, possibly. But I see a 25.3 style floor kit doing 50-150% improvement.
The product doesn't have to work, it just has to sell. Is it confirmation bias by people that spent the time welding it in saying yeah it worked, or am I biased against it because I just don't see it doing much, possibly.
My concern is that boxing the frame (in the way I see the hellwig kit is welded in) isn't strengthening the frame (in my eyes) in a plane where you want.
The failure people see from B pillars or whatever cracking is torsional, the chassis can twist from the front axle centerline relative to the rear axle centerline. The 'weakness' in the frame is (in my eyes) mostly in the front and rear crossmembers allowing the long pieces of the frame to twist relative t each other. The boxing kit is making the long runs of the frame stronger, sure. Let's assume they are PERFRECTLY straight and never bend. If you have 2 really strong frame members connected together with wet noodles, the frame pieces are still going to bend relative to each other.
Boxing the frame makes the frame stronger in lateral loads, like side impacts, or vertical loads, like if you are dukes of hazard jumping the car.
But, in a frame torsional case (turning a corner with a lot of load on one side of the car or launching hard), or a frame planar bending case (say you hit the brakes hard and one tire locks up and the other doesn't) where I see people wanting more strength, you still rely a lot on the front and rear crossmembers to hold the long runs of the frame square relative to each other.
I do believe a kit like this does increase the frame rigidity. It's putting structural reinforcement off the frame surface and making a more effective geometric/force stiffening shape.
Maybe I just expect that if I take the time to weld in weight that it provides significant improvement. Does welding the boxing kit in do something, sure. Is it 5-25% better, possibly. But I see a 25.3 style floor kit doing 50-150% improvement.
As someone who is known to be mouthy I'll go ahead and let you know that you're a bit out of line. You're being disrespectful to established members of a community that you've asked for help, and said members have proven their intelligence many times over whereas you're acting like a punk because you want to flex your new knowledge. It appears that you came here expecting people to agree with you and pat your back saying "Good idea, son" but got angry when it didn't happen.
That's why we value your input: because you consider situations such as vertical, horizontal, torsional, and planar loads and how they affect the frame in question. Thank you for shedding some light on things.
"Sir, we decided to remove our frame kit from the market"....."Why?''......81Cutlass on the gbody forum says it doesn't do anything"....."Does he have any experience in frame strengthening?"....."Well, no"......"Then why would anyone listen to what he has to say?''....."Well, he has some assumptions........
Your time to shine, college boy. Show us the way.
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Ah, I got you now.
Imo, the Frame FX kit is too much over engineering for too little benefit from what I’ve seen in the instructions. It’s a borderline frame wrap kit, and the guys in Cali have been doing that better for decades. A simple boxing plate with bulkheads welded in at either end to help it from bowing as well as supporting the trans crossmember mounts would be a better investment of time and money.
Heck, asking Hoppo’s to piece out this kit would be better worth your time:
82-86 G-Body Complete Reinforcement Kit
HopposOnline Vehicle Hydraulics and Air Suspension
www.hopposonline.com
And for anyone interested in that, I’ve asked, they will. At least for the inner plates that follow the rear back half from the lower control arm mounts to the spring pockets.
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