Structural Rigidity enhancement...

I was watching some Japanese tuner videos other an heard about a pretty intresting technique. Since most Japanese sportscars are hollow frame they injected liquid foam urthane into the structure of the car. It enters the body, fills then expands when it hits air and lasty harderens as tight as a rock in the body. Cheap and very effective more so then a roll cage supposedly. I might give it a shot on my FD.

Imput & Other Techniques...
(List only uncommon no strut-bars etc)

Within limits, that sounds like a good idea. You might want to be careful about rust prevention, any air flow requirement thru the panels, and any degradation of the foam itself over time with moisture, heat, etc.
Might even help quiet the car too.
Good luck!

and add a few hundred pounds in the process.
not really a good idea i think.

Actually, the foam is stronger per pound than steel. Its not that heavy.

Let us know how it goes. I would make sure sure sure that the inside of whatever you're injecting is squeaky clean. For that stuff to work it has to have good adhesion to the substrate for strength.

Actually, the foam is stronger per pound than steel. Its not that heavy.

Let us know how it goes. I would make sure sure sure that the inside of whatever you're injecting is squeaky clean. For that stuff to work it has to have good adhesion to the substrate for strength.

I definetly will. The whole car will be completely cleaned an cutted before the injection.

Greygoose ~ The amount to cover a whole tubular chassis like mine when compressed is smaller then a paint can. It weighs almost nothing. Watch JDM insider 2 and you will see an R32 GTR completely lined to the hilt with urthane. The amount when compressed was about as big as a can of paint thinner.

i must be misunderstanding the process.
what are you filling with foam.
the hollow parts of the frame, or the hollow parts of the body (like inside the doors)

i must be misunderstanding the process.
what are you filling with foam.
the hollow parts of the frame, or the hollow parts of the body (like inside the doors)

Only the hollow parts of the frame... "Structural Rigidity" Not "Exterior Rigidity"

ooh, i see. somehow i read your original post to mean that you were injecting this stuff into the body, which would have added a lot of weight.

Come to think of it, It could replace sound defining material as well. The material is lighter then metal an just as strong due to it's structure. Imagine hundreds of thousands of tiny archs to form one massive or in this case regual size structure. The foam isn't solid nor dense so it's very light, hence why I'm doing it over a roll cage.

IMO ~ It's impossible to inject it into doors with moving parts sych as power windows or even manual windows.

I remain sceptical.

While it'll be great for sound proofing and may possibly stronger than steel (weight for weight).

How is adding less than 1lb of foam to your car going to give a structural benefit?
There is no way that can ever compete with a rollcage for strength and safety.

The stiffness of foam is terrible. It will not be in any way comparable to adding extra metal to your car.

There is no way that can ever compete with a rollcage for strength and safety.

Strength yes, Saftey No.

Sometimes hollow is better and it's a foam that harderns into a solid plastic not a foam that turns into sponge or cushion. Do you know that your bone structure is almost the same structural patterns as this foam? Many things through the years have been many or hollow peiced an the fact is they're stonger. Perfect example is carbon fibre... Why is it so durable and strong because it's a fiber an not a solid monopiece structure.

Honestly I don't care about safety because a cage in an FD really won't do that much as far as safety at the speeds I access in the FD are no where near safe even for a cage.

Cell structure of urthane ~
http://www.onnooriinc.co.kr/images/elastogran-cell%20structure.gif

Cell Structure of Human Bone ~
http://www.esa.int/images/osto_bone_2_l.jpg

you do know that it doesn't take much lbs of torque to break bone right?

I don't think it's worth it.
if you increse the rigidity of the base frame, aren't you going to have to work on the suspension so you don't wreck your ride quality? And if it doesn't add that much rigidity to neccessitate re-tuning the ride, then is it worth it?

Incidentally, the strength of carbon fibre is because of the criss-cross layering of the superlight (material) fibres, not because it is "hollow", which it defintely is not.

And what speeds are you doing in that car which would render even a full safety cage useless?
:rolleyes:

I'm not going for ride quality (I'm installing full Race spec Re amemiya Quantum Flex Coilovers as well as a stronger an even more rigid strutbar (s) as well as lower bars an a custom X brace)

My last trap speed was 147mph before my boost cut-off kicked in. No it wasn't Qt time :wink:

Fyi - I was explaining how one solid structure is sometimes not as strong as servral not the hollow part. (Atleast thats what I mean't to say with the whole whole carbon explaination)

the other problem I can see from injecting expanding foam into a hollow tube frame is that while it adds rigidity, it also puts extra stresses on the joins and this is something you can't physically see or even measure without very expensive equipment. This in turn can actually weaken the structural integrity of the frame; not something you'd really want to do if you are intent on modding the car into a (pointlessly) overstiff straight line racer.

The reason why is because I fear the car has been damaged/weakend due to an accident six months ago which swayed the nose. the Rx7 is a very "flimsey" car persay. It has one of the best suspensions (Double wishbone) but the frame is very flexible an flexes very easily. I don't have very many tools at my disposal so when I need to do routine stuff I do it the "ghetto" way persay. I did an oil change once by pulling half the car up on a high curb an draining the oil out like that. When I opened the doors and an trunk to get somestuff an it was on an angle I couldn't close the trunk nor the hood or even the drivers side door! That is very serious flex to me.

ok.... so in short, you have wrecked your car then.
if there is that much flex to begin with, injecting expanding foam into the frame might not be the best thing to do and won;t actually do any good if the frame is already compromised. By the way, if simply putting the car on a curb causes body flex, then I'd say that something is/was wrong with your car. The RX-7 shouldn't be like that. From what I recall, the car is meant to be very stiff structurally but on softer springs/dampers; very much like the MX-5 and RX-8 and that is what makes it so progressive.

Strength yes, Saftey No.

Sometimes hollow is better and it's a foam that harderns into a solid plastic not a foam that turns into sponge or cushion. Do you know that your bone structure is almost the same structural patterns as this foam? Many things through the years have been many or hollow peiced an the fact is they're stonger. Perfect example is carbon fibre... Why is it so durable and strong because it's a fiber an not a solid monopiece structure.

Honestly I don't care about safety because a cage in an FD really won't do that much as far as safety at the speeds I access in the FD are no where near safe even for a cage.

You are not going to get any strength or rigidity at all out of urethane foam. Have you ever played with solid urethane? It is very flexible, hence the use in suspension bushes. It is so flexible that bicycles use solid blocks and rods of it for suspension springs.

If you don't believe me, then I suggest you do some experiments with the foam first. Fill up something like a balloon with it, let it harden and see how stiff/strong it is.
It'll be about 3 times stronger than a dry kitchen sponge..

Human bone does not compare to steel for strength. Neither does urethane foam.

Carbon fibre is not related to this discussion at all. But carbon fibres are exceptionally stiff, stiffer than steel.

if there is that much flex to begin with, injecting expanding foam into the frame might not be the best thing to do and won;t actually do any good if the frame is already compromised.

It's already been scanned and it's fine...

By the way, if simply putting the car on a curb causes body flex, then I'd say that something is/was wrong with your car. The RX-7 shouldn't be like that.

It is an I know there's nothing wrong with this Rx-7, 44k original miles an not one incedent up until 5 months or so ago.

From what I recall, the car is meant to be very stiff structurally but on softer springs/dampers; very much like the MX-5 and RX-8 and that is what makes it so progressive.

Depends on the package you get (the only difference is springs an a strut bar) FD's are very flexible cars maybe your confusing it with the FC3S. The Fc3s was a tank because of how structurally sound it was.

You are not going to get any strength or rigidity at all out of urethane foam. Have you ever played with solid urethane? It is very flexible, hence the use in suspension bushes. It is so flexible that bicycles use solid blocks and rods of it for suspension springs.



If you don't believe me, then I suggest you do some experiments with the foam first. Fill up something like a balloon with it, let it harden and see how stiff/strong it is.
It'll be about 3 times stronger than a dry kitchen sponge..

I will, But having seen a 700 4-whp BNR32 GT-R be injected with it for structural purposes I think it sets a good example. I'll trust the pro's at Apex'i tuning.

(Apex'i Kyoto Hakubai BNR32 GT-R) :smooch:

All cars flex, its just a matter of how much.

The foam has been shown in many applications to do wonders. Driveshafts that were installed behind Duramax diesels hold up to well over 1000 lb-ft in part because the thin-wall aluminum shaft is injected with urethane foam.

Have you guys ever used a can of that expanding foam? You know what its like after it hardens? Well the urethane foam is like that times ten. It is VERY effective at helping. How much depends on several factors, but I don't doubt that its an effective means of helping rigidity.

I know it seems illogical given its light weight, but seriously, its like adding epoxy to fiberglass. Neither one is very strong alone, but put them together and they are very strong. The foam gets its strength from the billions of geometric shapes formed in the bubbles.

then it seems to me that the reason for the stiffness isnt the foam at all, but the fact that it expands.
it is no mystery that when you put an object under tension it is stronger.
this science was recently used in golf clubs and yeilded huge gains in drive length.
not to say that golf clubs compare to a frame of an rx-7, but the general idea is the same.
preload the frame with a certian ammount of tension and it will be stronger.
how much stronger, i cannot say, but it could help some.


personally, i'd check that frame again.
if it contorts by simply putting it at an angle by driving it onto a curb, then you are starting way behind.
how hard would it be to find a doner car with the stiffer frame and swap in all your parts?
it would certainly be more cost effective than trying to stiffen a frame that is weak to begin with.

kind of like turboing your grandmothers buick.
it will help. thats obvious. its just a bad platform for a build.

thats just my opinion

then it seems to me that the reason for the stiffness isnt the foam at all, but the fact that it expands.
it is no mystery that when you put an object under tension it is stronger.
this science was recently used in golf clubs and yeilded huge gains in drive length.
not to say that golf clubs compare to a frame of an rx-7, but the general idea is the same.
preload the frame with a certian ammount of tension and it will be stronger.
how much stronger, i cannot say, but it could help some.

Yes, I see what your saying... almost a roman arch effect like a keystone.

personally, i'd check that frame again.
if it contorts by simply putting it at an angle by driving it onto a curb, then you are starting way behind.
how hard would it be to find a doner car with the stiffer frame and swap in all your parts?
it would certainly be more cost effective than trying to stiffen a frame that is weak to begin with.

kind of like turboing your grandmothers buick.
it will help. thats obvious. its just a bad platform for a build.

thats just my opinion

It's more of a promise to keep persay. I already had the frame checked an it's fine it just needs a new headlight assembly/structure. The way the car hit wasn't direct but on a spin an angle so it wasn't a direct hit to the frame just a tweak. Besides my chassis has to low of miles to give it for minor damage...

She's a real gem if you see her in real life :wink:

Yes, I see what your saying... almost a roman arch effect like a keystone.


It's actually the opposite. Roman arches work because they're in compression. Goose was talking about the structure being in tension due to internal pressure. Just like a tyre with the pressurised air inside.

Just because you see something done on a video, doesn't mean it's safe or even works.

I'd hate to see someone hurt or even killed because they think some plastic foam can make their car stronger than a roll cage will.

It's actually the opposite. Roman arches work because they're in compression. Goose was talking about the structure being in tension due to internal pressure. Just like a tyre with the pressurised air inside.
There's no pressured gas or air it just turns into a solid substance.


Just because you see something done on a video, doesn't mean it's safe or even works.
Like I said they showed runs with it an all. Launched an performed great. If it was some backwater shop I would'nt even think of it but Apex'i does wonders especially to their GT-R's and Fd's.

I'd hate to see someone hurt or even killed because they think some plastic foam can make their car stronger than a roll cage will.
A plastic foam won't make a difference in a crash. Like I said before I'm not going for saftey only rigidity enhancement and a stiffer ride.

There's always people who doubt that thing's "cannot be done" or "won't work" but ever since the invention of the 3 and now 4 rotor I come to think any thing is worth a shot.

You guys are missing the point of the foam. Its not pressure, ITS THE FOAM ITSELF. Try it sometime with just the cheap can of spray foam in a piece of exhaust tubing, then span it across a couple boards and stand on it. Compare it to a non-foamed tube and you'll see.

Think of it this way. Lets say you got inside the tube and welded in about 10 braces across the tube at random angles. It would strengthen it, right? Now, think about doing that with hundreds of billions of hard hair-strands of polymer. Its the same thing. You're taking a bubble of polymer (not very strong) and multiplying it billions of times in geometric shapes. Its strong stuff.

is it similar to "great stuff"
i've got a can or two of that laying around...

i'm aware that foaming the chassis works.
my point is, I'm not entirely sure if parking your car on a curb should be causing that much longitudinal flex in the chassis to a point where the doors or boot can't shut.
If there is a weakness there, filling it with foam might give you temperary strength but the frame is still gong to be compromised.

What kind of scan did your car have?

when he said that there is strength gained from internal pressure, he is talking about the pressure caused by the foam wanting to expand and the frame not letting it. This is also what I was talking about when I said it would put extra stress on the joints of the frame.

Why do you want a stiffer ride?

my biggest argument is that if the foam cracks, you will be left with an unevenly stiff chassis.
you compared it to bone, and bone cracks pretty easily.

i guess i have to try the "great stuff" experiment.

i doubt an aerosol of this foam will deliver the kind of rigidity you expect, if there is such a gain to be had, as shown by this GT-R i'd imagine they used some gear a little more "heavy-duty" than squirting a can of foam into the frame's hollows.

What kind of scan did your car have?

Don't know my friend owns a body shop he just told me it came out good and clear. I know it runs a systems where the whole chassis is scanned an then the numbers are imputed into the computer an compared to the original or what should be numbers. He said they were on par to the original factory #'s.

Why do you want a stiffer ride?

High speeds and Extremely winedy (Sp) roads...

my biggest argument is that if the foam cracks, you will be left with an unevenly stiff chassis.
you compared it to bone, and bone cracks pretty easily.

i guess i have to try the "great stuff" experiment.

If it cracks then I'll have it removed from the chassis and reinstalled until it happens again.

Try it and see for yourself. Experience is the best teacher...

you can walk the plank first, tell us what it's like. :tongue:

i doubt an aerosol of this foam will deliver the kind of rigidity you expect, if there is such a gain to be had, as shown by this GT-R i'd imagine they used some gear a little more "heavy-duty" than squirting a can of foam into the frame's hollows.

I'm sure it's a high grade of what ever urthane they use. Your thinking about it as if it were a base K-mart plastic. Isn't there is a difference between steel and forged magnesium... :wink:

you can walk the plank first, tell us what it's like. :tongue:

You guys are going to have to sit on it for a while. I'm at college an building funds for my little racecar. High performance parts aren't cheap ya know or would you :wink:

I don't think that the foam was used in isolation either.

The urethane foam is nothing like the spray can of foam. I just mentioned that as something you could try at home. Imagine the urethane foam like the cheap spray can times ten.

If the car is truly compromised, then it won't work miracles, but the foam is very effective.

I have to agree with how strong the foam can be, and its follows that from if injected into a cars chassis it could make more rigid.

I can however think of a few problems.
Once its in, its NEVER coming out. Not unless you cut the car up completely destroying it in the process.

ANY moisture that gets trapped by the foam, will cause rust. Lots of it.
I wouldn't do this to a car I planned to keep very long as a road car.
Suitable for race only applications IMO, where the cars life is going to be limited anyway.


I also don't think it will be as effective as a lot of others think it will be.

In order to make your car more rigid you have to find out why its flexing to begin with.
90% of the time its not because the existing structures are strong enough, but because they are poorly placed, or there are not enough of them.
If the flex is occurring over a long length of the body, for example the from the base of the floor to the top of a pillar, simply making that pillar stronger often won't have much effect.
The amount of flex across that distance only has to be a very small amount, to cause a larger change else where, say to wheel geometery.
Increasing the strength of that pillar to to stop that small amount of flex may require an exponential increase, in its strength. Even making it out of solid round bar might not be enough.

Instead what is needed is extra bracing, or even a redisgn of the pillar.


Its been mentioned that the foam works by forum millions of little cross braces with in its expanded from.
Well a car body works in the same way.
Its much more efficient to find where the flex is occurring, and adding cross bracing in the right places, than it is to simply try and reinforce he whole car based on its existing structure.

The best refinement Iv seen done, was to a Lotus Elan.
The owner made a scale replica of the chassis, and used it to observe the weak spot. It showed him only a very small (about 300mmx300mmx300mm) triangle needed to be fitted on each side in a spefic location, and the chassis rigidity could be almost doubled.
While a Lotus Elan chassis is much simpler than that of an RX7, the same princiables apply.


Besides, while the foam may have a very large amount of strength over a wide area, put pressure onto a small point of it, and it will collapse.
It would only take a small collapse of the foam with in the chassis, for the whole procedure to be rendered pointless.

/\ Very good points. Well the car won't be driven as a DD only to shows and races an most of the time if it requires long distances it will be trailered no doubt.

As far as the bracement issue I know what your talking about an the key flex point is under the engine atleast from what I've been told. I want to make a custom titanium X brace as done by this owner.

http://i90.photobucket.com/albums/k278/CMonakar/Chassis%20Fabrication/Chris_update07.jpg

What do you think?

Like moppie said the only thing I'm worried about is if it cracks it will be rendered useless. If the urthane was removable somehow (please tell me) then it would be a definite go ahead.

Moppie ~ Do you have more stuff on the Elans project I would like to see photos an such just to get Idea's.

Thanks

Don't know my friend owns a body shop he just told me it came out good and clear. I know it runs a systems where the whole chassis is scanned an then the numbers are imputed into the computer an compared to the original or what should be numbers. He said they were on par to the original factory #'s.

So he did a measurement check and it came out okay?

Did he check for popped spot welds? Cracks? Crumpled members?

So he did a measurement check and it came out okay?

Did he check for popped spot welds? Cracks? Crumpled members?

With what else a tape measure :lol:

Yes, There were poped spot weld in the front end past the front wheel pillars an since then they have been removed an a clip has been installed.

No cracks the only crumpled zone was the front right directly under the rad support an has been pulled an straightend to be brief. Structurally speaking the car is fine.

It was inspected tooth an nail. :)

Moppie ~ Do you have more stuff on the Elans project I would like to see photos an such just to get Idea's.

Thanks'


Sadly I don't know of any more details.
But the Elan chassis is just a simple back bone.


Ultimately I don't think there is any substitute for finding where the flex is, and fixing it properly with well engineered bracing.
It doesn't have to be complex, the above example of the cross brace looks very over the top to me. It may in fact make the problem worse, but over stiffening the front in relation to the rest of the car.

Also consider what sort of work the car will be doing.
You only really want a super stiff chassis if there is going to be a lot of hard cornering and fast direction changes on a nice flat track, and you have a lots of control over suspension set up.
I know people who have taken strengthening out because its made the car too stiff, and to twitchy.

And of course if your going to be racing in situations where the car may turn a corner at more than about 35mph then you need a roll cage. Even more so if there are other cars on the track.
Its doesn't take much to flip a car, and the more you race, the higher the chance it will happen.
You have to think of your own safety as well, and of course a cage, if built properly can do wonders to chassis rigidity.


I put emphasis on the built properly though.
I know of a car that was rolled up a bank (yes, UP the bank), then landed hard enough on its rear axle to break a wheel, disk and hub in half, and bend the rear axle, housing the lot.
Yet the cage held the car together in such good shape that we simply replaced the axle, wheel etc, and away it went again. (with some body work to the roof and front).
Yet that same cage allowed the car to flex enough that the A pillar separated at the base of the front window.
(of course a cage should be designed first to protect the occupants, which this one did).

I'm more into stright line speed but not 1/4 times though more or less 1 -2 mile sprints actaully (topspeed). I would do cornering but there aren't any real tracks here in N.Y (Atleast downstate). The other thing is it is mostly a track car for all purposes intended but I do like to take her out on joy rides as well as some nice cruises an meets. Also to nice occasions just going to the movies thats why I'm trying to find alternate ways instead of a roll cage. Not for anything but I like my car to have a stock look in the interior (No guages except a boost gauge a digital blitz Icolor 5 in one display on one screen), I'd hate to cut up anything my interiors its mint. Basically I use the car to take to shows, meets, races and also to treat a girl on a nice occasion. I'm not pushing major numbers (300-325 rwhp @ 12psi) but while the cars apart I'd like to do it, this way it will save me labor an time in the long run.

As far as vibration through the chassis I'm not worried I'm ordering the new Nexus GT ride control adjustable coilovers. They adjust stiffness as well as ride height where as most just have a pre-set rigidity.

If there is an issue with the area under the engine, I can't see how it would cause your doors and boot not to close when on a slope. If anything, your doors and boot not closing suggests to me that it is a longitudinal flex problem and an x brace under the engine isn't going to help this much; a brace here would be targeting torsional rigidity across the front axles.
what you need is a brace that spans the length of the car.

I'm going to try that as well. There are two main beams that run the course of the whole car. The X brace as shown before braces those beams but only in the front (obviously) but for the rear I'm getting a lower strut bar an see how it reacts to that.

I'm not sure if (independent) bracing at the front and rear is going to help much. It'd reinforce those elements to be more rigid transverely but it still won't help torsional rigidity (twisting between the front and rear suspension elements) or longitudinal flex (bending between the front and rear - what you seem to be describing when you talked about parking the car on a curb) in the overall chassis.
What you need, is a brace that ties the front and rear elements together. Without looking at how the car is put together, I'd say have a look at the transmission tunnel and see if there is enough space there to fit a member here. Or you can reinforce the floor pan.

Damnit, Once I get the car on the lift I will take a whole lot of shots for you guys the tunnel, front end and the whole entire underbody.

Not sure if this helps at all as far as the tunnel goes...

http://www.fd3s.net/rolling_chassis.jpg

what you need is a brace that spans the length of the car.

AKA roll cage.:grinyes:

AKA roll cage.:grinyes:

The brace would only span the monococke then not the length of the car. The foam would have a father span then the cage. Most cages made for the FD only go the rear upper strut bar an go as far foward as the firewall at most.

AKA roll cage.:grinyes:

i know a simple roll cage would solve all his problems.... but for some reason, he doesn't want a roll cage and seems fixated on foaming his chassis.
I suggested a brace in the transmission tunnel because I know how an RX 8 is made and there is just that in the chassis; a great big horizontal plane member.

Most cages made for the FD only go the rear upper strut bar an go as far foward as the firewall at most.

err.... the front firewall section of the frame is structural and is joined to the two rails; the rear suspension is also fixed to the rails.
the roll cage uses these two points because that is EXACTLY where they need to go. I'm going to guess that there are, or there are available braces that are meant to go from the top of the front towers to the firewall as well. Which brings to mind another little questionConsidering that the actual passenger cell area/door frame is also part of the structural frame, it is that little bit more worrying that having the car with one end on a curb would cause your door not to close. That implies that your passenger cell area is compromised.

That implies that your passenger cell area is compromised.

It would have happened to either side which ever was parked on the curb...

The flex was noticed before the accident.

i know a simple roll cage would solve all his problems.... but for some reason, he doesn't want a roll cage and seems fixated on foaming his chassis.

Since he knows all the answers already, I'm not sure what this post is about.

If I was running a car like that up to it's maximum speed, I'd sure as hell want a rollcage. Whether it was in a competition that required it or not.

IMO foam should be used for energy absorbtion (like crash helmets), steel is the best material for adding strength and rigidity.

steel is the best material for adding strength and rigidity.

Also the best for adding weight, I'd rather take advantage of the rotaries weight factor. If nessesary titanium will be used.

Also the best for adding weight, I'd rather take advantage of the rotaries weight factor. If nessesary titanium will be used.

Stiffness for weight, steel is better than titanium.

:iagree:

i think that a rollcage would be the best option.
if the foam cracks you will never get it out and will likely have to replace that part of the frame.

i dont know the specifics of this frame but would adding steel in specific places be an option?

for older cars, you can increase the rigidity by boxing the frame.
your frame is (i gather) made of square/round tubing.

you could weld extra metal onto the frame in the places that are flexing.

it sounds like in your case the middle of the frame is the weakest link.
blindly strengthening the suspension parts would make the problem worse.
what you need to do is put extra metal into the middle section.

i believe that someone suggested a brace along the transmission tunnel.
IMO this is the way to go.

but hey, its your car. do what you want.

I was watching some Japanese tuner videos other an
heard about a pretty intresting technique. Since most
Japanese sportscars are hollow frame they injected liquid
foam urthane into the structure of the car. It enters the
body, fills then expands when it hits air and lasty harderens
as tight as a rock in the body. Cheap and very effective more
so then a roll cage supposedly. I might give it a shot on my
FD.

Imput & Other Techniques...
(List only uncommon no strut-bars etc)

Old thread, whaa, whaaa, I know!

I reduced the squeaks n rattles in a low mileage 1981 Buick Century I drove to and from school back early '90s simply by moving all four door strike posts in a few mm!

Prior to that, this comfy, electric driver seat, power windows 5,000mile Century Limited "Estate" Edition(you know what that means!) was a floppy, drafty barn on wheels!

Afterwards, the cabin stayed warmer in winter, and cooler in summer, even without constant blasting heat or A/C. Oh and yes, the handling actually firmed up some: steering more "Germanic", better acceleration, braking, and the thing ROLLLLLED between taps on the gas pedal!

Basically, I transformed a late-'70s designed GM mid-size into a late-model Accord, climate and handling wise, just by 'pulling in' the four passenger doors slightly. And with little more effort required to shut them. Plus - I could hear more of the music from the stereo, at a slightly more conversational volume.

Your mileage may vary, as they say. Moving the door strikers at all, on something built within the last ten model years, might be impossible. And successive decades of engineering have made today's passenger saloons - including Buicks! - as much as several hundreds percent 'stiffer'-bodied, than my '81 Century college shuttle. Modern vehicles are less dependent on door tightness for body rigidity.

In fact, I completely loosened the two hex screws on a rear door striker on my 2015 Hyundai, and the striker slid barely a hair's-breadth in any direction against the door jamb sheet metal. Where as on the old GM A-body, it could be moved in/out/up/down as much as quarter-inch. It took just one-eighth inch inward to transform the Century from a floppy drafty barn to a taught 'library-on-wheels'. :D