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Actually, GM was making this claim when the 4th gen 'verts were introduced in 1994. It was one of the factors that led me to purchase my '94 Z28 M6 'vert. There is no structural (sheet metal stamping) differences between the '94-'97 MYs and the '98-'02 MYs. GM DID improve / increase the adhesives used for bonding some panels to the structure in '98, but that was part of the continuous process improvements, not in response to perceived complaints of the 'verts being "rattle traps".
I do find it interesting that most of the SFC suppliers don't have a 3-point version for the 'verts. Glad I purchased my Kenny Brown 3-point SFCs for my 'vert when it was available. Despite all of GM's claims that the 4th gen 'verts are much improved over the 3rd gen "afterthought" 'verts (which they are), they still exhibit a lot of cowl shake over bumps. Adding even a 2-point SFC helps this a lot, but not as much as a true 3-point SFC.
^^^ I had a little trouble following your assessment but I agree that the 4th gen 'verts are made well. I've had mine since 'new' and it has handled well and taken us all over the US. I do not race the car, or take it to the track, so the need for upgrades is minimal. On the other hand, for comparison sake, my old 2007 Mustang GT/CS 'vert had way more rattles. especially with bumps, RR tracks, etc..., My current '14 GT is still too new to have them at just 12k miles but I have a feeling it will be similar to my other in time.
K frame braces on the 2001 Camaro SS. No such oem braces on any other F body. At the tunnel brace is a four point nothing like the two point on all other cars, which have nothing beside them. On the vert, the two common points have welded in oem braces from the center to the outside of the car. THIS is why most other SFC's except UMI WILL NOT fit. Who claimed the 4th gen T-Top car and 4th gen vert where the same underneath?
Contrary to the above, GM was responding to customer complaints that their cars were rattle traps. Marketing was appalled. Hence the big alterations, bolt on and welded in you can see for yourself in the photos above.
GM welded in OEM the equal of frame connectors at the vert factory. Even so, most 4th gen verts do have rattles, etc.
The factory stock 'verts DID have a small stamped-steel plate that was supposed to reinforce the floor pan (that went under the driveshaft as you mention later) and held in place w/ 4 bolts. This was not present on T-Top or HT cars. But compared to a SFC, it was pretty worthless.
It was present on all T-Top and HT cars. On convertibles it was replaced by a four point one with braces welded in on both sides oem. Welded at the factory. They also have these: OEM convertible K frame braces
GM included OEM only on the verts, the budget, make believe, not frame connectors, cowl shake not eliminators at the vert factory. Even so, most 4th gen verts do have rattles, etc. but not as many as the 4th gen HT and T-Tops. Sad, but true. To get a clear look at the underside of a 98 T top car, time stamp 2:30. Look at how many oem welded in pieces of the convertible are missing on the T top car.
Got rattles? It's not just the rear hatch and GM knew it. Start with the SFC's, add the roll bar (4 point at least) and 3-point STB. NO more rattles. Not even from the rear hatch.
Last edited by LSX Thunder; 08-22-2023 at 04:26 PM.
Most of the rattles and squeaks in third and fourth generation F-bodies comes from the rear hatch area. That's why the fourth gen convertibles aren't as bad.
Most of the rattles and squeaks in third and fourth generation F-bodies comes from the rear hatch area. That's why the fourth gen convertibles aren't as bad.
That's true but most? As the photos show, the vert is very reinforced compared to T -Tops or HT. I've seen 4th gen convertibles with 80,000 miles and NO rattles or any other weirdness. I admit that car was driven from new by an elderly woman with a gentle touch.
That's true but most? As the photos show, the vert is very reinforced compared to T -Tops or HT. I've seen 4th gen convertibles with 80,000 miles and NO rattles or any other weirdness. I admit that car was driven from new by an elderly woman with a gentle touch.
I don't know if its most of the noises but from the hatch area is where I hear it the most on cars without SFC's. I don't hear it from cars that have SFC's even if they have 100,000+ miles on them. And of course the convertibles are reinforced compared to T-top and hardtop cars. They don't have a roof. The problem with the fourth generation cars is that the roof only really has a lot of support along the center bar line of the roof on either car. Thus, it doesn't do anything to resist twisting as the chassis deflects while going over roads etc. But it does brace the structure when you open the doors, etc. as the floor isn't enough on its own. The verts have reinforcement near where SFC's on T-top and hard top cars go to provide that same bracing the roof ordinarily provides.
It probably works better to resist rattles but again, they don't have the T-tops or hatch area which make noise as well. Beyond that, convertibles are noisier since you hear more of the outside world anyway. Minor rattles are probably less noticeable on a convertible.
I The problem with the fourth generation cars is that the roof only really has a lot of support along the center bar line of the roof on either car. Thus, it doesn't do anything to resist twisting as the chassis deflects while going over roads etc. But it does brace the structure when you open the doors, etc. as the floor isn't enough on its own. The verts have reinforcement near where SFC's on T-top and hard top cars go to provide that same bracing the roof ordinarily provides.
It probably works better to resist rattles but again, they don't have the T-tops or hatch area which make noise as well.
I've posted some installation video for various roll bars. Once the trim, seats and rugs are removed, it is obvious how weak the unibody is. It is easy to bend the body to get the roll bar exactly where you want it. Then use the holes at the base of the bar to drill holes through the floor and use the backing plate when bolting together the foot pad of the bar, the unibody and the backing plate. When it's tight you're only half done, it must be welded to the SFC or a fabricated plate that is welded to both the bottom of the roll bar and the SFC. Now you have a rigid platform that doesn't need any type of roof to make for a very strong chassis, that does not twist. OEM the roof of T Tops and HT's is so weak it does very little. Look at some often-fatal F body crashes. Most of the time the car accordions, crushes front to back. A major cause of injury and death. Only a very strong 3-point SFC and a very strong 4-point or more roll bar prevents that. Most think the roll bar is for roll over protection, but it does much more.
2001 Camaro convertible OEM, with K-frame OEM braces that NEVER appeared on any 4th gen HT or T Top. For those insisting there is no difference between the convertible (above) and the T-Top/HT cars which all have no welded in extensions nor the 4 point tunnel brace, nor the L brace attaching the sub frames to the floor on both sides opposite the tunnel braces. On Left: The welded in at the factory extensions from the tunnel brace that stop most SFC's from fitting the convertible. On right. 98-2002 T-Top F body. Many differences like both sides of the very different tunnel braces, vert has an L shape welded brace on both sides, the T-top does not. So those SFC's (BMR - web site says WILLNOT FIT CONVERIBLE) The photos show why.
In post #36 "There is no structural (sheet metal stamping) differences between the '94-'97 MYs and the '98-'02 MYs. GM DID improve / increase the adhesives used for bonding some panels to the structure in '98, but that was part of the continuous process improvements, not in response to perceived complaints of the 'verts being "rattle traps"
That turns out not to be the case. There IS major structural (sheet metal stamping) differences between the 94-97 and the 98-02 convertibles and HT/T-Top cars.
Last edited by LSX Thunder; 08-25-2023 at 03:33 PM.
In post #36 "There is no structural (sheet metal stamping) differences between the '94-'97 MYs and the '98-'02 MYs. GM DID improve / increase the adhesives used for bonding some panels to the structure in '98, but that was part of the continuous process improvements, not in response to perceived complaints of the 'verts being "rattle traps"
That turns out not to be the case. There IS major structural (sheet metal stamping) differences between the 94-97 and the 98-02 convertibles and HT/T-Top cars.
Dude, I don't know why you keep insisting that I claimed that there were no differences in the structure between coupes and 'verts. Re-read my post, I made no such claim. My entire reply (and this entire thread) is in the context of convertibles (well, at least until you started posting). Then, maybe if you could provide consistent descriptions of the objects you are referring to in the photos and annotate those photos to highlight the specific object you are referring to, then maybe you can convince me that GM made structural changes to the F-body between the '97 and '98 model years that would impact the fit of SFCs. Even UMI's subframe descriptions do not differentiate between the early (LT1) and late (LS1) model years, they are ALL advertised to fit '93-'02 F-bodies.
The factory stock 'verts DID have a small stamped-steel plate that was supposed to reinforce the floor pan (that went under the driveshaft as you mention later) and held in place w/ 4 bolts. This was not present on T-Top or HT cars. But compared to a SFC, it was pretty worthless.
Again, completely wrong. That "small stamped steel plate" was on all 4th gen T-Top and HT cars. OEM
[QUOTE=JohnnyBs98WS6Rag;20515830 GM DID improve / increase the adhesives used for bonding some panels to the structure in '98, but that was part of the continuous process improvements, not in response to perceived complaints of the 'verts being "rattle traps".
I do find it interesting that most of the SFC suppliers don't have a 3-point version for the 'verts. Glad I purchased my Kenny Brown 3-point SFCs for my 'vert when it was available. Despite all of GM's claims that the 4th gen 'verts are much improved over the 3rd gen "afterthought" 'verts (which they are), they still exhibit a lot of cowl shake over bumps. Adding even a 2-point SFC helps this a lot, but not as much as a true 3-point SFC.[/QUOTE]
The "rattle trap" descriptions started appearing in magazine road tests in 1967. Hundreds of them by the start of the 4th generation. As you wrote, by then GM sales brochures claimed a stronger chassis for them. GM redesigned the whole 4th gen line up differently for convertibles and T-Tops/HT's because the F body had been disparaged from 1967 on as flimsy and prone to squeaks, rattles and flex.
You wrote: "I do find it interesting that most of the SFC suppliers don't have a 3-point version for the 'verts."
That's because they can't seem to get around all the added steel welded in at the factory. Just look at the 3-point from UMI, the massive tube running under the doors. [img]blob:https://mail.proton.me/7a81c50f-c4a0-472d-8f3c-188902f70555[/img]
It sits MUCH lower than all the other makers SFC's to clear all the factory added steel. The L-shaped brace right beside the tunnel brace and the extensions block everyone else's SFC on convertibles. Unlike the bragging by the others that their SFC tucks up, the UMI is clearly visible by anyone at least 5 feet away. It does not hang low enough to reduce ground clearance as the exhaust sets that height. Your KB's have tiny one-inch square tubing. Sitting next to the two-inch square tubing of others' 2-point SFC's (like SLP's) it was obvious which one did more (not the KB).
" they still exhibit a lot of cowl shake over bumps"
Which is why GM included the K-frame braces (sadly only on the verts). Still a failure. The only way to delete all the rattles, etc. is to massively increase the structural rigidity of the whole car. My previous threads show how. UMI 3-point SFC Vastly superior to all others able to be welded to all its designated attachment points and to the pinch weld the whole length under the doors. Ideally you weld in a jacking rail under the doors to the pinch welds and then weld that to the SFC.
Last edited by LSX Thunder; 08-24-2023 at 11:15 AM.
Of course, they are harder to sell. The 4th gen verts were a victim of the 1st-3rd gen convertibles fact-based prejudice, "Rattle trap, as structurally sound as overcooked pasta" convictions, based on reality. It is the reason almost all the sub frame manufacturers have the same warning for their 3-point products "NOT nor convertibles". Those products will not fit the verts, which is strange when popular culture firmly believed the verts were structurally inferior to the T-Tops and Hardtops. Most buyers had no clue that the convertibles were so structurally better than all the other 4th gen models, Camaro or Firebird. Clueless. A GM education fail.
Wrong today for the used car F body buyer to prefer anything 4th gen to the convertible.
The opposite is true, the verts are structurally superior to the other 4th gens, which is why most 3-point SFC's won't fit. I'll dig up some photos of my 01 vert and 98 hardtop (which it is not. tear off the plastic hardtop panel and find the entire T-top structure. flimsy as it is) prior to making them full frame cars. You'll see they don't match. GM actually did add structural reinforcements to the vert which is why those 3-point SFC's won't fit (except the few specifically made for verts). You can see the difference between 4th gen cars at a glance.
The original question was why are 4th gen convertibles harder to sell than T-top/HT cars?
The original question was why are 4th gen convertibles harder to sell than T-top/HT cars?
That question is pretty easy to answer.
Convertibles in general have a bad reputation for their tops leaking and being a headache. Tops are practically a consumable item and to make matters worse, cars not explicitly designed to be convertibles from day one on the drawing board tend to handle worse than their conventionally roofed counterparts. Say what you will about a T-top car being flexible, the bar does do more than you think it does. It doesn't resist twisting, but does help with the car trying to fold itself in half at the mid-section. You can see an example of that in this
at the 3:30 mark. Convertible cars have a reputation for being too flexible and more flexible than any car with a traditional roof when you start making real power. The fourth generation convertible having bracing underneath making it better than a third gen combined with a lack of rattling doesn't really mean its sturdier than traditional T-top and hard top cars.
As I've said there are things that rattle in a T-top or hard top car a convertible doesn't have. Then there is the fact you get a lot more wind and road noise to your ears in a convertible which probably masks some of the cars actual noises. Many people, including myself believe convertible cars are less appealing aesthetically. I don't like the way they look and I'm not alone in thinking that. Then there are those of us who live in areas where AC is a must and having the top down really isn't fun. I've had a convertible before (not an F-body) and the novelty wore off fast. We don't have much of a spring or fall in Texas and what few days pass for either are the only days having the top down isn't torture. Hell I have only ever had T-top cars and I only take the tops out a few days a year. I prefer to have the windows up and the AC blowing. I just like the aesthetics of T-tops and having the glass ceiling. I take the tops out in the garage to work on the car more than I would to drive it.
While not everyone would agree with what I've said, I think a lot of what I've said is the general perception of convertibles even among car enthusiasts. Lets not forget, a lot of people buy these cars to make race cars out of them because they are cheap and have LS engines. Convertibles aren't ideal for this application.
Convertibles in general have a bad reputation for their tops leaking and being a headache. Tops are practically a consumable item and to make matters worse, cars not explicitly designed to be convertibles from day one on the drawing board tend to handle worse than their conventionally roofed counterparts. Say what you will about a T-top car being flexible, the bar does do more than you think it does. It doesn't resist twisting, but does help with the car trying to fold itself in half at the mid-section. You can see an example of that in this video at the 3:30 mark. Convertible cars have a reputation for being too flexible and more flexible than any car with a traditional roof when you start making real power. The fourth generation convertible having bracing underneath making it better than a third gen combined with a lack of rattling doesn't really mean its sturdier than traditional T-top and hard top cars. Having relocated the battery to the rear helps a lot.
While not everyone would agree with what I've said, I think a lot of what I've said is the general perception of convertibles even among car enthusiasts. Lets not forget, a lot of people buy these cars to make race cars out of them because they are cheap and have LS engines. Convertibles aren't ideal for this application.
"at the 3:30 mark" and "Convertible cars have a reputation for being too flexible and more flexible than any car with a traditional roof when you start making real power. The fourth-generation convertible having bracing underneath making it better than a third gen combined with a lack of rattling doesn't really mean its sturdier than traditional T-top and hard top cars."
In fact, the convertible is more rigid OEM than any 4th gen T-Top/HT. When new, OEM. Having deliberately bent a 98 HT just like in the 3:30 mark and did likewise with my 2001 convertible SS, the vert is much more resistant to bending OEM. I've posted photos of both. You wrote of making race cars "Convertibles aren't ideal for this application." You are dead right for 99% of cars and dead wrong about ONLY the 4th gen F body because for once GM was determined to overturn the rattle trap reputation.
My radically full framed 98 HT is not as rigid as my 01 vert SS with similar modification, because the vert started stiffer. The vert started stronger and finished stronger. The photos show my fabricated full frame for the 98 HT and the UMI welded in SFC used on the 01 vert. I too believed the myth about ALL convertibles and so went even more radical with mine. Unnecessary as it turns out. Both cars got a jacking rail carefully bent to follow the contours of the pinch weld, welded in, and then welded to the UMI SFC. Yes, I have created two of the heaviest F bodies in captivity. No matter, the right suspension components for both cars have also produced two of the best handling F bodies. "Luxurious ride" too and great brakes. Only making the suspension stiffer ruins the ride, not from stiffening the chassis. Rolls Royce proved that 80 years ago.
"at the 3:30 mark" and "Convertible cars have a reputation for being too flexible and more flexible than any car with a traditional roof when you start making real power. The fourth-generation convertible having bracing underneath making it better than a third gen combined with a lack of rattling doesn't really mean its sturdier than traditional T-top and hard top cars."
In fact, the convertible is more rigid OEM than any 4th gen T-Top/HT. When new, OEM. Having deliberately bent a 98 HT just like in the 3:30 mark and did likewise with my 2001 convertible SS, the vert is much more resistant to bending OEM. I've posted photos of both. You wrote of making race cars "Convertibles aren't ideal for this application." You are dead right for 99% of cars and dead wrong about ONLY the 4th gen F body because for once GM was determined to overturn the rattle trap reputation.
My radically full framed 98 HT is not as rigid as my 01 vert SS with similar modification, because the vert started stiffer. The vert started stronger and finished stronger. The photos show my fabricated full frame for the 98 HT and the UMI welded in SFC used on the 01 vert. I too believed the myth about ALL convertibles and so went even more radical with mine. Unnecessary as it turns out. Both cars got a jacking rail carefully bent to follow the contours of the pinch weld, welded in, and then welded to the UMI SFC. Yes, I have created two of the heaviest F bodies in captivity. No matter, the right suspension components for both cars have also produced two of the best handling F bodies. "Luxurious ride" too and great brakes. Only making the suspension stiffer ruins the ride, not from stiffening the chassis. Rolls Royce proved that 80 years ago.
Yeah, I don't believe that the 4th gen convertibles are stiffer than the hard top or T-top cars. I'm not going back over the whole thread because I don't care enough to do that. What I said applies to most cars and like it or not, that's the general perception of convertibles among car enthusiasts. Those reasons, whether they all apply to the F-body or not isn't even the point. The perception that these generally universal issues hold true are why they are harder to sell than hard top and T-top cars.
[QUOTE=Spamfritter;20516224]Yeah, I don't believe that the 4th gen convertibles are stiffer than the hard top or T-top cars/QUOTE]
Do you believe Sam Strano, especially when he tells you something independent of selling something. When he can be totally objective? When he cannot benefit in any way from his answer?
Ask Sam, he'll tell you the truth and the facts that make it so.
Yeah, I don't believe that the 4th gen convertibles are stiffer than the hard top or T-top cars/QUOTE]
Do you believe Sam Strano, especially when he tells you something independent of selling something. When he can be totally objective? When he cannot benefit in any way from his answer?
Ask Sam, he'll tell you the truth and the facts that make it so.
I'd be inclined to believe Sam Strano. If he said the convertible is more rigid than the hard top then it probably is. You are still missing the point. It does not matter. The perception that convertibles are worse than hard tops (in a variety of ways) is what matters and it answers the question I was responding to. As I said before there are lots of reasons why people don't like convertibles and even if they don't all apply to the 4th generation F-body, much of what I said is generally accurate for most cars.
The drawbacks of convertibles, both real and perceived limit the appeal of them to the average car buyer. It is that simple.
Yeah, I don't believe that the 4th gen convertibles are stiffer than the hard top or T-top cars. I'm not going back over the whole thread because I don't care enough to do that. What I said applies to most cars and like it or not, that's the general perception of convertibles among car enthusiasts. Those reasons, whether they all apply to the F-body or not isn't even the point. The perception that these generally universal issues hold true are why they are harder to sell than hard top and T-top cars.
You are forgetting the most important part. You have to want one. Not many people do. The care/upkeep is not easy, especially with no garage, and folks in northern states only get to enjoy the 'topless' experience a few months per year. Not worth buying. How many owners get to cruise topless each weekend in peaceful scenic areas. Not many. Convertibles are for owners that enjoy them immensely with many trips and 1 day adventures involved. My wife and I are those people. Our Trans Am 'vert has been our favorite convertible and we feel it is well made. 82,000 miles at the moment. All our other convertibles are long gone except the '14 GT. We really like Mustang 'verts as well.
Our past rides:
2002 Z3 with 3.0 225 HP 1995 Porsche 911 at Fontana Dam in western NC 2007 GT/CS on Blue Ridge Pkwy 2009 C6 with LS3 on Tail of the Dragon Current 2014 GT with 420 HP 5.0 Coyote Our all time favorite!!!
You are forgetting the most important part. You have to want one. Not many people do. The care/upkeep is not easy, especially with no garage, and folks in northern states only get to enjoy the 'topless' experience a few months per year. Not worth buying. How many owners get to cruise topless each weekend in peaceful scenic areas. Not many. Convertibles are for owners that enjoy them immensely with many trips and 1 day adventures involved. My wife and I are those people. Our Trans Am 'vert has been our favorite convertible and we feel it is well made. 82,000 miles at the moment. All our other convertibles are long gone except the '14 GT. We really like Mustang 'verts as well.
Our past rides:
2002 Z3 with 3.0 225 HP 1995 Porsche 911 at Fontana Dam in western NC 2007 GT/CS on Blue Ridge Pkwy 2009 C6 with LS3 on Tail of the Dragon Current 2014 GT with 420 HP 5.0 Coyote Our all time favorite!!!
"Our Trans Am 'vert has been our favorite convertible and we feel it is well made."
Better made than the popular consensus asserts. Enjoy the fact and ignore the wrong opinions. Stronger, a more rigid chassis, OEM than the other 4th gen F body cars. UMI photo, mine is a 2001 SS in Pewter. That SFC is the undisputed champ for a start toward a full frame car.
Does anyone even know that 4th gen convertibles exist??
What an appropriate title. This thread seems to show that while a few folks do know they exist, very few know how different they were from T-Top/HT 4th gen cars. In addition to all discussed here, the L shaped connector on both sides of the tunnel brace is folded over itself for added strength. There are even gussets welded in higher up. A mostly underappreciated final product. Of course, creating/fabricating a full frame all welded together turns the car into something extraordinary. By all means somebody should let Strano wax poetic about the now almost forgotten 4th gen F body convertibles.
08-22-2023, 10:30 AM
