Targa stiffness compared to coupe?

[Gideon911]

I'm curious what a longhood targa drives like compared to a coupe. If you own both or have driven both a lot, can you give your opinion? Clearly the coupe is stiffer, but I'm curious how a targa feels/handles in a canyon compared to a coupe.

[pampadori]

I don't have a longhood but i have driven both coupes and my targa back to back.

The targa is much less flimsy feeling when you have that top mounted. Take it off and you will immediately notice the cowl shimmy and move. Does it matter much? not really. it still pulls terrific cornering g's and steers much faster than most other 40 yr old cars.
With the top on, the difference is much less. Louder, yes. but you won't notice it feeling flimsy until you put the car on jack stands and the door gap at the b pillar grows wider. it doesn't do that with a coupe.
Again, a little flex isn't going to make the car must slower in the canyons. not until slicks are mounted and hundredths of a second matter does it become an issue that i'd worry about.

But now i'm reading your signature and I'm curious why you don't already have an informed opinion since you list both a 72 coupe and a 73 targa.

[GH85Carrera]

Like the 914, all Targas are a flexy flyer. A coup is certainly stiffer.

[cliyde]

Very noticeable difference without some Targa chassis stiffening, braces, etc. I liken it to sitting in the ocean on a surfboard vs an inflatable raft. You'll feel the difference when the waves go underneath you (like the road). The chassis flex is noticeable in that way. The Targa feels like it complies with variations in the road (waves), but at the expense of handling IMO.

Cheers.

[HarryD]

Must disagree. Unless you are someone like Walter Rohl, Jörg Bergmeister or Patrick Long, I doubt you would really notice much, if any difference in the real world.

I know when I jack up my 1973 at the factory jack points, the entire side goes up and I can still open/close the doors. If I put a jack stand on the rear high enough, the front will be off the ground as well.

Bottom line, find other things to worry about.

[cliyde]

The OP asked in this context.

Originally Posted by Gideon911

.... I'm curious how a targa feels/handles in a canyon compared to a coupe.

I guess all those DE and club racers guys have it wrong and should be running Targas instead!

[mepstein]

Originally Posted by HarryD

Must disagree. Unless you are someone like Walter Rohl, Jörg Bergmeister or Patrick Long, I doubt you would really notice much, if any difference in the real world.

I know when I jack up my 1973 at the factory jack points, the entire side goes up and I can still open/close the doors. If I put a jack stand on the rear high enough, the front will be off the ground as well.

Bottom line, find other things to worry about.

That's like saying rolling down the windows and opening the sunroof on a coupe is the same experience as a targa/cab. It might not have a big quantifiable differences but the feel is different, at least to some people.

It a similar question I've though while riding my bike. Does going slightly slower diminish my enjoyment. If I put on more aerodynamic wheels, I will go faster. Will that increase my riding enjoyment. Is faster better or does it just decrease the time I spend enjoying the ride.

[pampadori]

There are tradeoffs for sure. I'm just in the camp that maybe does 1 or 2 auto x every few years and probably wouldn't notice that I was 1 tenth faster around the track in a coupe.

[Superman]

Convertibles are usually heavier than coupes due to the additional chassis stiffening added to the floor and lower corners. Usually, the additional stiffening weighs more than the roof which was deleted. I do not know anything about whatever additional stiffening Porsche placed into Targa chassis'. It does not surprise me to hear reports of Targas having structural integrity. Porsche seriously knew how to build cars. That said, I don't think it takes a Hans Stuck to notice the difference between a Targa and a Coupe. Finally, I have heard some report a preference for Targas on the track. It seems counterintuitive, but I have heard this preference.

[Noah930]

I can't really tell the difference, targa vs coupe. But I also have an '87 coupe vs a '90 targa. And one car is a turbo and the other NA. So not exactly apples to apples.

I can hear the difference. The targa flexes and rattles around me a lot more. But the times I've been really hustling the targa in the canyons, I was more focused on my driving than little rattles and squeaks.

I can feel a big difference in the handling between my G-body coupe and my 964 targa. But I think the soft stock coilover suspension in the 964 is what makes the car wallow in corners much more than the torsion bar 930, because even when driving sedately on a street or freeway, the 964 feels a lot floatier than the hunkered down G-body.

IMHO, a targa doesn't negatively detract from the 911 driving experience. If you're slower in the canyons than someone else, it's not because of the different body styles of the cars. The targa isn't a crappy driving experience. And living in SoCal, it's great to be able to take the top off and enjoy our climate al fresco.

[Walt Fricke]

These are the extra stiffeners Porsche put into its Targas, and later into its Cabriolets.

The longitudinals under the doors have one extra layer of sheet metal included in the sandwich. And the A pillar/windshield frame have one extra layer. And the tire well covers (wheel housings) on both the passenger and driver's side have an extra layer of sheet metal (which is why you need different or trimmed aftermarket floor boards if you add those as replacements).

Plus a look at a catalog shows a variety of stamped parts which are listed as for the Targa.

I believe the Cabs (which came later, with the 3.2 Carreras?) have similar reinforcement.

And the Targas, at least early ones like a '68, have welded in mounts below the dash, and a bolt-in bar (cross tube in the catalogs) running from side to side.

Still, these cars have lower torsional rigidity that the coupes. There is a long discussion on this list from a few years ago by a guy who wanted to stiffen his Targa, but not have more than, I think, a welded in roll bar. Lots of ingenious stuff.

[s5uewf]

From Car & Driver in March 1969:
https://www.caranddriver.com/reviews/comparison-test/a15142518/1969-porsche-912-vs-911t-targa-911e-911s-archived-comparison-test/

A different chassis, required by the Targa's roadster style, adds only slightly to the weight of the car and proved to eliminate some of the handling problems Mark Donohue didn't like in the coupe versions. "It has trailing throttle oversteer (like the coupe), but it was much more predictable. Going through the banking you could hear constant tire squeal which means it's committed and predictable and you can change it around and it stays neutral, whereas with the others it was either over-steer or understeer. It's more a Fexible Flyer . . . maybe I should cut all the tubes out of the roll cage on my Trans-Am car."

FTW for all Targa lovers everywhere!

[coldstart]

I have a targa longhood and have driven multiple longhood coupes.

At this age, condition of the vehicle is the most important factor when considering the abilities and feeling of the car driving twisty roads.

My 1972 targa is super solid-- the doors close with a super nice ding even on the lift. There is little to no body flex on the road or when being raised on the lift. It has the original front pan and has had no past rust issues.

That said, a coupe in similar condition would likely be much stiffer and weigh less. I have driven longhood coupes that seriously would outhandle my targa (they were basically racecars) and coupes that had more flex than my targa due to condition issues.

They are all great cars! I recommend buying the car in the best condition with the least rust that makes you happy.

[1QuickS]

My friend's 72 Targa (rust free and in good condition) irritated me when I drove it, it reminded me of my parent's 1968 Ford station wagon, shuddering over the road when bumps or cambered curves were encountered.

I am convinced that Targas are donor cars for coupes.

Later model Targas I assume are much better and are for built for cruising, so ignore the wiggles.

[HarryD]

Originally Posted by 1QuickS

My friend's 72 Targa (rust free and in good condition) irritated me when I drove it, it reminded me of my parent's 1968 Ford station wagon, shuddering over the road when bumps or cambered curves were encountered.

I am convinced that Targas are donor cars for coupes.

Later model Targas I assume are much better and are for built for cruising, so ignore the wiggles.

FWIW, my 1973 with 175000 miles, during my 20 yr (and still going) ownership, has been taken to HPDE's, autocrosses and spirited driving regularly. I have none of the issues you state. There was something seriously wrong with that car.

[pampadori]

am I the only one that notices a huge improvement when the targa top is installed versus when its off?

[cliyde]

Originally Posted by pampadori

am I the only one that notices a huge improvement when the targa top is installed versus when its off?

nope. matter of fact, to improve stiffness on my '84 WITH THE TARGA TOP ON I ended up making a removable longitudinal brace that would fit snug between the targa frame. Noticed way LESS body flex on suspension compression. Somewhere on Pelican there's a post of me or others making the same brace with a hockey stick I believe.


Cheers!

[1QuickS]

It is easy to demonstrate the torsional stiffness between coupe and Targas:

Get a toilet paper tube and twist it. Then, smash it flat and try twisting it. The amount of material is the same but the torsional stiffness is dramatically reduced. The flattened tube is what a Targa is like compared to a coupe so adding any structural connection across the opening will help chassis stiffness.

Basic torsional stiffness is a 4th power function of distance from axis of twist "neutral axis" to each element of the structure. If the structure is a coupe then there is a greater distance from the neutral axis to the shell of the body vs. a Targa that has very little distance in the vertical direction. Coupe & Targa have the same width so they are comparable in that area for contribution to torsional stiffness. If the tunnel has increased material thickness and the sills also have thicker material then the Targa will have more contribution to torsional stiffness contribution in those areas than a coupe.

Front to rear bending of the chassis is similar in stiffness comparisons. Try bending the toilet paper tube before and after smashing it flat.

Since the Targa has no load path across the open top to transfer load other than the pan of the chassis it follows that torsional and bending flexure (stiffness) pale in comparison to that of a coupe.

[FA-18C]

Quick, great description. As others have said, not sure the majority will notice a significant difference unless you are flogging the car on a track or canyon. Mild differences in performance between my 70E no sunroof car vs. 72S Targa with dual webers. Feel was consistent for both at least for me. Not to offend anyone, but suspect that if I was blindfolded and had all noise cancelled I wouldn’t be able to tell.

[RSTarga]

I've had both and for the pure pleasure of driving, there is nothing like an open top car.
On the street nobody will ever notice the torsional difference.
I would say on the track the most notable downside would be the weight up top.
Only 911 guys like coupes better, XKE's Ferraris topless cars are favored.
I guess 356 Speedsters or Cabriolets are not popular among the coupe gang.
Since fewer Targas were produced maybe it's just jealousy