Torsional rigidity

It's bolted in at the top of the subframe, below the buttresses as well. About even with the top of the shocks.

 

You actually driven at speed a 355?
You actually know what you're talking about?

You saying Ferrari don't know how to secure an engine and suspension to a chassis...??
Jeez ....this crap never stops....that's what's shocking fella

 

???

+1

 

Yes have you seen how flimsy that is, it provides no rigidity what so ever to the engine cradle, just a length of inch by inch thin wall box section.

 

Yes I have thank you for asking.


have you ever even put a spanner to a 355 never mind dismantled one to its bare bones?

I have.

 

I would put five bucks on Ferrari knows how to secure a powerplant into a chassis

 

Certainly look like its up to the job of managing a v8 with a heavy 6 speed box strapped to it along with two suspension corners does it not when you can actually see it in the flesh, that along with the bottom row of bolts is the only thing holding it all in place out the back.

Twistier than a twisty thing, why do you think the buttresses crack on them.
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this is a separate issue.
the paint on the buttresses crack during the engine out when the body panels are left unsupported (without the frame support).
ferrari's fix was to spot weld the inside of the buttresses (under warranty)...and those that were repaired this way never paint cracked again.
mine was repaired this way by the dealer at the first engine out....and 2 decades later....no buttress paint cracks.

 

but not all 355's were repaired by the dealer when they were new....hence buttress paint cracking still exists.

 

Total tosh, the rear quarter panels are made of numerous separate sections welded together, they crack along the spot weld line where the buttress part meets the lower section.

The rear part of the body flexing causes the weld line to break away, the extra welding was applied to make that section more rigid thats all.

 

One I removed earlier. Any more armchair experts want to repeat what they have read on the internet? and just defend Ferrari, for the sake of defending Ferrari?
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you are correct that the 8 spot welds are applied to where the buttress parts meets the lower fender section.
My car has been tracked and been through 6 engine outs and does not have any subsequent buttress paint cracking.

I'm not in agreement with your theory but you are entitled to your opinion.

 

great pics though

 

Agree to disagree, I am fine with that

The rear cradle needs to be triangulated far better back into the rear cabin area, above the engine much like the F40 or even better the F40 LM

They have lasted 20 odd years without the back end falling out I grant you that, but for the sake of a bit of extra tubing it could have been much much better still.

 

Negative. Remove those bolts and put some hard miles on it. I think your definition of "provides no rigidity what so ever" will change.

 

Some other numbers further down that list which I found interesting:

Lamborghini Countach 2,600 (!)

McLaren F1 13,500

Lotus Esprit SE Turbo 5,850

Pagani Zonda Roadster 18,000

Porsche 911 Turbo (2000) 13,500

So the 355 at 10,000 is not too bad for the era I guess.

 

Its basically a ladder chassis, no matter how well its bolted above, simply follow the bolted part back a few inches forward as per my photos, the only thing all that is relying on for strength and rigidity is a bit of horizontal thin wall box section either side of the engine bay.

I am in my workshop today I will measure that section, if you think that's good engineering practice then good for you, I don't.

My current 355 project wont be relying on a piece of metal you could pick up in your local home depot to hold it all together that's for certain, but if Ferrari think its ok and that's good enough for you then all is fine and dandy.

This is the Ferrari that also designed the same car which regularly goes up in flames! but I am sure that is acceptable as well?

 

ive seen that countach number before and reckon that number is missing a zero or something. the figure is most likely a error or a typo that get tossed around on the internet. its a properly designed chassis triangulated in all areas. its been said the unstressed alloy body panels on the early cars are only 1.2mm thick! any significant deflection of the chassis would sure to show up on the panels

i know the esprit is a wet noodle. the track version X180R was caged and transformed the car dynamically. roger becker the lead engineer of lotus mention even the low powered S1 elise was 6x stronger. little chance the SE esprit is nearly twice the strength of the CT.

im not surprised with most of these figures. 355 coupe isnt bad until you chop the top off. the old rule of thumb is the rigidity cut in half. you dont need to be a season test driver to sense the difference between a TB vs GTS-Spider

we tend to forget these cars were designed 30-40 years ago. chassis loading forces have grown leaps and bounds since then not to mention cars are much larger and heavier with added content. the primary reason for rapidly increase chassis rigidity in modern cars even on mundane compacts is for passing safety crash tests. The many side benefits that comes along with the newer stronger chassis are more precise suspension control for better tuning and handling, better harmonics-NVH, less metal fatigue, and yes better RIDE QUALITY.

 

As a datapoint here is my experience. The 348 is such a flexi-flyer that an oem bolted in 348 challenge cage improved the felt stiffness of the car on the race track going from complete street 348ts to bolted caged 348ts. Then I welded a new well triangulated cage all the way to the front shock towers and wow! That difference was so great it took me a couple to trackdays to learn how to drive the car all over again. Had I kept that car semi tube framing would have been next which would have brought it to the next level. There is huge room for improvement but not if you want the charm of a late 1980's designed streetcar. Body flex makes suspension tuning unpredictable. That's important on the race track but not that relevant on the street because the speeds are so much lower and on the street we should be way way under the performance envelope of the car. Don't sweet it. Enjoy it.

 

So first it's only bolted below the engine, then "well it is but does absolutely nothing" to "the only thing all that is relying on for strength and rigidity is a bit of horizontal thin wall box section on either side of the engine bay".

Which one is it? Because your first statement is completely false, which is the point I made.

You may feel the materials could be stronger but that doesn't make a false statement true, it is in fact bolted to the car at the highest point possible on the rear subframe.

The entire rear subframe above the lower oval members is square and round tube. Certainly we can't cut all this out and throw it away.

Top of the subframe is square tube bolted to square tube. Could it be stronger? Of course. Doesn't mean it doesn't exist and does absolutely nothing.

Remove those 4 bolts and lift the car in the air by the jacking points. You think that interface will gap open or remain flush?

Leave those 4 bolts in and remove the 6 at the bulkhead and use the car as usual. What will happen? Probably major distortion of the bodywork as all of the load is transferred through the parts that do "absolutely nothing".

I'm not arguing it couldn't be stronger. Even the strongest chassis in the world can be improved upon.

Engine fires? Yeah that's completely acceptable to me and is entirely relevant to this discussion....??!?!?!

 

What I said was the uppermost bolting adds little to the torsional rigidity of the 355 because it is such a flimsy design therefore the whole engine cradle relies on the bolted section fore of the engine below the dry sump, so in essence making it a form of ladder chassis, if the upper bolted area was attached to a far better engineered triangulated structure then the torsional rigidity would be far far superior.

Just look at the vast triangulation of the engine frame around the gearbox, follow that up to the two bolting points, again a strong set up, then look to the crappy bit of metal it bolts to then follow that forward to a bare piece of box section just floating there on its own.

I cut off that particular bit of box section today from one of my 355s and took a photo, I have seen kids toys made of sturdier metal, that is all in essence that supports the upper part of the engine cradle at its weakest point into the body.
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It doesnt have a roof damn skippy its not solid.

 

Please stop adding cold, hard, first hand accounts into the mix it will upset the fan boys who think everything that leaves Maranello is engineering of the highest order.

 

There are many reasons to own a Ferrari but apparently few or none that you appreciate. If you are so dissatisfied with the car, why do you have one? Why not just get rid of it and move on to something you like better?