Strength & Front of Engine access

[924Srr27l]

Look how handy it could be if Porsche had of designed a removable front cross member ! (For belt / water Pump / alternator maintenance etc...)

I've removed the welded in front box section X member section and top bonnet catch metal panels for a relocation radiator modification
(Better Aero performance - Less drag)

And it's surprising how flimsy & thin gauge the metal is, obviously they were deemed strong enough in the 1970's design but I doubt this classic transaxle would pass a modern crash test, either way once the new position and angle have been sorted for the Radiator new structural Steel work will be made with more strength than the original.

R

 

[924Srr27l]

R

 

[Paul 290T]

I'm not so sure the 944 shell is bad as you think.

In a past part of my career i had access to late model Nissan Micra shells, also minus the engine and front cross member located at the radiator position. It was so flimsy that i could grab each engine support beam and twist the whoe bodyshell by hand, maybe 4 inches up and down on respectively on each engine support.

 

[924Srr27l]

I'm not so sure the 944 shell is bad as you think.
In a past part of my career i had access to late model Nissan Micra shells, also minus the engine and front cross member located at the radiator position. It was so flimsy that i could grab each engine support beam and twist the whoe bodyshell by hand, maybe 4 inches up and down on respectively on each engine support.

Yes Generally all the German stuff is well known for being well built and strong, your Jap, and French not being as regarded so !
Which is why I was a bit surprised how light the X member was, as I was expecting more of a thicker heavier girder...

The whole front end is fibreglass (wings / bonnet / badge panel / bumper) so this I see as the first thing that would disappear in many shards and hence
what's underneath this lightweight skin is pretty much all the armco or tyres will have to take an impact, however I will be making a substantial replacement
to brace the front ladder beams....

R

 

[924Srr27l]

With the nearside wing off (At the bodyshop) it looks even more flimsey !
R

 

[graham.webb]

Great photos! Don't forget, however, that from the '80s on manufacturers designed their structures for deformability to absorb crash energy. This is why a minor frontal is so expensive...the crumple zones do just that. I worked for a steel supplier then, and they did a lot of work on rivetted and glued box sections (for Jaguar I think). Fascinating at the time, but widely used now!

Interested to know about your revised radiator spec/location. Just had a burst rad on the S2...not cheap!

 

[924Srr27l]

Great photos! Don't forget, however, that from the '80s on manufacturers designed their structures for deformability to absorb crash energy. This is why a minor frontal is so expensive...the crumple zones do just that. I worked for a steel supplier then, and they did a lot of work on rivetted and glued box sections (for Jaguar I think). Fascinating at the time, but widely used now!
Interested to know about your revised radiator spec/location. Just had a burst rad on the S2...not cheap!

Yes true, Including F1 development who have specific load and shear strengths and structures designed to dissipate the energy in an impact....

Here's another photo I took before the grinder came out where the chassis / Rad cradle structure all makes it looks reasonably strong
The Radiator is being mounted low down and on a 45 degree angle, where a vertical tunnel (sealed) so the exiting airflow can evacuate smoothly out and over the bonnet. When you imagine where all the air goes to ? when it leaves the vertically mounted radiator it has to find it's way out through the cluttered engine bay
out the bottom and sides etc.. all drag that can be reduced in an Racing application with this intended modification.

R

 

[PSH]

Porsche Transaxle models are extremely strong for frontal and rear impact, there are reports of full frontal at well over 130mph with the driver walking away, unhurt. These cars weren't just built for speed, they were built to protect their driver in the event of a high-speed impact too.

Their crumple zones are very efficient

Pete

 

[924Srr27l]

It's difficult to compare (Unless you tested an old transaxle on a modern test) but generally any production car designed nearly 50 years ago will be a lot (less safe) to a car from the last 5 years.

Porsche used to do "Drop" tests, here with the 904 in the 1960's

R

 

[graham.webb]

That looks just like a stunt from Top Gear!! All it needs is a Morris Marina instead of the 904....

 

[vitesse]

What's wrong with Morris Marina's ,Graham-when I worked for Renold Chains ,in 1973,I had a Morris Marina 1800cc after my Hillman Avenger-with a certain amount of courage ,one could paddle it along quite briskly for that time-& it was a pain trying to keep to 50 mph on the M6 travelling from Midlands to Liverpool when the last fuel crisis happened.[]
Funny that it still had the same type internal door handles that my wife's 1973 blaze MGB GT had along with various Lotus's as well!

 

[PSH]

That looks just like a stunt from Top Gear!! All it needs is a Morris Marina instead of the 904....

Nah....if that was TG they would have a caravan underneath....

Pete

 

[924Srr27l]

Porsche Transaxle models are extremely strong for frontal and rear impact, there are reports of full frontal at well over 130mph with the driver walking away, unhurt. These cars weren't just built for speed, they were built to protect their driver in the event of a high-speed impact too.
Their crumple zones are very efficient
Pete

130mph walkaway frontal crash!... That sounds like PUB talk!
The tests Porsche would of done as in the pictures you posted would of been 70% less than this!

I didn't think or wouldn't consider that the (Project EA425) 924 was built for Speed, it was after all a budget coupe which in the USA form only had 95bhp!
And the management at VW decided NOT to make it but produce the Scirocco instead as their sports model.

Don't forget as (some prefer to) that your car and even more so 968 owners that all your car's are 924's with 300kg+ more weight added with heavier engines and components / suspension / brakes, and wider wings etc...they are all the same Steel chassis / body frame doors hatch etc...

I don't suspect it's a weak car that would crumple with a small shunt, but production and safety has come a long way over the last 5 decades so it's best and fair that it's only compared to other car's from the 70's like Morris Minor's!

R

 

[944Turbo]

130mph walkaway frontal crash!... That sounds like PUB talk!
The tests Porsche would of done as in the pictures you posted would of been 70% less than this!

I didn't think or wouldn't consider that the (Project EA425) 924 was built for Speed, it was after all a budget coupe which in the USA form only had 95bhp!
And the management at VW decided NOT to make it but produce the Scirocco instead as their sports model.

Don't forget as (some prefer to) that your car and even more so 968 owners that all your car's are 924's with 300kg+ more weight added with heavier engines and components / suspension / brakes, and wider wings etc...they are all the same Steel chassis / body frame doors hatch etc...

I don't suspect it's a weak car that would crumple with a small shunt, but production and safety has come a long way over the last 5 decades so it's best and fair that it's only compared to other car's from the 70's like Morris Minor's!

R

Except a marina would have been designed in the 60s probably. I had a fairly major head on in a 1976 TR7 with a Dodge charger, resulting in me ending up a 100 or so meters away upside down, the US crash rules it was designed around in the late 60s meant some innovations like the hooks for splitting the bonnet. the engine came out and everything bent but the central core and me were remarkably intact.
I am pretty sure the fillets introduced with the Turbo S on the inner wings are more to do with crash behaviour rather than any other improvement. There have been some fairly big crashes in the time I have been around the 944 community a few ending inverted but no really serious injuries thankfully. No doubt as with performance things have moved on - stategic use of high strength steel, crumple zones, explosives (airbags), pre-tensioners (though the handbook suggests you pull out the slack in the belts), ABS advances, EBD, ESM etc.
Weight distribution, visibility, Good brakes and handling helps to avoid the crash in the first place though
Tony

 

[vitesse]

The Morris Minor was a 40's design using rubbish Post war steel & no comparison with a Porsche 924.

 

[graham.webb]

Oh, Colin! You're right...50s/60s metallurgy was a curse when we were all running bangers. BTW the Marina was based on Morris Minor platform (torsion bar suspension etc). I worked for a company that had 1.3s and 1.8s and the 1.3 was a better drive....just a bit lighter, and the A series with its long stroke was usefully torquey. All of it, of course BL's answer to the Cortina but 10 years too late!!

Back on topic, I've wondered whether with fatigue in the welded structure a strut brace might be a good idea? Tricky to fit to a 16v car as limited clearance under the bonnet??

 

[scam75]

I have a strut brace in my turbo and it can only help in the event of a collision one would assume.

 

[blade7]

I have a strut brace in my turbo and it can only help in the event of a collision one would assume.

Unless it's a beefy brace that's welded in, I can't see it making much difference.

 

[scam75]

Well it is neither! It cant make the structure weaker though and adds strength between the turrets as well as sharpening up the handling. Bit off topic now.....[]

 

[924Srr27l]

Well it is neither! It cant make the structure weaker though and adds strength between the turrets as well as sharpening up the handling. Bit off topic now.....[]

Not at all, it's right on topic "Strength and front of engine access"

A steel bar connecting the turrets alone will and does for sure add rigidity, if you look at the picture again you can see without the front badge panel and X member just how open the two main box sections look. Yes they will deform and crumple in a front impact but any lateral structure will also add strength.

I used to have an aluminium for show strut brace which I knew would do nothing for Racing so a Steel brace was made to fit and connect the top mounted Spherical top mounts and this made a big difference to the handling.

Any extra stiffness in the body & chassis makes the suspension work better as it's not being distorted with the chassis flexing just like how an Anti Roll bar works, it's resists an amount of twist : fitting a smaller diameter bar allows more movement and a thicker bar vice versa..


R