Front engine safer than rear?

[Wills2]

SkinnyP said:

Thanks for that

Even Cayennes seem to get ripped apart, either the brand attracts loonies or Porsche can't make safe monocoque chassis'.

Or it could be that trees tend to win against cars, whatever the car....

[XJ Flyer]

SkinnyP said:

A bit off tangent, but the small overlap crash test doesnt half do some damage. Goes to show that no matter how new the car is if its not designed to pass a specific safety test in mind then it will probably perform poorly.

https://www.youtube.com/watch?v=-bdydHzCO5s

In general in the case of a car v car collision it is better to have a car that behaves as much as possible like the solid barrier in that test.IE make the opposition do as much of the crumpling as possible required to cushion the impact.

In all other cases it's then just a balance and a compromise between wether enough energy can be removed by either or both crumpling before either or both start suffering severe damage to their A/B posts/bulkhead/floor/roof structures.As I said in most cases it would be safer in that regard to hit something,with something,that has closest to the impact resistance of a tank.Regardless of it arguably,possibly,having less crumple ability of its own as a result.

Unless that is it is another tank or any other non deformable structure.In which case the lack of crumple ability will transfer more energy to the occupants by not cushioning the impact.

In which case having more metal in front and the engine,preferably a bigger engine,acting as a barrier in front of the bulkhead is arguably an advantage not a disadvantage.Bearing in mind that in most cases the choice will be either the engine acts a combination of a shield and a battering ram or if it isn't there that just leaves an exposed bulkhead and A posts which can only act as a relatively weaker last line of defence.Which is what killed the Volvo in the video being that the test was deliberately set up to keep its engine out of the equation as much as possible.

[XJ Flyer]

Wills2 said:

trees tend to win against cars, whatever the car....

^ This.

[B'stard Child]

B'stard Child said:

JoeMk1 said:

Does the Elise have a reinforced windscreen frame? If not the strength is impressive to deflect a Laguna!

No idea but it's not the first time I've seen that.....

Bloody hell my hard driver picture library needs some organisation

[Captain Muppet]

Wills2 said:

kambites said:

paulrussell said:

I'd say a front engine car would be safer, as with a rear engine car you've got a fuel tank in front of you.

I'd have thought most rear engined (as in with the engine behind the passengers) cars have the fuel tank in the back? Mine certainly does.

A 911's fuel tank is in front of the firewall just behind the luggage compartment, so very much in the front same with the boxster and cayman.

Mk1 and mk2 MR2s have them between the seats, hence the huge "transmission tunnel".

XJ Flyer said:

Wills2 said:

trees tend to win against cars, whatever the car....

^ This.

So the safest car would be one made of trees.

>pops to the classifieds to buy a Morgan<

[Finlandia]

Admittedly not read the full thread, so apologies if this is already discussed. In modern cars, is a transverse front engine safer than a longitudinal front engine?

[skyrover]

Vehicle size, height and weight tend to play the biggest role in crash test performance.

All things being equal, the larger and heavier vehicle will survive better.

[untakenname]

Finlandia said:

Admittedly not read the full thread, so apologies if this is already discussed. In modern cars, is a transverse front engine safer than a longitudinal front engine?

Think one of the reasons Saab gave from going from longitudinal to transverse in the 900 was due to it being safer in that configuration (main reason being GM and platform sharing).

Before buying a car I always look for the crash tests on youtube and also on the wrecked exotics website to see how the cars fare in real life.

I was looking at a few used turbo cars this summer before settling on my rx8 and came across quite a few different ones where to gain more airflow to the FMIC the owner had cut into the or even removed the slambar! I stayed away from all as surely in a crash that's going to reduce the structural integrity massively? imo it should be an MOT fail.

[XJ Flyer]

Finlandia said:

Admittedly not read the full thread, so apologies if this is already discussed. In modern cars, is a transverse front engine safer than a longitudinal front engine?

On the basis that the engine acts as a shield to spread the loads and resist penetration of the bulkhead area arguably yes.At least in the case of offset collisions like the example in the Volvo test posted previously.IE in the case of an offset collision the impact resistance of a longitudinal layout will probably be similar to that of a rear engined car because there is no engine there to act as a barrier.

Having said that assuming that there's enough metal in the front/inner wing etc structure of a longitudinal layout it could possibly still defeat a transverse one even in that worst case offset situation.

[Finlandia]

XJ Flyer said:

Finlandia said:

Admittedly not read the full thread, so apologies if this is already discussed. In modern cars, is a transverse front engine safer than a longitudinal front engine?

On the basis that the engine acts as a shield to spread the loads and resist penetration of the bulkhead area arguably yes.At least in the case of offset collisions like the example in the Volvo test posted previously.IE in the case of an offset collision the impact resistance of a longitudinal layout will probably be similar to that of a rear engined car because there is no engine there to act as a barrier.

Having said that assuming that there's enough metal in the front/inner wing etc structure of a longitudinal layout it could possibly still defeat a transverse one even in that worst case offset situation.

I would have thought that in an offset collision the transverse engine would help the rigidity of the structure in a way that a longitudinal engine cannot. In the case of a full on collision the shorter (front to back) transverse engine would be easier to steer under the car than a longitudinal engine, to prevent from pushing into the passenger area.

[paranoid airbag]

B'stard Child said:

Bloody hell my hard driver picture library needs some organisation

Ahem. More than we need to know mate.

[B'stard Child]

paranoid airbag said:

B'stard Child said:

Bloody hell my hard driver picture library needs some organisation

Ahem. More than we need to know mate.

Only pictures of cars on my hard drive - that's the only P0rn that I am interested in - Mrs BC is known frequently to ask why I don't look at stuff other normal men look at.......

[XJ Flyer]

Finlandia said:

XJ Flyer said:

Finlandia said:

Admittedly not read the full thread, so apologies if this is already discussed. In modern cars, is a transverse front engine safer than a longitudinal front engine?

On the basis that the engine acts as a shield to spread the loads and resist penetration of the bulkhead area arguably yes.At least in the case of offset collisions like the example in the Volvo test posted previously.IE in the case of an offset collision the impact resistance of a longitudinal layout will probably be similar to that of a rear engined car because there is no engine there to act as a barrier.

Having said that assuming that there's enough metal in the front/inner wing etc structure of a longitudinal layout it could possibly still defeat a transverse one even in that worst case offset situation.

I would have thought that in an offset collision the transverse engine would help the rigidity of the structure in a way that a longitudinal engine cannot. In the case of a full on collision the shorter (front to back) transverse engine would be easier to steer under the car than a longitudinal engine, to prevent from pushing into the passenger area.

In the real world it is doubtful wether an impact which is sufficient to push an engine through the bulkhead to any large degree would be survivable anyway.Realistically,at least in the case of a longitudinal layout,it will be mostly about using the bonnet length advantage and the engine/front structure to take out as much of the opposing car as possible, including defeating its transverse engine advantage,in a square on hit not an offset one.Having said that logically if you really want the engine to go underneath it would be the longitudinal idea which would do that best because of the need to find the right pivot point to tilt the engine in the right direction.However in the case of transverse engine layout at least it is probably better to keep the engine where it is to get the best advantage in it acting as a barrier and spreading the impact loads.

[Finlandia]

I suppose modern cars are so stiff and have such good crash protection that it doesn't really matter which way the engine is pointing.

[skyrover]

Finlandia said:

I suppose modern cars are so stiff and have such good crash protection that it doesn't really matter which way the engine is pointing.

to a degree... there is room for improvement as demonstrated in the small overlap crash test

https://www.youtube.com/watch?v=-bdydHzCO5s

[Finlandia]

skyrover said:

Finlandia said:

I suppose modern cars are so stiff and have such good crash protection that it doesn't really matter which way the engine is pointing.

to a degree... there is room for improvement as demonstrated in the small overlap crash test

https://www.youtube.com/watch?v=-bdydHzCO5s

True, there is always room for improvement. In the small overlap crashes, the overlap is so small that even a transverse engine misses the impact itself, so it doesn't matter which way the engine is facing, it's more a question of having enough tin at the front.

[Pan Pan]

I am reminded of the joke, about the last thing that goes through a flies mind when it hits your windscreen........Its A*se!

[XJ Flyer]

Finlandia said:

skyrover said:

Finlandia said:

I suppose modern cars are so stiff and have such good crash protection that it doesn't really matter which way the engine is pointing.

to a degree... there is room for improvement as demonstrated in the small overlap crash test

https://www.youtube.com/watch?v=-bdydHzCO5s

True, there is always room for improvement. In the small overlap crashes, the overlap is so small that even a transverse engine misses the impact itself, so it doesn't matter which way the engine is facing, it's more a question of having enough tin at the front.

Which is really just more confirmation of the fact that in most cases there is no real substitute for having a big metal lump of engine block adding to the impact resistance of the bulkhead area.Which is the most relevant issue for the topic.Although it is obvious that having as much metal as possible out front in addition can only help.But in general any frontal impact that doesn't allow the engine to play a part in impact resistance will be a lot more serious than one in which it can.While in the case of the rear engine layout that luxury obviously doesn't exist at all.

[james_gt3rs]

Captain Muppet said:

So the safest car would be one made of trees.

>pops to the classifieds to buy a Morgan<

[V8forweekends]

hoegaardenruls said:

As with a lot of things, I think Mercedes just did it first and the rest followed - the original A-class was a mid-90's design, when you average French hatchback would have been lucky to scrape two stars in an NCAP test. The height of the A-class just made it a bit easier to achieve.

I think (but can't find a link to substantiate) this idea was used by Rover in the Early 60s for the P6. Clearly the engine didn't start off under the floor like the A Class, but I'm sure the engine and box were designed to side out under the passenger compartment in an impact.