Bash plate

[Danielb 76]

So wanting thoughts from others I have a fairly standard challenger setup no lift etc but now wanting to upgrade body protection . Looking at boos plates 3pr 4 mm . What do most people go 3 or 4 mm mild steel or 4 mm stainless steel . Just wanting some options thanks

[Hatto]

3mm steel ones will bend with a decent hit. I've bent my intercooler guard off road before but have now welded in some gussets for strength. Wish I had 4mm ones now but boos only had the 3mm when I bought mine. If it's just for animal strikes and general road use with a bit of soft roading then 3mm would probably be ok. But really, the 4mm is not that much more expensive anyway. Also consider the extra 25% heavier the 4mm ones will be if vehicle weight is ever close to GVM when loaded for trips and or towing ect.

[Michaelj15]

Hey Daniel,

i have boos bash plate 3mm on my challenger. Overall i think they are good, way more solid than the stock splash guard.
I did however bend mine off road pretty bad, i believe the 4mm would have been bent too... I ended up reinforcing mine and reinforcing the brackets that attach to the chassis.

heres a link to a few of the pics

https://www2.pajeroclub.com.au/forum/showthread.php?p=563843#post563843

[old Jack]

I have bent all 3 of my 4mm Bushskinz and they are very difficult to straighten without a press. They have saved my gearbox, transfer case, engine sump and intercooler/radiators on many occasions, I would not go off road without decent underbody protection.

OJ.

[Apollo]

I have the 4mm boos plates on mine. They have taken a few decent knocks and are holding up ok. I have heavy duty brackets welded onto my chassis replacing the WAP factory ones.

[whereswes]

Value for money, Boos are hard to beat. 4mm would be better but 3mm still way ahead of the factory tin foil. I didn't know they did 4mm.

Note, there's little chance of the OEM brackets surviving a decent hit even on 3mm plates. As per earlier posts, at a minimum, zip weld the OEM brackets all round. Preferred, dock off OEM brackets and weld in heavier.

If your getting the tranny plate, you do need to over size the front holes and fit up some nutserts. I traveled from the other side of Melbourne to collect and Michael was happy to fit them up for me.

Cheers
Wes

[Danielb 76]

Bash plates

Thanks for all the advice gentlemen . So I haven’t decided yet which ones but I am going to get them to fit them . I am thinking either the 4mm mild steel or stainless steel . Cost difference only $5 . Can anyone tell me would there be much a a weight difference or a huge difference in rigidity . Not in the near future am I going super hard off raiding but I’m keeping this car for awhile . So I’m thinking just buy right stuff now with long term view rather than take shortcuts .

[whereswes]

Can anyone tell me would there be much a a weight difference

Not much. From memory in 3mm it's about 1/2kg per M2.

Pretty sure if you check some ferrous and non ferrous plate suppliers they'll have weight specs listed on their sites.

Cheers
Wes

[old Jack]

The weight of different steel grades varies only about 5%, a full set of 4mm Bushskinz plates for an auto Challenger weighs about 36kg. All steels have different strengths which is dependent on the alloying elements used and both the tensile strength and yield strength varies greatly. Yield strength is the force at the material can be permanently deformed, 440C stainless and 4130 chromemoly are by far the strongest but the most expensive, not all stainless steels have high yield strength so you need to be careful what grade stainless is used. 304 stainless for example has a much lower yield strength than mild steel. What also gives a bash plate it’s strength is the design, a pressed 2mm plate can be stronger than a flat 3mm plate made from the same material.

In a perfect world if bash plates were made out of high tensile 2205 duplex stainless 2.5mm sheet this would be ideal but the cost would be at least double if not triple of what is currently available.

OJ.

[old Jack]

Example of steel,yield strengths;
2205 stainless steel 450 MPA.
316 stainless steel 290 MPA.
Mild steel 247MPA.
304 stainless steel 215MPA.

OJ.

[whereswes]

The weight of different steel grades varies only about 5%, a full set of 4mm Bushskinz plates for an auto Challenger weighs about 36kg. All steels have different strengths which is dependent on the alloying elements used and both the tensile strength and yield strength varies greatly. Yield strength is the force at the material can be permanently deformed, 440C stainless and 4130 chromemoly are by far the strongest but the most expensive, not all stainless steels have high yield strength so you need to be careful what grade stainless is used. 304 stainless for example has a much lower yield strength than mild steel. What also gives a bash plate it’s strength is the design, a pressed 2mm plate can be stronger than a flat 3mm plate made from the same material.

In a perfect world if bash plates were made out of high tensile 2205 duplex stainless 2.5mm sheet this would be ideal but the cost would be at least double if not triple of what is currently available.

OJ.

Spot on OJ.

My question is, coming from a non engineering background, the dangers of high tensile strength components. If the impact energy must be absorbed somewhere, if not in the bash plates, then where? Mountings? Elsewhere?

If I take an unrepairable hit in a bash plate, $100 replacement through Boos, I can live with that.

Even if just a 3mm bash plate fail resulted in significant sump or transmission damage then I recon I've been 1) pretty unlucky or 2) pretty dumb.

Cheers
Wes

[old Jack]

Spot on OJ.

My question is, coming from a non engineering background, the dangers of high tensile strength components. If the impact energy must be absorbed somewhere, if not in the bash plates, then where? Mountings? Elsewhere?

If I take an unrepairable hit in a bash plate, $100 replacement through Boos, I can live with that.

Even if just a 3mm bash plate fail resulted in significant sump or transmission damage then I recon I've been 1) pretty unlucky or 2) pretty dumb.

Cheers
Wes

Correct Wes, this is why I would choose 2205 stainless as it is more "flexible" and has very good impact absorbing qualities without permanent deformation. If the bash plate is too rigid then as the chassis flexes the rigid plate loads up the mounts which then crack. If the plate is too rigid then any impact forces are transmitted as shock loads to the mounting points.

OJ.