RPM Strut Brace Fitment (or not)

[Motorhole]

Easy enough to resolve this.

Get some 30 x 1.5 mm aluminium bar. Try and bend it.
Get some 30 x 1.5 mm steel bar. Try and bend it.

Which is easier? Aluminium of course. Aluminium is less rigid than steel, like for like. As prescribed by the relative Young's moduli of the two materials.

Now get some 30 mm wide aluminium bar, say 500 mm long, weighing say 500 g. And then get some 30 mm wide steel bar, say 500 mm long, also weighing 500 g. Try to bend them both now - what happens?

Now I don't actually know whether aluminium is stiffer per unit mass in a situation like this - maybe it is - but my point is, the difference is much less apparent. Because of course, the aluminium bar is much thicker.

Bottom line is - in like for like components, steel will ALWAYS be stiffer. Aluminium components can be made of equivalent - or close to - stiffness and they may be lighter but they will either have to contain more material (greater wall thickness, bulkier or otherwise) OR will compromise rigidity.

[macas]

Put in an aliuminium lintel in on your new kitchen extension and see if the building inspector passes it....

[ajay]

All acro's on major commercial construction sites are aluminium as opposed to doing your extension at home and hiring something from Hss in steel! If alloy is no good can someone explain!

[jimmyspeed]

motorhole has explained it well enough in his last paragraph - the correct design ensures the alloy acro's are fine and they wont rust as a bonus

[toby]

Sorry for taking this off topic...

Back on topic - looks like RPM are offering good customer care here - will be interesting to hear the outcome as to why this particular brace didn't fit.

[penton08]

the RPM brace makers must of been smoking something at the time

What a retarded thing to say, The braces have been designed with ALL engine applications in mind. I have fitted more than 10 of these to e30's with all sorts of engines and never come across a problem. Imo for the price they are a good bit of kit!

[rich318i]

So AC Schnitzer use steel ones then do they ???

Think they would have more of idea on how and the best metal too use for the car.

Don't you think???? What do they use again for the metal ????

[pacerpete]

So AC Schnitzer use steel ones then do they ???

Think they would have more of idea on how and the best metal too use for the car.

Don't you think???? What do they use again for the metal ????

Sorry Rich, you are digging yourself a hole here ! AC Schnitzer are known purveyors of upmarket shiny tat . Weight saving will be second to shininess on the priority list.

Most people fit alloy strut braces for 'aesthetic' reasons , most people fit the steel Sparco and RPM braces because they work.

Most alloy braces have two platforms that bolt to the strut tower and a (shiny ) crossbar that is bolted at each end where it attaches to the strut tower platform. The bolted joint at each end means they are effectively 'hinged' which obviously completely defeats the whole point of fitting one ! But shininess matters !

[rich318i]

YODA has spoken... but the one i got its good cant knock it .

its all pros and cons

[gooner1]

All acro's on major commercial construction sites are aluminium as opposed to doing your extension at home and hiring something from Hss in steel! If alloy is no good can someone explain!

Ali scaffolding too, and I don't mean the movable tower version,
having said that, as RPM are in the process of trying to resolve the OP's problem, perhaps it may of been an idea to wait for the outcome before calling their product shit.

[ajay]

I can't comment on the RPM brace as iv'e had no experience of their product, but it would be interesting to get to the bottom of exactly what's wrong here: IE an issue with the car or the brace or a bit of both! Another thing that this thread has highlighted is exactly how good are Alloy strut braces ? Hartge/ sparco/ Mk motorsport for example all do one piece Alloy stut braces are they just cosmetic or is there any structural benefit to be gained from using one. EXAMPLE

Apologies for sliding off topic!

[ross_jsy]

Well given the lack of evidence of which one is best, just think they all look pretty similar ie the ali ones aren't a lot thicker etc. Knowing this and the fact steel is stiffer (unless you are one of the more special zoners) you can make an educated guess at which one will perform better.

At the end of the day no one on this forum is going to be able to tell the difference from the weight saving of an ali strut brace while driving so why compromise on a weaker material?