Ultra Racing-the right way?

[EviLNeeDs]

I've got the lower brace from Ultra Racing and some people have fitted them with the subframe bar intact(sorry I dont know the right terminology) and
vice versa.

Which is the right way? below are images I sourced from other forums.






Subframe bar fitted.







Subframe bar removed.







Lower brace from Sifo JP fitted without the subframe bar.

 

[KIKE_CRS]

I fit it with the original subframe bar, same as the first picture

 

[ryan197]

the first photo is a photoshop, but i would say with the lower brace fitted using the same fixing as the subframe bar, the subframe bar is pretty much useless and is dead weight, as all the strength is now in the lower brace.

 

[EviLNeeDs]

I feel there's more contact without the subframe bar.

 

[fmp]

Mine wouldn't fit with the original sibframe bar in place, so I had to remove it.

Make sure you get some washers big enough to cover the holes in the UR racing brace. Mine didn't clamp properly and you could hear the subframe knock under hard use.

I put the original one back on until I get round to sorting it out.

 

[Foxspeed]

thinking about it logically it should be removed as the better/stronger UR brace goes in its place

 

[EviLNeeDs]

Will get it fitted hopefully by tommorow.

 

[930Tech]

Mines fitted without removing any renault parts, fitted no problem.

Whats the extra brace in the second pic?

 

[EviLNeeDs]

It's not an extra brace, that's how it looks when you replace the oem bar with an ultra racing bar.

 

[BenW]

You're adding the brace to improve the stiffness, so you'll see more benefit if you leave the standard part in place too (extra stiffening!)

 

[chettle]

You're adding the brace to improve the stiffness, so you'll see more benefit if you leave the standard part in place too (extra stiffening!)

not so much. If its under the stiffer larger brace, its just dead weight as the stronger brace wont flex enough to cause tension on the original?

 

[deadmau5]

not so much. If its under the stiffer larger brace, its just dead weight as the stronger brace wont flex enough to cause tension on the original?

That would make sense to me.

 

[BenW]

I disagree, the more material the stiffer it will be. Could prove this with maths but can't be bothered to dig the text books out!

Just imagine a pulling on a thin piece of steel and then a fat piece of steel. Obviously the fat piece of steel will stretch less than the thin piece - why? Because there is more cross-sectional area. So, add the thin piece of steel and the fat piece of steel together - you're increasing the cross-sectional area which will mean the parts stretch even less. Apply that principal to the braces.

 

[chettle]

That would be all good and true if the second material being used was identical too the first (in all properties but size)

Add a second bar of toffee, and it doesnt increase strength at all....

That said, wouldnt be the first time i was wrong!!

Appologies i cant be of any use on the fitting, but be nice to hear if it makes much of a difference, what other bracing do you have?

 

[henderson]

That would be all good and true if the second material being used was identical too the first (in all properties but size)

Add a second bar of toffee, and it doesnt increase strength at all....

That said, wouldnt be the first time i was wrong!!

Appologies i cant be of any use on the fitting, but be nice to hear if it makes much of a difference, what other bracing do you have?

as said,both bits of steel would need to be of an identical size for this theory to work,if not all the forces will just be applied to the larger section

 

[EviLNeeDs]

Everyone's points are very interesting, the Clio is still in the garage for almost a month now because of a broken gear shaft till then I'll have to wait till its done.
I've got all of the ultra racing bars and new h&r springs waiting to be fitted.

 

[BenW]

That would be all good and true if the second material being used was identical too the first (in all properties but size)

Add a second bar of toffee, and it doesnt increase strength at all....

That said, wouldnt be the first time i was wrong!!

Appologies i cant be of any use on the fitting, but be nice to hear if it makes much of a difference, what other bracing do you have?

as said,both bits of steel would need to be of an identical size for this theory to work,if not all the forces will just be applied to the larger section

It's not true, add more of any material, no matter what it is and you increase the stiffness. Clearly using toffee wouldn't be a great choice but it would increase stiffness even if it's pretty much negligable.

Here's the proof:

The material property you need to look at is youngs modulus (a measure of how stiff a material is - denoted 'E').

The force exerted on a material when it is stretched/compressed is calculated by:

Force = Youngs Modulus * cross-sectional area * change in length/initial length

So, even if you're using toffee which has a youngs modulus 1000 times less than steel it will still require some force to stretch.

So no matter what material you have between the chassis mount points it will require some force to stretch (or compress), these forces can pretty much be added together if you have more than 1 component.

I say all this after studying mechanical engineering for 4 years and working as an automotive design engineer!

 

[chettle]

I stand corrected ;/

 

[930Tech]

It's not an extra brace, that's how it looks when you replace the oem bar with an ultra racing bar.

I know that, i have the same ultra brace on mine.

On the second pic there is an extra strip of flat bar/brace across the front of the subframe, mine does not have this.

More towards the front of the car.

 

[EviLNeeDs]

Update

Decided to fit the lower bar without the original bar, But my front strut brace wont fit because of the newer style top mount so fail on my side






Yes its dirty I know,the rain in this desert country makes everything S***
I assumed it would fit as I checked with Ultra Racing in Malaysia and I told them its for a Clio 200. What now?