Is it worth upgrading the front strut brace? Will it provide any noticeable improvement over the OEM?

[plas87]

The Ultra Racing front strut brace is circa £120. Is it a worthwhile upgrade over the OEM strut brace?

[Bigblueknight3k]

I have done it but not tested yet but i think it better as one piece and all round the strut top

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[Bigblueknight3k]

As in picture

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[plas87]

I have done it but not tested yet but i think it better as one piece and all round the strut top

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Let me know what you think once you have given it a drive with the new setup!

[Rotary Potato]

What do you mean by 'upgrade'?

It'll be a visual upgrade (look prettier).

It will make absolutely zero noticable difference to performance. From memory someone once did some experimentation and the strut towers don't move ... so no need for any additional bracing.

[plas87]

What do you mean by 'upgrade'?

It'll be a visual upgrade (look prettier).

It will make absolutely zero noticable difference to performance. From memory someone once did some experimentation and the strut towers don't move ... so no need for any additional bracing.

Upgrade in the sense of handling; less body roll

[Conan]

It will have absolutely no effect on body roll
It’s unlikely to have any effect whatsoever as the RX-8 chassis is very stiff anyway.
Pete

[mi60o0]

They do look preety

[Scartlead]

I 'changed' mine, but only for looks, so if that fits the bill, go for it

[plas87]

Great, thanks!

[Dr. FrankenRex]

Same. I have the Carbon Cusco one - but it doesn't do anything other than look nice

[warpc0il]

It's always worth searching, before you post a question...
viewtopic.php?f=144&t=75081&p=1109960&h ... t#p1109960

[PeteH]

I've said this lots before, but the RX8 doesn't have struts.

If it did then a strut brace might make a difference. But it doesn't. So they don't.

I took the OE brace off my race car. The weight saving is the best upgrade you can do to this component..... (Although if I had a road car I'd leave the brace on. And if I was bothered about looks I might even "upgrade" it )

[warpc0il]

Unlike cars with MacPherson (or similar) struts, the RX8 suspension units have nothing to do with wheel location, other than in the vertical plane (bounce & rebound), so the forces that a strut brace is designed to resist don't exist on an 8.

We should rename it "the engine cover support bracket".

Edit: - I should have refreshed before I started typing.

[RenesisRaceBuggy]

Rigidity is incredibly important for damper performance - which is what strut braces are there for on mcpherson strut cars too - it's not to stop the geometry moving around (a minute amount of flex at the top of a strut tower would make almost no difference to the geo) - it's to lift the localised stiffness/frequency well away from the operating frequency/harmonics of the dampers and springs.

[mi60o0]

I have front brace and rear brace in the boot haha I do love the rear stopping some shopping sliding.

[PeteH]

Rigidity is incredibly important for damper performance - which is what strut braces are there for on mcpherson strut cars too - it's not to stop the geometry moving around (a minute amount of flex at the top of a strut tower would make almost no difference to the geo) - it's to lift the localised stiffness/frequency well away from the operating frequency/harmonics of the dampers and springs.

It's not. Strut braces prevent lateral movement of the strut top, which directly and adversely affects the camber control. Strut braces are in totally the wrong plane to contribute to vertical stiffness. McPherson type struts take a huge amount of camber moment. Enough to require larger diameter damper rods.

I could just about bend the Rex strut brace by hand in the vertical direction.....

[Conan]

As PeteH said earlier in the thread about the strut brace possibly having something to do with the crash test.
I also think this may be an explanation, I thought about it sometime ago when I considered a second hand one to give me some bling under the bonnet.
I was feeling a bit left out when everyone opened there bonnets I had to keep mine closed to hide the lack of blingness
Pete

[RenesisRaceBuggy]

It's not. Strut braces prevent lateral movement of the strut top, which directly and adversely affects the camber control. Strut braces are in totally the wrong plane to contribute to vertical stiffness. McPherson type struts take a huge amount of camber moment. Enough to require larger diameter damper rods.

I could just about bend the Rex strut brace by hand in the vertical direction.....

Of course you could, that doesn't mean it doesn't constrain the strut top in a 3rd plane to allow the vertical constraints to work better, however
In which case it would be loaded in tension, the same case as it would be if it were for camber control.

Struts run larger damper rods to stop the flex in the rod from creating massive friction/stick-slip issues in the bearing and seal pack - the lateral forces at the top of a damper strut even in a mcpherson setup are tiny compared to the axial damper loads - your lever arm is huge just due to the strut length.
This is the same for the bearing and seal pack, your forces at the top mounting are at their lowest when your forces at the bearings are highest because it's when the suspension is extended - the lever arm for the bearings/piston bands then is probably only about an inch compared to the top of the strut being 40-50" away from the balljoint pivot.
That's why struts and heavy duty rally suspension will always have spacers between the bearing packs to stop them the lever arm getting too short.

It's also the reason strut braces were never really for camber control but more for localised stiffness for damper performance or just for stopping localised cracking under heavy loads - old rally escorts, etc - you have to move the top of a Mc strut a fair way for any meaningful camber change.

[PeteH]

OK. We'll have to disagree, because we'd have to do sums to prove our points, and I can't be bothered!

I will just say that vertical movement at the strut top doesn't create any significant brace tension. The whole engine bay "parallelograms", and the strut brace can do almost nothing in this mode.

And when I designed the struts for the Freelander I was very concerned about the implications of the local stiffness of the strut tops in the control of camber. It was a long way from nothing (and Freelander had an unusually stiff monocoque). The lever arm is large, but so are the loads.

You are right that punching through the strut tops is an issue. But that can be dealt with via local plating. You don't have to put a bar between the two struts. It's an unrelated issue.

[Rotary Potato]

A strut brace makes a massive difference on a 1982 Ford Capri ... #completelyirrelevent

[PeteH]

Has it got struts?

[Conan]

A strut brace makes a massive difference on a 1982 Ford Capri ... #completelyirrelevent

A strut brace makes a massive amount of difference on a lot of cars
Especially the Ford style cars of the 80,s etc
This is why some people think they will make a difference on all cars.
They do look pretty though and I do want one for dirt cheap so I can open my bonnet in company.
Pete

[RenesisRaceBuggy]

It's not punching through the strut tops, it's bringing the local stiffness up to where it's outside of the top mount and damper frequencies. The lateral loads at a Mcpherson strut top are tiny compared to the wishbone and subframe loads. Generally an order of magnitude lower.
If camber control was such an issue that you need a strut brace at the top mount there's no way in hell you'd ever run a rubber bush in the lower suspension arms.

You mention Freelanders - I've got 6 x dampers from a rally Land Rover right here in front of me that I'm currently upgrading/rebuilding as we speak if you want some sizes to work out the forces.

[Conan]

A strut brace makes a massive difference on a 1982 Ford Capri ... #completelyirrelevent

Can anyone do me a four link kit and Atlas diff for my RX-8 as I think it may improve the handling.
And where’s the popcorn ( preferably delivered by one of those girls from the cinema with short skirts )
Or is that considered sexist and non PC these days
Pete