Rear Subframe Brushings...

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HarSc
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Rear Subframe Brushings...

Post by HarSc »

Right-o, about to get cracked on with the subframes on the 'nana, so just stripping them down ready for powdercoating. Aiming to get the old bushings out - but does anyone have any recommendations for new replacement bushings?

I've seen Strongflex and the rear subframe bushings they do - both in red and yellow for differing hardness, not seen any offerings from others in my searching.

Potentially leaning towards the yellows, definitely not just because of the colour match :lol: all other bushings on the car will be absolutely bone stock and new, full set of rear and front arms. The only other set that may end up being poly would be the diff ones, since they only come new from Mazda with the carrier at great cost.


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Re: Rear Subframe Brushings...

Post by mrspiller »

I didn’t like the strong flex
Bit wobbly and an easy to slot in for the subframe
The oem bottom washer didn’t fit over so had to use a big washer to hold it in place
That was a while ago
So may have changed
Diff ones but we’re sh*t , wish I could have retained the OEM or cleaned and coated the subframe with POR15
Pretty sure was super pro , or power flex
There’s never much wear on diff Carrie so clean it up , clear coat and keep standard ones ?


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Re: Rear Subframe Brushings...

Post by rotatopotato »

I've got the reds in my rear subframe - yellow could be a bit too harsh, but there's very little (if any) NVH so you might be fine with yellow.
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Re: Rear Subframe Brushings...

Post by HarSc »

I've actually gone and done a silly.... Got a hold of some Sikky solid subframe bushings :lol: so hey, if my teeth get rattled out it'll be my own fault :paranoid: :lol:
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Re: Rear Subframe Brushings...

Post by rotatopotato »

Offt bugger that - solid bushes are for race cars 😬
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Re: Rear Subframe Brushings...

Post by HarSc »

Going on the nana, so it'll be the guinea pig for when I'm fully resto-ing my R3. Got sikky solids for the subframe, powerflex blacks for the diff, new genuine Mazda engine mounts, and all 10 arms rear + 4 arms front are new genuine Mazda, along with my (recently installed) bilstein B8's with tein springs. So we shall see how that mixes up and feels.

It'll firm up the rear big time I reckon, but we shall see how harsh it makes it. I'm hopeful that the Mazda arms/suspension bushings will keep it ok for bumps/undulations, but it's uncharted waters as nobody's been silly enough to do this combo :lol: mat well have got it wrong, but will report back if I have :giggle: every day is a school day :study: :study: :study:
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Re: Rear Subframe Brushings...

Post by HarSc »

Truth be told though, they were half the price of the Strongflex ones and came with an entire subframe to boot. Not one I can use mind you, as it's the actual sikky one for a quick change diff lol and nobody has the money to sink thousands into a QC diff on the 8 that I know of!

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Re: Rear Subframe Brushings...

Post by warpc0il »

I recall having a (translated) discussion with the RX-8 Development Engineers at a the Ford test track in Belgium, back in 2002.

They were talking about chassis stiffness and flex. The RX8 bodyshell was the stiffest production car that Mazda had produced (at that time) and they were explaining how that worked with the designed flex in the subframe and suspension mounts.

The flexible mounts were crafted not only to isolate NVH but the rear especially is designed so that lateral forces from cornering produce a given amount of deflection, resulting in rear wheel steering. This is one of the reasons that the RX-8 was handling so much better than its competitors.
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Re: Rear Subframe Brushings...

Post by HarSc »

warpc0il wrote:
Tue Feb 04, 2025 6:02 pm
The flexible mounts were crafted not only to isolate NVH but the rear especially is designed so that lateral forces from cornering produce a given amount of deflection, resulting in rear wheel steering. This is one of the reasons that the RX-8 was handling so much better than its competitors.
Am I reading into this wrong? I read as the suspension arms/bushings do most that work and the subframe flexible mounts/bushings just for NVH? :-k

I'm genuinely rather excited to see what it does though :D who knows, I may love it, I may hate it. But that's half the fun of the yellow car, it's the one to experiment and play with :twisted:
Last edited by HarSc on Tue Feb 04, 2025 7:13 pm, edited 1 time in total.
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Re: Rear Subframe Brushings...

Post by warpc0il »

They weren't specific as to which elements provide that rear wheel steering effect.

I had previously assumed it was mainly the suspension arm bushes, but it's possible that the subframe mounts have a role too.

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Re: Rear Subframe Brushings...

Post by qwakers »

if you want to throw that subframe in my direction i will swap it for a s1 rear painted in whatever colour you want (as long as its a ral colour...) and that one may find its way into the racecar, if i can mod it to take a stronger lsd....
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Re: Rear Subframe Brushings...

Post by rotatopotato »

HarSc wrote:
Tue Feb 04, 2025 5:15 pm
It'll firm up the rear big time I reckon, but we shall see how harsh it makes it. I'm hopeful that the Mazda arms/suspension bushings will keep it ok for bumps/undulations, but it's uncharted waters as nobody's been silly enough to do this combo :lol: mat well have got it wrong, but will report back if I have :giggle: every day is a school day :study: :study: :study:
You may feel a harder "shunting" when loading/unloading the transmission - I definitely noticed that with mine, though it's not overt. I have the RRP engine mounts which could be contributing in conjunction as well though.
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