Diyman25

Since Rx8 get a lot of torsion stiffness
The amount of gap at bushing and rubber flex at subframe bushing can really affect ur corner exit speed !!!

Install Garage revolution front subframe nut
And Re amemiya Rear subframe bushing

But is raining season here at Taiwan, I wonder should I still go test out not ?

Loki

iTrader: (1)

I don't think you should test it. Testing is for suckers. Wait till race day.

Diyman25

Dude this is street car, Who race street car at track ? On race track don't mean u are racing
I go Track day or track member day to to some lap time datalog using Racelogic Vbox HD2

Loki

iTrader: (1)

Im sorry man I can no longer see the road you're on. The mods you're applying are super minor, they make no sense on a mostly street car. Without a well tuned coilover wheel and tire setup they will have no effect except NVH.

Also I race my street car on track. There are appropriate classes in most organizations.

Diyman25

You time trial or track day not race
If u ever do wheel to wheel race like I do ,u wont call time trial or solo1 a race
U think is minor , why not think look how much gap it had ??
U think simple subframe nut can hold every thing in place under ? Think about it wheel need to be hub centric ? And subframe dont ?
Then why Mazda speed USA come with solid subframe bushing ?

NotAPreppie

Don't tell that to NASA and SCCA TT drivers. TT means "time trial". They mix it up wheel-to-wheel all the time. Also, subframe bushings are useful when competing against a clock regardless of whether open passing is allowed.

This subframe modification will help in the absolute sense but there are many other modifications that will affect lap times to a much greater degree.

Your wheels being hubcentric analogy doesn't apply here. Wheels being hubcentric is because wheels need to be securely located to ensure smooth conversion of rotational kinetic energy to linear kinetic energy. The subframe, drivetrain, and chassis don't rotate relative to the ground the same way.

MazdaSpeed has solid subframe bushings to support motorsports. That's why it was called MazdaSpeed Motorsports Development (now just Mazda Motorsports Development).

Also, I can't tell if you are installing this on a street car or a race car... You say it's a street car but then you start talking about using this for racing. Which is it? For a street car I would definitely not bother.

Diyman25

When I say street car, meaning car will interior and registration, u can still track street legal car,
I have clear it because my track car is a RHD ex Super endurance Rx7 race car that I do wheel to wheel race



I pick a example because this is most easy one
People might relate it
Some people can can say tide is tide, but is not (^_-)-☆

Loki

iTrader: (1)

So, if I read this back to you, you're saying you've installed a mod that is very important in wheel to wheel racing on a car which will never see wheel to wheel racing. Maybe you should start a build thread or something that shows what all you have done is, because individual threads about each of your mods make it difficult to understand what you're doing and comment effectively.

Diyman25

despite 90% thunder storm chance !! we still have dry track !!! so suprisely. so i went to track to testing my new set up

here are the video of it. compare to bone stock RX-8 i did a 2:06.6. i mange to improve 2:05.4
without any power mod, just fcous on setting up the car
here are the video of my fastest lap. i have get a cool down lap because after first lap coolant temp already rock to 108c

As compare Stock BRZ clocking 2:08 at same track drive by Taiwan pro Racer

kevink0000

I, for one, am very glad DIYMan does these modifications and provides these posts and is enthusiastic about the RX-8.

Thank you for taking the time to do these. It doesn't matter if I agree or disagree with what you are doing to the car or why, your vitality is to be commended.
It improves the quality of this forum, period. Please keep it up.

TeamRX8

iTrader: (25)

Did it over 10 years ago except made custom UHMW rear subrame bushings with aluminum stud sleeves due to the class rules

there are probably some pics on the forum from back then

Diyman25

Thanks man~
Building up track day project and share idea on forum is always fun part too

Some can agree, some might not disagree is always ok, along as we can discuss all this thing
Is professional manner (=???)?

Diyman25

I co build E36M3 track project before, and knowing subframe play big part of carry speed out of corner~ and After reading some of oversea tunner recommendation on this is must mod for Rx8 for track day and seeing Mazda speed Motorsport have made soldid one too, I know this is thing I want to try on my budget track day Rx8

On street u can already rear get firm up a bit
Kinda da like change stiffer bushing type of feel
But still very liveable

TeamRX8

iTrader: (25)

sounds like you should write a magazine article ...

Diyman25

No way , can u tell I sound like FoB(¯?¯)

MC8jai

iTrader: (1)

when installing these front subframe nut, how easy did you find? I’ve tried to install these on a 05 RX8, it wouldn’t go in all the way to fill the gap. Seems like the nut is too big. What year is your rx8?