Might want to start a new thread. There aren't that many people that actually track or race the FD as hard as you are going on the ring and can make use of a spring rate that high.

Personally, the rules spec 700 lb springs for Spec Miata @2,300 lbs on 205 Hoosiers/Toyos so I'm not surprised that 800 ish / 14 kg might not be sufficient for the power levels, weight, tire size, aero of your FD.

Here's a post from Wouter / racingdriver on spring rates for his old 3 rotor race car for reference: https://www.rx7club.com/race-car-tec.../#post12463831

Also, @ptrhahn has some specs on his suspension here: https://www.rx7club.com/build-thread.../#post12586924

Good luck

 

Nice!

Thanks for the pointers! Just read all fo the threads and information there.
Some very useful stuff and things to consider.

My problem when going in and reading other people threads is my experience in how each racetrack differs so much on what it is demanding from a car.
And that magical place in Germany is so particular with such unique parts on the track.
I still have not driven any circuit in the US to date but i have driven a lot in Europe and i can confidently say that some of the corners in that place cannot be replicated in other tracks.
The elevation change and rapid change of direction in some places makes it quite demanding.

But if my feeling currently is that the 14kg spring fell short, i can definitely relate to the people mentioning higher spring rates in their builds.
And seeing how these people are a bit more avid track users makes me kind of validate my feeling further.

Thanks again.
Konstantinos.

 

Yep. I imagine the Ring is a unique beast to setup for. Probably need stiffer spring rates, a higher ride height to deal with the compression and bumps and really good shocks/dampers with valving to deal with it.

Good luck! Looking forward to living vicariously through you in your next video.

 

800lbs is def a compromise on mine, as I'm still holding on to the street/track car use case. I'm also not running very heavy aero. However, I can't imagine there's anything Watkins Glen won't throw at a car, it's a very high speed circuit with a lot of elevation change, and I don't have any problem spots. I'll reassess once my drop spindles are done, as those should naturally decrease roll.

 

Small update with a new video regarding the last visit at the Ring.
During lap 6 at the Nürburgring, my Mazda RX-7 FD3S (The Ring Dorito) suffered front splitter damage—and the aerodynamic balance changed instantly. In this video, I break down exactly how a damaged splitter affects downforce, aero balance, stability, and why the car suddenly became unwilling in high-speed corners.

 

It looks like the welds failed.

Did the splitter contact the track before it failed, possibly even during a previous track day?

I would use four to six smaller bolts with rounded or flat (recessed) heads on the bottom of each bracket instead of those two honkers, which are likely hurting the aerodynamics somewhat.

You might want to also add some supports to left and right sides to distribute the load more.

 

Indeed it had many times before starting with Spa, going down to Eau rouge every single time almost.
And continuing at the Nurburgring, all the previous laps the splitter was a little bit touching in many places.
So it could very well be fatigue over time if this is where you are going with this.

All points very well noted and make complete sense.
Next version will be definitely better in every aspect. I am now even considering adding those wire like supports at the front sides (are these the ones in which you are referring too?) just to make it even more rigid.

Someone reminded me that i also have a rear diffused from a 992 Porsche GT3 laying my garage, due to slight damage, which is maybe worth investigating fitting on the RX7.
Will report back with this.

 

I mean something like this:

https://www.battleaero.com/cdn/shop/...g?v=1734131363

Support rods on the front would probably be good if you make it any longer.

 

Ah yes, now i see.

Will definitely help with the rigidity and keeping the splitter better attached.
Will be doing a list with all the hardware needed soon and hopefully get cracking soon enough.

Thanks again for the input, appreciated.
Konstantinos.

 

Since you’re in Europe, I’d consider buying these and calling it a day…

https://racingcult.co.uk/products/rx...fJudnlaN2pbiO5

The shipping and exchange rate is a bit too rough for me, so I’m going to look into making my own chassis mounts.

My current hardware store brackets are a bit too flimsy, although they seem to be good enough for 210 km/h (but probably not good enough for Fuji or the Ring).

 

thats actually a good idea… i will be mounting my front splitter and i have been thinking that manufacturer solution is not great… thanks for that