Chibo

He doesn't need to run a huge rear bar with those rates... I actually looked up the rate on an AP1 rear bar (427 lbs/in), which would explain a lot. I'm 15k/11k and run a little bit lighter than a Miata rear bar (179lb).

DefSport

What are you doing for bumpsteer? The AP1 bumpsteer geometry is very severe in the rear, so you can end up chasing your tail on the rear on transient events due to the rear bumpsteer being all over the place.

dsddcd

See below responces

Yes you are correct, I am chasing points so I chose springs to give an equivalent motion ratio given the chosen front spring rate. I derived those rates based on information Rob Robinette published and my own R&D. Here is a small portion of the overview page. The front spring rate was chosen by consulting others with winning cars and my own experiences leaving on the rear spring to tune the bias. Note I run the car heavy 2900# so I needed a bit more spring than others might normally choose with a stripped car.




The rear was very important first to correct the AP1 geometry and second for the ability to run more camber. At the same time checked the front which was not a problem at my ride height.


Thank you again all that are sharing!

Chibo

That spreadsheet looks interesting

ViperASR

The very strong rumor is that TTC is going away for TT4/5 next year. My advice would be to get sway bars to fix the issue and not worry about points.
TTC is going to end up split across TT4 and TT5, with the idea of TTD cars being able to slot into TT5.

thomsbrain

I'm confused, do you take a points hit by changing the stock rear sway bar or removing it? A 16k/12k spring stagger on the S2000 gives ride frequencies of roughly 2.03 Hz front and 1.72 Hz rear (depending on the motion ratio you use; there are a few different numbers floating around for the S2000). Your front frequency is 18% higher than the rear, which is completely backwards from what it should be. The general rule of thumb is to shoot for rear frequency 10% higher than front because the rear needs to respond faster than the front in order for all first-order suspension movements to resolve at roughly the same time after hitting a bump.

robrob

I tried a little rake in my car and it definitely liked having the rear as low as possible. Every time I raised the rear ride height I lost lap time.

InsaneSp

What turns at what tracks are you having issues putting power down? Are you waiting on the nose? Wheelspin?

michaelnyden

Maybe try hondata traction control (it's adjustable on the fly).

Jimbo_STWOK

I had the same issues on corner exit. Vtec Crossover didn't help either, but what did help me the most was disconnecting the rear sway entirely. I recently switched to a higher sprung setup from my Ohlins and it only got better. I feel it's more of a ratio f/r than a largr lbs/in game.