So I took my recently bought Shinka out for an autocross event. She feels very balanced and nice... didn't experience any excessive oversteer / understeer.

I was originally planning to compete in STX but seeing how well the car does with stock suspension and the minimal body roll, I decided to stay in C-Stock. I'll simply get a set of V710s or A6, a good alignment, and HP+ pads. I think any other mod (front sway bar, cone filter, struts) won't be worth the money and may not do much. What are your thoughts?

Also my biggest problem with the first event was the headroom... I didn't test drive the car with my helmet on and now I can't sit in a comfortable position. I have the seat lowered completely and angled enough so I can still see the cones around. But staying in stock I have two options for this:

-Somehow modify the seat railing to lower it 1 or 2 inches (that's all I need)
-Get a 4 point harness to hold me back with the stock seats while I angle the seat more... I tend to lean forward regardless of how my seat is positioned.

Any thoughts?

 

^Can't modify the seat in stock class, but the harness is legal.

You will also find that once you mount up the R-compounds, the car will roll much more than it does now. This is why most everyone in stock class upgrades their shocks.

As for the front sway bar, people have used all sorts of approaches around here. I personally found that, while I was in stock class, I only wanted a small increase in front roll stiffness, which I got by drilling the stock front bar. But that was on 245 V710s - I have no idea what I would have ended up with had I been running BF Hoosiers.

[edit] The other thing you'll find is that what feels well balanced on street tires may not work out so well on R-compounds. This is due again to the increased body roll, which changes how far the bump stops are engaged, etc.

So, I'd suggest you figure in a set of shocks and possibly a front bar into the budget, even if you don't go that way initially.

 

Well, keep in mind that the Shinka has a stiffer suspension to start with which makes me want to avoid making any mods to it.
BTW how does drilling your front sway bar work? What exactly does it change? I believe I have the urethane filled sway bars.

 

The oem swaybars are solid steel. Drilling the new hole, closer to the pivot point, makes the bar effectively stiffer.

 

^Correct about the drilling, but not the solidity. Stock front bar is hollow.

As for the Shinka suspension, I could be wrong but I'd bet that you will still want Konis or Tokicos.

Anyway, there is nothing wrong with mounting up the fast tires and then making a determination then. Your performance will still be mostly determined by your driving skills, even with the stock shocks, assuming you get a good alignment. However, most people find the car easier to drive fast with the quicker transitional response afforded by a good set of shocks.

Good luck.

 

A lot of people subscribe to the idea that it's best to learn autocross on street tires for a couple years before transitioning to race rubber. I'm one of those people. I think race tires can cover up driving errors that street tires won't be as forgiving of. But if your goal is just to have fun in the short term a set of sticky tires will go a long way to making the car faster.

For what it's worth the 2009 Nationals winning RX-8 in what was then B-Stock ran the stock front sway bar with Koni Yellow shocks, lightweight exhaust, light wheels, 285 Hoosiers, and an alignment. The setup is dead simple on these cars. We tried drilling the sway bar and I didn't like it - the car became tougher to drive at the limit and I had to wait too long to get on the throttle coming out of corners. We tend to have more sweepers around here. Folks that autocross on runways where it's almost all transitions generally prefer a bigger front sway bar. I thought the car transitioned well enough on the stock bar myself.

I believe we were running OEM brake pads too, although I've heard Mazda reformulated them recently and they're not as good as they once were.

The downside to the Koni struts is you cannot adjust the rear shocks once they're installed on the car. We ran them full stiff for autox, which meant a bumpier ride on the street.

Fun car though, I have yet to drive anything that handles better outside of a CSP Miata.

 

100% ,agree

 

Totally agree with learning on street tires. I must have mentioned that this was not my first time auto-xing just the first time in the Shinka. I have done my share of events with a number of cars on street tires and then a good number of events on semi slicks... I'm running on all seasons for a few more events on the RX8 to learn the car as well but I want to have the car ready for next year's national tour....

I have to stick to the mods I've mentioned for now. I don't really like the initial bite (or lack) of the stock pads. They have good power but they are not as responsive as HP+ pads would be. I guess the best way to find out would be for me to try these and see how it goes. It's always better to not mod than to mod and find out it you wasted money.

The RX8 is a great car for track and autocross... I observed a few of them at our club and considered a number of other cars but finally fell in love with Shinka

 

Didn't like that poor handling MX5?

 

It's a push pig but it gets the job done.

 

oink oink!

 

Don't let him fool you. He loves making the piggy squeal ....

 

I personally am not particularly dainty on the brake pedal, so I prefer autozone pads for autocross. It gives me a slightly softer initial pad bite that keeps me from really upsetting the car, or worse activating ice mode.

Still get all the braking I need, but with a bit more control.