Serious Autocrossers?

[kngrsll]

really, the last thing you need to worry about with the yaris is chassis stiffness. its a pretty damn good chassis actually. what you really want to do is improve grip, lose weight, and pick up power! i forget the exact rules of ST now, but its basically bolt ons.

grip: so grippy tires like the Toyo R1R is good at a 205/50/15 (i think 205 is the max width for ST?) there are very few shock choices available, with the Tokico Blues and HTS. The HTS has much higher valving and are adjustable. I have yet to see any data from any of the coilover companies shocks. there are very few springs available, the Teins are probably best for motorsports at 3kgF/3.5kgR. there are some sway bar options as well, front and rear through MicroImage. there are very few other parts available, so anything else will have to be creative and custom. as for alignment, crank in the front camber, toe out the front, and leave the rear alone at the minimum. The consensus around here is for the best handling, use springs, shocks, and rear sway bar but i havent followed anyones progress really so who knows how it works.

lightening: this is pretty limited as the car is already light. a light battery would probably help a ton. i havent looked into this area much, but i think its probably pretty limited in SCCA autox.

power: there are some bolt ons available, intake, header, pulleys, exhaust so on, all class legal.

now my opinion, i think the Yaris could actually be a decent ST car. you need grippy street tires, id say at least the Star Specs, but the R1R's are supposed to be better. ive even heard the new A08 is even better, but that will cost some coin. the current suspension up seems pretty tried and true, you should be fine with Blues, STechs, and a Rear bar. id try to get as much camber dialed in the front as you can, the car needs it. as for power, the mods will do a little, but dont expect a huge leap. i cant comment on the intakes, i think they would all perform about the same in general. the only header i would consider buying is the DC. i think an exhaust is a waste of money, if i wanted to do anything, id get a shop to make a straight pipe and just bolt it on when i go race to save a little weight. a pulley is nice, since its cheap, id get one. after that, we are pretty limited on class legal power mods. personally, id like to see what we can do with the camcon by power enterprises, it is used to modify vvti. may be able to pull a couple hp with it. the best thing we can really do is lighten as much as you can. i havent looked at the rules in a long time, but weight goes a long way! improves both speed and grip! id go with a light battery, lighter seats for sure. i need to look at the rules again and figure out where you can shed more weight before i can expound on that topic.

but yeah to get started: 15" light wheels, 205 grippy street tires, springs, shocks, rear sway bar should get you 90% of the way there. things like a dc header, pulley, intake, seat can all help a small amount in terms of performance. that is my personal set up and it has netted a couple 1st places in ST class at local events, but is in no way a nationals type set up. im experimenting with that now