Autoxing my FB
 

I took my FB to autocross this weekend and was shocked by the amount of UNDERsteer i got out of it. I had good tires, and recently redone stock suspension.

Is there any suggestions for reducing it? I'd like to start going to autox a bit more, and the car isnt a daily driver for me, so I dont mind feeling a few more bumps

Re-speed coil overs, tokico illumina struts, sway bars, strut bar....i would upgrade all of the suspension if i was going to auto-x my car a lot.

There is no such thing as understeer. You were simply driving the car beyond it's limits. Some key things I know about road racing may apply to this but I can be certain as I don't autocross, but I always brake before entering the corner and if you need to rotate the rear end around to simply lift the throttle partially. Again These are my tactics for road racing and not necessarily on base with autocrossing

if you are braking a lot while turning its going to induce understeer....just keep practicing & you should get it....i have never autox'd...just like taking local twisties fast.

Mine acted the same way. I was little disappointed. Recently ordered all new bushings springs and shocks (OEM spec) from victoria british and removed the rear sway bar. There is quite a bit of body roll.

It's no secret. Lowering the car 1-1.5" and using a stiffer spring and shock rate along with a nice set of tires will be your best bet. Then spring for the big sway bars and brake kit.

Also lightening the car up as much as possible will help alot.

Good luck!

front sway bar.

ask kentetsu

The settings on a stock car are designed to be “safe,” so no one gets themselves in trouble. One way the factory does this is by setting the car so it does tends to plow in a corner if you come in too hot. There are tons of things you can do to alter this.

First, take the rear sway bar off. It tends to promote that plowing feeling in low speed turns (although it is helpful in higher speed turns). Next adjust in as much negative camber as you can get (do this by rotating the strut tops). Then, add tons of caster and a touch of toe out. The toe out helps the inside tire grab in a turn (this will make the car a bit squirrelly at higher speeds). I generally run about 4 or 5 pounds more of air in the front of the car then the rear. Next, learn to tune your tire pressure by reading your tires after a run. There a ton more things you can do with your suspension, but this will give you a good start. The next place to spend you cash would be on a bigger front swap bar.

Second, driving…We all hate to hear this but if the car is driven right, it will plow very little. Generally if we are coming into a corner too hot, we have to turn too hard and the car will plow. If you can get ahead of the turn, turn less (yet earlier) the car will not plow and you exit the corner much faster. This tends to be easier to say then to do and seat time is the real cure for this. Many clubs have autocross schools which are really worth their time. At my first autocross school, I was instructed by a regionally competitive Rx7 driver. I learned more in the day than in the year prior of racing.

Good luck racing ~

Slower into the corner = faster out of the corner
Friction used for braking cannot be used for turning.

Track time (with instruction if possible) is super valuble.

The upgrades will help but even if you throw money at it, if your driving style is not right it will only help a bit.

Good luck.

If it was your first time you were probably braking too late and going in too fast and just plowing through the turn. Next time try going into turns slower and progressively take it faster until you find the traction limit

Yep, just like all the others said, you are going into the corner too fast. It took me two years to get over that problem myself. Enter slower, and accelerate through the turn, using more gas to rotate the car if needed. You're just plain trying too hard. Slow down a little and think more about "driving" the course rather than just beating it into submission. :)

Ive raced stock suspension rx7's at autox events.

I rarely have had understeer problems except when first started out, its driving technique.

Brake before you turn, use the brakes hard as you can so you are using them for the shortest amount of time possible.

If you have to turn and brake, brake lightly and your speed better be correct.
dont turn the wheel further towards lock if your allready understeering, straighten it out a little.

On a stock suspension I had great results without a rear sway bar.

the stock strut tops can be adjusted for more camber by rotating the entire mount, max out your camber, itll handle way better.

I'm used to autoxing my Subaru. It understeers a bit, but always makes up for it by mid corner. I'll try disconnecting the rear sway bar next time and braking a bit earlier. So its the front sway bar that helps reduce understeer?

Generally, to get a better handling vehicle for autocrossing with a rear wheel drive car you want a larger front bar or no rear. For a front wheel drive car you want a larger rear bar.

man, only one person touched on it, TIRES!! Im telling you. for an autox car this is the biggest improvement you can make if your running some crap @$$ all season. Get something thats more geared for performance and is made by a reputable company. then track time. See if you can ride with one of the fast regulars. Im sure they will be happy to let you ride along, find out that has the same set up as far as rear wheel drive.
Slow is smooth, smooth is fast. it took me about 3 sesions to get that down. Even still my first lap is always a bit crazy as I get my adrenaline back down. Maybe I should try making it more. Damn field exercises

+1 for good tires.

Catatonik, where did you AutoX this past weekend? The MCO hasn't posted its schedule yet!

I'll be looking forward to swapping notes this year, since I'm in my 2nd season of autocross, and I've now got RacingBeat swaybars and a ReSpeed Rack and Pinion :)

Jon

stock alignment is 1 degree positive camber which causes understeer. get realigned with as much negative camber you can get. ends up being around .7 to 1.0 * neg camber. that alone really helped me out way back in the stock days.

+1 to what everyone else here said.

Everything has been touched on here but I want to add this, and really its what everyone has been already been saying: weight transfer. Try being smoother on your entries and exits. When you get it down you'll find that corners feel "easier" than before. Brake and throttle control is key here. Be smooth but dont be slow. Find your balance. Its gonna take time and practice.

Tires will make him faster overall, but they are not going to correct a handling problem.

I moved! I'm in Peterborough now, Jon!

I posted the vids on youtube. Just search PMSC Solo II, or PMSC RX7 :)


What tires are you autox guys running on the stock 13s?

You are too throttle happy, sliding=slow, look like you want to just have fun instead of going fast.

LOL! You're 100% right. It WAS fun... but my times were embarassing. I was beat by an 87 Prelude field car with 4 blown shocks. :wallbash:

Tires can really help, but they can bump you out of a class as well. It really depends on where (class wise) you want to race. Some clubs have a novice class, stock class, street tire class, and various prepared classes. Check out the rules for your club.

If you are going to race in a street tire class, check and see what rules there are. See if you can update/backdate to a 1983 LE wheel (which is 14”). This will give you some usable sticky street tires, like the Azenis 615. If you need to stick to the 13” rims there are no real sticky street tires available.

If you want to go to a real autocross tire you have options. DOT approved race tires or like Kumhos and Hoosiers, or even full on slicks (each has its set of car class issues). I run 215/50/13 Kumhos on 8” rims and I think they are great. They are easy to learn on and very forgiving. Work well when it is cool and stick when it is hot. I also have some Hoosier AS05s which would be great on a hot summer day, but like precise drivers )that is not me yet).

The biggest pain with race tires is having to swap rims at the track. It would be much easier to get a set of 14” rims and buy some Azenis 615 and call it good.

Sumitomo HTR200's are a sticky street tire used by many on the forums. Hoosier makes an R compund tire in the same size

i use kumho V710's and there great when they get warm but kinda soapy feelin when there cold and i usualy run between 25 and 30 PSI.