To aggressive?? Alignment
 

I forgot about caster adding to camber or something in a turn so I might be kinda high. I got front spl arms on and aligned today but my casters way up at 6.2/6.3 from mid to low 5's I think when I was oem. I could of backed camber down some but I rub and these aren't the easiest to adjust so I let the guy leave it.

I can also never remember toe. I was on a hunter and I though + was toe in and - was toe out. But this Hunter was a little pic next to the "total toe" which you can see I'm wrong.

Idk it feels ok but I have to track test it first I guess.

http://i39.photobucket.com/albums/e1...ps7pnih9ac.jpg




Hunter.com says I'm right though...

http://i39.photobucket.com/albums/e1...psfcmlfezo.jpg

That caster is actually pretty mild for a track setup.

Good to know.

Looks good to me as well, I went to -2.0 rear camber and the car was pushing some so I think I'll back it down to -1.7 like you've got and try that

More rear camber.

Not yet haha. I'm still on the 12k's.

I'm 11k rear and running -2.1, it holds/performs well but tire wear/temps suggests I should run a little less.

What's your weight? True type?? I'm like 3056 but 57/43 ratio. I can't touch the throttle without spinning even in 3rd. Rear cage is next to add some weight back there and probably drop down to 8k. New apr gtc-250 is on the way so that should help too.

I had similar issues- car was kill-you-loose/snap over-steer at really weird times, but mainly on the mid speed/50-60 mph exits. It held fine oddly enough in the high speed sweepers 80+.

I am probably around 3100 lbs although I haven't weighed it, I have trunk pulled completely, some sound deadening removed and as much plastic crap pulled as possible, rear is definitely lighter though. My spec is pretty limiting in what you are allowed to remove etc.

I started 12K+ rear sway full soft. Car tried to kill me.
11k Rear + rear sway full soft. Car tried to kill me.
11K + no rear sway. Car is a beast. Feels very well balanced and neutral can make it understeer or oversteer, am very happy w it currently.

Try disconnecting a rear endlink. If you like it, just remove it if you are allowed. Otherwise, I would probably drop the rear rate to about 9K if I had to run any sway bar at all. I am on OEM pickup points shock/bucket spring. No aero currently just OEM spoiler.

O see I'm on a 12k true type!!!

As for rules I'm going XP or unlimited. Getting my azz handed to me but I want my car to be the best it can be, no rules :).

12K true type seems a bit stiff to me(especially with bar) unless you have some aero to tame it, but for autoX I know they tend to spring a lot different than the road course guys. Makes sense, we have bumps and hills to deal with and require different things. A buddy of mine whom puts in some fast times at the tracks we go to runs 11K true types with OEM bar, but he gets pretty drifty on the sweepers and has been contemplating removing rear bar as well. Personally, I don't think I will ever put the rear bar back in until I move into aero or make some other major change on the car. A different friend(clintfocus here on the forums) likes to use the G35 bar.

Everyones told me its to stiff. I will be going down. I'm waiting on my GTC-250 wing to show up and I do have a front splitter and canards. No plans on a diffuser yet. After it gets here I might try it out, then try no bar, then send in for revalve and 8k's.

It's only "too stiff" if softening makes the car faster with everything else constant. :)

Spring rate by itself doesn't tell you much - ride frequency is a more useful and universal number because it takes into consideration unsprung corner weight and the motion ratio of the spring. To start to make a guess how a car handles, you also need to know the front ride frequency for a comparison.

Camber looks ok for a dual purpose street/race car but for more optimal cornering I'd add .5-1 degree additional negative all around. Depends on what's suggested by your tire maker too - some (like bias-ply slicks) prescribe smaller amounts of negative camber for optimal performance.

03threefitfy had me at 2.1F 2.75R I believe :(

I do notice one thing I believe to be the sways fault, after backing out of my driveway and turn to give it gas my traction light comes on and one wheels spins out a little at 1mph. I'm on a slight incline so I'm guessing the sway isn't letting the one wheel touch the ground all the way and its pulled up when it should be down. Will I ever experience this on a track? No, not unless it's a rally course. But it might help.

On another note I did gun it hard going to work today on an on ramp. The car did have a nice squat when I puched it and it gripped and went. Can't wait for the wing and cage!!

What type of tires to you run/race on? Square sized or staggered?

2.75 isn't outside the ballpark for a car on R-tires or slicks. For a track car with aero (which adds normal force at speed) it maybe puts it in the ballpark for a good street tire.

What stands out to me is the disparity between front and rear. Your ride frequency split is a good starting point for a FWD race car on street tires :-)

If your front ride frequency was raised to 2.8-3.0 and you had a square wheel/tire setup with sensible bars and alignment, I bet you'd find the car was fairly well balanced - without having changed the rear. But overall those frequencies are a little high for surfaces that aren't pretty smooth.

Every car is different, and what's best depends on the type of racing, level of grip (at each end), and power levels (including where it gets sent), among others.

For a decently balanced and moderately powerful RWD autocross car on good modern street tires, I like starting around 2.5 front and 2.2 rear. The higher the power for the grip level, the bigger the difference I'd probably end up with - a Miata might be 2.5/2.5, but a Corvette I might go 2.7/2.1 - the reasoning being, the more powerful car needs to work the drive tires a little bit less in the corners to make use of its power. Obviously swaybars and their contributions come into play and can influence the resulting frequency splits.

Smoother surfaces and higher grip tires trend those numbers up; rougher surfaces and lower grip tires trend them down.

Good luck, have fun, be safe on the streets!

RS-3's right now but later conti slicks. I'm 285/35 square on these RS-3's on 10.5's.

03threefifty did my numbers, how did he figure them out? How do I turn up the front?

Ok I've removed an endlink on the rear. Quick question...why doesn't everyone run a high spring rate and remove the rear bar (for weight reduction) :)?

Some of us do. Not so much for weight, though.

:tup:

I thought you told me but what size? True type? What about me being on track and you doing autoX? Won't I want a better rate and rear bar for really long sweepers? Ideally of course.

The principles are the same really....

I am not on a true type, but I might toy with it a bit this rear. I run a lot of spring, though and it will be higher this year since it has real aero.

Same here. If Martin is correct and my GTC-250 has a ton more down force than an Aeromotions, then it's a step in the right direction. Now if I can only figure a new tank setup, I want to run the exhaust out the quarters or side skirts. This would allow a real diffursor (took some notes from a 458 :) ). After that and a flat bottom I should be golden.

The real focus on aero should be up front...

Can't do more than that.

Although I was thinking about some edges for the sides of the canards. Like a 90* side there.

Scott you have a lot of good questions but they require conveying a body of knowledge exceeding what makes sense to post. Here's a couple books that make great entry-level to intermediate texts:
http://www.amazon.com/Chassis-Engine...dp/1557880557/ (my favorite)
http://www.amazon.com/How-Make-Your-...our+car+handle

From them, you can gain an understanding of the pros and cons of stiffer vs. softer spring rates and sway bars...

As for how to increase front ride frequency - the easy way is to up spring rate.

There is a whole lot more you can do up front, but it is wasted effort unless you can prove it first with sufficient, reliable CFD or in a tunnel. Cost = $texas.

Jason is right, there is a lot to be learned, but there is no reason not to baseline your start point off of what others have proven to work. That said, everyone is not the same in what they look for in a car, so it should be just a starting point. It took me almost 3 years to get a consistent set-up for differing surfaces we run in national autox. Once I got it...I decided to go road racing and had to change everything :icon17:.

Bottom line, you need to ditch that rear spring. There is no reason to try and cure an oversteery car by adding a ton of rear wing/drag to the butt of the car. It's all about balance, man.

Yeah leave aero alone for a while, would agree. This car does not need a ton of aero in the rear to put in good times. If the problem is the springs, don't fix the springs by adding more aero. ;) Like 350 said, it takes a long time to dial in. My car was barely drivable, scared the hell out of me from last august to just this april. It's not gran turismo unfortunately lol, it takes a long long time. If you keep adding problems on top of problems, you will never figure anything out.

Guys I'm just talking, not taking everything seriously. Just having a conversation and seeing what's done. I know there's more to it and know about the springs. Just learning something new everyday and finishing my build 1 thing at a time.

Scott, when are you going to get this thing on the track? That's the only way to know for sure on what your set-up is. Playing around on the street is one thing. The track is a different beast. You should know that. ;)

I know and I've said that. Soon I hope, just a few more things to do. Mid Ohio has a few days coming up.

I feel like I have to write a disclaimer everytime I post. Like I'm talking about changing a light built and people think I'm going to build a nuclear reactor.

Anyways just curious for knowledge based info...I've always read coils at valved for +/- 2k. What would a coil do or react if you went more? In my case lets say lower and with every 1k lower, what would you see?