Planet 9

Apollo · #1 05-14-2009, 11:55 PM

I will be taking my CS for an alignment. I AX 2-3 per month, but I also put 10K miles on it.

My plan so far is to do max negative camber up front, and do about -1.7 in the back.
My question now is about toe-in (or out). I don't want the car to dart everywhere for highway use, but little better turn in would help me with AX numbers.
I have read many threads here, but I am not finding consensus.

Should I keep the back at zero toe-in in the back, or should I do .09 degrees toe in on each side?
For the front, .04 toe out or .04 toe in?

mjchip · #2 05-15-2009, 04:46 AM

I can't give you a definitive answer but I'm trying to sort this out as well. Here are my current alignment specs:

Front toe: +0.125" (in)
Front Camber: -2.45 deg
Rear toe: +0.125" (in)
Rear Camber: -2.25 deg

I'm running Kumho V710s in 245/35-18 and 305/30-18. The last event at Devens the car pushed a little and turn-in was sluggish. I had a few very experienced and proficient drivers in the car (both as drivers and passengers) and the consensus is the car feels really good except for turn-in being sluggish and slight push. The recommendation is to go to the following:

Front toe: -0.125" (out)
Rear toe: 0.000"

I'm going to do this for the next event and see how it goes. I will also be logging tire temps to find the right inflation pressure and fine-tune camber.

MJ

Jim Michaels · #3 05-15-2009, 09:52 AM

Apollo: One reason you're not finding complete consensus is probably that some drivers are willing to make more compromises for AX driving than others. mjchip's alignment (including recommended toe changes) sounds right for AX, but you might not like it for your 10k road miles. A little toe-out helps turn-in, but you'd probably need to make more steering corrections just driving straight down the road. The recommended zero toe for the rear would help bring the rear out with throttle application, but you might not like the less settled feeling during road driving. You could try an AX alignment and see how you like it, and change it back if you don't care for it on the road.

Apollo · #4 05-15-2009, 10:49 AM

Well... at $200-$300 a pop for alignment, I am not exactly keen to experimenting.

How unsettled would 0 toe-in on the back be compared to how they come stock (I think OEM setting is 1/16th" toe out)?

So on the front I should than be running instead of 1/16th of an inch toe out to 1/16th of and inch toe in?

My main goal is to reduce that understeer and have a bit more balanced car on the AX course. I can get the butt loose now on the AX courses where I need to, since I got the hang of how to play with tire pressures in the back. It is the understeer in the sweepers and tight corners that pisses me off.

**KS-CS** · #5 05-15-2009, 12:54 PM

Originally Posted by Apollo

. . . How unsettled would 0 toe-in on the back be compared to how they come stock (I think OEM setting is 1/16th" toe out)?

So on the front I should than be running instead of 1/16th of an inch toe out to 1/16th of and inch toe in?. . .

There shouldn't be any toe-out on the rears, because that will cause the car to "crab" down the road. I agree with Jim above, I went with .04 deg toe-in on the rears which I think is the best compromise between stable road handling and AX/Track handling. I also went with 0.04 deg toe-in on the fronts for the same reason. Since my car is a DD, and I mainly AX for fun, I didn't want to destabilize the road handling with toe-out on the fronts. I'm very happy with how my car handles.

mjchip · #6 05-15-2009, 04:38 PM

The only other commentary I can give is the following:

Toe out in the rear is something I do not like at all. It can be downright scary in fact.

The rears for a street car should have positive toe (in) a little. I'm going to try zero toe but will quickly go back to positive toe if the car snaps.

Positive toe in the front makes the car sluggish on turn in but is inherently more stable and less darty. Again, I'm going to try negative toe to see how the car feels at the AX and on the street and adjust from there.

I do my own alignments so there isn't any expense (except for time) for me. If you want to set it and forget it, I would recommend you leave toe alone and add camber plates to give you more negative camber in the front. This will reduce push without compromising street handling (tire wear will go up if you exceed 2 deg negative). Make sure you do the plates BEFORE you get the alignment or you will be back there resetting toe.

YMMV,

MJ

wpmjr · #7 05-15-2009, 07:07 PM

slight toe out in front (1/8)
slight toe in in rear (1/8)
if stock, max neg camber in front (~-.9 degrees)
less neg camber in rear (~-.5 degrees)

you want less neg camber in rear because you need to overcome stock understeer

Mike_in OH · #8 05-17-2009, 06:56 PM

0 toe in front; 1/16 toe in in the rear. Very responsive and no odd tire wear on the street.

Apollo · #9 05-17-2009, 09:52 PM

I have decided to put any work on the car on pause for right now.
I am trying to figure out if I want to do Nitto NT05s, if I want to do H&R sway bar in the front. Once I make up my mind on that... than I will pull the trigger.
I am tempted to put in camber plates too, but I need to do a lot more research to see who my competition in Production class would be, since I definitely will be out of Showroom Stock with 245s up front and 275s in the back.

... but before I start blowing more money, I need to find a "real job", since the last company I helped start just did not survive. Oh well... off to lick my wounds.