I was at an autocross last Sunday, and my car was understeering like crazy. I have Tein RE, azenis, and an R rear sway. I had the front dampening pretty stiff, and it still wouldn't steer right. Is there anything else I can do to recuce that much understeer?

 

At first make sure it isn't your driving. What is your autocrossing experience?

 

This is my second year.

 

How many events though......

Slow in, fast out. Adjust tire pressures. Rear damping should be full stiff, not front.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by .RJ &raquo;</TD></TR><TR><TD CLASS="quote">How many events though......

Slow in, fast out. Adjust tire pressures. Rear damping should be full stiff, not front.</TD></TR></TABLE>

I think I've driven in 6 events. I went slow in fast out, but always in the middle of the corner it understeered really bad, also in the U-turn at the end of the run it was crazy bad. I didn't have either at full stiff. I had the front at 9 and the rear at 7. And I had 5 more psi in the front tires than the back.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IntegraBoy04 &raquo;</TD></TR><TR><TD CLASS="quote">I think I've driven in 6 events. I went slow in fast out, but always in the middle of the corner it understeered really bad, also in the U-turn at the end of the run it was crazy bad. I didn't have either at full stiff. I had the front at 9 and the rear at 7. And I had 5 more psi in the front tires than the back.</TD></TR></TABLE>

Is this a new problem for you on the same setup, or have you changed your setup since the last event and now you're having this problem? What did you run your front tire pressure at? With 5psi over rear, perhaps you overheated them. What are your spring rates front and rear?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IntegraBoy04 &raquo;</TD></TR><TR><TD CLASS="quote">

I think I've driven in 6 events. I went slow in fast out, but always in the middle of the corner it understeered really bad, also in the U-turn at the end of the run it was crazy bad. I didn't have either at full stiff. I had the front at 9 and the rear at 7. And I had 5 more psi in the front tires than the back.</TD></TR></TABLE>

from my experance every thing is backwards, put more PSI in the rear and have the shocks stiffer in the rear.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IntegraBoy04 &raquo;</TD></TR><TR><TD CLASS="quote">I think I've driven in 6 events.</TD></TR></TABLE>

Not enough time.. even though its been "2 years" since you started, 6 events is at best a little more than half a season.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IntegraBoy04 &raquo;</TD></TR><TR><TD CLASS="quote">I went slow in fast out, but always in the middle of the corner it understeered really bad, also in the U-turn at the end of the run it was crazy bad.</TD></TR></TABLE>

Still sounds like you are entering to fast, everything is loading up and then causing the push.. or, you are apexing too early and causing the same thing.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IntegraBoy04 &raquo;</TD></TR><TR><TD CLASS="quote">I had the front at 9 and the rear at 7. And I had 5 more psi in the front tires than the back.</TD></TR></TABLE>

Both wrong direction probably, typically you soften up the end you want to grip.. so run shocks softer up front. With tires.. go by rollover because too much or too little in the front could cause the same thing..


Jon K
http://www.seat-time.com

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">it still wouldn't steer right</TD></TR></TABLE>

because

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">I had the front dampening pretty stiff...And I had 5 more psi in the front tires than the back.
</TD></TR></TABLE>

Full soft front, full stiff rear, reverse your tire pressures.

How about alignment?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by FlyZlow &raquo;</TD></TR><TR><TD CLASS="quote">

Is this a new problem for you on the same setup, or have you changed your setup since the last event and now you're having this problem? What did you run your front tire pressure at? With 5psi over rear, perhaps you overheated them. What are your spring rates front and rear?</TD></TR></TABLE>

The last time I drove I didn't have a sway bar at all...and I had Kuhmo 712s. And then I had lots of oversteer. I had the front at 50 and the rear at 45.
The rates are 14k front and 10k rear.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slammed_93_hatch &raquo;</TD></TR><TR><TD CLASS="quote">

from my experance every thing is backwards, put more PSI in the rear and have the shocks stiffer in the rear.</TD></TR></TABLE>

I was always told the opposite.

Also, would camber have any part in this?

 

What is the ride height? Your complaint sounds exactly like what happens with not enough suspension travel. The front shocks bottom and the spring rate goes infinite causing massive understeer. If it was the front shocks being too stiff, it would happen entering and exiting the corner. Middle of the turn is from spring and sway bar not shock. Tire pressure could contribute too but I would start by verifying the front is not bottoming.

 

^^^ but from who? what cars do they drive? if they drive a rwd car...then it will be opposite for a fwd like ur integ. and it should be more tire pressure in the back and stiffer in the back. if you are getting too much oversteer, just make the rear shocks softer.

imo, i rather get oversteer than understeer.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mohudsolo &raquo;</TD></TR><TR><TD CLASS="quote">What is the ride height? </TD></TR></TABLE>

The car has about a finger gap in the rear and right on the tires in the front, but not tucking. This is on 215/45/16 azenis.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IntegraBoy04 &raquo;</TD></TR><TR><TD CLASS="quote">
The rates are 14k front and 10k rear.</TD></TR></TABLE>

This setup will understeer for sure.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SPiFF &raquo;</TD></TR><TR><TD CLASS="quote">

This setup will understeer for sure.</TD></TR></TABLE>

Why is that?

 

trust us with a FWD car, most people run softer up front stiff in the back, with a big sway bar in the back and either small or none up front. Its how FWD operate best.

YOu could also have the front stiffer then the rear, with a big sway in the back and then really rely on your alignment settings and tire pressure to get the car to rotate.

 

I was thinking more about what shock travel is available at your ride height. Depending on the shocks, you could easily have too little travel and hit the bumpstops.

The general concensus on front drive suspension setup is to go stiffer in the back on springs and sway bar. This allows the front to stay planted and make more of the roll stiffness be carried by the back. Higher rear tire pressure keeps the tire surface from sitting flat on the road and further reduces rear tire grip.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IntegraBoy04 &raquo;</TD></TR><TR><TD CLASS="quote">Why is that?</TD></TR></TABLE>

More spring out front means weight will transfer off the front wheels and they will loose grip, AKA more understeer.

More spring out back means more weight up front, AKA less understeer.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mohudsolo &raquo;</TD></TR><TR><TD CLASS="quote"> Middle of the turn is from spring and sway bar not shock. </TD></TR></TABLE>

I can see the suspension travel being an issue, think an evo i was at a test with last week is having some issues with that.

But.. mid corner out is going to be a shock rebound issue or sway bar. the suspension has compressed and in an autocross situation, is probably coming back off full compression, which does make it the rebound issue. (I can dig out some books with some setup sheets that detail this)

Though.... entering, middle, or exit is hard to judge here with no idea of what driving line might be affecting as far as what exactly mid corner.. (mid corner geographically might not be where the car is in other words)

Jon K
http://www.seat-time.com


Modified by racerjon1 at 9:00 AM 1/21/2005


Modified by racerjon1 at 9:01 AM 1/21/2005

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">I was always told the opposite.</TD></TR></TABLE>

By *WHO*?? Knowledgeable autocrossers, or some other jackass? I'll bet it was the guy who sold you those Teins....

You got a front strut tower bar? Also, I don't think I've seen you say anything about alignment yet. That has a DRAMATIC effect on autocross handling...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MaddMatt &raquo;</TD></TR><TR><TD CLASS="quote">

By *WHO*?? Knowledgeable autocrossers, or some other jackass? I'll bet it was the guy who sold you those Teins....

You got a front strut tower bar? Also, I don't think I've seen you say anything about alignment yet. That has a DRAMATIC effect on autocross handling...</TD></TR></TABLE>

The guy that sold me the Teins did tell me that...But also a few of the big time autocrossers here told me that as well. I have a Neuspeed 4 point strut bar.

What about the alignment...I have had one, but do you mean the specs of the alignment? also, does camber have anything to do with it, because I have -.5 in the front.

 

Mid-corner understeer *could* indicate where the car has achieved a near-steady-state condition, which makes sense as his springs bias roll stiffness to the front.

Corner entry understeer would be due to the shock settings.

RE: alignment - Front camber is only -0.5?? That's way low. You should(?) be in the vicinity of -2.0.

Here's a quick lesson in handling balance: If the front suspension, through a combination of springs, antiroll bar, and shocks, is STIFFER than the rear suspension, then you will have understeer. If the rear suspension, through the same formula, is stiffer, you will have oversteer.

It's more complex than that, but it's a guideline.

 

Yea...I figured the camber was too low as it is set for daily driving..But I didn't have time to get it set differently.

 

FWIW, my setup consists of full soft shocks up front, full stiff in rear, ~250lb. springs up front, 325lb. in rear, 3/4 rear sway, tires pressures 2 psi. more in front vs. rear, and car rotates like a top. When I was on Azenis, I was running 5 psi. more in front, and car rotated the same, setup the same vs. R-comps and Azenis. Front toe-out 1/8in., rear toe at 0.

I think tire pressures vary with each car/driver. I try to start with 35psi all around, and go from there, according to sidewall rollover, tire temps, etc.

 

Most of the teins I've seen (and used to have as a matter of fact) came with craptastic spring rates. In my case, they were 9k front, 4k rear, which was horrible for auto x. higher speed stuff was a little better with a big rear swaybar, but I still wasn't happy with my setup (tein flex).

you could try putting a softer spring up front, and/or reducing the damping. this will allow the front end to grip more and reduce understeer.

also, if you are only running -0.5 camber up front, that is way too little. like someone else said, you need more. you can run up to -2 or so without wear problems, as long as you get your toe aligned to spec.

alignment specs can really make a difference as well. you might want to zero out the rear toe, or run a bit of rear toe-out, but just realize that it will make the car have a tendancy to wander more at speed, but will help with inducing oversteer.