The common notion is if you think about it in terms of weight transfer.
More pressure in front meant less weight transfer to the front - think of it as getting a stiffer front bar.
Stiffer front bar -> more understeer
I'm not too sure of what you mean by "increase traction" and "decrease traction", as there is no reference to front or rear?

To the original poster...
All of the typical recommendations of what you want to do can be easy found by a proper search.
Do a search in this forum, or hell, do a global web search (i.e. Google), and you will find the same information.
Coming in here proclaiming you can drive is just...brash.
People were making suggestions, and you were shooting them down cause it wasn't what you were looking for.
If you had done a proper search in the first place, you wouldn't be in the situation.
The current rules prohibit just yelling SEARCH as a reply, but I really think you need to do it.

BTW, how old are you?


-Ted

 

RETed, your not helping me, but thanks anyways, and why do you care how old I am, age has nothing to do with this. My question to you is, how long have you been working with rx7’s? 22,335. That is a lot of posts, why are you shooting me down, you obviously have been around here for a wile.

Every car reacts differently. I just wanted to know what direction I should go.

 

I agree with jgrewe's suggestions. It is amazing how much you can change just by altering your driving style. The zoom-zoom thing was the first time I have truly pushed a car like that and by experimenting with different approaches I could tell noticable differences in times. While I'm not saying can't drive, there are very few people that can't learn to drive faster.
And I feel you on the tire prices. When I went to replace my wife's 17" tires I just about choked. Even the "cheap" ones were as much as my damn nice 16" tires.

 

Why are you so defensive about your age?
I'm 37.
See, that wasn't hard wasn't it?
My post count?
If you know me, I don't give a rats *** about my post count.
Others seem to be very hung up on it though...
How long?
I've owned my FC turbo since 1995.
That means I've been working on it for over a decade.


And this is why I shoot you down...
I have this problem with people who like to brag.
Bragging and boast is not the best way to get people to help you - agreed?
If you had just asked the question and not get too defensive when someone questioned your ability to drive, then I wouldn't have jumped on your so harshly.

BTW, the way you formed the question wasn't very good either.
Understeer keeps you in control.
This is so important, I'm going to repeat it again.
UNDERSTEER KEEPS YOU IN CONTROL.
Oversteer causes you to spin out.
For the majority of people who drive, understeer is the safe state the car should be in when it loses traction.
Understeer is purposely designed into the suspension dynamics to keep people causing accidents, killing themselves, or killing other people...you get the picture.
To question why the car understeers is just plain stupid.
If you can't understand why, reread this entire paragraph again.

Now, again, if you're such a good driver, you should be able to sort things out yourself?
Why ask the peanut gallery on what you should do?
This just doesn't make any sense...


-Ted

 

Ted, I think what his problem is, is that he doesn't want to understeer quite so much. Any FC I've ever driven will understeer pretty horribly if you push it too hard, the majority of that at low speeds (Not knowing what you're doing). If he's THAT worried about it, maybe he should just put crappier tires on the back, pump up the rears and soften the fronts or try out a few rally driving tricks to induce more oversteer than there will be understeer when he autocrosses?

This thread has gone a tad far with the flaming. No one needs to be in here throwing insults around and taking stabs at other people, no matter how subtle or obvious it may be.

Rotorpower: Bottom line, man, take all the advice people have given you thus far and use it. There's nothing more than can be said. Experimentation and practice will get you what you want...this thread continuing on, however, will not.

Case closed.

 

Well after reading all of this I still don't quite understand what understeer (or oversteer) is. So, could some one explain it to me please?

 

Understeer: when the car turns less than you expect. I.e. the front tires lose grip and the car 'plows' or 'pushes'. You leave the road nose first.

Oversteer: when the car turns more than you expect, i.e. the rear tires lose grip and the car is 'loose' or 'fishtails' or, in more extreme cases, spins.

Understeer tend to be safer. Imagine going into a corner too fast, and the front end begins to lose grip. The natural instinct is to back off the throttle, which transfers weight forward and re-establishes grip. You go wide, but make the corner.

Oversteer is less safe on the street. Again, imagine going into the corner too fast, and the back end starts to come around. You back off the throttle, transferring weight forward and decreasing grip at the rear - you spin more.

On the track, especially in autocross, oversteer can be used to help rotate the car and increase speeds. However, the margin of error is small, and spinning is always a possibility. Not a good situation for the street.

Older 911s were bad for this, with the engine hung out the back. The worst thing you could do was back off the throttle in a corner - counterintuitive for most drivers. They say that 911s are tapered at the rear so they can penetrate the shrubbery more easily when they go off the road backwards.

BTW, if a car understeers badly, the answer isn't to induce oversteer. You can reduce understeer and aim for neutrality, without going all the way to oversteer. Also, these conditions are speed dependent. A car that is nice an neutral at autocross speeds will be an oversteering nightmare at track speeds.

All suspension tuning is a matter of compromise. The trick is to get a setup that matches the intended use and the driver's preferences. Hence, there is no "best" setup for all conditions.

 

my car is totally neutral now. i all i have done is dtss eliminators. adjustable endlinks. and new front tires(falken ziex 195 60r 15 with cooper cobras in the back 205 60r 15) no understeer at all. handles perfect. maybe its just me though

 

My experience with the tire pressure adjustments goes way back to auto-xing 20 years ago. I was running a front drive car and we used to pump up the fronts so the car would point into the turn quicker and lower the rears so they would slip from the sidewall flexing.
Some people after me have had different opinions on which way to go with pressures and they may be right, as I said there comes a point when pressures do the reverse of what they started to do for you. Pump up a tire passed its design pressure and you end up running on only the center of the contact patch. Since he has been running below the rated pressure I figured he hasn't been getting the most from either end.
Getting temperatures are pretty tough after a short auto-x run but its the best way to find out what is going on.
I still say the easiest way to fix a push is to slow down and let the tires work to move the car. You can't ask the tires to give more than 100%, if you are using 100% to turn the car you have nothing left when you try to accelerate and turn. I can make ANY car push, the trick is to learn how to not make it push by driving correctly.

 

I totally agree, and someone had already mentioned that.
I think the OP just went into the turn too fast.
If we all knew about weight transfer (and trail braking), it would've been end of discussion a long time ago.


-Ted

 

If you said that the car squats and rolls a lot, maybe your rear suspension is worn out. If your rear suspension is all worn out then that would affect the front/rear balance. If the front suspension is still in good condition, it would essentially be like running a higher spring rate in the front, which could cause understeer because of the upset in balance.

I say check out your rear suspension components. Try pushing down on the back corners of the car and see how spongy they feel, and watch how the suspension reacts after you push down and let off.

 

this has me thinking , anyone know how the SA / FB / FC / FD's (stock/normal tire pressure) compare with each other on understeeer / oversteer ? ... hopefully not a thread hijack