I've been searching and reading through autocross and spring rate threads and I've found that there's a consistant difference in spring rates for the same kind of racing.

Japanese rates follow the front/rear bias fairly mathematically. Ie for a FWD with a 60F/40R weight distribution, they release springs at 10F/6R or sometimes slightly against like 8/6.

Americans go in the opposite direction and go more like 6F/8R and sometimes even more extreme in the rear.


Do Americans like oversteering more or is there some secret hidden in the formula to achieve a neautral ride?

I think my car is 960kg, 60% Front and I'm thinking of running 8kgmm/6 for private hillclimbs (circuit quality tarmac) and daily driving.

 

It's represents a different philosophy in set up, due in part to the make up of the track surface... I follow more the Nippon style myself, but I know plenty of others that do not. As it relates to Auto X i don't know, I don't auto X. But as it pertains to bigger tracks and high speeds I do know, it's much more predictable without snap over steer when your average lap speed is approaching that 100mph barrier

 

Keep in mind that the Japanese have a different philosophy about tire sizing as well. They tend not to run as wide of a tire as we do in the States. They also have some crazy compounds that we don't get over here.

 

Yes indeed. good points

 

Right now my car is at 10k F/ 14k R. Buddy Club.

However, I eventually I will end up redoing the rears to something along the line of 10k F/ 18k R

 

Do they auto-x in Japan?

 

No idea. What exactly defines auto-x?

I just want to develop a neautral handling at the point of traction loss, suitable for public and private hill climbs.

All the coilovers for my car suggest 8F/6R - 450/335, but not many commercially released coilovers using the American philosophy, so I was hoping to get a technical explanation as to why it's chosen that way over there.

 

Most of the off the shelf coilovers are meant for a Street car with occasional track time. For real race cars ( Track Only Cars) you do not need to worry about hitting the old man next to you in a Buick when you are making that turn at the light. The US setups are very fast Very Looose. So if its a street car get JDM setup. Track Race only car US setup. THATS it , I run 700F 1000R most people run more than that..

Edo

 

With this 700/1000 can you do ANY trailbraiking?
I'm a bit inclined thowards the american setup, but I'm starting to realize that with 550/550 I have to be quite careful when braking and entering and I'm even more conserned as I'll be very soon driving 450/550.
I love trailbraking and letting the back step out a bit, but a bit is a bit and if it gets too much and too easy I'll have to abandon trailbraking and thus speed.
so mr. edomoto (Edik Stepanian right?) do you trailbrake?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1net &raquo;</TD></TR><TR><TD CLASS="quote">With this 700/1000 can you do ANY trailbraiking?</TD></TR></TABLE>

Trailbraking is for understeering pigs.

Any weight on the inside rear, could have been on the inside front. The front tires are doing all the work, just get the front as flat as you can and stiffen the rear (relative to the front) to achieve that.

Seems simple.



-Chris

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by glagola1 &raquo;</TD></TR><TR><TD CLASS="quote">Do they auto-x in Japan?</TD></TR></TABLE>

Yeah, Gymkhana.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1net &raquo;</TD></TR><TR><TD CLASS="quote"> mr. edomoto (Edik Stepanian right?) do you trailbrake?</TD></TR></TABLE>

I do if needed I also run a 32mm ASR bar in the rear. I will trailbrake if im trying to outbrake someone. But if i dont have to i will brake going straight and get back onto the gas as soon as i can to increase the time on the Gas pedal. The long Wheelbase on the Integras helps.

Edo-EdoMoto-Edik Stepanyan

Edo.

 

on an itr, with the amercian way of thinking, with higher rates in the rear(12kf14kr), if you were to install a smaller sway bar in the front(ls) and a larger sway bar in the rear(asr32mmhollow) it whould give more oversteer correct? from what iv been reading it does, this is the setup im goin with, and wanted some opinions from people who have ran simalr setups

 

I ran 900/800lbs on KYB SSGs and a 22mm front bar and 23mm rear bar... I loved the setup. I'd run same sized tires front/rear and ~3deg camber front, ~2deg rear... typically 0 toe (many street miles between events).

Car turned in amazingly and handled very well with a bit of a tendency towards oversteer.

My only unworked out thing in the setup was rear end squirm under high speed braking. I bet toe changes or a rear wing could have helped that some.

This was on a 92 civic hatch.

 

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

Trailbraking is for understeering pigs.


</TD></TR></TABLE>

Hahaha, a bit too general for me. I hope you are joking.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EdoMoto &raquo;</TD></TR><TR><TD CLASS="quote">I will trailbrake if im trying to outbrake someone. But if i dont have to i will brake going straight and get back onto the gas as soon as i can to increase the time on the Gas pedal.</TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 01-0720 &raquo;</TD></TR><TR><TD CLASS="quote">on an itr, with the amercian way of thinking, with higher rates in the rear(12kf14kr), if you were to install a smaller sway bar in the front(ls) and a larger sway bar in the rear(asr32mmhollow) it whould give more oversteer correct? from what iv been reading it does, this is the setup im goin with, and wanted some opinions from people who have ran simalr setups</TD></TR></TABLE>

Yes, the bigger rear bar will definitely increase rear slip angles on the setup you mention.

I would recommend not running even a slightly loose setup on the street as it is asking for trouble - and it wouldn't neccessarily be your fault when your car spins out and nails someone when you get cut off or something and you lift off the throttle when your car has even a slight amount of yaw velocity.

 

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

Hahaha, a bit too general for me. I hope you are joking.</TD></TR></TABLE>

70% joking. My old ITR I would trailbrake into every corner because it didn't turn in. My Prelude I can only get away with that in a couple places or else I'm spinning backwards.

 

Trail braking is not something that should be avoided and is not an indicator of a car that has a persistent push. The ideal setup would be one that rotates well mid corner, on throttle while giving you a docile corner entry behavior that allows aggressive trail braking. If you can't get a fwd car to turn in, you are doing something really wrong. Poor turn in can just as easily be caused by insufficient front roll stiffness overall or relative to the rear roll stiffness as it can be caused by too much front roll stiffness.

And while Chris is correct, weight on the inside rear could have been weight on the inside front, at the same every millimeter the inside rear comes off the ground is potential grip lost. You want all the weight off the inside rear tire, but you DON'T want to lift it off the ground.

I've run severely front biased setups before (700/550 with a 24mm front bar, 23mm rear bar) and massive understeer is not how I'd describe the balance of the car. Well, at least not after I dialed out the rear camber. Wheelspin wasn't an issue, and I was pulling over 1g on street tires, so I didn't pitch any grip out the window. At least not from the axle that matters. All I'm saying is that just because the stiffer spring is on the front axle does NOT automatically mean the car is an understeering pig. Anyone who tells you that should not be listened to for suspension setup advice as they clearly do not understand the multitude of variables that affect grip and balance.

 

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

I will trailbrake if im trying to outbrake someone. But if i dont have to i will brake going straight and get back onto the gas as soon as i can to increase the time on the Gas pedal.
.</TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by solo-x &raquo;</TD></TR><TR><TD CLASS="quote">You want all the weight off the inside rear tire, but you DON'T want to lift it off the ground.</TD></TR></TABLE>

Why not?

 

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

Why not? </TD></TR></TABLE>

1. The rear suspension's contribution to roll stiffness is gone as soon as the inside rear leaves the ground.

2. From the point the inside rear leaves the ground, any additional increase in roll angle is accompanied by an increase in understeer.

3. We lower our cars to get the cg down. Lifting the inside rear dynamically raises the cg, increasing the total lateral load transfer which happens across the front axle. This is accompanied by more roll, which raises the cg higher, increasing the total lateal load transfer increasing roll....

You can choose to not believe me if you like. I've long since given up trying to convince anyone to change their approach to setup. It just irks me when people say "ah, stiff springs on the front, must mean its gonna understeer!". On formula fords, we run more spring on the rear axle then the front axle. That doesn't automatically make that car oversteer, just like putting the stiff springs on the front of a fwd car won't automatically understeer. Nor will putting the stiff springs on the rear of the car automatically make it oversteer.

Going back to trail braking. Imagine for a minute if you will a corner that you have to slow to 50mph to take. Imagine a straight line braker taking the corner and a trail braking braker taking the corner. Both have to slow to the same speed by the middle of the corner. The straight line braker slows to 50mph before turning in. The trail braker doesn't finally slow down to the 50mph speed until just before the apex of the corner. Both driver's get on the gas at the same time because they were both at the same speed at the same point before the apex. The trail braker spent less time in the corner and just as much time accelerating.

Braking, the last thing a racer ever learns to do right...

Nate - has the theory all worked out, now about that execution stuff....

 

Solo-x has it nailed IMO.
Of course you can’t effectively trail brake in all types of corners, but there is definite advantage to do it wherever you can.
However, you must never affect mid corner speed, and I think this is where most get it wrong and find it doesn’t work for them. People figure to do it correctly you better be a madman on entry crushing the outside front, but often its pretty easy to blow your mid corner speed.
I don’t and never have been a big believer in “slow in, fast out", slow in is, well, slow.
Some corners this is the way to go of course, but that statement is just far to general for me.



Modified by pmachan at 3:13 PM 4/10/2008

 

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

1. The rear suspension's contribution to roll stiffness is gone as soon as the inside rear leaves the ground.

2. From the point the inside rear leaves the ground, any additional increase in roll angle is accompanied by an increase in understeer.

3. We lower our cars to get the cg down. Lifting the inside rear dynamically raises the cg, increasing the total lateral load transfer which happens across the front axle. This is accompanied by more roll, which raises the cg higher, increasing the total lateal load transfer increasing roll....</TD></TR></TABLE>

I agree with 1. I agree with 2. I agree with 3 to some extent, but I'm not sure how much.

I'm not advocating the "pissing dog" stance for cars. I'm just saying, get all the weight off the inside rear, and if you turn into a pissing dog, raise the front roll stiffness.

Here's my car lifting the inside rear, even on the gas exiting a carousel.
I'm the #117 Prelude. Forward to 00:25 seconds. It's a little off camber on the outside of that corner but not much.
http://www.youtube.com/watch?v=wwDJfE7Vdj0
It's only up about an inch. I don't need more rear roll stiffness, but I wouldn't get rid of much of it.

(Credits, Inness is the videoing car, Andrie is the white-ish Civic, the Red Integra is Mike Lee, and the White Integra is my old ITR, Matt Lang)

 

Very interesting... so if i am lifting the inner rear it means that i need to increase the front roll stiffness.. i am currently running without a front bar 800/1000 springs. Should i reconnect my front bar? Reconnect and drop front spring rate maybe?