quest for cheap lateral grip

[JimD]

Total

He means 1/8" total.

 

[wannabfast]

i realigned it today, it feels way better, and it corners really good now, hopefully it makes it to sunday's event.. im sorta adamant about this site, everytime ive been to this site, my x has broken down enroute to the event...

but that was 2 years ago

 

[Black-Tooth]

Yeah Thai... this site is "HEXXED"...

... and just for YOU!

HA!

Good luck at the event... I've personally removed all hex's for this weekend.

 

[wannabfast]

made it to the event, but i had a slight mechanical issue on one of my runs, i couldnt shift into 2nd gear... it was the lollipop that worked its way loose, minor fix but still was annoying as it was an otherwise great feeling run, i say feeling because a run can still feel fast and still be sucky

side note car felt pretty good, but it still sorta oversteered but only when i was on the brake with the wheel turned

i keep coning my runs, and its minor stuff like i turned in too soon

 

[racerx]

to keep

the oversteer from happening do your braking before you turn in for the maneuver .

good to hear the car is working better for you. the one thing I can tell you about autox is the more events you attend the better you will get.

To avoid hitting cons try a couple of runs a little slower and try and smooth out your run .

smoother is faster

 

[wannabfast]

yea i know, i need to brake in a straight line, but sometimes its more fun with oversteer...

my issue with cones is that i turn in too soon

 

[abec]

yea i know, i need to brake in a straight line, but sometimes its more fun with oversteer...

my issue with cones is that i turn in too soon

No you don't need to brake just in a straight line, in fact if you want to go faster then you should be using your brakes as you enter a corner.

http://virtualracersedge.com/trail_braking.htm

A quote from the link above

Ricardo Nunnini: "Never take your foot completely off the brake until you reach the throttle application point..."

 

[racerx]

Yes

your are right but for some one that hasn't learned to left foot brake (trail brake ) braking before turning is good way to keep from oversteer.
well stop turning to soon and you won't hit cones
like i said before slow it down smooth it out
smother is faster
next time you go to an autox watch other cars the car that looks fast is the one driving violently but has slower times some of the fastest cars look slow because they are smother .

 

[abec]

your are right but for some one that hasn't learned to left foot brake (trail brake ) braking before turning is good way to keep from oversteer.

I am not sure if you mean to say left foot braking is the same as trail braking or not, but that is kinda how I read that.

To clear any confusion left foot braking is not the same as trail braking though. You do not need to left foot brake in order to trail brake. It just happens that trail braking is a key technique used when left foot braking.

 

[wannabfast]

yup, when the foot isnt on the brake, its on the throttle.. or at least should be

altho when i hit the brakes in a turn, the rear just wants to come around, so i would need to compensate with less of a steering angle, and a little bit of throttle

 

[Steve Hoelscher]

Ricardo Nunnini: "Never take your foot completely off the brake until you reach the throttle application point..."

Never heard of Ricardo Nunnini. Trail braking is a technique that use you ONLY when the situation requires it. The above statement includes the word "never". He couldn't be more wrong. There has been a lot of debate about trail braking. Bob Bondurant's school teaches trail braking. When asked about trail braking, Jackie Stewart discounted the technique. The interviewer then noted the Bondurant school's use. Jackie's reply; "...so how many World Championships does Mr. Bondurant have?"

I only trail brake when aboslutely necessary. A typical example is in a decreasing radius corner where entry speed is well above apex speed. With those few exceptions, trail braking causes more problems than it solves (early apex, shallow entry, late throttle application, slower overall corner speed, etc...).

Trail braking does feel faster. On the clock it surely is not. You cannot achieve maximum braking if you are turning. Nor can you achive maximum turning if you are still braking. The friction circle proves this. The correct technique is to blend or slightly overlap braking and turning. That is; you release the brake pedal gradually as you turn into the corner. The more steering angle the less brake. By the time you have the maximum steering angle, you are completely off the brake pedal.

The same goes for the throttle. You roll into the throttle as you unwind the wheel.

 

[abec]

Never heard of Ricardo Nunnini.

Trail braking does feel faster. On the clock it surely is not. You cannot achieve maximum braking if you are turning. Nor can you achive maximum turning if you are still braking. The friction circle proves this. The correct technique is to blend or slightly overlap braking and turning. That is; you release the brake pedal gradually as you turn into the corner. The more steering angle the less brake. By the time you have the maximum steering angle, you are completely off the brake pedal.

The same goes for the throttle. You roll into the throttle as you unwind the wheel.

Me neither, it was just a quote from site i linked. It was just one of the first things on google when I searched trail braking.

That is my understanding of what trail braking is, using your brakes as you start your turn in and reducing the braking force as you turn your wheel, then getting on the gas as you exit and unwind your wheel.

 

[Steve Hoelscher]

That is my understanding of what trail braking is, using your brakes as you start your turn in and reducing the braking force as you turn your wheel, then getting on the gas as you exit and unwind your wheel.

In practice, its way more than that. The "blending" or overlap is only a brief period of time. As the driver turns into the corner he winds the wheel in one smooth confident motion. As he does this, he releases the brake pedal, in one smooth release. The overlap occurs only at the turn-in point and only for a a brief moment.

Trail braking is carrying the braking process right through the turn-in point and gradually trailing off the pedal as the car approaches the apex. By necessity, the brake pressure would have to be modulated as the driver turned the wheel. The brake is only fully released at the apex when the driver then goes to the throttle therefore the car never achieves maximum braking or turning.

Trail braking is not an efficent use of traction resourses.

 

[autox19]

So True!

I learned to trail brake in a parking lot from a friend racer. He believes that like other skills, it is a tool in a tool box. you may never use all your tools, but there are times that a specific tool comes in handy.
Steve made me think of 2 point that I use almost everyday while driving. (especially in winter) the first being there can only be 100% force on a tire. you have to combine all directions together, but you cannot go over 100. if you have 50% of the force working on the turn, and 50% on braking, you are safe. Push the brake or turn a little sharper and you will start to lose traction (you are over 100). It is one of the reasons I have taught every friend I can, this lesson. In the snow if you are braking while turning and start to slide, you have 2 choices, steer less or brake less and traction will start to return.
The other is with trail braking. Go to a parking lot and go into t circle. doesnt need to be fast. Hold the steering wheel at one angle and start to press on the brake. you will see that without changing the steering wheel position you will be turning shaper. I tried to explain once, but left it as PFM (Pure freaking magic) Maybe one of our handling gurus can explain it.

well back to pretending to work


Odie

 

[spiggs]

...
Anyhow, you often talk about spring rates but I don't recall you mentioning dampers. Is this simply because there is such a limited selection for the X?

My own personal experience (in both my track X and my street Scorpion) is that using spring rates higher than about 300# with lower-end dampers such as KYB GR2's result in a "pogo-ing" feel, and in a turn, if the suspension is upset, it can make the car feel like it is skipping (which I imagine it is, as the spring oscillates).

Any info appreciated.

Thanks,
Pete

I would be interested in some good shock info as well. Trying to go budget I bought a set of Bilsteins for my X. From my research (lots of web searching) the stock valving is supposed to be good for 300lb - 400lb springs. I assume this is on the rebound side, compression I don't know if its in the ballpark for an X. Of course I plan to go higher with the rates. Not sure if it would be worth installing then as is and trying higher rates or if I should have them revalved by Bilstein first, and of course would Bilstein know how to revalve them correctly for a high rate X (~650f/450r). FWIW I am told these are linear rate inserts, what is the trade off vs digressive for an autox car? Bilstein publishes their data in newtons and meters per second, the stock valving is listed as 251/73. Following is the shock dyno from Bilstein converted to english units. So are these going to work?

 

[wannabfast]

how much higher does the front need to be to maximize the grip? i have the rear about 1/4" lower in the rear than the front, should it be enough with the stiffer springs in the front?