stevensimon

iTrader: (11)

i understood all of what you said, you were just 1/2 wrong.

http://books.google.com/books?id=BJU...eight.&f=false

http://grassrootsmotorsports.com/art...orner-weights/

http://books.google.com/books?id=i2Z...eight.&f=false

SpideyFan6010

.......i am right and you are right. I am speaking only from the standpoint of the front/rear bias I am not talking about the cross-weight from side to side. From the cross weight standpoint you are correct but from the front/rear bias you are wrong.

If raising the Back right increase the weight how is it also going to increase the weight of the front left?(not talking about the entire left hand side just that tire) If you increase one you decrease the other that is why i used the seesaw analogy{should have said scale}. I think you are getting confused in the seesaw analogy because usually the side with more weight is lower(but in this case it is the opposite)

I was only using the seesaw analogy to represent the relationship between the Back Right/Front left and the Back left/front right. Which was a bad idea lol

stevensimon

iTrader: (11)

no. you dont get it. you have a table that is perfectly level. you make one leg longer(raising that corner) and the cross leg takes more load as well. the table will now rock along the line between the leg you lifted and its cross. this is what i was trying to convey in my original post. the only way to actually change the front to rear weight bias is to physically move weight around(or add it).

if i raise the right rear, it will send more load to the right rear and left front. if i raise the left rear, it will send more load to the left rear and right front. so lift or lower either both the front or rear in relationship to the tires and you are cancelling out any change to front to rear bias but possibly/probably changing left to right.

sideways-FC

Im going to jump in with a question on seting up my drift car. how would a light weight fly wheel afect drifting compared to the stock fly wheel on a turbo and none turbo car.I have an aluminum light weight fly wheel and I plain on building an na engine with turbo irons and am doing a large street port.

SpideyFan6010

............put word for word from the link i posted earlier cause when i read it i understood it perfectly and there was no confusion at all.

........."....determine which is the heaviest corner of your car(usually the driver's side front) and lower the suspension slightly(1/2 inch) in that corner. You will be shocked by what happens. That corner gets lighter! How can that be? The car is lower to the Ground. Doesn't that make that corner heavier? Actually, it's just the opposite. Repeat after me:"Lower is lighter" If your scratching your head, think of it this way:when you raise a corner, what the suspension is actually doing is pushing down harder on the scale in that corner. Thus, when you lower the corner, the suspension pushes down less in that spot. If you get that in your head, the rest of this exercise will be a piece of cake.

So where did the weight go when you lowered the driver's front corner? It went diagonally across to the passenger side rear. With some practice and a lot of trial and error, you will soon have a well balanced car."

This is from the link i posted earlier on Page 43.
http://books.google.com/books?id=AUs...ifting&f=false

stevensimon

iTrader: (11)

correct. that weight is being distributed more evenly between the two points. it doesnt mean that you can dump (or raise) the front of the car and have the weight change from front to rear which is the point of our discussion right? that would defy physics. if this were true, i could grab any 4000 pound muscle car from 1973 and pick the rear end up, with no mechanical advantage, easily.

he should have stated that it was distributed between the two corners. no way is 100% of the displaced weight going to the opposite corner.

stevensimon

iTrader: (11)

sounds awesome to build a high comp 4port. a lighter flywheel should allow it to revv faster. i dont see a lightened flywheel playing a pivotal role in driving characteristics or handling though

SpideyFan6010

............You can perceive the information that i have posted anyway you want. I understand how to change the weight bias of a car by changing the ride height, at each corner to yield what i want so i can get the car to handle how i want it. I was just trying to make sure you understood how it works. I understand what you were saying in the post after about cross balancing so that both left and right sides of the car are equal( 50% on the left side 50% on the right) so that no matter which direction you turn it is perfectly even. Even if you are drag racing it is still beneficial to have equal balancing on both(left and right) sides to provide equal traction on both rear wheels.

My whole discussion was merely about changing the stock weight bias from 48/52 to 55/45 as i have done this in GT5 to better suite how i like the car to handle. You can only change/adjust the front and rear on GT5 it doesn't let you adjust each individual corner. With that being said I can't do a corner balance on GT5 I can only adjust the weight bias between the front and rear. You we assuming I was talking about cross-weight but I wasn't. Having a car be 50/50(Front to back) is different than 50/50(left to right). The video of the NSX was for balancing 50/50(left to right)

stevensimon

iTrader: (11)

so on GT5 you change the weight bias by raising or lowering the front/rear(im pretty sure that weight and ride height are separate in GT5 as it is in all video games)? you are the one that posted video about cornerweight so it was an easy assumption to make. i was just explaining how the things in the video worked. still my information is factual and real world and it still stands to attest that the only way to change front to rear bias is by adding/moving/removing weight. its a bit more complex than just sliding a bar in the tuning/setup menu on a console game.

cvzg77r

iTrader: (10)

^+1

SpideyFan6010

I forgot a cardinal rule on this forum. Never use the term right and wrong in context to what someone is saying as it is easy to misconstrue what is being/trying to be said. I servilely apologize if I said anything that personally offended you man I really do that was not my intent.

If belittling me and my lack of real world knowledge makes you feel any better then so be it, but don't claim what I know is wrong just cause I use it for a Video game medium. I came in this section of the forum for help just like anyone else. Just because it wasn't geared towards my personal car(which i made perfectly clear in my first post) doesn't give you the right to claim my knowledge is obsolete.

Everything else aside, I hope all your future RX-7 endeavors go well and I only wish the best of luck to you man.

Peace

Vell

Well, guys, it depends ... You don't change the lateral weight transfer but you are changing the way it's transfered.
So if one is talking about static weight measure and the other is talking about weight transfer on corners, you can talk like that for almost 10 months.

Anyway, if you change the center of gravity when raising / dropping, you'll change the lateral weight transfer = you definitely change the weight applied to each corner. If you're keeping the same center of gravity (which is near from impossible even for a 50/50 car), you will not change a thing.

For a given radius corner, a given condition (road, tire, etc), the only way to change it is to change : a) the center of gravity b) the track width.

By the way,

I don't know if you have really done it before, relatively small adjustments can bring a 45/55 near to 50/50.
(And no, if you start with a 65/35 car it will not be that easy )

SpideyFan6010

............you know when you have too much negative chamber? What are some of the noticeable side effects?

Also, with more front camber does that mean more toe-in in the rear is necessary for more stability(or is the toe adjustment there to get as much grip as possible)

Generally from what I have heard Toe-in in the rear helps manage oversteer and Toe-out in the front helps manage understeer. Is this correct?

stevensimon

iTrader: (11)

Front spring rate increase:
More under steer; increase in proportional weight transfer to the front when rear wheel rate is not increased; reduces front traction when rear rate is not changed.
Usable adjustment: 150-600 lbs/in
Symptoms of too much adjustment: terminal under steer; front of car hops in corners; excessive wheel spin on inside front tire on FF cars.

Front spring rate decrease:
Less under steer; decreases proportional weight transfer to the front when rear wheel rate is not increased; increases front traction when rear rate is not changed.
Usable adjustment: 150-600 lbs/in
Symptoms of to much adjustment: Too much over steer; over steer then under steer if spring is so soft that the car bottoms out on lean, car bottoms out excessively with a jolting ride.

Rear spring rate increase:
More over steer; increase in proportional weight transfer to the rear when front wheel rate is not increased; increases rear traction when front rate is not changed.
Usable range: 100-600 lbs/in
Symptoms of too much adjustment: too much over steer; sidestep hop in corners; twitchy; pretty scary.

Rear spring rate decrease:
Less over steer: decreases proportional weight transfer to the rear when front wheel rate is not changed; increases rear traction when front rate is not changed
Usable range: 100-600 lbs/in
Symptoms of too much adjustment: car under steers; if way to soft car under steers then over steers as car bottoms out on lean; car bottoms out excessively with a jolting ride.

Front anti-roll bar stiffer: more under steer
Usable range: none to 1.25 inches in diameter
Symptoms of to much adjustment: terminal under steer; lifts inside front tire off the ground witch can cause massive wheel spin on FF cars; also not good for most effective tire usage as inside tire is now doing nothing.

Front anti-roll bar softer: less under steer
Usable range: none to 1.25 inches in diameter
Symptoms of to much adjustment: overstate scary; more like fun

Rear anti-roll bar stiffer: more over steer
Usable range: none to 1 inch in diameter
Symptoms of too much adjustment: Big-time over steer. Can cause inside rear tire to lift off the ground.

Rear anti-roll bar softer: less over steer
Usable range: none to 1 inch in diameter
Symptoms of to much adjustment: under steer; slow and boring

Front tire pressure higher: less under steer by reducing slip angels on most tires
Usable adjustment: up to 55psi hot
Symptoms of too much adjustment: no traction- tire crowned so more under steer; adds wheel spin in FF cars; jarring ride; center of tire wears out

Front tire pressure lower: more under steer by increasing slip angles on most tires
Usable adjustment: not less then 20psi
Symptoms of too much adjustment: edges of tire wear quickly because tire is folding over; feels mushy; tires chunk because low pressure means heat build up.

Rear tire pressure higher: less over steer by reducing slip angles on most tires
Usable range: up to 45psi hot
Symptoms of too much adjustment: no traction—tire is crowned so more over steer; bad wheel spin on FR cars; jarring ride; center of tire wears out.

Rear tire pressure lower: more over steer by increasing slip angles on most tires.
Usable range: not less then 20psi
Symptoms of too much adjustment: edges of tire wear quickly because tire is folding over; feels mushy; tires chunk because low pressure means heat build up

More negative camber front: less under steer because of better lateral traction as tread is flatter on the ground under side load.
Usable range: up to 3.5 degrees negative
Symptoms of too much adjustment: poor braking; car is road crown sensitive; twitchy; front tires wear on inside edge

More negative camber rear: less over steer because of better lateral traction as tread is flatter on the ground under side load. More rear grip
Usable range: up to 2.5 degrees negative
Symptoms of too much adjustment: more over steer; car feels twitchy in back; tires wear out on inside edge; less breakaway warning when limit is exceeded.

Ride height to low (typical beginner mistake): car is twitchy with unpredictable dynamics. Bump steer make you life miserable.
Usable range: usually 1.5-2.0 inches lower then stock unless car has been modified to go lower.
Symptoms of too much adjustment: everything that could possibly go wrong: sudden over/under steer; twitchy due to bump steer; very harsh ride; premature tire wear.

Toe in – front: car is stable going straight. Turn in is average
Usable range: 0-1/8th inch
Symptoms of too much adjustment: car has slow twitchiness under braking; feels odd; kills outside edge of tires

Toe out – front: Car turns in well; works pretty well on FF car as they tend to toe-in under load.
Usable range: 0-1/4 inch
Symptoms of too much adjustment: Car is really twitchy under braking; car wanders on straight road; kills inside edge of tire

Toe in – rear: car is less likely to over steer when the throttle is lifted
Usable range: 0-1/8th inch
Symptoms of too much adjustment: weird, slow, rocking movement in back; feels slow but still unstable; wears outside edge of tires.

Toe out – rear: Helps car rotate useful in low speed and slalom courses; very common on FF pro rally cars.
Usable range: 0-1/8th inch
Symptoms of too much adjustment: not to good for street driving; causes lift throttle over steer; makes violent side to side rocking motions in the rear; tie wears on inside more.

Positive front caster: helps stability; suspension will get more negative camber when turning; reducing positive caster reduces steering effort. (Negative caster is not usable)
Usable range: 4-9 degrees positive
Symptoms of too much adjustment: can increase under steer especially in cars with wide low-profile tires. Can increase steering effort.

Single adjustable shock stiffer: Better turn in; better transient response; causes slower onset of over/under steer by slowing weight transfer depending on what end of the car is adjusted.
Symptoms of too much adjustment: suspension becomes unresponsive; ride gets harsh; car skips over bumps, loosing traction; Causes a big delay in weight transfer resulting in strange handling like under steer then late corner stage over steer.

Single adjustable shock softer: slower transient response; quicker onset of over/under steer
Symptoms of too much adjustment: car oscillates due to under dampened spring motion, like a boat. Car gets twitchy in turns. Feels unstable.

SpideyFan6010

Does having bigger/wider rims effect toe settings?

theshdwconspracy

This whole post should be added to the first post of this thread. One of the best descriptions I've seen (except the one about lowering)

The last two are some of the most commonly confused settings for beginners. Even up to this year I confused about how shocks worked

A stiffer shock actually slows down the movement while a softer shock actually speeds up movement.

and wheel size doesn't effect toe

Hayseed7

iTrader: (2)

I am a new rx7 owner, trying to get some bearing on what I need to start succeeding at some upcoming local drift meets. Off the top of my head, my car has: '87 NA shell, s4 13b Turbo swap/s5 mani/s5 550cc injectors/s4-s5 hybrid turbo, PBM Coilovers, JTP Knuckles, and some random other mods (half cage, etc). I think for now I'm decently well off power/engine wise. (someone told me its good to learn to drift at lower power levels, then build up to it?) I'm just confused as to what suspension mods I should be saving for? I devoted, er, wasted years in the "stance/fitment" game for my old tC and now I am trying to get smart on what I need to do to my FC to start getting a basic grassroots drifting setup. From the looks of what I'm researching so far, looks like I'll need new tie-rods, spindles, tie rod ends, spacers, and.... well like I said, I'm new to this. Thanks!

theshdwconspracy

have a good seat?


GO DRIVE, your car has everything

Hayseed7

iTrader: (2)

Yeah experience is what I do need, but I'll go out late and just see what I can learn. And yes, I am ordering a Sparco, maybe an rtek as well. Just trying to figure out what more I NEED in my suspension, or if I should just enjoy where I am

Justen

iTrader: (12)

@stevensimon, very nice summarization... I'll definately be using that this year to tweak things a bit and watch how the car reacts.

But does anyone else think that points about tire pressure seem backwards? I mean I've heard of plenty of guys in underpowered cars that crank rear tire pressure up to 55+ psi to break the rear end loose. Shouldn't more rear pressure = more oversteer?

Justen

iTrader: (12)

I absolutely agree. In fact, that's the point I'm trying to make.
That particular section says, "Rear tire pressure lower: more oversteer by increasing slip angles on most tires."

driftfcbuckey

iTrader: (8)

even with more power i still really like my car at 60psi rear pressure, and 30-35psi front

driftfcbuckey

iTrader: (8)

my car bogs on 35psi or less. here's 2 videos to compare what i'm talking about. it's super noticeable to those of you who think otherwise like i used to.

30-35psi rear (hot) on 265/35/18 NEXEN N6000s.
http://www.youtube.com/watch?v=IwlXw...1&feature=plcp

65psi (cold) on 265/35/18 NEXEN N6000s.
no burnout before this run:
http://www.youtube.com/watch?feature...&v=D3tg2ZCXtK4

phatty burnout before this run
http://www.youtube.com/watch?v=zRv2shsMVRo

car felt super greasy the 2nd run.

T2mike222

The info that steve posted is for general set up, road racing/auto cross. Thats why the tire pressure info is different than what "DRIFTERS" are used to seeing. Most people might not be able to use this info when just getting started, but as you and your car get better all of that stuff steve posted really starts to help out.
Its already been said but great post steve. Im glad someone else posted on the corner weighing front to rear, I read that a couple of days ago and decided not to get involved.

stevensimon

iTrader: (11)

correct. the tips are geared towards making a very neutral handling car. with it being neutral, it is easy to drift and control. some things do not apply as well as others since drifting usually has settings at one extreme or the other but it will give a person a good idea on why their car is handling and behaving the way it is.