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Old 7th August 2010, 22:04   #91
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Regarding the original post and ways to increase performance...

First thing to do is put a set of tyres on it! A decent set of performance tyres will increase youir grip for accelerating, braking and cornering!

Consider your wheels too at this point. The bigger the wheels you have the more mass they have. The heavier the wheels the more resisantance they offer to accelerating and deceleration. Keep your wheels as light as possible by choosing good quality rims or keeping size small. 18 inch rims may look awesome on a car but they will sap the performance of the engine!

Weight removal is your best cheap tuning option. The initial removing of anything that is not required is not only free but in some cases can generate revenue for more modifications. I always fully strip my tracks and race cars and sell off all the parts that arn't required. I never run back seats, carpets etc etc. Sound deadnening is always removed entirly, its suprising just how much that can weigh! Dash modifications always depend on the series regulations though.

By removing the weight from the car, it will accelerate quicker, stop quicker and be able to corner quicker. It improves the all round performance to the car.

Weight distribution is important and this can be shifted around if you have ajustable suspension while on the corner weight scales.

I would always make this setp the first modification i do to a car.

Secondly I would sort the suspension. OEM bushes are soft and designed for comfort rather than performance. bin them and put some polyeurathene bushes in. Different shore ratings are available and can be specced dependant on what aplication you want to use the vechile for.

Coilovers are highly desirable, then after that look at other parts of suspension depenedant on your car and its setup. I'm a big fan of eccentric top mounts that can be moved around to allow people to ajust the castor and camber. I also use compression struts where possible in place of stock arb set ups and the run an ajustable arb in conjunction with the compression struts.

Rose joint where possible!

After sorting the suspension components then a good alignment set up is needed. Each car will have its optimum set up that can then be tweaked by the driver until the car suits his driving style over time. In order to look at what to start with as a ball park figure you really need to understand what all the changes will do to the handeling of the car and work logicaly towards your choosen direction. (I have got somewere a list of factors and brief explanations someware in an old university report i did, i'll dig it out and post it up if its any interest to people?).

Once you've sorted you handeling out on the car and reduced the weight you really need to look at what is stopping you. You'll be carrying a fair bit more speed by now so its important to be able to stop, but more importantly, good brakes will allow you to break much later therefore allowing you to carry more speed for longer before cornering. Budget modifications would be uprated pad materials and possibly discs. Then followed up by bigger brakes (either from higher speced models in the range or new aftermarket brakes), lighter if possible too to reduce the unsprung weight your carrying. Change fluid to a type with a higher boiling while your at it and replace it regually too!

Some kind of ajustment of the bias is desirable for getting the optimum from your car, weather this be just a bias valve in the line to the rear brakes or a decent pedal box.

Once you have all this sorted your chassis is pretty sorted but you can look at reducing flex though with strut braces, strenghting plates, seam welding and adding mutlipoint roll cages.

Once your chassis is as good as you can get and you find that you can't get any quicker then its time to spend money on the engine right?

Well not in my experience. Spend some money on driver training. The guys i have worked with in the past have always been meglamaniacs and think power is the soloution to everything, even their shortcomings as drivers (that they will never admit to having). Good race driver instruction is worth every penny. I have seen drivers shave more time off a lap time from improving their driving style than they would of saved by spending that money on tuning.

Now the cars handeling isn't holding you back and you have the skills to get around the track quickly and smoothly you can start upping the power.

Keep looking for the choke points and improve on them!

The best way to do this depends largely on your engine and any regulations you have to conform to . Different engines respond to different methods of tuning. Finding whats best for you is down to research and experimenting. As a general guidline though you have to understand that every engine has a choke point (limiting point) this could be the cam shaft for example. By increasing the duration and or lift of the cam you will move the choke point elseware in the engine, possibly the next limiting factor will be the ports size / shape or the exhaust manifold.

Ill say it again! Keep looking for the choke points and improve on them!

The first choke point that you will identify on your engine when you look at it will be the EMS. These are set for reliablity, fuel economy, emmisions and warrenty concerns by manufacturers. You will get so much out of a new EMS that is mappable. Your engine can be dyno'd and you can release all that dormant power that the manufacturer wouldn't give you!

In addition to this every modification form here on that you make can be made the most of by altering the engine management to suit it.

Piggy backs and remaps are an option that you can take but stand alone EMS is where the real longterm development gains are going to be for anyone serious about tuning!

Turbo's / superchargers are a great option for increasing power long term. I've read various different opinions on here about them and everyone seems to have different veiws. I won't put my comments in here, I'll do that in depth in one of the turbo threads at a later date. i'll just say that most stock engines are capable of running with 1/2 bar boost pressure on stock internals AS LONG AS fueling, ignition and inlet charge temps are kept in the safe zones. I've built cheap turbo conversions to settle bets / challenge cars and it can be done very effectivly on a shoe string budget if you plan it out properly. It is far nicer though to sit down with a big boxed of forged goodies and assemble a monster capable of huge boost pressures though. It just depends on what you have the money for and making the best of whats available. I also have seriously different opinions than many of you regarding CR changes on boosted applications and again i'll explain my veiws in more depth in another turbo related thread.

Nitrous is another option, again most cars can handle a decent squirt of gas but just like the boosted applications, additional fueling and ignition requiments need to be looked at if you want the engine to last reliably. It is an expensive option though, the equipment is relativly cheap to purchase but the gas refills soon start to add up! I've spent upwards of 300 in a week on N2O before!

So heres just a few options available to you. When I tune a new car I always do it like that...

New tyres (usually R888's in the UK as a good starting point if they have to be E marked and not slicks)
Weight removal, chassis strenghening, suspension modifications and set up.
Brake improvements.
Driver improvements.
Engine management system and data logger.
Engine tune up / turbo conversion (depends on regulations for class / future applications etc, of course road cars and thankfully drift cars allow open choice of modifications!)

Cheers
Tom
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Old 9th August 2010, 00:56   #92
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Originally Posted by doughnutter View Post
After sorting the suspension components then a good alignment set up is needed. Each car will have its optimum set up that can then be tweaked by the driver until the car suits his driving style over time. In order to look at what to start with as a ball park figure you really need to understand what all the changes will do to the handeling of the car and work logicaly towards your choosen direction. (I have got somewere a list of factors and brief explanations someware in an old university report i did, i'll dig it out and post it up if its any interest to people?).
Please do dig it out. Would be good to know how to set up alignment according to my driving style
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Old 9th August 2010, 17:51   #93
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As requested a brief and geberal outline of handeling cause and effects

RIDE AND ROLL RESISTANCE-SPRING

Too much spring: overall
■ Harsh and choppy ride
■ Much unprovoked sliding
■ Car will not put power down on corner exit - excessive wheel-spin

Relatively too much spring: front
■ Understeer - although the car may initially point in well
■ Front breaks loose over bumps in corners
■ Front tyres lock while braking over bumps

Relatively too much spring: rear
■ Oversteer immediately on application of power
■ Excessive wheel-spin

Too little spring: overall
■ Car contacts the track a lot
■ Floating ride with excess vertical chassis movement, pitch and roll
■ Sloppy and inconsistent response
■ Car slow to take a set � may take more than one

Relatively too little spring: rear
■ Excessive squat on acceleration accompanied by excessive rear negative camber, leading to oversteer and poor power down characteristics
■ Tendency to fall over on outside rear tyre and "flop" into oversteer and wheel-spin

ANTI-ROLL BARS

Too much anti-roll bar: overall
■ Car will be very sudden in response and will have little feel
■ Car will tend to slide or skate rather than taking a set - especially in slow and medium speed corners
■ Car may dart over one wheel or diagonal bumps

Relatively too much anti-roll bar: front
■ Corner entry understeer which usually becomes progressively worse as the driver tries to tighten the corner radius.

Relatively too much anti-roll bar: rear
■ If the imbalance is extreme can cause corner entry oversteer
■ Corner exit oversteer. Car won't put down power but goes directly to oversteer due to inside wheel-spin
■ Excessive sliding on corner exit
■ Car has a violent reaction to major bumps and may be upset by "FIA" kerbs

Too little anti-roll bar: overall
■ Car is lazy in response, generally sloppy
■ Car is reluctant to change direction in chicane and esses

Relatively too little anti-roll bar: front
■ Car "falls over" onto outside tyre on corner entry and then washes out into understeer
■ Car is lazy in direction changes

Relatively too little anti-roll: rear
■ My own opinion is that on most road courses a rear anti-roll bar is a bad thing. Anti-roll bars transfer lateral load from the unladen tyre to the laden tyre - exactly what we don't want at the rear. I would much rather use enough spring to support the rear of the car. The exception comes when there are "washboard ripples" at corner exits, as on street circuits and poorly paved road circuits.

SHOCK ABSORBER FORCES

Too much shock: overall
■ A very sudden car with harsh ride qualities, much sliding and wheel patter
■ Car will not absorb road surface irregularities but crashes over them

Too much rebound force
■ Wheels do not return quickly to road surface after displacement. Inside wheel in a corner may be pulled off the road by the damper while still loaded
■ Car may "jack down" over bumps or in long corners causing a loss of tyre compliance. Car does not power down well at exit of corners when road surface is not extremely smooth

Too much bump force: general
■ Harsh reaction to road surface irregularities.
■ Car slides rather than sticking
■ Car doesn't put power down well - driving wheels hop.

Too much low piston speed bump force
■ Car's reaction to steering input too sudden
■ Car's reaction to lateral and longitudinal load transfer too harsh

Too much high piston speed bump force
■ Car's reaction to minor road surface irregularities too harsh - tyres hop over "chatter bumps" and ripples in braking areas and corner exits.

Too little shock: overall
■ Car floats a lot (the Cadillac ride syndrome) and oscillates after bumps
■ Car dives and squats a lot
■ Car rolls quickly in response to lateral acceleration and may tend to "fall over" onto the outside front tyre during corner entry and outside rear tyre on corner exit.
■ Car is generally sloppy and unresponsive

Too little rebound force: overall
■ Car floats - oscillates after bumps (the Cadillac ride syndrome)

Too little bump force: overall
■ Initial turn in reaction soft and sloppy
■ Excessive and quick roll, dive and squat

Too little low piston speed bump force
■ Car is generally imprecise and sloppy in response to lateral (and, to a lesser extent longitudinal) accelerations and to driver steering inputs

Too little high piston speed bump force
■ Suspension may bottom over the largest bumps on the track resulting in momentary loss of tyre contact and excessive instantaneous loads on suspension and chassis

Dead shock on one corner
■ A dead shock is surprisingly difficult for a driver to identify and/or isolate
- At the rear, the car will "fall over" onto the outside tyre and oversteer in one direction only
- At the front, the car will "fall over" onto the outside tyre on corner entry and then understeer.

WHEEL ALIGNMENT

Front toe-in: too much
■ Car darts over bumps, under heavy braking and during corner entry - is generally unstable
■ Car won't point into corners, or if extreme. May point in very quickly and then dart and wash out

Front toe-out: too much
■ Car wanders under heavy braking and may be somewhat unstable in a straight line, especially in response to single wheel or diagonal bumps and/or wind gusts
■ Car may point into corners and then refuse to take a set
■ If extreme will cause understeer tyre drag in long corners

Rear toe-in: too little
■ Power on oversteer during corner exit

Rear toe-in: too much
■ Rear feels light and unstable during corner entry. Car slides through corners rather than rolling freely

Rear toe-out: any
■ Power oversteer during corner exit and (maybe) in a straight line
■ Straight line instability

Front wheel caster or trail: too little
■ Car too sensitive (twitchy?)
■ Too little steering feel and feedback

Front wheel caster or trail: too much
■ Excessive physical steering effort accompanied by too much self return action and transmittal of road shocks to the drivers hands
■ General lack of sensitivity to steering input due to excessive force required

Front wheel caster or trail: uneven
■ Steering effort is harder in one direction than in the other
■ Car will "pull" towards the side with less caster - good on ovals, bad on road courses

Camber: too much negative
■ Inside of tyre excessively hot and/or wearing too rapidly. At the front this will show up as reduced braking capability and at the rear as reduced acceleration capability. Depending on the racetrack and the characteristics of the individual tyre, inside temperature should be 10-25 hotter than the outside. Use a real pyrometer with a needle rather than an infra red surface temperature device.

Camber: not enough negative
■ Outside of tyre will be hot and wearing. This should never be and is almost always caused by running static positive camber at the rear in an effort to avoid the generation of excessive negative camber under the influence of aero download at high speed.
- A better solution is improved geometry and increased spring rate. Dynamic positive camber will always degrade rear tyre performance and if extreme, can cause braking instability and/or corner exit oversteer.

Bump steer, front: too much toe-in in bump
■ Car darts over bumps and understeers on corner entry

Bump steer, front: too much toe-out in bump
■ Car wanders under brakes and may dart over one wheel or diagonal bumps
■ Car may understeer after initial turn in

Bump steer, rear: too much toe-in in bump (same as solid axle steer on outside wheel)
■ Roll understeer on corner entry
■ Mid phase corner understeer
■ "Tiptoe" instability when trail braking
■ Darting on power application on corner exit

Bump steer, rear: too much toe-out in bump (same as solid axle steer on outside wheel)
■ Instability on acceleration
■ Good turn in followed by a tendency to oversteer at mid-phase and exit

TYRES

Too much tyre pressure
■ Harsh ride, excessive wheel patter, sliding and wheel-spin
■ High temperature reading and wear at the centre of the tyre

Too little tyre pressure
■ Soft and mushy response
■ Reduced footprint area and reduced traction
■ High temperatures with a dip in the centre of the tread

Front tyres "going off"
■ Gradually increasing understeer - Enter corners slower, get on power earlier with less steering lock

Rear tyres "going off"
■ Gradually increasing power on oversteer - Try to carry more speed through corner and be later and more gradual with power application

LIMITED SLIP MALADIES

Limited slip differential wearing out
■ Initial symptoms are decreased power on understeer or increased power on oversteer and inside wheel spin. The car might be easier to drive, but it will be slow
- When wear becomes extreme, stability under hard acceleration from low speed will diminish and things will not be pleasant at all

Excessive cam or ramp angle on coast side plate (clutch pack) limited slip differential
■ Corner entry, mid-phase and corner exit understeer. Incurable with geometry changes or rates - must change differential ramps. In 1998, virtually everyone is running 0/0 or 80/80 ramps.

SUSPENSION GEOMETRY

Excessive front scrub radius (steering offset)
■ Excessive steering effort accompanied by imprecise and inconsistent "feel" and feedback

Excessive roll centre lateral envelope: front or rear
■ Non-linear response and feel to steering input and lateral "G" (side force) generation

Rear roll centre too low (or front r/c relatively too high)
■ Roll axis too far out of parallel with mass centroid axis, leading to non-linear generation of lateral load transfer and chassis roll as well as the generation of excessive front jacking force.
■ Tendency will be towards understeer

Rear roll centre too high (or front r/c relatively too low)
■ Opposite of above, tending towards excessive jacking at the rear and oversteer

Front track width too narrow relative to rear
■ Car tends to "trip over its front feet" during slow and medium speed corner entry, evidenced by lots of understeer (remember trying to turn your tricycle?)
- Crutch is to increase front ride rate and roll resistance and increase the camber curves in the direction of more negative camber in bump (usually by raising the front roll centre)

INSTABILITY

Straight line instability: general
■ Rear wheel toe-out, either static due to incorrect (or backwards) setting, or dynamic due to bump steer or deflection steer
■ Vast lack of rear download or overwhelming preponderance of front download
■ Wild amount of front toe-in or toe-out
■ Loose or broken chassis, suspension member or suspension link mounting point
■ Dead shock absorber

Straight line instability: under hard acceleration
■ Malfunctioning limited slip differential
■ Insufficient rear toe-in
■ Deflection steer from rear chassis/suspension member or mounting point
■ Rear tyre stagger (car pulls to one side)
■ Dead rear shock absorber
■ Wildly uneven corner weights

Straight line instability: car darts over bumps (especially one wheel bumps)
■ Excessive Ackermann steering geometry
■ Excessive front toe-in or toe-out
■ Uneven front caster or trail settings
■ Insufficient rear wheel droop travel
■ Dead shock or uneven shock forces or incorrectly adjusted packers/bump rubbers
■ Wildly uneven corner weights
■ Front anti-roll bar miles too stiff

Instability under hard braking: front end wanders
■ Excessive front brake bias or uneven corner weights or excessive front damper rebound force

Instability under hard braking: car wants to spin
■ Excessive rear brake bias
■ Insufficient rear droop travel
■ Wildly uneven corner weights
■ Excessive rear damper rebound force
■ Unbalanced ride/roll resistance - too much at rear
■ Insufficient rear camber (usually in combination with one or more of the above)

RESPONSE

Car feels generally too heavy and unresponsive
■ Tyre pressures too low
■ Insufficient ride and/or roll resistance (springs and bars)
■ Excessive aerodynamic download, or insufficient spring for the amount of download
- If high speed acceleration is sluggish, the culprit is often too large a rear wing Gurney lip

Car feels sloppy, is slow to take a set in corners, rolls a lot, doesn't want to change direction
■ Insufficient tyre pressure
■ Insufficient damper forces
■ Car too soft in ride and/or roll

Car responds too quickly "has little feel" slides at the slightest provocation
■ Excessive tyre pressure
■ Excessive bump force in shock absorbers
■ Car too stiff for inexperienced driver
■ Excessive ride or roll resistance
■ Excessive front or rear toe-in
■ Insufficient aerodynamic download

UNDERSTEER

Corner entry understeer: car initially points in and then washes out
■ Excessive toe-in or toe-out (car is usually "darty")
■ Insufficient front droop travel (non droop limited cars only)
■ Incorrectly adjusted packers (car rolls on to packers)
■ Insufficient front damper bump resistance (similar to roll stiffness example)
■ Insufficient front roll stiffness - car may feel like it is pointing in but may actually be falling over onto the outside front tyre due to insufficient front roll stiffness or diagonal load transfer under heavy trail braking. Initial understeer can often be cured by increasing front roll resistance, even though doing so may increase the amount of lateral load transfer.
■ Non linear lateral load transfer due to spring and/or bar geometry. Or to non-optimal roll axis inclination

Corner entry understeer: car won't point in and gets progressively worse
■ Driver braking too hard, too late
■ Relatively narrow front track width
■ Excessive front tyre pressure
■ Excessive front roll stiffness (spring or bar)
■ Relative lack of front download (excessive rear download)
■ Incorrectly adjusted packers or bump rubbers (car rolls onto packers)
■ Insufficient front toe-in
■ Insufficient Ackermann effect in steering geometry
■ Front roll centre too high or too low
■ Insufficient front damper bump force
■ Insufficient front toe-out
■ Insufficient front wheel droop travel (on non droop limited cars only)
■ Nose being "sucked down" due to ground effect
■ Excessive Ackermann steering geometry
■ Can also be caused by unloading the front tyres due to rearward load transfer under acceleration - cures include:
- Increasing front damper rebound force
- Increasing rear damper low speed damper rebound force
- Increasing rear anti-squat
- Droop limiting front suspension (will also make turn in more positive and will reduce overall understeer)

Mid-corner (mid-phase) understeer
■ Excessive front tyre pressure
■ Excessive relative front roll stiffness
■ Excessive front toe (in or out)
■ Excessive Ackermann steering geometry
■ Insufficient front dynamic camber
■ Relatively narrow front track width
■ Insufficient front wheel travel (car rolls onto packers or bottomed shock)
■ Insufficient droop travel (on non droop limited cars)

Corner exit understeer: slow corners
■ Often a function of excessive corner entry and mid-phase understeer (whether driver induced or car induced) followed by throttle application whilst maintaining the understeer steering lock. The first step must be to cure the corner entry and mid-phase understeer. If this is impractical, then corner entry speed should be reduced slightly in order to allow earlier throttle application. Sometimes we have to be patient.

Corner exit understeer: fast corners
■ Relative lack of front download - often caused by negative pitch angle (squat) due to rearward load transfer on acceleration. Can be helped by increasing rear anti-squat and/or by increasing rear low speed bump force, increasing front droop force and by limiting the front suspension droop travel.
■ Relatively narrow front track width
■ Excessive ramp angle or pre-load on clutch pack or plate type limited slip differentials.

Understeer stronger in one direction than in the other
■ Uneven corner weights
■ Uneven caster
■ Uneven camber (especially front)

OVERSTEER

Corner Entry Oversteer
■ Excessively heavy trail braking
■ Excessive rearward brake bias
■ Severe rearward ride rate/roll resistance imbalance
■ Rear roll centre too high
■ Diabolical lack of rear download
■ Severely limited rear droop travel
■ Broken or non-functioning outside rear damper
■ Broken or non-functioning front anti-roll bar

Note: A slight feeling of rear "tiptoe" type hunting on corner entry can be due to excessive rear toe-in or excessive rear damper rebound force.

Mid-corner (mid-phase) oversteer
■ Driver threw the car at the corner to get through initial understeer - only cure is to educate the driver and/or decrease understeer
■ Excessive rear tyre pressure
■ Excessive relative rear ride and/or roll stiffness
■ Rear suspension bottoming in roll
■ Insufficient rear droop travel (non droop limited cars only)
■ Very loose rear anti-roll bar linkage

Corner exit oversteer: gets progressively worse from the time the power is applied
■ Worn out limited slip differential
■ Excessive anti-squat geometry
■ Excessive rear ride and/or roll stiffness
■ Insufficient rear spring, bar or shock (low piston speed bump force) allowing the car to "fall over" onto outside rear tyre
■ Excessive rear negative camber
■ Too little dynamic rear toe-in
■ Relatively insufficient rear download

Note: If car feels as though it is sliding through the corner rather than rolling freely, reduce the rear toe-in and see what happens.

Corner exit oversteer "sudden" - car seems to take a normal exit set and then breaks loose
■ Insufficient rear suspension travel (lifting the inside wheel on non droop limited cars or bottoming the outside suspension due to lack of bump travel)
■ Incorrectly adjusted packers
■ Dead rear damper
■ Sudden change in outside rear tyre camber
■ Too much throttle applied too soon - often after the drivers confidence has been boosted by the car taking a set.

Car does not put the power down smoothly on the exit of smooth corners
■ Worn out limited slip differential
■ Excessive rear ride/roll resistance
■ Excessive anti-squat geometry
■ Excessive rear tyre pressure
■ Tyres gone
■ Excessive rear damper low piston speed bump force
■ Excessive rear dynamic camber - either from download or from camber change on squat
■ Relative lack of rear download

Car does not put the power down on the exit of bumpy corners
■ Any or all of the above for smooth corners
■ Excessive rear damper high piston speed force
■ Excessive rear damper rebound force (jacking down)
■ Insufficient rear droop travel

TRANSITIONS

Understeer in, snap to oversteer on power application
■ The most common complaint of all! Usually caused by too little roll resistance - car falls over on entry and then snaps.
- Increase front bar and/or spring and/or front damper low piston speed bump force. Stiffening the bar will also transfer some load on to the inside rear tyre on acceleration.
- If the suggestion above cures the understeer but the car still snaps, the culprit is almost always the car falling over on the outside rear tyre on longitudinal plus lateral load transfer. Add rear bar or spring. Bar will transfer load away from the inside rear tyre. Spring will not. Spring will, however, decrease traction over exit bumps while bar will not.
■ Loose anti-roll bar linkage/blade sockets can have the exactly same effect

Car is slow to change directions in chicanes or esses
■ Insufficient ride/roll stiffness, especially at front.
■ Relatively narrow front track width.
■ Insufficient front damper low piston speed bump force.


BRAKES

Brake pedal gets soft, spongy and/or long during session or race
■ Fluid boiling in calipers. Not pad fade! Upgrade fluid and/or cool calipers.

Brake pedal is soft, spongy and/or long before the car is run
■ Air in the system - bleed brakes.
■ Brake pads badly taper worn - replace

Reduced stopping power with normal brake pedal
■ Pad fade - due either to unbedded new pads or to temperature beyond pad capacity. Upgrade pads.

Long pedal with little effort required
■ Master cylinder(s) too small or pedal mechanical advantage too great.

Rough braking - pedal vibrates under pressure
■ Organic pickup on discs - clean discs with garnet paper (not aluminium oxide sandpaper) and upgrade pads
■ Warped (not grooved) rotors. Grind (or, if you must, turn) rotor surfaces
■ Insufficient axial float on floating discs

Uneven braking - car pulls to one side
■ Stuck piston(s) - rebuild calipers

Brake bias changes during application
■ Excessive clearance between master cylinder push rod clevises and bias bar bearing housing.
■ Rod end bearings used instead of clevises on master cylinder push rods.
■ Bias bar incorrectly adjusted. Bar must be perpendicular to vehicle longitudinal axis with full foot pressure applied. Contrary to popular opinion, relative length of master cylinder pushrods is immaterial.
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Old 9th August 2010, 18:08   #94
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Good one Mi10. You have spoken what was on my mind when it comes to mods.

Weight reduction is the main thing that comes to my mind as stated by you regarding the power to weight ratio.

But along with reducing the weight you also need to balance the weight of your car in a 50:50 ratio and not make it front heavy to aid handling along with the boost in performance.

Dont ask me how as i am still learning the tricks of the trade and am as noob as you in this field.

But you have made some really good points and it was refreshing to read your post.

me thinks a 70:30 front:back is better suited.more traction needed by front when the weight shifts to the back during launch in our predominantly Front wheel drive market.

why such disparity?
either a premier padmini or a BMW for RWD....
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Old 9th August 2010, 18:16   #95
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me thinks a 70:30 front:back is better suited.more traction needed by front when the weight shifts to the back during launch in our predominantly Front wheel drive market.

why such disparity?
either a premier padmini or a BMW for RWD....

The weight that moves under acceleration and deceleration will not only depend on the weight bias but also any anti dive and anti squat buit into the chassis design. Some cars are much better than others for this!

Not so sure about the Premier you speak of as I have no exerience of them but theres better options than a BMW for RWD. BMW used to have the accolade of being the drivers car. The latest ones sadly don't live up to that name. I'd rather drive a RWD Nissan than a modern BMW for a true drivers car.
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Old 9th August 2010, 18:46   #96
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The weight that moves under acceleration and deceleration will not only depend on the weight bias but also any anti dive and anti squat buit into the chassis design. Some cars are much better than others for this!

Not so sure about the Premier you speak of as I have no exerience of them but theres better options than a BMW for RWD. BMW used to have the accolade of being the drivers car. The latest ones sadly don't live up to that name. I'd rather drive a RWD Nissan than a modern BMW for a true drivers car.
cant say much here.The premier is our very own "fiat" as it was called.And there are hundreds of other RWDs,some better, and some worse than a BMW.What i meant was the price/refinement being at opposite ends of the spectrum.the premier padmini beaing one of only 2 cars available in india til the 80's, and the other being a , well, bmw.last heard, the premier came for about Rs.60k from the factory(help someone????).
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