Alloy wheels and their impact on performance

Some rally style alloy wheels are lighter – (less weight = more speed) and also are designed to increase the cooling of the brake disks. Some designs hold up better to being curbed than others and some break very easily when hitting a pothole or curb at speed – always go for the best quality alloy wheel that you can afford and read the reports and reviews. If you do go for a different overall size you must get the suspension and tracking realigned to avoid uneven wear under acceleration.
lighter wheel will improve handling - less weight is rotating around the hub so components such as suspension and even brakes will last longer. The gaps in alloy wheels also aid brake cooling and allow the brakes to do a better job at slowing up the car.

Big wheels look really cool but I have not found anyone yet who says that they have improved the ride or handling of their car – keep the overall wheel width with tyre dimension as the OEM provided but go for a larger alloy and ultra low profile tyre if you really want the big wheel look. Lower profile tyres are noisier and due to their low flexing they give excellent handling characteristics.

Wider alloys are much better than taller ones and improve the handling. Many users complain that taller wheels affect the speed and handling adversely and cause tramlining and bumpy rides.

If you are contemplating alloy wheels try to keep the overall rotational diameter the same. If the rotational distance is larger (taller wheel size) then you will need to get your speedo recalibrated a 10% larger rotational diameter means that each mile you cover is 10% shorter and each mile per hour you are doing is 10% out - I'm building a calculator to suggest alloy wheel and tyre sizes to match your existing rotational diameter join the club to be one of the first to use it. Bigger wheels are often heavier so you should compare the weights of alloy wheels with the standard wheels you have. A rotating wheel will have a gyroscope effect and resist a change of direction so handling can be slightly affected with different wheels. Low profile tyres also increase grip, but the ride is harder and the tyres are more expensive.

Some alloys are designed to be light weight (they can snap more easily though) and have a pattern that increases the airflow to the brake disks aiding your breaking efficiency. When you buy an alloy you need to check the pattern of nuts matches your car (Obviously!) PCD, you also need to check the offset and bore measurements. The last thing you want is the wheel not fitting properly over your brake disks or a wheel that grinds into the arches when you hit a bump or turn a corner. You may need to get your arches rolled or cut. Anything other than the original rotational dimensions will definitely require suspension adjustments. You should always get your camber, toe in/out and other suspension components checked for alignment when you change tyres, alloys, or hit a curb or bump that jolts the car.

Fact of life - ALLOY WHEELS GET CURBED. Choose a pattern that will not stick out too much and hit the curb (split rims are good for this). If the alloys have a chrome finish they can cost a fortune to get refurbished but look dreadful when scratched.

Summary: Keep the rotational diameter the same. Buy alloys for performance based on weight and brake cooling. Buy alloys for aesthetics based on their longevity and try to get an alloy pattern that will curb gracefully. (When you get the tyre balanced ask for the weights to go on the inside - so many national 'MrFastFit' tyre retailers stick them on the outside like ears - ruining everything you have tried to aesthetically achieve.)

Supercharger

For those contemplating fitting a supercharger as a means of performance enhancement, whose knowledge of its operation is small, this is how a supercharger works. Put simply, supercharger is an air pump that forces air into the engine. As the power of an engine is dependent upon the volume of air that can be fueled and burnt in the cylinders, supercharging is a vastly superior method of induction than allowing the engine to suck its fill of air, as even with the most efficient engine it will not suck enough to fill the cylinders. A supercharger is similar to turbocharger insofar as it acts as an air pump; the crucial difference being a supercharger is a mechanically driven pump whereas the turbocharger uses the power of hot exhaust gases to power the pump. Supercharger vs Turbocharger Why a supercharger rather than a turbocharger? Turbochargers are inherently more difficult to control due to the tremendously high temperatures they generate and the way they produce a dramatic rise in air pressure, resulting in instantaneous large horsepower increases. Although this may sound ideal it usually results in uncontrollable wheel spin and loss of handling to the point of making driving dangerous, forcing the driver to back off and losing the benefits of all this power, always assuming he's still on the road. All these problems of a turbocharger can be tamed to a certain extent but it involves much extra technology and cost. Apart from this drivability problem the other downside is that this sudden rise in pressure, means very careful engine management adjustments to set the fueling and ignition correctly to avoid engine blow ups. Several Saxo turbo's that we have heard of produced reasonable power but destroyed themselves and the installer then rebuilt them with lower boost to preserve the engine. This did cure the reliability but then power was way down. Another example of this was a turbo conversion on a Ford Fiesta done by a well know company, the result was only 30% increase in power, in our opinion not worth the bother or expense. Another downside of turbo's due to the very rapid increase in power, is the effect on the transmission components, all turbo's wear out clutches and gearboxes more quickly. These components like gradual torque increases not sudden violent increases. There are several types of superchargers, most compress the air with the use of vanes screws or rotors, these types of units are called positive displacement supercharger, meaning that they suck in a set volume of air and compress it into a smaller higher pressure volume. This method means you have to have a large unit in comparison to the volume it compresses and because of its size, plus the physical effort of compressing the air, it takes a lot of power to drive it. This creates several problems, one being that due to the high power needed to drive them, they need a large heavy-duty drive train, usually consisting of a wide toothed belt driven off the engine crank shaft by means of a custom made pulley. The other main problem is the power it takes to drive. It is not uncommon to take 45 or more horsepower to drive them even for a relatively small unit. While these two problems can possibly be accepted these units are only really suitable for vehicles with large engine compartments due to their physical size, also, due to the complex engineering needed to build them, they are expensive. Another downside of a displacement supercharger is that they produce maximum boost at about 3000 engine rpm and then slowly tail off, this may seem great to get such high boost quickly. The reality is that it is bad from a driving situation, especially if you want maximum acceleration from a standing start. As you know any car will spin its wheels when driven away fast in first gear, the last thing you want is near max power at 3000 rpm, this just aggravates the problem, nor do you want power reducing the higher up the rev range you go, this is just the opposite of what you need. What you need is the ROTREX type charger that is centrifugal and is basically a gear driven turbo charger. The benefit of this type of charger is it takes little power to drive and the pressure builds up gradually from 1000 rpm at a linear rate, making driving a lot easier and the power more useable.

Toyota Avensis to be revealed at Madrid Motor Show

- New Clean Power D-4D diesel engine joins line-up
- Fresh exterior and interior styling for more sporty look
- Further enhancements to ride and driving pleasure


The 2007 Avensis, the flagship for Toyota in Europe, will set higher standards in the upper-medium car segment thanks to its refined driving pleasure and premium build quality.

2007 Toyota Avensis will feature a fully competitive diesel engine line up, including the new, high tech 2.0-litre D-4D 125. The new engine will offer an excellent combination of fuel economy and lively performance. The D-4D 125 is also a further development in the Toyota Clean Power strategy to reduce harmful emissions thanks to the availability of a diesel particulate filter.


Exterior and interior design changes to the 2007 Avensis will bring out a more sporty character. At the same time, a number of detail changes to the interior will enhance quality standards and driving pleasure.


The Toyota press conference will take place on the 25th of May, at 12:20, Hall 7.














Related Links: www.toyota.com

The Fast and the Furious: Tokyo Drift Soundtrack Announced

The soundtrack to the third installment of The Fast and the Furious film franchise will be released on Tuesday June 20th, 2006, just four days after the film hits theaters.

Like the soundtracks to the previous two The Fast and Furious flicks, Tokyo Drift features a bevy of street savy tunes from artists such as DJ Shadow, N.E.R.D., Don Omar, Juelz Santana, and underground upstars like Evil Nine and Japanese rap crew Teriyaki Boyz (who actually perform the title track).



The Fast and the Furious: Tokyo Drift Soundtrack - Track Listing:

1 Teriyaki Boyz - "Tokyo Drift (Fast & Furious)"

2 DJ Shadow feat. Mos Def - "Six Days"

3 5,6,7, 8's - "The Barracuda"

4 Evil Nine - "Restless"

5 Far*East Movement - "Round Round"

6 N.E.R.D. - "She Wants To Move (DFA Remix)"

7 Teriyaki Boyz - "Cho Large"

8 Dragon Ash - "Resound"

9 Julez Santana - "There It Go (The Whistle Song)"

10 Don Omar feat. Tego Calderon - "Bandaleros"

11 Don Omar feat. Julez Santana - "Conteo"

12 Brian Tyler feat. Slash - "Mustang Nismo"


















Related Links: www.thefastandthefurious3.com

AeroDynamic tuning

Table 2. cw values for vehicle modifications

Effect of .. on aerodynamics Lowering vehicle height by 30 mm. Smooth wheel covers Wide tires Windows flush with exterior Sealing body gaps Underbody panels Concealed headlamps Outside rearview mirrors Airflow through radiator and engine compartment Brake cooling devices Interior ventilation Open windows Open sunroof Roof-mounted surfboard rack

delta cw in % approx. -5 (better car aerodynamics) -1...-3 (better car aerodynamics) +2...+4 (worse car aerodynamics) approx. -1 (better car aerodynamics) -2...-5 (better vehicle aerodynamics) -1...-7 (better vehicle aerodynamics) +3...+10 (worse vehicle aerodynamics) +2...+5 (worse aerodynamics) +4...+14 (worse vehicle aerodynamics) +2...+5 (worse car aerodynamics) approx. +1 (worse car aerodynamics) approx. +5 (worse vehicle aerodynamics) approx. +2 (worse vehicle aerodynamics) approx. +40 (worse vehicle aerodynamics)

	Effect of windshield slope on the cw value (- = better, + = worse aerodynamics)

Windshield slope 50 deg. 55 deg. 65 deg. 40 deg. 30 deg. 0 deg.

cw 0.345 0.342 0.340 0.349 0.349 0.369

delta cw in % -- - 0.8 - 1.4 + 1.1 + 1.1 + 7.0

NOS tuning

For those who don't want to pay hundreds of dollars for a Progressive Nitrous Controller, there are '2 stage' nitrous controls units. This means that the nitrous flow is delivered at two levels. The first level comes in (at a reduced nitrous flow rate) and then the second level (At full flow) comes in after a delay. The length of delay is user settable and can be fine-tuned for best results.

You can use a microprocessor controlled nitrous time delay switch to activate a second stage of nitrous oxide or use it to delay your single stage to help traction.

2-Stage units are simple (but effective) and of course, cheaper than a Progressive Nitrous Controller unit.


Delaying the nitrous line - Why this is important?

A need for a delay in turning on the nitrous solenoid sounds so reasonable for compensating for the fact that the nitrous moves along the pipes faster than the fuel as its pressure is greater than the fuel. If the solenoid to injector lines are long this effect is more noticable, or if the power level is set very high.

It is always safer to overfuel the engine rather than running lean, even for a very short time



Tube Bending Tool

A very special tube bending tool from NOS, is designed for tight radius bends and will greatly simplify tube bending with very professional looking results. Excellent for use on any direct port type nitrous kit.



Nitrous Switch Center

Dynotune's nitrous oxide switch centre (nitrous switch center) puts all your switches in one place. It has bottle opener, system power, bottle heater and purge switches mounted in a neat billet aluminium round housing.

You can mount the switch center in a pod or any 2-1/16" hole. It works with all types of remote bottle openers, DynoTune, NX, compucar, Zex, NOS etc...



Nitrous and Fuel Solenoids Explained

Their job is to switch the flow of nitrous or fuel on and off.

The solenoid part of the unit is an electromagnetic device that applies a magnetic field to the valve's plunger when an electric current is applied to it. The valve part of the unit is what starts or stops the nitrous oxide or fuel flow. Put together we have an electrically controlled valve. Put 12V on it and it opens the valve, take the 12V off and it closes the valve.

In regular nitrous oxide setups the solenoid is simply switched on to start the flow and off to stop it. The electric current coming from the wide open throttle switch.

In setups with progressive or staged controllers the solenoids are 'pulsed' which is where the name 'pulsoid' comes from with some manufacturers. The pulse rate is constant but the width of the pulses is altered to make the valve's 'duty cycle' higher or lower. The more 'on time' that the solenoid gets the more nitrous or fuel it flows.

Typically the valves are pulsed at 20 times per second. If the pulse width is 1/20th of a second then 20 pulses at 1/20th of a second equals a valve that is open all the time. If the pulse width is 1/10th of a second then it is open half of the time. This method of control is known as 'pulse width modulation' or 'PWM'.

In a 2 stage nitrous controller, the first stage of nitrous is a reduced 'shot' and then, after a programmable delay has expired, the full shot of nitrous is injected.