ozkiaworldsfastestkia

There isn't a car enthusiast out there who hasn't bragged just a little regarding the acheivements or specification of their own or preferred vehicle; some just do it more than others. Think about fisherman and 'the one that got away'.

However the downside to all this is people expectations when they modify their own vehicle. I've spent some time in the last few days having a look around various web sites dedicated to car entusiasts including various forums.

While obviously I enjoy the Kia sites, this certainly isn't limited to just 'us'.

The laws of physics tend to spoil the party just a little and in so many ways. Doubling power output doesn't mean the doubling of top speed of halving of
acceleration; there are so many factors including power loss through the drivetrain (typically 20% at least), wind resistance and rolling resistance of larger diameter wheel and so on. If my memory serves me correctly it would require power to be multiplied by a factor of four to double top speed.

Over the years I've competed in organised 1/4 mile drag racing events and learned a lot about not only driving, but a lot about the engineering that goes into a race car. Granted that I've only ever competed in street / modified street classes but the priciples remain the same; it's usually the budget that is the limiting factor on how much power your car can produce. It's then up to the driver to make the most effective use of that power.

I'll use some examples from one of the Kia sites I regularly visit; I have to say that this particular site I log into is pretty good as far as the members go; most seem pretty clued into the Kia scene and have useful contributions to make on the technical front. However there are always going to be unrealistic claims which is pretty sad.

Let's look at the facts. Kia don't make a performance car at this time. Simple. Generally they're underpowered by varying degrees and using engines and other parts which is second hand technology built under licence from companies such as Mitsubishi and Mazda. It's fairly current technology but never cutting edge ie multi-cam and multi-valve but nothing like VTEC or other variable camshaft timing innovations which seems to be all the rage these days.

The Sportage has a rated output of 94kW (128hp) which isn't bad for a 2.0 engine. However compare it to Toyota's 100kW from it's 1.8 engine or 124kW (169hp) from the Renault Clio Sport 2.0 then it's not looking quite so flash. However at the end of the day the Sportage isn't designed to be a sports car or quarter mile racer though a bit of extra power and torque wouldn't go astray.

The Sportage weighs in at around 1610kg (3542 lb); round that off to 1700kg with a driver and fuel (3740lb) and we get a power to weight ratio of 18kg for every 1 kW of power. My handy power/weight calculator tells me this equates to a high-18 to 19-sec flat 1/4 mile time which in the real world actually works out about right in real world testing. There are always variables to these calculations such as reaction time, temperature, gearing and so on but it's a remarkably accurate calculation considering.

Most 4-cylinder cars small sedans and hatches produce 1/4 mile times in the 17 second range with very few exceptions; Kia's such as the Rio, Spectra, Shuma (etc) are all in the mid-high 17 sec bracket. To get ahead of the next guy is relatively simple up to a point and 1/4 mile times can be slashed by around a second or so with some simple modifications. Anybody who claims anything more than this has either turbo/supercharging, nitrous or half the value of the vehicle spent on a complete engine rebuild with racing spec heads, injection and the like. Or they're full of it which is usually the case.

A good quality air filter (K&N and the like), headers (or extractors as some people call them) and a well designed 'sports' exhaust with a high flow catalytic convertor can produce anything from 10 - 20% power increase at the flywheel depending on the car. This is a relatively inexpensive way of unlocking the power potential of your vehicle and will equate to perhaps a 1 second improvement over standard on the quarter. Top end power (and top speed) is usually increased. In the Kia sedan/hatch case you're looking at high 16's or if you're lucky mid-16's at best.

A stock Spectra 1.8 has a rated output (Australian spec) of 82kW (111hp) and weighs in at around 1200kg (2640lb) with driver; this equates to a quarter mile time of 17.7 sec which once again is within a few hundred's of a second of actual road test data. With a good air filter and exhaust giving a realistic 15% power increase to 95kW (129hp) then the formula gives a revised quarter mile time of 16.9 sec, a net reduction of 0.8 sec. Might not sound like much but in the real world this is a significant improvement finishing over 25 metres ahead of a similar unmodified rival.

The next step to increasing power output gets more complicated from this point on. Aftermarket ECU chips are available for some vehicles and often require high octane petrol. In Australia pump fuel (ULP) is rated at 91 RON; PULP is 95 RON and Shell Optimax / BP Ultimate rated at 98 RON. This allows more aggressive timing advance and fuel curves allowing more power to be extracted from the engine. If another 10% was possible then the Spectra engine output would be at 105kW (143hp) then we're looking at potential 16.4 sec quarters.

Let's compare this to a real world car; Ford Focus 2.0 Zetec is a similar mass (to a Spectra) and has a rated output of 96kW (131hp). It has a road-tested quarter mile time of 17.12 sec and a 0-60mph (100kph) of 9.86sec. This can be applied to many other cars and they all produce comparison similar to what we're looking at here.

Look at it from another angle. To make a Spectra pull mid-15 second times then then you would need around 170hp (125kW) from the little 1.8 which equates to a gain of 59hp (44kW) and represents an increase of 47%. Even with high flow injectors, larger throttle bodies, cam and headwork etc, such gains aren't realistic; think radical modifications such as turbocharging etc. Sure there are cars such as Honda's S2000 which produce enormous outputs from a non-turbo engine but there is variable valve timing on both inlet and exhaust valves and the latest race technology to make it all possible. This technology (unfortunately) can't be applied as a retro-fit. Other factors can help decrease these times such as close ratio gearing and lower ratios overall but I doubt these a rare for any car and non-existant for Kia's. An amusing factor in all this are the American's with some of their performance clains as their pump fuel has the octane rating of only 87 RON. Even our often criticised 91 RON ULP offers more scope for performance than the US pump fuel. What this means is that relatively tame ignition curves are required to prevent pre-ignition and engine damage; it also explains the relative lack of aftermarket ECU chips which take advantage of the higher octane ratings found here in Australia.

Another factor to consider is the vehicles mass; reduce the mass and the power to weight ratio improves giving better performance. However gaining mass with subwoofers, big stereos and the like will detract from your performance. Making a car lighter isn't easy though alloy wheels and low profile tyres are a good start over heavy factory steel rims and heavy high profile tyres. Unless your prepared to turf out the back seat and the spare wheel (for starters) then you're not going to shed weight to any great extent. Look at the Spectra again with an additional 50kg worth of accessories (stereo, subs etc) and another 70kg for your best mate in the passenger seat; we'll take off 20kg for the flash alloy wheels you've just fitted. The net mass of the vehicle is now at 1300kg (2860lb) with half a tank of fuel on board. Your 105kW / 142hp toy now only pulls 16.9's again with a full half second loss.

My Sportage has had a fair bit of work done to the engine; aftermarket ECU running 95/98 RON fuel, huge stainless steel 2.5" low resriction exhaust with high flow cat, port work, K&N filter and so on. I honestly don't know what sort of output it's making but considering I have a substantial added mass in accessories (bash plates, roof rack - albeit aluminium, big stereo etc) I haven't found a Sportage that comes close on the street. However it hasn't been a cheap exercise achieving that kind of power output which I would estimate to be 20-25% over standard. I honestly don't know what quarter mile time 20 KIA is doing either but doubt it would be any lower than low 17's. This is based on the fact that I can take standard Kia Rio's, Spectra's etc (manuals) and other similar cars and beat them on the quarter by relatively small margins. However the huge mass of the Sportage is a limiting factor and lag behind in the first 100 metres until the vehicle winds up. To go significantly better would involve turbo's and the like which is a place I don't want to go.

Larger engine capacity is possible which would also produce improved performance particularly since torque is relative to engine capacity; torque is what you need to overcome mass effectively and is also proportional to power and rpm's. To make a heavy car perform then stroking a motor is a viable option in some cases (or an engine swap). Once again though there isn't anything particularly practical to achieve this at least at the moment.

I guess the point of this page is to induce a little reality; don't expect miraculous power and performance gain on a small budget. Basics such as regular servicing, quality parts such as spark plugs, synthetic oils etc on top of a decent air filter and exhaust will be worthwhile performance gains without breaking the bank; however whenever somebody makes wild claims about how fast their car is ask them for a dyno sheet or time card from the local dragstrip. Put up or shut up. Sorts them out pretty quick ...

Top speed is also a topic of wild fantasy; once again most Kia 4-cylinder cars have a top speed (factory rated) of between 104 and 115mph (166-185kph) which once again is pretty much ball park for other similar spec cars. However once again many web site forum are throwing claims of 130mph (210kph) or more which is absolute crap. You don't need maths to work this one out; there isn't a Kia that can rev hard enough in it top gears to reach such speeds; real world comparisons such as WRX's which produce twice the rated power of a Kia 1.8 aren't capable of much more than 130mph; indeed later model WRX's (etc) have 6-speed transmissions with higher overdrive gears to achieve these speeds.

Dave Wolin who is the CEO of a large company in the US which has it's own race fabrication facility and has the official speed record for a Kia. His 2001 Kia Spectra race car recorded an official time of 131mph (211kph). He also has a heavily modified Kia Sephia and has recorded 114mph (183kph) in a 1.5 litre Kia Rio during the 'Big Bend Open Road Race' (2001).

Above and below: Dave Wolin with his Kia Optima 'Bonneville' which has been officially timed at 156mph (251kph) and again with the '00 Kia Sephia which recorded speeds of 139mph (224kph). Down the bottom is the 2001 Rio at Fort Stockton, Texas competing in the 'Big Bend' open road event and recording 124mph (200kph).

Performance - Facts and Fiction & The World's Fastest Kia !