Ask the Experts - A Q & A with HKS

There’s no big mystery around drag racing, but it can sometimes seem like you’ll get different opinions from different people when it comes to talking about car preparation, so when the opportunity to chat to one of the top guys at HKS came up, we grabbed it with both hands.

Interview with Masaya Yumeda, HKS Europe

Q - What is the key to a good drag racing suspension set-up?
 
In drag racing, the suspension is setup purely to enable good traction off the line and to keep the car stable throughout its quarter mile run. HKS Drag suspension has very little bump on the rear. Also the suspension stroke is increased for more compression travel. The front suspension is the opposite of this, with very little rebound, allowing the car to “squat” at the back and lift at the front as the car launches. This minimises the amount of power that “escapes” and makes for the best drag launches.

The rear suspension has the low bump as mentioned above but has a lot of rebound. Similarly the front has a lot of bump. This is so that the car does not nose dive when the throttle is lifted for gear changes etc. keeping the car stable throughout its run.
 
Q - What should I look for when choosing a turbo, and what other bits do I need to change if I upgrade?

Choosing a turbo depends on many factors. It’s very dependant on the vehicle, the engine size and type and most importantly, what the end user wants to achieve as a result of their tuning. The argument many people make is always about power versus response and that still remains true to a certain extent. When changing turbo on your car, make the most informed decision that you can. HKS offer turbo kits for many vehicles and each one is aimed at fairly specific power tuning levels for common applications.
 
You can only ever produce as much power as the weakest link, whether that is the turbo, engine internals or drive train parts and so each car would require different upgrades in order to accommodate the extra power you are tuning for. For most applications, the standard fuel injectors are not able to cope with the extra demand for fuel the new turbo would require. The new injectors would also need to be controlled by a good quality engine management system (why spend thousands of £££ on your new engine and then skimp on the “brain” that makes it all work properly?). For big power, the engine internals, such as pistons, rods are prone to failure and so they may need replacing with strengthened items. HKS offer capacity upgrade kits which are primarily designed to be used with quite a large turbo for the engine size. By increasing the displacement of the engine, the engine is able to increase throttle response at lower RPM which is often an issue with large turbo kits. These capacity upgrade kits (stroker kits) are made up of strengthened materials so that they can cope with large power outputs without sacrificing low end response.
 
Q - What developments from racing can we look forward to as consumer products soon?
 
There are some interesting things going on with HKS at this time. HKS Japan is very keen on the brand new lineup of cars which are coming out of Japan. The new GTR, Lancer Evolution and Impreza STI are likely to lead the way in terms of development over the next year.
 
HKS Europe has concentrated its development efforts towards the new Honda Civic type R. This car is only available in Europe and therefore the development would have to take place locally. Many engineers have come over from Japan to examine and develop parts for the car and we will soon have parts available exclusively to HKS authorized European dealers such as, exhaust systems, intake systems and suspension parts.
 
Q - What do you think separates the UK Jap car scene from the one in the USA and in Japan itself? What do we do differently?
 
The Japanese car scene in the UK seems to take a lot of influence from Japan and the USA. I would say that the UK scene doesn’t have a distinct identity, but is picking out the best bits from around the world. There are obvious influences from traditional motorsports also which is starting to shape the UK scene into something quite unique and hopefully it will be recognized abroad and develop into a style of its own. The thing that has driven the US scene is the whole “Domestic V. Import” debate which fuels the industry. Unfortunately this doesn’t exist so much in the UK. I hope that the UK and European scene will continue to grow in its own way and HKS will be around to support this progress all the way.
 
Q - How do I do a burn-out in a 4WD car like Tim Webster? Do I need a line-lock? (John Fuggles)
 
Japanese 4WD sports cars are normally orientated in one of two ways. One is based on the front wheel drive layout and the other on a real wheel drive layout. 4WD cars based on a front wheel drive layouts have transverse mounted engines and the gearbox sits beside the engine. Examples of this layout include the Mitsubishi Lancer Evolution and Nissan Pulsar GTIR. 4wd drive cars based on a rear wheel drive layout, have longitudinally mounted engines with the transmission behind the engine. Examples include Nissan Skyline GTR, Subaru Impreza and Ford Escort/Sierra RS Cosworth.
 
The Skyline GTR as used by people like Tim Webster and Andy Barnes, is not full time 4WD. The car is essentially rear wheel drive by layout with a transfer which sends torque to the front wheels. This is controlled by the on board computer which determines the amount of torque which should be allocated to the front and at times it may not drive the front wheels at all. During a burnout, these cars are not engaging the drive to the front.
 
The brakes on all cars work a lot harder on the front than on the rear to maintain stability of the car during braking. Due to this brake balance, it is possible to hold the car on the brakes and still spin the rear wheels as there is very little braking force stopping the rear wheels compared to the force stopping the front wheels. When going for a full on drag setup, the teams will use various different methods to brake only the front wheels so that the rear wheels can spin freely.  
 
Q - Will HKS release compressor maps of their turbos? (GarethK)

Unfortunately not. This is one of our secrets which make HKS turbos unique.
 
Q - Will HKS ever release a twincharging (turbo and supercharged) kit such as available on some VWs? (Gavman)
 
Ever since HKS was founded in 1973, Turbo technology has been the key to the HKS product lineup. HKS’ very first product was a turbo kit for non turbo cars in the 70’s. Supercharging is something that HKS have very recently taken on as part of our product line up. As HKS continues to grow and develop to the future, it may be the case that we could have twincharging kits available if the developers feel that there are sufficient gains to be made through this system.
 
Q - What’s the official line on the HKS R33 drag car? Has it been retired? (Lex)
 
We at HKS Europe have heard no information about its retirement, although we haven’t heard about it running on the strip for some time either. We’ll have to wait and see what the motorsport team at HKS Japan do or say about the situation.
 
Q - Why should I trust HKS above any other parts supplier? (Dave W)

HKS has subsidiaries in both the US and Europe, and is one of very few companies in the tuning industry to have a proper presence globally. HKS Europe is specifically in existence to supply parts for the European market and coordinate development for European specific parts. HKS Europe is currently leading several projects such as the civic type R (mentioned above) and non Japanese marques cars also. HKS design and produce most of their goods in house, meaning that the quality can be controlled at every step of the way from the drawing board to under the bonnet of your car. Whilst we are not the cheapest items on the market, we believe that HKS products are priced competitively considering the quality of the product lineup. We hope that people who try HKS parts can feel the quality and benefits for themselves and continue to choose HKS as a brand they can trust.