The Suzuki GSX1400 Owners Club

The Suzuki GSX1400 Owners Club

Reviews

"Liberated Attitude" - MCN borrowed Richard Albans TTS modified GSX1400 and put it through its paces. Please go and buy MCN to make up for the fact this is their article and not ours!

Releasing wilder horses gives Suzuki’s brute the muscle to match its street presence.

Muscle bikes are all about street presence. But looking the part isn’t everything. Having the, er, muscle to back up your attitude is important to many. Just under 100bhp is pretty handy for a naked bike, and that’s what you get with Suzuki’s GSX1400. But there are many more and wilder horses waiting to be set free, and it’s relatively cheap and easy to release them.

Which is where Richard Albans of TTS tuning in Silverstone comes in. He took one 5000-mile GSX1400 and set about improving the motor.

The shocker – even to him – was how easily he was able to liberate power from the bike. It’s gone from 97.9bhp to 133.9bhp peak power with just three bolt-on goodies. The Akrapovic full system exhaust is the most expensive. But at £600 for steel pipes and a titanium end can, even this isn’t horrendous. Then there’s a set of camshafts. Done on an exchange basis (you give him your stock ones, he gives you a new set) they cost £250. And finally the TFI fuel injection adjuster box will set you back £176.20. That connects to your fuel injection system and helps to fill in fuelling gaps in the standard settings to smooth the power curve. And the improvement goes all the way to the red line – power on the stock bike rapidly tails off from its peak to about 6500rpm.

At tick-over the burble is sharp but not offensive. Get it wound up a bit and it starts to bark. On full chat your neighbours won’t thank you. By itself, the pipe liberates an impressive extra 14.7bhp, showing how strangled the four-into-two original set-up is. You notice the change in tone from the pipe at the same time as you feel the extra power through the bars. Below 5000rpm the bike is similar to stock on the road. Then there’s a rapid build in power from 4-5000rpm. Above 5000rpm the world starts moving much more quickly and the bars try to break your grip all the way to the red line.

That red line (at 9000rpm) comes round amazingly soon – it’s time to swap cogs again and again almost before you realise it. And if you do that you’re going to be pulling big speeds. Overtaking traffic, a quick squirt of throttle sees you sprint from 80 to 120mph in no time. The wind tries to push you off the bike. Like most naked bikes, the riding position is upright with wide bars. That means you catch about as much wind as possible and at these speeds you really feel it. On a track Albans has seen something around 160mph on the clock – or rather off the end of the dial.

The stock suspension is a bit soft and would need some attention if you really wanted to exploit the motor. As it is, it’s fun when you’re just playing but feels like it could tie itself in knots if you really tried to get it going. And the brakes are capable of overcoming the forks.

Albans describes the engine as a “cooking version”, by which he means it’s in a low state of tune.

He says: “A Suzuki GSX-R750 would be a fair comparison with the GSX1400 as it runs similar size valves which should mean similar cam lift. The camshafts in a GSX-R750 run 8.5mm lift on the inlet valve and 8mm on the exhaust as standard. On the GSX1400 you can hardly call them cams they’re so mild – it’s more like an off-centre circle. The stock cams are 7.2mm inlet lift and 6.5mm on exhaust. When we tune the GSX-R750 we take it up to 10mm inlet and 8.5mm exhaust and that’s not too radical. After re-grinding the GSX1400 cams we have 9mm inlet and 8.2mm exhaust. That’s not much more than a stock GSX-R750, so you can see it’s not a heavy tune.”

In that case, why not go even more radical with the cams then?

“Because the compression ratio is so low. If you use too much valve lift the speed of the gases through the valves drops and if it gets too low you end up with a peaky engine with no mid-range. To run more valve lift you need to increase the compression which will keep the gas speed high,” Albans explains. “The GSX is running just 9:1 compression – a stock GSX-R750, for example, runs 12.2:1. We haven’t touched the compression on the GSX1400-yet!”

So there’s more to come then?

“I think there’s tons to be got from it. We’ll probably go to about 11:1 by fitting flat top pistons – the standard pistons are dished. Then we can take it up to around 1600cc by giving it a big bore. Then there are the fuel injectors. At the moment the bike only runs 34mm injectors. I expect we’d use a 40mm injector and could see 200bhp.”

If you fancy a conversion of your bike to the spec of the one we rode, TTS will relieve you of £1400. Just don’t expect Suzuki to honour the warranty.