Why so few Turbo boosted bikes?

[Courier265]

[Shaft]

[Polarbear]

Those were the days they did it because they could. New designs rolled off the production line every few minutes. Loony bikes, loony designs with some absolute masterpieces scattered among them. I mean, Suzuki built the RE5

I haven't ridden any of the old turbo bikes but old turbo cars had a horrifying issue called turbo lag that kicked in just when you didn't want it to, I would hate to have that on a bike.

In the modern day there is just no need for it. Fuel injection, mapping, light small engines, power to weight ration etc. have all but eliminated the reasons for a turbo on a bike.

Maybe a supercharger for the lols, but necessary? no chance.
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Triumph Trophy Launch Edition

[B5234FT]

The main reason for turbos is emissions vs driveability, not power.

People rarely use full power in mundano commuter cars, but a 1.6l naturally aspirated mondeo is awful, to make it 'nice' to drive, i.e. torque at low RPM, you need a far larger engine, which bring increased emissions. A turbo allows you to have both.

This simply isnt a problem on bikes, as they weigh 1/4 as much and nearly always have excess power, theyre also geared shorter, making more torque available.

Take the Mondeo for example, nowadays, 1400kg (1550 with a couple of people in it) and the nat asp 1.0 and the 1.0 turbo are both in the 130bhp range.

The average bike is 250kg with a ride on board, imagine a 20bhp fullsize bike and you start to see the issue.

The key difference is that bikes and cars all use 12-20bhp to maintain 70mph, so having 100bhp/tonne in a car just means it's not quick. Having the same in a bike means you struggle to maintain motorway speeds at all.

TLDR, most bikes are MUCH more powerful than most cars already.

[grr666]

[Polarbear]

[grr666]

[stevo as b4]

I'm being a twat I know, but the above sounds more like 'boost threshold' to me and not lag. Lag is only ever momentarily and describes the delay in throttle response typical compared to a more eager nasp engine in going from a closed throttle to an open throttle. You don't get stunning throttle response in most forced induction set ups, especially if the boosted air is coming from an exhaust turbine driven compressor.

Modern cars with drive by wire ECUs and direct injection are massively better at drivability, especially as like others have said most forced induction engines are eco-boost style with emissions and mpg driven set ups from downsizing.

In fact today if your a volume car manufacturer you really almost are forced to make nearly all your petrol engines turbo charged across the overall model range, as it's extremely hard without a turbo to meet the Euro 6, and it takes alot of left field expensive alternative engineering like Mazda use to get clean enough emissions with an acceptable level of performance and mpg. Emissions and mpg in many cases are completely opposed and getting one criteria really good usually hurts the other.

Back to bikes, one thing I did like on the Yamaha XJ650T design, was the induction set up using reed valves, so under vacuum conditions the engine could inhale air without it having to go through all the restrictive long turbo plumbing, and when the inlet manifold went into positive pressure, the reeds would shut and it became a turbo engine like any other.

I wonder if it really helped and if so why no-one else has used turbo bypass systems like this?

Anyway out of the factory turbo bikes, I'd have voted CX650T if only it wasn't so fucking heavy. If they could have made it under 200kg it would have been much faster.
History says the Kawasaki was the best and arguably that'd be right, but I wouldn't swap a GPZ1100A for one, as the big brother was still quicker in top speed at least and weighted only 11kg more.

[Tdibs]

There is still rumblings of this

https://www.bennetts.co.uk/bikesocial/news-and-views/news/2017/october/suzuki_turbo_recursion_production_2018
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Previous : 09 Vanvan 125| 02' Sv650s || Current: 1999 Xj600n | 1992 DR650 RSE | 2005 Fazer 1000

[RhynoCZ]

[RhynoCZ]

[BusterGonads]

[MCN]

If you fit a turbo you need to upgrade every Power Band in the engine too or you will be sorry.

The O.E.M. (red colour) ones will not last long at those higher settings.

There are new ones on the market (Chinese but decent quality) that are a better design.
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Disclaimer: The comments above may be predicted text and not necessarily the opinion of MCN.

[Pete.]

[MCN]

[chickenstrip]

[Pete.]

A turbo/supercharger increases TORQUE. Power is derived from that and revs. Where it produces that extra torque depends on the size of turbo you fit. Use a small unit you'll get huge torque increases at lower revs, where a bigger unit gives large torque increases higher up the revs.

Which of those suits you is down to personal preference but the bigger units are easier on the engine, the smaller ones more fun.
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[chickenstrip]

[arry]

[Fisty]

[B5234FT]

[grr666]

[Fisty]

[MCN]

[dydey90]