I didn't want to spam up Albert's exhaust thread in the technical forum, so I thought that I'd start one off here.

I want to tune my CR for torque rather than outright horsepower - I don't ever envisage riding this bike at 140 mph ( even if I could hold on ) so I am quite prepared to sacrifice some top end for more low down grunt - but how do I go about this - most of the aftermarket exhaust offerings seem to want to chase top end horsepower so how can I get a pipe/tune combination to achieve torque ?

Discuss ...

Despite popular belief, bike manufacturers spend so much effort on exhaust-design these days that only few after-market exhausts achieve the torque / power curves of the originals, let alone exceed them. Even some of the sports-exhausts that generously breach legal emission and soundlevels aren't always delivering the promised goods.

For getting more torque at lower revs you usually need a longer stroke, smaller valves and / or gentler valve lift- and timing. Chosing a 145 bhp sports-twin is not necessarily the best starting point for all that

But a mass produced bike is surely built as a compromise between horsepower/torque - I can easily chase horsepower, I have an R for that and there is plenty of info out there for doing that - but there doesn't seem to be an awful lot of info on getting more torque - as you stated there is more than enough horsepower on tap so it wouldn't hurt to sacrifice a little.

Rather than pursuing engine tuning, why not try altering final drive gearing?
Bespoke pulleys and belt ( the pulleys could be machined to accept a more common belt tooth pitch) and maybe a tensioner would give drastic changes to at the wheel torque , you could build a proper wheelie machine that still has 120 mph potential! Would be cheaper/safer than developing a motor too.

If you alter the pulleys then the speedo will be wrong - another thing to bear in mind.
The CR already has different gearing to the R - it is geared lower for better acceleration. I want more torque for 2 up riding, other manufacturers will retune an engine to produce different models for different uses - touring, off-road, etc so it must be possible - just not sure how to go about it.

No real challenge, speedo output is adjustable through eeprom parameter.

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"It is often said that before you die your life passes before your eyes. It is in fact true. It's called living."
Terry Pratchett

Or.... http://www.about-bicycles.com/bicycle-speedometers.htm

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Spencer Racing... www.spencerracing.co.uk

longer primaries will give more torque lower down the rev range,
isn't it grunty enough?
i have no complaints about mine apart from its very lumpy when pottering through 30 limits

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Buell X1
Buell xb12s
Buell 1125r
Ebr 1190rx
Bimota Db7
Norton v4rr??



http://www.aph-performance-engineering.com

Mine is the same and I got caught in the rain the other day coming back home from work when it cut in the morning and it was hell-ish

Should've got the lower geared CR....or better yet, a real Buell

....if Mcr. wont or dont know how to de-noid, fetch it round and I'll sort it for ya

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Mithered ta death.
92 MB
96 S2T
98 S1W
00 M2
01 X1
03 P3
10 CR

Iam round on sat i think if Rab ever gets back to me - the denoid etc will have to wait as I have just paid for a holiday and getting a house sorted at the mo

The resistor for the denoid costs about £6 and if you can remove the seat yourself then you can do it ...

You don't have to remove the solenoid - just unplug it from the wiring loom and plug the resistor in its place.

......and obviously......I keep the resistors in stock

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Mithered ta death.
92 MB
96 S2T
98 S1W
00 M2
01 X1
03 P3
10 CR

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FUBAR pilot

You only need two bikes in life-an S1 and a Multistrada!

If this was a car you were talking about then longer intake path would give better 'ram charging' at lower RPM. Is this a possibility on this bike?

Another possibility would be lower Compression Ratio.

Or change the cam timing slightly - I think retarding the exhaust would do it??