Restricting GS1200

[snerkler]

Not so you could be riding at 7000 with the throttle closed producing nil bhp or minus bhp JJH

Whilst true you'd have to get to 7000 in the first place, and as BHP is a product of torque and RPM, in order to get up to 7000 RPM and still only produce 33hp's the torque would have to be extremely low and it would struggle to propel the bike.

 

[AberdeenAngus]

Power is a function of revs. Torque isn't.
You will still get a lot (most) of the torque from a 1200 with a 25kw restrictor fitted.
Probably find it just gets flat and gutless above about 3000 rpm.
Just have to change up sooner and use it in 'chug' mode.

I wouldn't do it, but you'll probably still have a useable bike with the restrictor fitted.

Be interested to hear how you get on.

 

[snerkler]

I don't think anyone said torque was a product of revs? Also max torque does not come in until well after 3000 RPM. Looking at the power curve below the power curve doesn't even measure a HP low enough to be able to use it as a restricted engine, therefore in order to not go above 33HP (24.6kW) you'd have to limit the bike to 2000rpm or there abouts, in which case it would be horrible to ride. Unless of course when they restrict it it's like a remap in which they alter the torque/power curves?

 

[AberdeenAngus]

25kw on that map is about 2700 rpm. You still get about 90Nm.

It would be flat but useable - I reckon. The OP said he didn't have the option of another bike and doesn't want to get rid of the GS so I say, go for it.

If its unusable - what's been harmed ?

 

[Bones]

I took the restrictors out of T'Missus' one years ago !

I'd never thought of derestricting the misses. Goes does she?

 

[snerkler]

25kw on that map is about 2700 rpm. You still get about 90Nm.

It would be flat but useable - I reckon. The OP said he didn't have the option of another bike and doesn't want to get rid of the GS so I say, go for it.

If its unusable - what's been harmed ?

Yep you're right, and 90Nm is still more than a lot of 600cc bikes out there so maybe not quite as bad as I thought. I wouldn't know what a GS/GSA feels like under 2700RPM as I'm always using it at 3000RPM and higher. Maybe I'll try it one day

 

[JJH]

I don't think anyone said torque was a product of revs? Also max torque does not come in until well after 3000 RPM. Looking at the power curve below the power curve doesn't even measure a HP low enough to be able to use it as a restricted engine, therefore in order to not go above 33HP (24.6kW) you'd have to limit the bike to 2000rpm or there abouts, in which case it would be horrible to ride. Unless of course when they restrict it it's like a remap in which they alter the torque/power curves?

You are looking at a full throttle graph. The throttle is not open fully all the time maby as little as 5% of the time or never so a 1200 engine can produce 33 bhp at 7, or 8,000 rpm it dose not have to produce max power just because it's at "x" rpm. JJH

 

[snerkler]

You are looking at a full throttle graph. The throttle is not open fully all the time maby as little as 5% of the time or never so a 1200 engine can produce 33 bhp at 7, or 8,000 rpm it dose not have to produce max power just because it's at "x" rpm. JJH

Fair point. So does the restriction just limit throttle opening then? Or is there more to it?

 

[JJH]

As far as I know the throttle is restricted by how much it will open on the BMW. Some factory restrictons are in the ecu also and retard the ignition and cut the fuel at certin pre detirmend points. Remember at a steady 100 mph you are probly using 25 to 30 % of the full potential of the engine give or take. It takes more than twice as much power to do twice the speed probly nearer 3 times as much. I think a restricted gs would be like riding at 30 % on a standard bike at higher speeds. It would only be at high speeds and acceleration that you would notice a lack of power also caring a pilion might be tricky JJH