R1100S throttle bodies

[~Stef~]

Ive heard fitting S model throttle bodies gives a boost in HP to the 1100GS yet this chart states that there all the same 45mm bore

http://www.largiader.com/tech/tb/

anyone tried it ?

 

[Colban]

I dont think HP increases are obtained by just changing the TBs.There are other factors to consider.
Compression Ratio.
Valve sizes.
Cam profiles,lift and duration.
Injector bore size (presumption on that one).
The fuel map in the ECU.
I take it you are after a few extra cheap ponies.

 

[ciderman gs]

i think it may be the inlet tubes from the airbox to the throttle bodies that give a better response on the throttle due to their shape increasing airflow speed

 

[~Stef~]

I dont think HP increases are obtained by just changing the TBs.There are other factors to consider.

I take it you are after a few extra cheap ponies.

Basicly...yes
Ive been looking into the differences in compresion ratio etc against hp output, it varys from model to model. Cant find any info on cam profiles.

 

[~Stef~]

i think it may be the inlet tubes from the airbox to the throttle bodies that give a better response on the throttle due to their shape increasing airflow speed

Think i'll need to pay a visit to my friendly BMV dealer and look at part numbers for the inlet tubes and a wee chat with the workshop guru

 

[DrAlf]

I’ve been using R1100S inlet tubes on my 1150GS for the past few years – as have a number of my 1150GS riding mates. The 1100S inlets won’t give you any more power, they simply shift the power up the rev range. For top end power fit the 1100S tubes. For low down grunt, use the GS inlets. The big bore tubes are the same diameter on at least the R1100S and R11XXRS models and possibly others – (RT etc).

Interestingly, I read an article about R1100RS owners fitting R1100GS inlets for more low down grunt. Guess the grass is always greener on the other side.

The inlet tubes don’t cost a lot of money and are easy to fit so give it a go and see what you think.

 

[Muppet]

You could do what I'm doing........putting an 'S' engine into my 1100 GS

As far as I know, the differences are compression ratio and maybe valve sizes? There is a slight difference in the ECU's, the S has 3 more connections on it than the GS, but I've not been able to work out what they are for yet. I've got the complete wiring loom, ignition and fuelling system for the S but there are subtle differences which make me reluctant to change the whole loom. I'm going ot fit the engine with the GS loom and ignition/injection system and see how it runs on a dyno.

Will post up when it's all finished, but it will be some months yet.

 

[~Stef~]

You could do what I'm doing........putting an 'S' engine into my 1100 GS
Will post up when it's all finished, but it will be some months yet.

I'll look forward to see how you get on with that. Ive a mate wants to put a 1200 Daytona engine (147bhp) in an old style Tiger should be interesting

 

[Isaac]

Word of warning, Muppet.....the 1100S spec. engine will be great for the first few thousand miles, then you'll start to want more.
My 1100GS engine is now 1100S specification, (with carbs and one-off ignition system), and underslung silencer.
But I've a set of 12.0:1 compression pistons to fit this winter.....
Then there's the bigger inlet valves, and the improvements to the crankcase breathing.......

 

[davegs]

air Inlet tubes

It used to be a standard "mod" to put 1100 gs inlet pipes onto 1100 RT'S,
this gave you more midrange toque and slightly reduced top end. I did on my
RT and it did workk quite well. Dunno what reversing this on a gs would do,
any one wants find out send me £1.50 for postage and they can have my old RT pipes.
dave GS. ( £1.50 U.K. only).

 

[Paul Young]

Fitting the larger bore inlets gives most of the improvement when fitted with a freer flowing air filter (K&N) & EFi mods such as a chip or Powercommander. It's all about getting more air/fuel into the engine & then out again as fast as possible...

The 1150 models took the 1100S heads & mated them to 1200C barrels to give the extra power over the original 1100GS.

HTH,