Gas flow or other engine mods
Moderators: slparry, Gromit, Paul
Gas flow or other engine mods
Has any one had there 1100s gas flowed? If so did it make any real difference. Or have you had any other engine mods done that improved performance?
I love my R1100S!
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winger
Quote from a man that builds factory Ducati motors 'Best stock castings i've ever seen,when i asked him how he knew,i got the answer 'cuz i had yours in bits before i sold it to you'!!!!
Engine wise it's bottomless pit,as BM are finding out you can only go so far,different cranks,(R1200)shorter rods and barrels to match(Das Boxer),but for most punters there are two simple options,either SJ bigbore kit which is stock BM GS barrels and pistons,or your BBP man who offers several options which get more complicated the more you look at them,the problem being the moment you go for a different cam,your going to loose the linear motor and with a peaky cam comeing in and out it'll make setting the suspension up a nightmare.
Engine wise it's bottomless pit,as BM are finding out you can only go so far,different cranks,(R1200)shorter rods and barrels to match(Das Boxer),but for most punters there are two simple options,either SJ bigbore kit which is stock BM GS barrels and pistons,or your BBP man who offers several options which get more complicated the more you look at them,the problem being the moment you go for a different cam,your going to loose the linear motor and with a peaky cam comeing in and out it'll make setting the suspension up a nightmare.
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bigblackfalco
- Posts: 1922
- Joined: Wed Feb 18, 2004 10:05 am
- Location: Darkest Aberdeenshire
On the whole, the internals on a BMW engine are pretty good. You won't gain much by gas flowing or balancing/ lightening etc.
Your best bet for better performance are:
Letting the engine breath (in and out) more easily.....filter/intake/exhaust system.
Ensure you are running good suspension (Ohlins with a ride height adjuster are a revelation).
And if your wallet stretches far enough.....a set of Dymag wheels.
If you want explosive performance.....get rid of the BMW and get a GSXR or similar!
Bailey.
Your best bet for better performance are:
Letting the engine breath (in and out) more easily.....filter/intake/exhaust system.
Ensure you are running good suspension (Ohlins with a ride height adjuster are a revelation).
And if your wallet stretches far enough.....a set of Dymag wheels.
If you want explosive performance.....get rid of the BMW and get a GSXR or similar!
Bailey.
Honda VFR750 FV 1997 Red and dirty, 130K miles.
Honda VFR800 Xf Crossrunner 2016 White and dirty, 120K miles.
Honda VFR800 Xf Crossrunner 2016 White and dirty, 120K miles.
What he said.bigblackfalco wrote:
If you want explosive performance.....get rid of the BMW and get a GSXR or similar!
Bailey.
There's always going to be a trade-off between bhp & rideability. One of the great things about the Boxer motor is its low-down shove. It doesn't feel especially quick but ride with other folk (who are on 600's for example) and they'll tell you how bloody hard it is to keep up with a well-ridden R1100S.
I'd do as Bailey says - and is basically what the vast majority of the good folk on this forum have done: Sort out the in/out breathing bits and get some decent suspension.
Sure one could, if one felt compelled, throw huge wedges of cash at the motor in the quest for more serious bhp (it would be quite good fun) but tbh I couldn't really see the point.
This is only my opinion, but I agree, cat eliminator (y-piece) and end cans will give you about 8 hp straight away. You might/might not need to sort the fuelling out after doing this.
That's the end of the guaranteed improvements - after that you have to try really hard: my heads are flowed and skimmed - its given me 2 -3 hp before 5000rpm. Nothing above that (but one tuner's idea of a flow-job mightn't be another's).
Some people big-valve, but check out the valve sizes for the sister models - the most-powerful-in-the-range 's' has got the smallest valves of the lot!
I've tried camshafts, no joy yet. It's probably good advice to check your cam timing (I've read) that these engines are a bit notorious for 'late' cams, and mine certainly was. Getting this right gave it worthwhile extra power before 5700rpm, which saves a lazy man a gearchange when overtaking on the motorway.
I've dynoed along the way. You will need to as well if you're going to change the pipe - if you get 98+ rwhp (on a cold, moist day) and no dip in torque before 5700 then wrap it up and take it home.
And put some suspension on it!
That's the end of the guaranteed improvements - after that you have to try really hard: my heads are flowed and skimmed - its given me 2 -3 hp before 5000rpm. Nothing above that (but one tuner's idea of a flow-job mightn't be another's).
Some people big-valve, but check out the valve sizes for the sister models - the most-powerful-in-the-range 's' has got the smallest valves of the lot!
I've tried camshafts, no joy yet. It's probably good advice to check your cam timing (I've read) that these engines are a bit notorious for 'late' cams, and mine certainly was. Getting this right gave it worthwhile extra power before 5700rpm, which saves a lazy man a gearchange when overtaking on the motorway.
I've dynoed along the way. You will need to as well if you're going to change the pipe - if you get 98+ rwhp (on a cold, moist day) and no dip in torque before 5700 then wrap it up and take it home.
And put some suspension on it!