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Re: crisp throttle response, etc.
Posted: Tue Oct 25, 2011 3:41 pm
by Jean
"Right now I have crisp throttle response, great acceleration and a broad power band with a lot of low end torque."
So....what ELSE did you REALLY want? Maybe a paint job...
Re: crisp throttle response, etc.
Posted: Tue Oct 25, 2011 6:22 pm
by vanzen
Jean wrote:"Right now I have crisp throttle response, great acceleration and a broad power band with a lot of low end torque."
So....what ELSE did you REALLY want? Maybe a paint job...
1st, glad that you are satisfied with what you got, Jean.
As regards the "So ... what else" –
Perhaps the topic attempts to be an evaluation & understanding
of how these exhaust system changes might affect the performance of the machine ...
i.e. Not everyone might be satisfied with
your happy agenda, eh ?
No offense intended, just sayin'.
Re: trying to tune with new mufflers
Posted: Tue Oct 25, 2011 8:29 pm
by twist
I am always curious if there is a way to improve. If it's possible to tweak a bit at the exhaust. It's fascinating to me as I'm new to this.
Re: crisp throttle response, etc.
Posted: Tue Oct 25, 2011 9:16 pm
by SteveD
vanzen@rockerboxer.com wrote:Jean wrote:"Right now I have crisp throttle response, great acceleration and a broad power band with a lot of low end torque."
So....what ELSE did you REALLY want? Maybe a paint job...
1st, glad that you are satisfied with what you got, Jean.
I think Jean was actually quoting Twist, then asked him a question. edited : 
Re: trying to tune with new mufflers
Posted: Tue Oct 25, 2011 9:35 pm
by vanzen
vanzen@rockerboxer.com wrote:Well then, I won't be glad that Jean is satisfied ... or not using the quote feature.
... or red font colours
Re: trying to tune with new mufflers
Posted: Tue Oct 25, 2011 10:03 pm
by twist
is it possible to be satisfied? It seems there is always something new to learn and implement. Like the muffler/exhaust relationship to where the power range is. Balanced with intake and air flow. This is fun stuff. I am now seeing the relationship between sag and handling performance. I never realized front and back need to be balanced to the riders needs and style.
I kain't get no ...
Posted: Wed Oct 26, 2011 2:34 pm
by vanzen
Re: trying to tune with new mufflers
Posted: Fri Oct 28, 2011 7:59 pm
by Jean
Exhaust tuning is a tricky business. It is highly developed with single-cyl 2-stroke engines...lots of books on the subject.
With a twin OPPOSED 4-stroke, my guess is there's not nearly as much. If you like to experiment, it's a wide open field.
But a bit of engineering advice: ONLY change ONE thing at a time. AND, at this point (refer to the quote), I'd say a dyno would be needed to honestly evaluate any further tweaking.
Yes, I WAS quoting...not acquainted with the QUOTE function.
tuning mufflers, LINK (not)
Posted: Sat Oct 29, 2011 10:32 am
by Jean
Found it...
Title: Intake and Exhaust system tuning for BMW Airhead Motorcycles
http://bmwmotorcycletech.info/InExTuning.htm
cut and paste. I thought it would be a live link.
Sorry vanzen...I cannot make the letters turn RED either.
Ah! NOW I see the QUOTE button. I'll try that sometime.
Re: tuning mufflers, LINK (not)
Posted: Mon Oct 31, 2011 12:08 pm
by vanzen
A competent introduction to exhaust theory
if only a rudimentary introduction to exhaust tuning –
However, (several) generalizations regarding exhaust systems
fitted to the BMW
might best be described as fulfilling the writer's subjective preference
based upon his own (strictly defined) performance expectations
rather than any objective consideration of exhaust system theory
as it might be applied to achieve certain (alternative) performance results.
And therefor, best "swallowed" with that proverbial "grain of salt".