Exhaust Mod Part IV

[zebulon]

I don't need more midrange power in my V11 but +10bhp on top would

be welcome. Opening up the intake and exhaust is the way to

Hey goran

 

what about your bike , is it ready to ride ?

[Motomonster]

Hey, I just got my ceramic coated pipes back from the shop and was very surprised at the difference.

 

First, they are quieter now. There is still a rumble, but it is not so sharp.

 

Also, the acceleration is smoother and there is more throttle response.

 

My flat spot at 42K seems less noticeable.

 

Despite the claims, I didn't really expect such a noticeable improvement. If any of you are thinking about doing this, go for it.

 

PS: They look baddass too.

[gthyni]

I don't need more midrange power in my V11 but +10bhp on top would

be welcome. Opening up the intake and exhaust is the way to

Hey goran

 

what about your bike , is it ready to ride ?

no, luckily it still cold up here below zero at night and just a couple of

degrees C at daytime. But I'm starting to feel the pressure.....

 

I need to get hold of a pair of Brembo calipers during this week or I have

to remove the Paioli fork. For the time being the Marz probably gets back

on again.

Everything except the calipers is ready for a fairly quick switch

some rainy weekend during the riding season.

 

My modified exhaust, new LED backlight and some kind of fender eliminator

+ Pirelli Dragon Corsas is going to be mounted during this week.

[Guest Neronut]

Wow Motomonster, I would like to see more information about your pipes. Did you have you originals done or new ones made up? What cost and color? who did it for you?

[Guest Fonzarelli]

I still have a question for you all: What does hard engine braking MEAN? or, conversely, what does easy engine braking and coasting MEAN? Does anyone know?

I don't know what 'easy' or 'hard' engine braking is referring to, sounds like a play with words.

 

Engine braking in itself is the FRICTION from the engine and driveline that transfers to the rear wheel to give a braking effect.

 

This friction includes the piston rings, valve springs, cam and lifter friction, trans drag, driveline, rear differential, just about every moving part in the engine has some level of friction.

 

This braking effect that is experienced when the throttle is closed at speeds is the result of engine friction, NOT compression or cylinder pressure. To put into perspective, when the throttle is closed and the bike is moving, there is now very little air/fuel to be compressed. Cylinder pressures take a nosedive.

[Motomonster]

Wow Motomonster, I would like to see more information about your pipes. Did you have you originals done or new ones made up? What cost and color? who did it for you?

I had the originals done as well as the aftermarket crossover. I had them done in satin black by Performance Coatings:

 

http://www.performancecoatings.com/

 

Total cost was 105 bucks.

[Guest Fonzarelli]

The manufacturers spend literally millions of dollars and untold hours studying these events, we see it as computer controlled valves in the high end japanese sportbike exhausts. They throttle the exhaust to reduce the effects of bad timing and to extend the good timing of the pulses to effectively increase the power across the rpm range making these engines much more user friendly. We can only hope that Guzzi would follow suit, again, not likely. I would guess there just aren't enough of us to justify the expense. 

Hmm..

and every serious jap sportbike owner replace the whole thing

with an Akrapovic/Yoshimura/Hindle full system which removes the Exup

(or similar) exhaust throttle.

Gives about 10 bhp on top and loose a little in the low/midranges.

 

I don't need more midrange power in my V11 but +10bhp on top would

be welcome. Opening up the intake and exhaust is the way to

go for more peak power even if it does not please the authoritize.

Jeff is actually right on the mark here!

 

The manufactures do spend millions on development. This includes thousands of hours on the dyno with squillions of intake and exhaust combinations. Then the consumers (us) think we can reinvent the wheel and make changes to find performance gains. This not only creates a large market for add on parts, but inflated claims as to what the products will do for your bike.

 

When a company engineers a motorcyle they are given a set of perameters that must be met. You cannot, unfortunately, 'have your cake and eat it too', so the manufactures make the best powerband to fit as many needs as possible. All of these are tradeoffs. Wan't more top end? You will lose bottom end. And visa versa. This is how the internal combustion engine works.

 

Sure, you can add a cool set of cans or a complete system to your bike and see 5-10 PEAK horsepower gains. But, what happens to your midrange? Where did the drivability go? It is very true, the factory systems work very well.

 

The EPA required equipment is another story...

[al_roethlisberger]

Yes, I have noticed bikes are rather loud at the race track. And, you are correct, I've never seen one of those highly engineered stock air/exhaust systems on any of the bikes there either.

 

..... unless you are talking about Laguna Seca, where they don't allow "race cans" <_>

 

If you want to do a track day there, you have to fit your stock exhaust, or at least an exhaust that is below something like 80db or so. They even have track db sensors, and will pull you from the circuit.

 

It has to do with all the wealthy homes surrouding the track area from what I've heard

 

al

[belfastguzzi]

I still have a question for you all:  What does hard engine braking MEAN? or, conversely, what does easy engine braking and coasting MEAN?  Does anyone know?

I don't know what 'easy' or 'hard' engine braking is referring to, sounds like a play with words.

 

Engine braking in itself is the FRICTION from the engine and driveline that transfers to the rear wheel to give a braking effect.

 

This friction includes the piston rings, valve springs, cam and lifter friction, trans drag, driveline, rear differential, just about every moving part in the engine has some level of friction.

 

This braking effect that is experienced when the throttle is closed at speeds is the result of engine friction, NOT compression or cylinder pressure. To put into perspective, when the throttle is closed and the bike is moving, there is now very little air/fuel to be compressed. Cylinder pressures take a nosedive.

No, surely not 'parts friction'.

 

Cylinder compression acts as a brake. Take the spark plugs out – the engine turns easier because air compression has gone, not because the parts have all gotten a lot slippier. High compression engines brake hard, low compression engines don't. Diesels give great engine braking. Then there's the 2-stroke system...

[Guest Jeff Kelland]

Cylinder compression cetainly does play a part in engine braking, some air gets into the cylinder even when the throttle is closed. It would be even better if the throttle were open and the ignition was off. Diesel engines have excellent engine braking because they have no throttle, air is introduced into the cylinder constantly and throttle is controlled soley by fuel flow. Even better braking horsepower (yup, that's how it's measured!) is achieved if the engine is equipped with an engine brake. This is a hydraulically operated device that opens the exhaust valve independently of the cam. It opens the valve just before the top of the compression stroke. The engine absorbs all the energy used to compress the air (diesels have much higher compression than gas enines, almost 20 to 1) and then is denied the power stroke when the valve opens. This gives engines so equipped that distinctive BLAAAAAAAAAH sound. With the advent of electronic injection in the mid 80's, the engine ecm cuts the fuel delivery during braking to prevent emission of unspent fuel. Even before then at idle fuel delivery is a very small amount. Most of these brakes are variable by using some or all of the cylinders in the braking event, they can be extremely effective!

[belfastguzzi]

New tail pipe

That style is tried and tested, though most see it as a temporary measure.

 

A big box of coloured felt-tip pens are great for further mods.

 

 

Doesn't usually increase speed.