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Do silencers make any difference?
Major Stare - 6/9/10 at 08:49 PM

Curently have 5PW R1 with tuned length primary's into a Techcraft can.

Can is about 6" wide and about 2' long.

Does my can effect the engine in a possitive or detrimental way? (It certainly doesnt sound like a bike engine through the can).

Would a bike can be better suited?


A1 - 6/9/10 at 09:01 PM

from what Ive learned, any can will have a bad effect.
naturally, some will be worse than others, a race can would be the best thing for you, probably post IVA


Major Stare - 6/9/10 at 09:07 PM

Car is runing, so no worries with IVA.

Also running stock airbox and air filter.

What do you mean by "any can will have a bad effect?"


carpmart - 6/9/10 at 09:08 PM

Its putting a resistance to the gas flow and this will ultimately rob a little power.


bonesetter - 6/9/10 at 09:13 PM

Don't all engines need some back pressure?


Major Stare - 6/9/10 at 09:21 PM

quote:
Originally posted by bonesetter
Don't all engines need some back pressure?


Thats what ive always thought.... but im not sure on bike engines.

Im interested to know if a can for the R1 would be bette than my large Techcraft??????


mark chandler - 6/9/10 at 09:30 PM

Depends on the type of can really, once your primaries and secondaries are all balanced and correct a free flowing can that is correctly sized will have minimal impact upon performance, the only thing is that a locost with side exhaust does not allow suffcient length to get the primaries and secondaries correctly sized.

You then get two types of can, baffled or free flowing, a 2" free flowing can will allow you to drop a ball slightly less than 2" in ine end and it will pop out the other, very little restriction, a baffled can has plates and tubes and other such gubbins restricting the flow and will rob power (a standard R1 can).

A retrofit bike can that is free flowing releases power as it takes away the baffles generally at the cost of noise as they tend to be the same physical size.

If you can roll a ball down the inside of your existing can putting a standard R1 can in its place will slow you down.

nb/ moving gases have weight, tuners use this is used to pull the inlet charge into the cylinder, back pressure is a misnomer if you are looking for performance. People refer to 'banna type' manifolds as extractor maifolds as they pull all the old burnt gases out, you get a better charge as no burnt fuel or air is left in the cylinder.


Regards Mark

[Edited on 6/9/10 by mark chandler]

[Edited on 6/9/10 by mark chandler]


NigeEss - 6/9/10 at 10:22 PM

quote:
Originally posted by bonesetter
Don't all engines need some back pressure?


Nope, back pressure is bad and prevents the cylinder from clearing exhaust gases.
In the perfect world you actually have a vacuum sucking gases out.
Google "pulse wave tuning" to save me writing an essay.


Dangle_kt - 6/9/10 at 10:29 PM

some road bikes have end cans that rob the engine of 10BHP, until a race can is fitted - problem is they are stupidly noisy, or can be.

So yes - you can MIGHT be having a negitive effect, but it might not.


Major Stare - 6/9/10 at 10:43 PM

Ok, so im looking at something like this designed for an R1................



To replace this existing silencer from my old X-Flow............


omega0684 - 7/9/10 at 06:53 AM

i am looking at a techcraft silencer at the moment. Can i ask what the quality is like and the workmanship. I went to visit the chap at his workshop in Warwick and he seems like a very knowledgable man.

i am torn between running a 6" or 7" diameter can. Then theres the option of Stainless or Titanium?


iank - 7/9/10 at 07:09 AM

I think the back-pressure myth happened because if you fit a free flowing exhaust to an engine that's running well (or your rusty exhaust falls off) you will lose power until you get it re-tuned.

The best silencer for power is a turbo


Major Stare - 7/9/10 at 07:23 AM

quote:
Originally posted by omega0684
i am looking at a techcraft silencer at the moment. Can i ask what the quality is like and the workmanship. I went to visit the chap at his workshop in Warwick and he seems like a very knowledgable man.

i am torn between running a 6" or 7" diameter can. Then theres the option of Stainless or Titanium?


Quality, send to non and worth every penny. 6" or 7".... up to you. Titanium or stainless... how deep are your pockets


What are you guys with bike engines running for silencers? Bike cans or something designed for cars?


bonesetter - 7/9/10 at 08:10 AM

I've had to change this can as it failed noise at a recent track day - it read 104 on a drive by which is loud.



So I have decided to go one of these cans from Paul Gooderham. He uses Acousta-fil for wadding. This expands after a couple of heatings and does not get blown out. The centre pipe is titanium, and the outer is stainless. He will custom make any size too.

I'm hoping this will quieten down my car's noise






Hellfire - 7/9/10 at 08:53 PM

quote:
Originally posted by Major Stare
What are you guys with bike engines running for silencers? Bike cans or something designed for cars?


We're running a race can on our Indy. Although it is slightly loud, I wouldn't say it's excessively loud compared to others.

It's ideal for trackdays that have sensible noise limits, dragstrips and road driving.

We do have the original ZX12R can which is noticably quieter but it strangles the power.

Our intentions were to get a custom map for the Power Commander, which would then enable us to easily switch between road & race cans, depending on the noise limit restrictions.

Phil