Power increase C800

Put the endcaps back on my exhausts after running nearly empty pipes for a while. The power has increased I think. New pipes coming next week, I presume power increase will be due to it's tuned shape - we'll see. From what I have read debaffling loses some back pressure. The trouble is when a bike sounds louder we might think it is more powerful. I suppose only a Dyno test would tell. The modern fuel injected Intruder is very clever with it's sensors - it adjusts so quickly when we make changes. Whatever I seem to do, the bike takes it on board - up to a point I suppose. But it's a very clever machine nevertheless. It looks all traditional and basic but in reality I think its a wolf in sheep's clothing. Being able to go one step further and remap makes it a very modern tool indeed.

Back pressure will make a major difference, you may or may
not have noticed but all aftermarket pipes are smaller in diameter than stock
pipes for the intruder. The ones that have a very small diameter have the back
pressure they need even as a straight through pipe, this is because the air
pressure is slowing down towards the end of the pipe & the newly combusted
gases are pushing against them creating the required back pressure. As pipes
get bigger they will then generally have some form of packing or baffle inside.
The thing we need to remember is that packing or baffling has several purposes,
not just one. On the Vance & Hines Cruzers for instance they are much
smaller in diameter and are a hell of a lot shorter than stock pipes and they
do not have what you might recognise as any kind of baffle inside them. What they
do have to keep the noise down or to baffle them slightly and to get the back
pressure that they require is a system of coiled wire running around the
muffler like rifle barrel. Back pressure is always required to some extent and
there is many different ways of getting it but we must have it or we will lose
power. As the Bluesman says our modern Intruders are very clever but even they
can only go so far with regards to the air & fuel ratio. If we open our
pipes up or put pipes on that require a high gas flow to reach a back pressure
that is within the optimum zone and we don’t allow the air flow in via an
aftermarket air filter, then no matter what the bike tries to do it will never
reach the back pressure required for optimisation and a loss of power will be inevitable.

Mr Intruder wrote:

On the Vance & Hines Cruzers for instance they are much
smaller in diameter and are a hell of a lot shorter than stock pipes and they
do not have what you might recognise as any kind of baffle inside them. What they
do have to keep the noise down or to baffle them slightly and to get the back
pressure that they require is a system of coiled wire running around the
muffler like rifle barrel.

I read this with great interest as I have V&N cruzers on my bike, the so called baffle in them is removeable but to keep the back pressure you must leave these in I assume which I have done.Do these baffles need to replaced at any time or do they usually last the life of the bike?(I hope this do'nt sound like a stupid question).

Yeah I found that an interesting read too

pledge wrote:

I read this with great interest as I have V&H cruzers on my bike, the so called baffle in them is removeable but to keep the back pressure you must leave these in I assume which I have done.Do these baffles need to replaced at any time or do they usually last the life of the bike?(I hope this do'nt sound like a stupid question).

I would have thought that gutting the V&H Cruzer exhuast would do you no favours at all, there is very little in there to begin with. We need to remember that a lot of time and effort goes in by the manafacturer to get the maximum output from aftermarket exhuasts after all the V&H Cruzer is classified as an enhanced performance exhuast not as bling!
Although they really are purty 8)
And no they would never need replacing!

Yes thanks for that and I agree they are awesome.

On the last comment,do the baffles need replacing,you can renew your wadding as this will not last forever,so V/H say.Hope this satisfies your curiosity,exhausts are tricky things,I tried to make mine a little quieter by placing a proper baffle of the right size in the baffle already on the V/H Cruiser,it did quiet it down but choked the power,it is a science that these companys look into and work to.Incase you are wondering why I wanted to quieten the pipes down it was personal choice love the look,but at times to loud.

alfie92 wrote:

Incase you are wondering why I wanted to quieten the pipes down it was personal choice love the look,but at times to loud.

I have the same issue at 4 in the morning on a hot summer day when all the neighbours windows are open and they are still in the land of nod. I love the look and sound of the cruzers but it aint fair on the neighbours in the middle of the night.
:sleep: ........................

Bluesman if you have any worries about whether or not your bike's ecm has been able to cope with your new pipes when they have been fitted, then go back to what we used to do in the old days.
Have a look at your spark plugs after you have clocked up a few miles, simple!!!


Enlarge the image to be able to read the diagnosis

Mr Intruder wrote:

Bluesman if you have any worries about whether or not your bike's ecm has been able to cope with your new pipes when they have been fitted, then go back to what we used to do in the old days.
Have a look at your spark plugs after you have clocked up a few miles, simple!!!

Good tip and great chart - I'll keep an eye on them

Mr Intruder wrote:

Bluesman if you have any worries about whether or not your bike's ecm has been able to cope with your new pipes when they have been fitted, then go back to what we used to do in the old days.
Have a look at your spark plugs after you have clocked up a few miles, simple!!!

Hi Bluesman, What MR I says above is very true but to find out how your bike is fueling at any given revs/speed. You'll need to perform a "Plug chop" ....It's dead easy to do, Just ride along at whatever your normal cruising speed is for a few miles then hit the kill switch, coast to a stop and take one or both plugs out and have a look at them compared to the chart supplied by MR I' or have a look in a Haynes manual for a similar chart

The reason for doing it this way as opposed to looking at the plugs after you've arrived home on your driveway is that it gives an accurate indication of the bikes fuel/air mixture at the exact moment you hit the kill switch i.e. during your sustained cruising speed. During a 20 mile ride at 70mph the bike maybe running as lean as hell. Then as you slow down as you approach home the mixture may richen up and therefore when you check the plugs at home you will get misleading info about what's happening to your engine the other 80% of the time?

If you don't want to perform this at the roadside and you live within a reasonable distance of a fast bit of road? You could always push the bike home to look at the plugs?

I hope that makes sense mate?

Dozers-Dad wrote:

Mr Intruder wrote:

Bluesman if you have any worries about whether or not your bike's ecm has been able to cope with your new pipes when they have been fitted, then go back to what we used to do in the old days.
Have a look at your spark plugs after you have clocked up a few miles, simple!!!

Hi Bluesman, What MR I says above is very true but to find out how your bike is fueling at any given revs/speed. You'll need to perform a "Plug chop" ....It's dead easy to do, Just ride along at whatever your normal cruising speed is for a few miles then hit the kill switch, coast to a stop and take one or both plugs out and have a look at them compared to the chart supplied by MR I' or have a look in a Haynes manual for a similar chart

The reason for doing it this way as opposed to looking at the plugs after you've arrived home on your driveway is that it gives an accurate indication of the bikes fuel/air mixture at the exact moment you hit the kill switch i.e. during your sustained cruising speed. During a 20 mile ride at 70mph the bike maybe running as lean as hell. Then as you slow down as you approach home the mixture may richen up and therefore when you check the plugs at home you will get misleading info about what's happening to your engine the other 80% of the time?

If you don't want to perform this at the roadside and you live within a reasonable distance of a fast bit of road? You could always push the bike home to look at the plugs?

I hope that makes sense mate?

Got that, thanks. My 7,500 service is due up soon and the bike is running very well so I will just see how they get on with the plugs. If nothing is said then I'm quite happy. The plug removal on the Intruder is a bit of a pain with having to take off the air cleaner!

So if I fit V&H cruzers on there own will they add power or do I have to change the airfilter to see any power increase. If I add an airfiler I assume I will need a power commander. If I mod my stock pipes I will lose power but If I add an airfilter will this compensate for the mod and recreate back pressure?????



I want more noise but dont want to lose power, or too much dosh!!

Sounds like you got it pretty much worked out, aftermarket pipes will give a minimal increase power and your bike will cope as long as thats all thats done on a FI bike.
If you mod your stock pipes you will not loose power on a FI bike as it will compensate for it.
If you add a hi-flow filter then you will have to add a fuel processor

If your looking for a power increase then it's gotta be all 3, exhaust, hI-flow filter & FI processor

If i either drill holes in the backplates or completely remove the baffles in my stock pipes my FI will compensate for the loss of backpressure, and no power will be lost? Sorry if i am repeating myself but I want to get it right in my mind before I get my drill out!

Gutting then will lose power due to the lack of back pressure
.
Taking the baffles out as well as belting an iron rod through the plates further up the exhaust will loose you power, due to lack of back pressure
.
Debaffling alone is open to debate on what it does, probably just give more noise
.
Drilling holes in the end cap will just make more noise.
.
The problem is that exhaust shapes are tuned, the are not just put together in a particular shape because that's what looks good.
.
Yes your FI (arguable) will compensate as long as it is only the exhaust that is modified or changed

Drill, debaffle, V&H???? Decisions!



Cheers for info Dave.

V&H all day,shorter,better looking.No comparison to stock pipes,which I feel are long and ugly.

stone wrote:

Drill, debaffle, V&H???? Decisions!

Here's my experience for what it's worth. After drilling,bashing,debaffling and finally aftermarkets I would say bash a pipe up the middle through 3 plates and don't drill. That way your pipes will still look like stock but will be louder and deeper, not massively but better than stock. Drilled pipes look a bit silly for just a slightly louder but a bit 'farty' sound. If you could afford aftermarkets anyway, may as well give the 'bash' a go - you can always go aftermarket once you have heared them. As for power decrease - if the back plate is not removed you will notice hardly any at all and the louder sound will make it seem better anyway. If you debaffle you won't lose that much but if you gut you will lose more. My pipes were nearly gutted with new backplates refitted so they looked un-tampered with. I quite liked them but decided to go for the aftermarkets for more noise. Sometimes I wished I had my altered stocks back on (early mornings, when neighbours stare, cops etc) but on the whole more noise the better for me.

Here's a pic of my 'bashing bar' - a 3/4" tube sharpened at one end with a tommy bar at the other (essential for twisting it back out). I used a heavy club hammer. I found it much easier to make a pilot hole first using a thinner steel rod. Pic shows drilled holes which are no longer there on my stock pipes. My pipes are in storage in case I ever prefer to sell the bike with them on.

Cheers guys

Did the bash! sounds better than stock. It will do for now and it was inexpensive.

stone wrote:

Did the bash! sounds better than stock. It will do for now and it was inexpensive.

how far does the bar have to go in and how many bits does it have to brake through. someone did mine last season not sure if the  bottom pipe was done right. and can the bar be bashed in to far to cause damage   

I have a 08 m50 muffler that's been cut in half out in the back yard that I was going to use for a boat anchor. I will go and have a look for you.

I may have spoken too soon. The last 2/3 has been gutted and sent off in the trash... but from memory... Going through the first plate would be OK and carefully through the second and no more. After that there's a honey comb of thin steel up to where the pipe comes into the muffler. That could have been crushed and caused a restriction. I suggest some nice new pipes for your baby.

First baffle is about 9 inches in second is about 13 inches.

  with the measurements Tex has given  

Thanks all 

  

Ooh, reading this makes me wish I had another virgin Intruder to deflower - ramming that pole into a tight hole for the first time was a wonderful experience! Those plates are surprisingly thin, not quite a knife through butter but only about 2mm I would imagine.

I have the carb version and gutted my stock pipes, I havent noticed any decrease in power or torque over the standard stifled pipe !! Back pressure is a must in 2 strokes but 4 strokes its a massive debate as some say yay and some say nay, the internet is full of the great back pressure debate.
All I can say is I liked the look of the standard pipes so after ripping the insides out I got the sound I wanted, the same performance and the look for £0 cost !!!
One thing you got to remember on the standard pipes is the down pipes are where the restriction is as the internal diameter is tiny which is why you dont have to re-jet after the baffle mod, after market pipes have larger diameter down pipes so will normally need a re-jet.
Best way to look at it is the smallest diameter section of your pipe is where the most restriction is, the baffles in the end can are just a noise reducer.

Jim.

Jim you say about the size of the downpipe as the bit where the restriction is due to its small diameter and to an extent that is true but only in some circumstances. I dont know not a great deal about this sort of thing but I chatted to (Dave) Mr Intruder about it only a week or so ago and he explained internal header pipe width to me a bit like this but I gotta be honest and say I can't remember all that he said
He said that it all depends what you want out of the bike and how you will use it that really determines the importance of the header downpipes diameter. Apparently if I remember properly if you ride within the rev's that arnt at the lower end of the engines range like he does then you are more in need a bigger diameter pipe but if you are a predominantly a plodder or easier rider and want torque down low in the rev range of the engine then the smaller diameter pipe of the stock bikes header downpipes are what are really needed. Basically the header pipes internal diameter is either advantageous or disadvantageous depending on the type of rider you are and where you predominantly want the torque to be and why and the power that is available from the engine in various ways
Sorry if I have not explained it properly but I am working off of memory

CC thats a great bit of info mate, I always like to learn new things,
Cheers.
Jim.

No worries Jim   
In short the bigger bore of aftermarket pipes is always well worked out by the maker to give the potential maximum torque availability for the potential expected air & fuel mixture added. Also messing with the stock pipes to get more noise actually never does more than that with the stock air and fuel flow, all it does is give more of is noise. Many people make minor adjustments to their exhausts and do nothing else to any other part of the power giving areas and although they often claim that they are getting more power the actually are not, they are just hearing more. What they are getting is more noise and less power but let them believe what they want and be happy in their ignorance while we just smile and say nothing   

Hi guys. I haven't been on for a time. I now have a nice set of saddle man boxes some extra spots an nice cobra exhaust and k&n filter. I have noticed an increase in fuel consumption, only getting around 110 miles between fills.. Does this mean I need to fit a power commander now. Any ideas. ??

I'd fit a fuel processor of some type Simon, your bike will be running "very lean" in it's present state.