Agostinis on the Cali Custom

[Cool Runnings]

There is a very good reason for that.

Styling...

[Kiwi Dave]

I've also been thinking about changing the mufflers of my Custom, but does anybody make anything SHORTER?  The stock length is so long...

Joe

Talk to Todd @ GuzziTech.

[JeffOlson]

Stock vs. with DB killers vs. without DB killers:

https://youtu.be/_Yv7nxWTcBY

[Waltr]

When there is a hurricane forming in the Gulf of Mexico do the weather presenters say "There is a large tropical 'Suck' forming in the Gulf."

As the piston descends in the bore it creates a depression in the cylinder. Atmospheric pressure pushes the air into the cylinder. It isn't 'Sucked' anywhere.

THANK YOU PETE!  I you expand on what Pete is saying opening up the exhaust does not always equate to lower BACK PRESSURE.  Back pressure in a way is a misnomer.  A properly sized exhaust system will allow a low pressure area at the the area around the exhaust port and opening it up actually causes a slowing or stall in elimination. And depending on cam overlap (California has 31 degrees overlap) a (more restrictive) exhaust will allow better cylinder fill. Opening up the exhaust and you will more than likely find you loose ride ability at low to moderate throttle demand.  You may pick up on top but the rest will suffer.  We are not talking about 2 valve heads here and we have a single throttle body.

[Vasco DG]

I hate the term back pressure, it's a sort of catch-all for a variety of effects and events but that can go through to the keeper.

If there is one thing that we have established very clearly it is the propensity for the 8V Guzzi motor to, (Using another simplistic term.) 'Over-scavenge' if the exhaust is opened up and most particularly if the airbox/filter is interfered with.

Don't believe it? That's your perogative but note that everyone you ask who has gone down the open airbox and pipes and especially if fitted with something like a Power Commander box says their bikes drink fuel at a colossal rate. The reason for that is because enormous amounts of it are being flung straight out of the exhaust valves and the uncombusted oxygen is playing havoc with the WBO sensor signals to the PCV.

I used to describe the necessity of having *Restriction* in the pipe. This was probably a bad choice of word. What is important is slowing the gas down. Also vital for optimum performance is making sure that as well as the main map the delta correction factors are adjusted correctly. While this is particularly obvious on Grisos because of their exhaust system it is true will all Guzzis and in fact any 90* twin due to the 450/270 firing intervals and different pipe and intake configurations.

Short pipes may look 'Cool' but they'll screw up the fuelling big-time on any 8V. There are very good reasons why the Cali 14 uses long pipes and why the Mistral Hi-Pipe is the most successful AM pipe we've found for the Griso.

Pete

[Cool Runnings]

I hate the term back pressure, it's a sort of catch-all for a variety of effects and events but that can go through to the keeper.

If there is one thing that we have established very clearly it is the propensity for the 8V Guzzi motor to, (Using another simplistic term.) 'Over-scavenge' if the exhaust is opened up and most particularly if the airbox/filter is interfered with.

Don't believe it? That's your perogative but note that everyone you ask who has gone down the open airbox and pipes and especially if fitted with something like a Power Commander box says their bikes drink fuel at a colossal rate. The reason for that is because enormous amounts of it are being flung straight out of the exhaust valves and the uncombusted oxygen is playing havoc with the WBO sensor signals to the PCV.

I used to describe the necessity of having *Restriction* in the pipe. This was probably a bad choice of word. What is important is slowing the gas down. Also vital for optimum performance is making sure that as well as the main map the delta correction factors are adjusted correctly. While this is particularly obvious on Grisos because of their exhaust system it is true will all Guzzis and in fact any 90* twin due to the 450/270 firing intervals and different pipe and intake configurations.

Short pipes may look 'Cool' but they'll screw up the fuelling big-time on any 8V. There are very good reasons why the Cali 14 uses long pipes and why the Mistral Hi-Pipe is the most successful AM pipe we've found for the Griso.

Pete

Yes,  if the airbox/filter is interfered with! 

[Vasco DG]

Even if the airbox is left alone it will still screw stuff up. Look, do what you like,its no skin off my nose. I just don't want people who actually want their bikes to run well to waste money on crap that doesn't work or actually has a net negative impact. If its more important to look 'Cool' and try and impress people go fear yer life. Just don't kid yourself its making your bike run better because it won't.

pete

[bsanut]

So is it possible to get just a little more rumble without mucking things up? 

The stock exhaust on my old EV sounded near perfect to me.  The 1400, not so much.

Joe

[Cool Runnings]

Even if the airbox is left alone it will still screw stuff up. Look, do what you like,its no skin off my nose. I just don't want people who actually want their bikes to run well to waste money on crap that doesn't work or actually has a net negative impact. If its more important to look 'Cool' and try and impress people go fear yer life. Just don't kid yourself its making your bike run better because it won't.

pete

Some like it loud, it's an American thing.

The Pusher 

[AH Fan]

I hate the term back pressure, it's a sort of catch-all for a variety of effects and events but that can go through to the keeper.

If there is one thing that we have established very clearly it is the propensity for the 8V Guzzi motor to, (Using another simplistic term.) 'Over-scavenge' if the exhaust is opened up and most particularly if the airbox/filter is interfered with.

Don't believe it? That's your perogative but note that everyone you ask who has gone down the open airbox and pipes and especially if fitted with something like a Power Commander box says their bikes drink fuel at a colossal rate. The reason for that is because enormous amounts of it are being flung straight out of the exhaust valves and the uncombusted oxygen is playing havoc with the WBO sensor signals to the PCV.

I used to describe the necessity of having *Restriction* in the pipe. This was probably a bad choice of word. What is important is slowing the gas down. Also vital for optimum performance is making sure that as well as the main map the delta correction factors are adjusted correctly. While this is particularly obvious on Grisos because of their exhaust system it is true will all Guzzis and in fact any 90* twin due to the 450/270 firing intervals and different pipe and intake configurations.

Short pipes may look 'Cool' but they'll screw up the fuelling big-time on any 8V. There are very good reasons why the Cali 14 uses long pipes and why the Mistral Hi-Pipe is the most successful AM pipe we've found for the Griso.

Pete

Yup ............ I believe he speaks the truth. I went with the after market goodies with an open wallet and in the end the dyno was all the proof I needed to leave those 8 valve motors alone..... in the end had a stock engine same year pull more on the dyno than mine after a small fortune in tuning and parts purchased by so called masters.

Ciao

[Vasco DG]

Nope, its because I'm an idiot with an axe to grind! Allegedly......

There are plenty of ways to make an 8V work better. I'm not trying to sell anyone anything. All I want to do is to get people to think enough, to do a bit of research, before throwing often large sums of money at shit that doesn't work.

There are a whole host of factors at play in the way any engine works but an understanding of the most basic laws of physics is necessary to getting your head around each and every separate engine. Too often the same formulas, often ones developed for completely different technologies, are applied when they are redundant or irrelevant. Because these theories are 'Internet Standard' anything that contradicts them is often scoffed at. Why? Because the most vocal scoffers are stuck in the mindset of their youths and have a pathological hatred of seeing what they see as their *Knowledge* base undermined.

You have got to keep looking and learning or you atrophy and your mind shrivels up and dies! You don't need to even want to be part of change, (God alone knows there are lots of things in the world I want no part of! Facebook for instance!) just see that its not all bad and sticking your fingers in your ears and going "La-La-La!" very loudly isn't going to make it go away!

Pete

[Cool Runnings]

So much for those Agostinis.

Thinking Vasco DG is one of those know-it-all types. 

Carry on........

[sib]

There's nothing wrong with experimenting, as long as your expectations aren't unreasonable.  Professional research scientists know all too well that most experiments fail.

[JeffOlson]

So much for those Agostinis.

Thinking Vasco DG is one of those know-it-all types. 

Carry on........

Pete DOES know it all. He is very knowledgeable and a huge asset. He solved two problems with my Norge from half way around the world, problems that my dealer's mechanic caused. I owe him much beer. 

[Vasco DG]

So much for those Agostinis.

Thinking Vasco DG is one of those know-it-all types. 

Carry on........

The fact that you don't like or cannot understand what I'm saying doesn't make me a know it all but that's fine, I'm done here.

Pete

[Cool Runnings]

Focus your opinions towards mjptexas (OP)! 

[mjptexas]

Focus your opinions towards mjptexas (OP)! 

OK, lot's of interesting comments.

So, I put the Agostinis on for two reasons: I like the looks, and, I was looking for a change in exhaust tone.  I've never had an issue with the Cali's performance.  If I want to go fast I'll ride my Ducati.

I totally get the the whole issue of exhaust tuning, especially in the era of modern electronic fuel injection.

However, I also know that manufacturers have to meet stringent requirements for emissions and noise level that lead to decisions that are detrimental to performance and mileage.

So Pete, given that the Agostinis are about the same length as the stock pipes what should I expect in terms of mileage and performance change? (no difference is a perfectly acceptable answer).

[Vasco DG]

Mike, as long as you don't radically open them up performance will remain pretty much the same, the ECU will happily trim within certain parameters. The problems start to occur when you open things up too much and the charge transition issues begin to play havoc with the trimming.

[oldbike54]

Pete DOES know it all. He is very knowledgeable and a huge asset. He solved two problems with my Norge from half way around the world, problems that my dealer's mechanic caused. I owe him much beer. 

 Well ... Pete doesn't know it ALL , but he is working on it  In looking at some of the discussion here , any chance ATE is in someone's ear ?

  Dusty

[mjptexas]

Mile, as long as you don't radically open them up performance will remain pretty much the same, the ECU will happily trim within certain parameters. The problems start to occur when you open things up too much and the charge transition issues begin to play havoc with the trimming.

Thanks Pete. I'm good with that.

[Cool Runnings]

Moto Guzzi ElDorado 1400 with Agostini exhaust db killers removed