Griso Mid/Y-pipe: why…

[diedel]

is this thing bend as a snake? Besides ugliness and the fact that mine has also now (11500 Km) a half broken holder - how essential is this curved shaping for proper fueling/all over tuning?

Thanks for input,

Dietrich

 

[Penis Rotor]

It adds physical resistance, (Not to be confused with 'Back Pressure'.) to the exhaust system. You don't say if your bike is an 1100 or a 1200 but its function is far more important on the 1200 than the 1100.

Pete

 

[Charlie J]

The trouble with the standard Y pipe is the material its made from, its thin gauge and the mount system.I have used 2 of these pipes and they just kept on cracking,in different areas.No matter how careful I was when fitting them up and making sure everthing was tightened in the right sequence and kept tight.Todd sells one that looks the business. I made my own. I was worried that making one without the horseshoe in it may have been too short and moved the power up the rev range,but that doesnt seem to be an issue.

 

[diedel]

It adds physical resistance, (Not to be confused with 'Back Pressure'.) to the exhaust system. You don't say if your bike is an 1100 or a 1200 but its function is far more important on the 1200 than the 1100.

Pete

(Yes Pete, it's 1200 8v – i should mark it better in the signature).
Some kind of resistance – this was my "intuition", too. I really wonder how deep the italian engineers develop the whole input/output-system… Those f.i.-guzzis respond often quite sensitive to manipulations on Airintake/Exhaust, but nevertheless the out-of-the-box-bikes – without any tweaks – run like a sack of shells esp. at low revs. I can't believe that the layout of the Griso exhaust is particularly sophisticated designed, it looks too half-hearted concerning function AND style. From my point of view (as a product designer) i sorely miss the clean and stringent layout of the good 'ole LM1 Lafran's tubes and mufflers. If i had the bucks i would go for the tubes and muffler (and oil cooler) of the 1200 8V Sport, i guess this will fit on the Griso.
So should i replace the cracked original y-pipe e.g. with Todd's straight one (which is at least a much better looking substitute) and risking drawbacks in running smoothness, or welding the original y-pipe with better holding straps and a self-made "modesty panel" to give it a more straight-pipe look or whatever?
Hm, i'm little bit puzzled.

Dietrich

 

[Penis Rotor]

Those f.i.-guzzis respond often quite sensitive to manipulations on Airintake/Exhaust, but nevertheless the out-of-the-box-bikes – without any tweaks – run like a sack of shells esp.

(Sigh.) No they don't. Not if they are tuned properly.

Pete

 

[diedel]

Those f.i.-guzzis respond often quite sensitive to manipulations on Airintake/Exhaust, but nevertheless the out-of-the-box-bikes – without any tweaks – run like a sack of shells esp.

(Sigh.) No they don't. Not if they are tuned properly.

Pete

What i meant to say with "run like a sack of shells" is in other words "run like crap" (constant driving bucking* between 2.000-4.000). Do i get you right and you would say e.g. an actual Griso standard oem with somewhat 3000 Km or so will run smooth at these revs?
No offend, Pete. I simply want to avoid to get trapped by my poor english skills therefore i ask again.

*goo... translate

Dietrich

 

[Penis Rotor]

Dietrich, there are many tuning aids for most bikes, Guzzis are no exception. I have no problem with people exploring these, many of which are offered by Todd who runs this board.

The thing is that if a stock bike is tuned properly it will fuel up well and be be an enjoyable ride.

I have yet to have a single customer who has their bike tuned properly, by the book, complain about the fuelling once, in the case of the early bikes, a map upgrade has been performed or, in the case of the later bikes simple tuning.

I know Todd disagrees with this but it is my firm belief that the vast majority of the problems associated with the 8V engine over its life have been manufactured by workshops who quite simply don't have a clue.

I can't control the Guzzi service network. God help me I would hate that job! That aside though a well tuned modern bike can and will run well right out of the box. Before you start getting stuff to 'Help' at least make sure that it actually needs help!

Pete

 

[GTM®]

One thing I agree on is that the bike needs to be set up properly as a baseline. Far too often I see brand new bikes from the dealer(s) that were never properly set up. They count on the crated bike to be assembled and ridden. Not true.

If you are the type of rider that is happy if it starts and will ride around the problematic areas like heat/lean fueling and pre-detonation, or you prefer the quietness of the stock machine, then my improvements likely aren't worth it. However, know it can be made to run better in stock trim outside of Euro3 emission/fueling.
If you are the type of rider that can detect the flaws in the stock fueling, and don't like the heat and pre-detonation... or if you like to hear the music when it's uncorked, with impressive fueling and power you didn't know was hidden, that's where I can be of help.

 

[Penis Rotor]

Todd? Can you tell me what 'Pre-detonation' ? It's a term you've used before but is not a phenomenon I've ever heard of.

Pre-ignition? Yes.

Detonation? Yes.

Pre-detonation? Never.

Pete

 

[GTM®]

Semantics.
Definition: Pre-Detonation or Pre-Ignition; is basically Abnormal Combustion.

Predetonation: An ion-current measurement can also determine whether there had been pre-detonation or knocking when the cylinder fired.

 

[Penis Rotor]

Ah, ok. Both pre ignition and detonation are abnormal but both have entirely different causes and consequences that's all.

Pete

 

[MrMorrisSD]

Hmmm. Interesting. Those are both terms I've always assumed to be equivalent with "pinging" or "engine knock", as in from using gasoline of insufficient octane, etc. Same things as "dieseling", "run-on" once the ignition's been turned off?

 

[Penis Rotor]

Pre ignition is just that the mixture is lit prematurely, usually by a hot spot in the combustion chamber, a piece of glowing carbon or the edge of a valve with insufficient margin. Detonation is the result of the charge being unable to remain un combusted due to its volatility or too high a compression ratio for the quality of fuel. In those circumstances rather than burning evenly in a progressive wave front across the combustion chamber the entire charge explodes at once, hence 'Detonation' it imposes large, sudden forces on the piston similar to beating on it with a hammer and will eventually lead to the top of the piston disintegrating. The most common signs of detonation are tiny, shiny aluminium particles deposited on the plug and if the piston is examined its top will appear pockmarked. With pre ignition the damage more usually appears that the top lands of the piston appear to have been gnawed by alloy eating rats.

Pete

 

[diedel]

Todd, Pete,

i can easily follow you both, but i should make my first intention more clear as i maybe not did while starting the original post:
1st problem: broken straps at y-pipe
2nd problem: the s-bend y-pipe looks generally that ugly (at least in my eyes)
Possible solutions:
a) replace by OEM stock part (under warranty, which is in progress either way)
b) repairing/welding/reinterpreting the holding issue of the old part and wait until total failure and then replace (a) plus build yourself a modesty panel to fit my "visual needs"…
c) go for a none-OEM part (e.g. like Todd's straight one or whatever) IF (!) it will optical fit and will be more durable.
A plus will be a better function in terms of fueling etc.
But IF i will go for c) i will exclude as far as possible the risk of a drawback because the rest of my bike is standard OEM (no pcv, rubber snorkel in place, well rode-in, not too much oil, synced TBs etc.pp. and so on) or in other words: would a straight y-tube possibly alter the run culture of my bike in a good or a bad manner?

And sorry guys (don't slug me), I must admit that in my case i missed to point out that my Griso (8AM Motor) is fitted with the recommanded Termignoni muffler from MGs accessories store from day one… errrhm.

And here's maybe the (big) hair in the soup: i have the feeling that the mapping of my Griso (no. XXXXX…03) doesn't fit very well with this muffler and i wonder if it will even get worse when changing the mid-pipe for an other one then OEM.

Dietrich

 

[Penis Rotor]

No intention to 'Slug' anyone?

Look, the fact that you say your bike doesn't fuel up well strikes me as pure supposition if there is a dirty great crack in the centre pipe. Fact is air will be getting pulled in and will be goofing with the O2 sensor so its bound to run like a pig.

While some early 1100's had mid pipes that had chronic breakage problems that had to be addressed with a recall/tech update the 8V bikes are not noted for cracking this pipe unless there are other alignment issues with the exhaust.

Lastly, you say the TB's have been balanced? By whom? And what was the procedure followed? Are both air bleeds open?

First things first. Get a new mid pipe and install it making sure it is un-stressed and well supported, this is a warranty item so it will cost you nothing. Secondly, once the exhaust is sealed then tune it properly following the instructions in the manual or mine posted in a photo essay here somewhere I believe? (If they aren't here somewhere I can C&P them I'm sure.). Remember only one air bleed should ever be open otherwise bottom end fueling will be crap. While I still encourage people with an aftermarket pipe to use a dB killer the 03 map doesn't seem quite so picky about this as the #68 map so this is of less consequence on your bike. It will still run nicer with it in though.

If, after you have ensured everything is correct, you are still dis-satisfied with its performance? Then start throwing money at it. 95% of all first time customers bikes that end up in my workshop aren't tuned properly. Once they are most of their owners are pretty happy. A few still embark on further 'Improvements'. The most important thing though is to make that decision knowing that it is running the best it can in stock trim. If it has busted components and isn't tuned no amount of money is going to make it run right.

Pete

Edit. TB balance instructions clearly explained here.

https://www.guzzitech.com/forum/190/9082.html

 

[GuzziMoto]

I agree with what Pete said, make sure it is running as well as it can stock before you go throwing money at it. But I did not see where it was indicated that there was any kind of air leak in the exhaust system. There was the original slant of this thread about the exhaust mount bracket breaking off the stock mid pipe. That is all I saw.
Either way, make sure it is set up correctly. The throttle bodies need to be sync'd properly, there is the whole bleed screw aspect, etc.
If you go with a different mid-pipe (I have Todds right side exit set up) you may find that it no longer fuels as well as it did. But Guzzi's are not all the same nor are the standards to which their owners hold them. What works well enough for one might be dismal to another. Until you try it you will not know.
My 1100 required much tinkering by the dealer to get it as good as it gets. Then I spent a chunk of change on Todds full kit because "as good as it gets" was not good enough for me.
Exhaust tuning is a funny thing by the way. There is theory, and most of the time things works as predicted. But sometimes things do not. Something that should have resulted in an improvement, like free'r flow, sometimes result in a decrease in performance. The 8 valve motor seems to have too much overlap and maybe too little lift. But you have to work with what its got. A shorter but larger diameter pipe should result in a wash, but until you try it you don't know for sure.

 

[diedel]

… if there is a dirty great crack in the centre pipe…

Pete,

there's no crack in the tube itself, therefore no airleak (as GuzziMoto pointed that out, too). And exhaust gaskets seem to fit well and dense. If checked by hand no blow by is perceptible.

… Lastly, you say the TB's have been balanced? By whom? And what was the procedure followed? …

By my dealer. Didn't asked him for a script… they've done recently the 10000 Km service and TB sync was also affirmed (at least marked on the bill). Normally i've a good relationship to him (he only works on/sells Guzzi, ex-BoT-Racer and 2 times Guzzis ww dealer of the year) and he helped me through a bunch of teething troubles because of the bikes bad assembling quality.

… Are both air bleeds open? …

Is on my checklist, but winter (here) is coming and my garage is without electricity/heating…

… First things first. Get a new mid pipe and install it making sure it is un-stressed and well supported, this is a warranty item so it will cost you nothing. Secondly, once the exhaust is sealed then tune it properly following the instructions in the manual or mine posted in a photo essay here somewhere I believe? (If they aren't here somewhere I can C&P them I'm sure.). Remember only one air bleed should ever be open otherwise bottom end fueling will be crap. While I still encourage people with an aftermarket pipe to use a dB killer the 03 map doesn't seem quite so picky about this as the #68 map so this is of less consequence on your bike. It will still run nicer with it in though.…

full ack, i'm on your side

… If, after you have ensured everything is correct, you are still dis-satisfied with its performance? Then start throwing money at it. …

So this was my hypothesis: if everything is correct as it can be, what would another mid-pipe than oem can do?

… Exhaust tuning is a funny thing by the way. There is theory, and most of the time things works as predicted. But sometimes things do not. Something that should have resulted in an improvement, like free'r flow, sometimes result in a decrease in performance. The 8 valve motor seems to have too much overlap and maybe too little lift. But you have to work with what its got. A shorter but larger diameter pipe should result in a wash, but until you try it you don't know for sure.…

… and there we go. Thoughts like this are on my mind and i'll try to find out the right stuff.
Surely puzzling them out in a "Pete"s manner ;-)

…TB balance instructions clearly explained here.…

Great!

Dietrich