I am going to make a new exhaust for a cali ev. How essential is the balance pipe between the 2 sides? I know it will screw up the fuel injection so I am going to switch to carbs anyway, but is the balance pipe just a noise cancelling thing or does it really affect the power? Has anyone actually done this and got experience of whether it makes a big difference to the running of the bike or not? I know that on a Harley removing the balance pipe tends to improve them somewhat (but then removing most things on a Harley tends to make them better).
A balance pipe usually improves bottom end power, ie the bit you use most.It also makes balancing between the pots easier.Why would it screw up the FI?
The fuel injections ecu on this bike is a huge marelli box of a fiat car or similar. It is a alpha - n system; it just uses throttle position and engine speed to work out Yeh fuelling (plus temp corrections etc) it doesn’t measure the air directly. So any changes to the intake or exhaust will change the air inflow and screw up the fuelling. I am actually building a trike out of the bike so the exhaust needs extending, and I will probably mot use the original silencers. This bike has a huge cross over box, which I was assuming contained a cat, which wad part of the reaso. I was going to dump it, but on reflection I don’t actually know that it had a cat in it. Does anyone k.ow if 2000 cali ev’s we’re fitted with cats?
Guzzis work better with a balance pipe so much so that some Le mans have 2 balance pipes one at the front over the altenator and the one under the gearbox.
No doubt some one wot is klever can explain all about the back pressure and pressure equalising and all that sorta stuff.
While I was writing this, he writ that Ah yes, [pushes glasses up nose] a cross pipe creates a break in the downpipe cross section which causes a negative pressure pulse to return to the exhaust port after valve has opened; this sucks out a bit more exhaust gas so a bit more fuel gas can go in. Due to the short length this occurs at high r.p.m., i.e. it boosts top end speed, usually, where power is starting to flag due to piston action alone no longer being able to move inlet and exhaust gases in and out fast enough. Furthermore Le Mans’es and BMW R twins have TWO ‘balance’ pipes so they have two steps of boost at two different speeds. So logically if you take the balance pipe off you might actually lose a few m.p.h. off the top end. HTH
Mike H2013-05-25 18:51:45
I knowed someone wot is Klever would 'splain it
With multiple edits for typos and such…
I’m fairly sure you could swap that ECU for a Cliff Jeffries MyECU, which is tuneable.They are also inexpensive. Quite a few here have experience of them.
That sounded like Will Hay
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You might be surprised at how forgiving that WM P9 EFI system is to changes in the intake and exhaust - there are any number of bikes that have had modifications to the intake & exhaust, (some quite radical), and they still run okay if not better. The alpha-n is modeled around the volume being passed through the throttle bodies, so you can get away with modifications to the inlet and exhaust tracts without detriment. Plus the P9 ECU also has a degree of manual adjustment to the ‘idle’ mixture setting that actually applies a fair bit further into the rev range.As you will likely be having to shell out a considerable extra amount of cash to convert the engine to run on carbs - there’s no distributor drive for a start - why not try it with the existing EFI? The P9 has a removeable EPROM so you can always obtain different chips or, as some of us have done, use a Jefferies MyECU and dial in your own fuelling and ignition settings. There’s always the PowerCommander option to consider, although I’m not a personal fan of such devices.
I am actually building a trike out of the bike so the exhaust needs extending, and I will probably mot use the original silencers.
There is a guy in the States who is running a Cali Stone Hydra injected engine in a Blackjack Zero trike which has a considerably extended and modified exhaust. AFAIK he hasn’t had any problems with it running the original EFI - he fabricated new throttle linkages and put a PCIII on though.There are a series of YouTube vids:http://www.youtube.com/watch?v=Dw0k1v3y3eA
A replacement balance pipe without the gubbins in it is not very expensive many oem ones out there 2nd hand as one fits all, and there are a fair few manufacturers of stainless that make just the H pipe
Can I just chip in, I removed the balance, knocking up some stainless kinks in 38mm to relace it thus running the exhaust system unbalanced. I have noticed a major reduction in top end performance since, shell just about pull three figures in forth, solo, but dies once top is selected. When stock, shed pull 120 two up with luggage.I have popped up to Streffords to get her ‘sync’d’ and the CO set, it has NEVER had dealer attention since new, ten years back, but the lack of oomph persists.Back to stock methinks.I plan fruity pipes for my new mkV lemans but will stay balanced I think.
i removed the strait though heder pipes that wher fitted to my cali 3 when i bought it.thay made the tickover rougher than rough, but the bike whent like a roket at high reves,but no puling power low down the range. i removed them and replaced them whith standard pipes and a new (second hand )crossover pipe. the bike now runs pefectly. ie" guzzi perfect". dont get rid of your H pipe you will regret it. PPS the pipes are for sale on our site, thay are sutable for a trike or morgan replica bild wher you want longer heders. but still fit the balance pipe,
There MUST be a damn good reason why Guzzi add the H pieces, Norton did the same and on the V11 and other Le mans they add a second X over.
I know the V11 Le Mans does work better with the less restrictive X over tho’
Dare I mention again about the crosspipe location creating tuned pipe lengths which in turn creates negative pressure pulses sucking more gases through the engine at high r.p.m. so you get more oomph at the top end etcetera etcetera etcetera ad nauseum Sorry…
Mike I think mate you are kinda wasting your breath… I sometimes wonder if folk actually read and take note of anything, but then I may just be being Mr Grumpy …
Hey GB, people always take note of your advice! I’ve started a new exhaust thread, but how weird to have more than one Cali with issues in that area.
Ya think I should have learnt by now
Known problems are the BIG X over box thing the baffles do come loose noist but it still works, BEST solution…get rid and replace with a stainless one
If the headers are not replaced correctly
i.e new gaskets and make sure the old ones are taken out I have worked on bikes with 2 sets left in cos you can’t see them
Over tightened headers crushing the gasket and rendering it useless
Occasionally a silencer will come loose, it happens often due to wrongly sized clamps.
My Le mans has the right hand one come loose , annoyingly after the 2nd time it happened I looked into it.
2 things 1 new exhaust clamp and I realised when it goes into the shed I sometimes catch it on the door jam … noticed a very tiny bit of white paint on the outer corner.
Guzzis like many twins DO produce a BIG bang so it is something that happens…I had the Norton 750 then made up to 810 it used to have zorsts come loose, mates Harley Annies 535 even it happens to.
Never ever had it happen on a Jap 4 tho’