Ridemalibu Motorcycle Rentals & Tours – Los Angeles CA
  1. Ciao Guest - You’ve landed at the ultimate Guzzi site. In SoCal? See the Service tab above for the best in service, tires, tuning and installation of our products or custom work. NEW REGISTRATIONS REQUIRE EMAIL ACTIVATION - CHECK YOUR SPAM FOLDER. ALWAYS TRY A SEARCH BEFORE STARTING A NEW TOPIC - AND PLEASE DON'T BE A DRIVE-BY POSTER: Most questions you may have are well answered on the Forum. As a common courtesy, check back if you are posting elsewhere on the web. There is zero tolerance on personal attacks and off-site links to other Forums or competing products. Note there's decades of Guzzi hands-on experienced help on this site, all whom give endless amounts of their time for free - be courteous. Also be sure to click on the Store link also above for our 600+ product inventory, including many of our 100% Made-in-house-USA GTM products and engine kits. We are still mostly a one man operation (not Amazon), so thanks in advance for your patience on orders. We do our best to get things out as quickly as possible, and we also aren't in control of things like customs & weather delays, etc. PLEASE refrain from emailing about your order Status, as you will get an email with tracking info when your order goes out; Email inquiries on orders slows everything down. Orders are currently being shipped once or twice a week. You can always sign into the online Store system to check the status. Please refrain if at all possible about emailing for an update; If you must ask for order info, please reply on the actual order email. You will get shipping info when it goes out via our online Store system (check your Spam folder), and if you want to cancel your order, please notify us direct email (do not post or use the Forum) and allow 7-10 business days for a reply BEFORE disputing the charge. We don't want your money if we can't deliver. Special order items are subject to a 15-20% cancellation fee. We cannot answer questions direct unless it’s about something on the Store or that you have purchased from us. We do NOT have a phone number - We are online only - Do not email and tell us to call you. You will find us highly responsive via email on the Contact page with any questions on our products (only). We appreciate the consideration, understanding and your business... past and future. Also be sure to see our GTMotoCycles.com custom BUILDS tab above.

8V Griso and PCV mis-information

Discussion in 'Griso-Bella Chat & Tech' started by GuzziMoto, Nov 27, 2013.

  1. GuzziMoto

    GuzziMoto GT Reference GT Contributor

    Joined:
    Nov 7, 2008
    Messages:
    1,821
    Likes Received:
    243
    Location:
    B'more, Md
    Not sure where I should put this, but since it is about using the PCV and A/T on an 8 valve Griso here seems like as good a place as any.
    On another site there is a discussion about how great the GuzziDiag software is (which I don't really have an issue with) and how bad the PCV with AutoTune is. Seems there are some people who have taken the stance that the PCV A/T does not work on the 8 valve Guzzi and that everyone who is happily using it is ignorant while their motor is grossly over fueled. The funniest part of that to me is the idea that while the PCV and A/T can't properly fuel the 8v Guzzi motor somehow the GuzziDiag software is the great savior. That is all the more interesting when one of the people who is trumpeting the GuzziDiag approach has for the longest time insisted that there is nothing wrong with the stock fueling and no reason to use something like the PCV and A/T, that if you have a fueling issue it is from inadequate set up.
    Now, I did try to point out some of the irony and conflicting logic there but as I am not an 8 valve owner (my Griso is a 2 valver) it is not really something I can lay personal claim to.
    Just thought you guys might be interested in this. I go to that site mainly for the Aprilia XV technical info (of which there is plenty) and not for the Guzzi technical info (of which there is none) and found it strange to have such mis-information there. But when I tried to point out some of the flaws in logic (like how does the stock ECU correctly trim the fuel using the stock O2 sensor but somehow it is not possible for a PCV and A/T to trim the fuel using a wide band O2 sensor) I was met with a complete lack of understanding of how the PCV and A/T even worked, yet full conviction that it does not work correctly.
     
  2. Scot

    Scot Just got it firing!

    Joined:
    Jan 31, 2012
    Messages:
    16
    Likes Received:
    0
    Location:
    Yarrawarrah, NSW
    I thought this would be interesting, seems to me you have just taken your bat and ball and decided to play on this forum because you got so soundly beaten up on the other.

    Let me post a link to the thread for you...

    apriliaforum.com/forums/showthread.php?282370-Fun-with-mapping/page3

    cya
    Scot.
     
  3. ghezzi

    ghezzi High Miler GT Contributor

    Joined:
    Jul 7, 2011
    Messages:
    835
    Likes Received:
    14
    Location:
    Brisbane
    I own neither of those bikes and profess to know nothing.
    But two mechanics have commented to me they have seen bikes with the full PC-V & A/T set up with sumps full of fuel.
    Ok, the "sumps full" is an over exaggeration, but to my limited understanding a rich mixture may get rid of flat spots, help cooling of an overly lean standard set up, but too rich can lead to dilution of the oil and constant washing of the bore.

    My personal experience with Ducati Performance ECU's, is exactly that!

    My Bellagio has a PC-V fitted, but then I had it dyno tuned with a custom fuel map for each cylinder.

    Easy way to verify the situation with any set-up, have your oil analysed by a lab.
     
  4. Scot

    Scot Just got it firing!

    Joined:
    Jan 31, 2012
    Messages:
    16
    Likes Received:
    0
    Location:
    Yarrawarrah, NSW
    Bringing science into a religious argument just isn’t fair...

    cya
    Scot.
    Reasionably happy with my stock map on my stock Griso 8v..
     
  5. GuzziMoto

    GuzziMoto GT Reference GT Contributor

    Joined:
    Nov 7, 2008
    Messages:
    1,821
    Likes Received:
    243
    Location:
    B'more, Md
    I don't recall anyone there beating me up. If someone saying that everyone who has a PCV and A/T on their Griso is ignorant and that their motor is over fueled, and that it on me to prove them wrong instead of on them to offer proof that their statement is even remotely correct is getting beat up, then you would be correct. Personally, as I suggested over there, I chose not to argue with someone who does not show some sort of grasp of the subject.
    A PCV with or without A/T is a tool, and only does what you tell it, Much like GuzziDiag. Can you over fuel with either? Sure. But there are plenty of people who have a PCV set up on there Guzzi and get excellent results. To actually be filling the sump with fuel would require some serious mis-use of the tool, but it may be possible. Used correctly a PCV and A/T set up will not cause your Griso to be drastically over fueled. It only does what you tell it to. It was also suggested that the PCV set up will somehow screw up the fueling because the different requirements of fuel between the two cylinders and the PCV only having one map. They do not appear to have a grasp of how the PCV works. I was assuming that the people here were more technical and did understand how things work. Perhaps I am wrong.
    Personally I have two Guzzi's with Power Commanders on them, a V11 with a PC3 and a 2 valve Griso with a PCV and A/T from Todd along with his ECU reflash. Both of them work well, the PCV and A/T works better than the PC3 but they both fuel cleanly and neither has fuel in the oil.
    I just thought people over here who have PCV A/T set ups on the 8v Griso (which I am not one of) would like to know that over there it is being suggested that they are ignorant and their Guzzi is over fueled.
    I go to that site for technical info on Aprilia XV's, it is the best site I have found for that. It utterly lacks technical knowledge about Guzzi's and is mainly a fluff site in that respect. I saw no reason to argue further with a newb who demonstrated a lack of understanding about how FI worked. There was nothing to be gained by me and as he did not seem interested in actually learning about what he was talking about I decided to walk away before I got into a pissing contest with him.. So far this seems to be the most technical site I have found for CARC Guzzi's. So I thought people over here might be interested in what is being said about some of them on a different site.
    Or perhaps you would like to explain why the stock ECU, using a single narrow band O2 sensor, is able to properly trim the fueling based on reading the exhaust but a PCV and A/T is not able to do it using a single wide band O2 sensor......
     
  6. double.d

    double.d Cruisin' Guzzisti GT Contributor

    Joined:
    Oct 27, 2008
    Messages:
    313
    Likes Received:
    3
    Location:
    BRISBANE AUSTRALIA
    I had the PCV, Autotune and reflash on my Griso as well and it transformed that bike, as it also did on my K1300R.

    The PCV map supplied for each bike is roughly suited to that bike but a few points of change in the AFR's can give better performance. As for filling ?? sumps with fuel, one would have to be a complete bufoon and not have the slightest idea of what they are doing for this to happen.
     
  7. kiwi dave

    kiwi dave GT Reference

    Joined:
    Oct 28, 2008
    Messages:
    1,827
    Likes Received:
    256
    Location:
    Auckland, New Zealand
    I may be asking the wrong crowd, but is the over fueling supposedly limited to the Griso 8V? What about the 1200 Sport 8V or the Norge 8V?

    My experience is that the Autotune can be fooled, and can produce results that does not allow the motor to run cleanly. The approach is to zero out the map in the PCV, and let the AutoTune start again. This occurred on my 1200 Sport 2V, but I have performed this same action on one Griso 8V. YMMV.
     
  8. Charlie J

    Charlie J Cruisin' Guzzisti

    Joined:
    Jun 19, 2009
    Messages:
    162
    Likes Received:
    3
    Location:
    Taree, Australia
    I have an 1100 Griso and have no experience with the 1200's bar a short test ride. The PCV A/T and reflash made a substantial difference to my bike. As did cleaning up the inlet ports. As did my home made 2 into 1 and muffler. But the most improvement was after I had him on a Dyno.
    Yes the fuelling mods are tools and can be used correctly or abused.I regret not putting him on the dyno as soon as I installed the PCV.
    It is on my wish list to either make matched length headers (lot of time and effort at no real great expense) or investigate individual injector manipulation. Anyone got any ideas?
     
  9. GuzziMoto

    GuzziMoto GT Reference GT Contributor

    Joined:
    Nov 7, 2008
    Messages:
    1,821
    Likes Received:
    243
    Location:
    B'more, Md
    Header design is a whole nuther conversation.
    Not trying to go to deep into it here, perhaps another thread for it would be good.
    Charlie, have you considered the aspect of unequal firing interval between the two cylinders on a Guzzi motor? Normally perfectly equal headers tubes is considered best, but on a Guzzi with the unequal intervals between firing one cylinder and than the other would likely negate that aspect to some extent. I am sure there is an optimal header length for each header but I am not sure they are the same for both header pipes. If you are trying to use the negative pulse from one cylinder to help evacuate the exhaust from the other cylinder than the timing (and thus length required) is different between the two.
    Then if you factor the difference in intake between the two it gets even fuzzier.
     
  10. ghezzi

    ghezzi High Miler GT Contributor

    Joined:
    Jul 7, 2011
    Messages:
    835
    Likes Received:
    14
    Location:
    Brisbane
    Personally, I believe Guzzi's small air boxes (compared to other manufacturers), combined with the close proximity of the two venturi's inside the box, and no divider between them has a far greater impact on fuelling and performance, than unequal length headers. My Bellagio requires a difference of 20% fuel between cylinders at specific points in the map.

    Charlie, the only way to prove the point is dyno your bike, design and build your headers then re-dyno.

    Designed and built mufflers for a mates modern 750SS and got good results, hated the unequal length stock headers and restrictive X type collector. Custom exhaust builder quoted a $1000 to rectify my perceived problem but stated I would see a gain of less than 1HP. If the heads and cam had full race treatment, the new headers would then have a greater benefit.
     
  11. cytocycle

    cytocycle Cruisin' Guzzisti

    Joined:
    Dec 14, 2009
    Messages:
    155
    Likes Received:
    4
    Location:
    Scottsdale
    wow more mis-information from people that don't dynotune their bikes or use setups that Todd already did the testing to achieve the results.

    I have the ECU tune from GuzziTech to ALLOW the PC-V to control the complete fueling otherwise if you don't have the stock ECU modified the PC-V can only control a limited range (aka not worth it). I have the PC Auto which Todd tuned with a base map, and then based on his experience with his Pipe which I also own, he manually blocked out sections for closed versus open fueling to be controlled by the autotune, and test rode it till he got it dialed in. Plus I have the airbox ring to allow the Griso to breath.

    Results- Bike runs way cooler, revs way faster (stock it was congested over 5k), makes linear smooth power to redline, doesn't buck like it did stock at low speeds, and the exhaust stopped liver spotting from being so lean.

    I would treat this as a mandatory upgrade for a Griso, especially the 2009 models! but then again most people just stick pipes on and wonder why they run even worse than stock but say it runs better/faster...
     
  12. uzidzit

    uzidzit Cruisin' Guzzisti

    Joined:
    Aug 12, 2012
    Messages:
    227
    Likes Received:
    6
    Location:
    Knox
    With you big time on the above...It is really true that the balance difference in the 4v can be large, I see 20% on the stelvio difference from left to right as well, and it switches from the left to right at some points. I will admit that I have removed my AT at this point as I got down to it making at most 1-3 point corrections and am now running my developed map. with just the pcv.


    I had to add in a few things that can go wrong: (maybe for the novices out there)
    There was a release of the auto tune software and pcv software that WAS BAD REALLY BAD, it caused brutal high speed misses, and really bad mismatch in the cyl map balance. I went through hell with my stelvio trying to get the flashed ecu, pcv and at to work correctly together. (it is simply stunning now)

    The Stelvio uses 2 lamda sensors and, I have seen in a few hardley ablesons that also use two, the inputs were switched so the wrong cylinder gets leaned, this with the software issue might have been a cause of fuel in the sump. (the other cylinder gets way too much fuel)

    One other thing that really screws up a pcv and autotune is a blown exhaust gasket!!!! the at will just start dumping fuel. this shows up on the guzzi, quicker than I have seen it on other bikes as the sensors are really close to joints.

    I have been using the AT module recently to run some dyno vs AT tuning maps. I have noticed that the maps I have worked through on a sv1k, on the dyno and on my suspension tuning circuit look very similar....but The AT maps are a little more ride able at the smaller throttle openings.

    Saying that dyno tuning and ecu flash is better or the only way to go is fine if you have unlimited access to a dyno or unlimited money. At least for a bike that is going to be a track pig or race bike. I have free access to a dyno, and spent a ton of time with partial throttle pulls setting up PCs and the AT gets similar results after riding an aggressive circuit for a while, quite a few iterations are needed to catch everything, and you have to use a little sense as well and be willing to keep a few records
    The AT will catch a few bad readings here and there (this has to do with sampling rates and times, vs. throttle openings etc.) It sometimes catches a roll off lean spot and has it written into the table but it is easy to spot these and correct manually when you save the table to the pcv (if you kept riding these get corrected out pretty quickly and you really do not notice when you are riding letting the AT run all the time as long as you have the max AT correction set to a reasonable % . I do not see the benefit to dyno tuning over pcv/at on a street Guzzi, provided you pay attention. (you also have the benefit of an alternate performance and economy or touring map if you desire)

    The Griso really needs to be be set up with 2 sensors just like the Stelvio though.

    As for hunting for speed, after the fueling has its rough spots cleaned up the thing that adds speed more than anything on the Griso is suspension!!! get it right and it the stock engine makes all the chassis can handle, The weight savings of aftermarket exhaust is really the big benefit, as is any other weight savings.

    I will be sharing my Showa cartridge re-build on the forum as soon as the school semester ends. with pictures and how to.
     
  13. bounty320i

    bounty320i Tuned and Synch'ed

    Joined:
    Apr 22, 2012
    Messages:
    26
    Likes Received:
    7
    Location:
    Dubai
    +1 !! Makes perfect sense though I profess, I am not expert on FI, or mapping. I've had the PCV and AT for 5 months now and most of the early fueling issues have been sorted out. Initially, on the first few runs after installing the aftermarket pipe, filter and the PCV I had flat spots everywhere especially at 7k rpms and beyond. As it stands today, it's not 100% but quite close and I'm happy with the setup.
     

Share This Page