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tuning after adding a slip-on exhaust is it needed.

Discussion in 'Technical and Troubleshooting Torque' started by OscarA, Sep 25, 2010.

  1. I purchased a z750 recently which has a MIVV slip on. The previous owner didn't retune it as he was told it didn't need it.
    I have read that new bikes are tuned from factory a little rich and retuning is a benefit. So if true even without the slip-on a tune, re-map (whatever it is they do) is recommended so I'm assuming with the slip-on it's even more important.
    I haven't ridden this bike much as restrictions still apply but the few times I have I can feel it's a touch rough, slight flat spot when accelerating then a little surge (not always) and sometimes a little popping, backfiring when engine braking.
    I'm also thinking about a power commander not for extra speed or anything but for a better smoother running bike.
    New air filter will also be added, K&N most likely.
    Any thoughts?

  2. if the specific slip on mufler that's fitted was made to suit the bike/model you have; then it's not neccessary to tune it... it's just like a replacement muffler, bolt on rideaway.
    typically though, after fitting a less restrictive muffler bikes do tend to run a lttle out of tune throughout the entire rev range.. you'd likely find you have a bit more get up and go off the line, but at the price of top end power.
    it's not really going to do the bike any harm in the short term to leave it as is.
    you do mention you've noted flat spots in the power curve though, so there is definately room for improvement.
    if you get it dyno tuned you"ll be able to sort it as good as it can get... they may reccommend a piggyback cpu or you may not need one.
    better if you put the high flow air filter in first because that's altering the air/fuel mixture slightly again.
    but discuss with the mechanic what you want out of that tuning.
    dynoverks is local to you but they do like to tune bikes to go hard... as opposed to economy/efficiency.
    some piggyback cpu's have switchable mapping.
    Brett at MadBiker can get it dynoed, but you have to leave the bike with him 2-3 days.. i think he takes it over to a mob in Brighton.
    meanwhile you get his current courtesy bike, the two stroke 'scooter of death'.
    with the big butterfly stickers all over it. (which is actually a lot of fun, until you have to park it somewhere and get odd looks from people)
    Brett is more inclined i think to have it tuned for economy, general street use.
    he gives you the print out and it only needs to be done once.
    but yeah, just discuss with your mechanic what you want it tuned for based on the type of riding you do with it.
  3. My girlfriend was reading over my shoulder when I checked out this post.
    She wants to know, is a "slip on" the same as a "strap on" ? And why do you get exhausted ?
  4. the only way to know if the bike needs a tune or not, is to put it on the dyno for a diagnostic session ($100 or there about). during the session the bike will be run up at different throttle openings, and the air:fuel ratios checked. this is different to a wide open throttle run, as that is only at 100% throttle.

    e.g. at 100% throttle, my R1 with slip-on's, BMC filter, Factory Pro Velocity stacks... needed only small adjustments to the fueling to be spot on. However at very low throttle openings at cruising rpm's, the bike was dangerously lean, thus a PC3 & tune was done, and now she's spot on!

    so, if you're serious, get it on the dyno, get the diagnostic session done, and make a decision from there. if you need a place to take it to (since you're in melb), I know that Dynoverks do a diagnostic run deal that if the bike needs a PC3 & tune, they deduct the diagnostic run's price from the PC3 & Tune package.
  5. Thanks monkeyman and SHEPPO some seriously good advise from both of you.

    Sheppo can you give me an idea on what the PS3 and tune will set me back?
    You can PM me if you like.
    I'm planning on keeping this bike a while so don't mind spending some money on it but having said that I have to be realistic on how much I spend.
  6. Power Commander's Website for the Z750:


    Cost US $370. Australian distributors probably bought their stock when the exchange rate was less favourable and as a result may want > AUD $500. If you buy it direct from the States it will cost ~ AUD $395 plus postage.

    However, tuners in Melbourne will probably charge you full price on their services if you supply the power commander (because that they can't make profit on it), so you'll have to make a call on who to buy it from.

    The following link will give you an idea of what's currently going on with the bike:


    The red line is before, and is bad because the bike goes from running lean to running rich. The blue line is after tuning, and is as good as you can get.
  7. $250-500 for PC3 (new) - buy overseas with the dollar the way it is.
    $0 for installation, DIY and save!
    $300ish for the custom map.

    if you go the DIY route, install the PC3, hook it up to your laptop and load a "zero" map. this will make the PC3 redundent for the time being. then ride it to the dyno joint, and get them to tune it for you.

    that's all i can tell you in regards to price. best ring around and get quotes, but i do recomend Dean at Dynoverks from my experience.
  8. I installed a yoshi slip-on on my fireblade, the internet told me that I didn't need a custom map. After a couple of weeks I wasn't happy with the way it was running, so I booked it in to a place to get a pc-v and custom map as well as a k&n air filter. The difference is like night and day, I ended up gaining 9.5hp, and it was worth every penny of the $1000 it cost me.

    On the other hand, I installed an akrapovic slip-on on my '98 ZX-9R and I never had a problem, it still runs really well.

    Given that you feel the bike is running a bit rough as it is, my advice to you would be to get a power commander, aftermarket air filter, and dyno tune. It will probably cost about $1000 for parts/installation/custom map, but it is money well spent if you plan on keeping the bike for a while.
  9. Thanks guys, just got this quote

    Power Commander III $485.00
    Installation and blocking off pair valve. $120.00
    Dyno tune using "Tuning Link" $395.00

    A little rich for me but I'm an impulsive sort of guy.
    As for the bike running rough I probably made it sound worse than it is.
    The bike needs a service in 1000ks so being on restrictions for another 4mths means it'll probably need a service in 5mths. That'll give me time to put a few pennies aside and I'll get Brett at madbiker to give the bike a squirt and see what he thinks.
    If it needs it it'll get done.
  10. I have just had the same thing completed on my 600RR. It was running shocking and was lacking power.
    Got it dynoed and it was worse than shocking. Spent some serious coin to get a power commander installed, new filter and dyno and a service and the thing has never run so well. Should have done this when the Yoshi was put on.
    Ended up with 102hp on the dyno.... happy!!!