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Turbo busa hp and mapping?

Discussion in 'Tech' started by regularguy, Oct 15, 2012.

  1. regularguy

    regularguy Always Krispy

    Customer brings in a 08 busa with a Mr. Turbo bolt on kit to my buddys shop and says he wants a tune. We strap it on to the dyno, block off the PAIR valve intakes (which were wide open) and do an intitial pull of 167hp showing 5psi of boost on the gauge. AFR is showing 10:1 with horrible torque and hp curves all over the place. The customer says the thing burns fuel like crazy and hiccups and farts and doesn't pull smooth.

    The bike has two PCIIIs on it (one for upper and one for lower injectors. Not having much (any) mapping experience with bikes with boost, we go very conservative and lean it out to 12.8:1- 13:1 and the bike produces a smooth hp and torque curve. Shows 193hp and a super flat torque curve showing 96 lb ft torque at 5psi boost.
    My buddy takes it for a test ride and says it's pulling clean and smooth and the rear tire is breaking loose under hard acceleration.

    The bike was purchased by the guy from a used car/bike lot. It shows 14000 miles on the odometer. We have no idea who put on the kit and no idea on engine internals. We did a comp check and the bike is showing 160, 155,160, 145 across.

    The customer shows up and takes it for a ride. He comes back and says it's still hesitating and not pulling smooth. We take a look at the bike and it threw a c40 code. We explain to him we have to fix the code before we can determine if it has a mapping issue. The customer gets a bit pissy and says the bike should make more power than that and he had it on a dyno the week before. He says this shop did an initial run in the 150-160hp range, then the guy "saw a screw missing near the boost gauge" replaced the screw, and the bike made 252hp. Then he says this other shop (which has a sniffer on their dyno) tells him it is in need of a tune.

    The customer says he wants max hp and wants us to crank up boost. We tell him no way without looking in the motor and seeeing how it's built (for liability reasons). This "discussion" goes on for an hour before the customer leaves.

    So, a couple of questions with you guys with boost experience. Should the bike make more HP than 193 hp with 5psi of boost and what AFR should we target on this thing?

    BTW, the PCIII map for the upper injectors had increments of 5
    (20,25,35,45,50) indicating someone just pressed on the adjustment buttons on the PCIII. The PC III for the lower injectors had a crazy map showing huge negative adjustments for below 4000 rpm(-17,-15), then once again (25,35,40) above 4000 rpm where someone hammered on the external adjustment buttons.
     
  2. RM Racing

    RM Racing Tool user

    193 hp is low for 5 psi on that bike. Was it spinning the tire a lot on the dyno?
     
  3. regularguy

    regularguy Always Krispy

    It spun a bit at first. We tightened it down some more.
     
  4. TurboBlew

    TurboBlew Registers Abusers

    Pull the Mr turbo kit off and sell it to someone that doesnt know any better.
    An average n/a piped bike will make ~180 on pump gas with 98 lb ft. Low boost kits should be low 230s/110lb ft+ all day long. A/F is usually around 12.8 or so.
    Personally I wouldnt touch a bike with that kinda history/owner. They are looking to hang blame on someone.
     
  5. regularguy

    regularguy Always Krispy

    I agree since he's had the bike for two weeks and already been to two shops with a dyno. The dealership in town where he bought it is shady. We run motor numbers with DMV from bikes that were bought there and gee guess what, this motor is from a stolen bike....
     
  6. RM Racing

    RM Racing Tool user

    5 psi should net 220 or so minimum. A/F should be 11.5-12.0:1 or so when on boost. Something else is going on here. Sounds like your buddy might want to fire the customer and save the headaches.
     
  7. regularguy

    regularguy Always Krispy

    I think that's the plan. Thanks for the AFR on boost.
     
  8. SpeedWerks Racing

    SpeedWerks Racing Well-Known Member

    Having the correct and constant fuel pressure needed is critical.
    depending on the set-up a rising rate fuel pressure regulator is needed.
    hook up a quick gauge and monitor the pressure at idle and thru the run,5-7psi is safe and should make just shy of 250 on a dynojet.....
     
  9. regularguy

    regularguy Always Krispy

    FYI, appears to be the stock fuel pump unless it's been modded internally
     
  10. Handicapped Racer

    Handicapped Racer Well-Known Member

    2008 busa from what I've seen are around 188-204hp and 108-111 tq ft lbs I know the Hp #'s are broad but that's what i've seen. The one that made 188 made the most torque out of all of them 111. 7 psi i've seen 260, from 1st Gen Busa's

    5 psi should put you around 240-260 on a 2nd Gen, I've seen low numbers from alot of Mr Turbo bikes, self installed, and some they've installed.
    Something is wrong with the one you had on the dyno though.

    Also those compression numbers don't surprise me, They never seem to be were the Svc manual says they should be at.
     
  11. Handicapped Racer

    Handicapped Racer Well-Known Member

    He could have a after market fuel pump in place of the stock one, but if the A/f isn't going lean on the top end, it would indicate you are getting enough fuel, that is in it's current setting which is POOO. Ie Stock HP numbers.
     
  12. sonicnofadz

    sonicnofadz Well-Known Member

    To properly tune a boosted bike, you need to ditch the power commander and get a real engine management system (i.e. one that has boost input, knock input, wide band input, and can alter ignition timing maps. You are just going to blow something up using a power commander only. AFR's definitely need to be 11-12, 13 will melt/detonate something. You might want to install a wideband afr gauge, EGT gauge, and Fuel pressure gauge just to see whats going on as well.
     
    Last edited: Oct 20, 2012
  13. Handicapped Racer

    Handicapped Racer Well-Known Member

    That's odd I've seen many with just PC's on em and they seem to be doing just fine.
     
  14. sonicnofadz

    sonicnofadz Well-Known Member

    You want ignition timing control with a turbo charged engine, you can't run the same timing as a NA setup when running the turbo. You can make a turbo busa run off of a power commander, but don't expect to flog it day in and day out before it goes boom. You don't see any of the land speed or serious drag guys using a PCV on their busas, because its a joke.
     
  15. RM Racing

    RM Racing Tool user

    We were trying to be nice to the OP. All the techs with turbo experience know this.
     
  16. mpp12

    mpp12 Well-Known Member

    I have a friend wit lots of turbo experience with cars, he is Haltec customer service for America, and one day he was tuning a new busa in the states and I asked him, he told me 245hp on stock parts but he installed the power commander to read instead of rpms it reads the map sensor.

    I have a turbo Sti, and anyone that rides even a turbo lawnmower knows that boost does not depend on rpms only, it depends a lot on the load the vehicle has and the TPS...so fuel will depend on that.
    Ex. when you are on 1st gear at 50%tps at 6500rpms you will have less boost that in 5th gear same conditions so you will need substancialy less gasoline.

    aFR should be max 12.5.....

    On the client. Usualy those clients have a lemon and are just looking to blame their piece of shit bike on a shop. with strange stories. so they can say you damage their bikes.

    I only do mech work on my bike and on friends bike when I have the time, I usualy do (when Barrick lets me) programing and some modifications (cams degreen, etc), BUT I never recive a bike that does not start, has a code or sounds weird.
    Also 99% of racers DO NOT pay, they think that Im sponsoring them. So money upfront.
    Also here in DR with few exceptions, race bikes are piece of shit since 99% of mechs dont know what their doing.


    Hope this helps
     
  17. GrayGhost

    GrayGhost Well-Known Member

    Actually , yes you can. The stock timing maps on a hayabusa are just fine for boosted applications. What you CANT do is run 12.8:1 AFR with any frequency ( that is not conservative on a boosted bike, its lean as hell) . For reference, I made 430rwhp on a street busa of mine with stock timing.

    The PCV thing is fine as long as its coupled with a larger pump and a boost referenced regulator (fmu or the likes) , is this the best system? No, but it works . The 08 Hayabusas don't hold as much boost on a stock motor as the Gen 1's do to the compression ratio and some say the ti valves make it more prone to detonation . That said, at 5 psi if it isn't making 210+rwhp on an honest dyno then something is wrong.
     
  18. Handicapped Racer

    Handicapped Racer Well-Known Member

    Thank you for this info, I was unaware!!!!!!!!!!!!!!!!!!!!! -__-
     

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