How to drive?? First timer need help with Turbo

    So I am a little embarrassed to say but I have come to realize that I may not really know how to operate my Turbo SS. This is the first Turbo vehicle I have owned and I have no clue what all I am reading, what is good or bad. I have been driving my SS all summer and probably should have asked these questions earlier but I thought I would just figure it all out. Guess not.


    I have a Hahn stage 2 Turbo running 8lbs with a Kaso AFR/boost gauge. A very early setup from 2015.
    When I am idling the gauge normally reads right at 14.7 (I know thats a good thing). As soon as I give it gas and start to drive it hard it jumps way up into the low to mid 20s. Then when I shift into the next gear it drops real low before I gun it again. After I have settled down mashing thru the gears and am just cruising its floats around 14-16 AFR range. Its hard to give the exact numbers as I am paying attention to my driving and not the gauge.
    Is this normal? Should I be worried? I havent done ANYTHING with the engine since I have bought the SS from the original owner and I know he took great care of the bike. But I will admit I do drive the snoot out of her 99% of the time.


    Any other tips/tricks/advice you have for someone who has never owned a turbo engine before? I am very mechanically inclined and do all my own work (minus tranny stuff) but this is new terf for me.


    X-2 Boost Gauge with Wideband Air/fuel Ratio & Temperature - Koso North America

    OUCH. And it's still running? You must head right out now and by some powerball tickets for Saturday's drawing. Just the basics first off. Yes, your 14.7 a/f at idle is perfect (and one not normally seen with the tune most people have with the ecu being reflashed. As the numbers rise, the engine is leaner; as the numbers drop, the engine is richer. It is normal to see the a/f numbers to be as low as the 12's and mostly in the 13's when under boost as you want to run a little rich to keep the engine safe. To see numbers in the 20's (or even as low as 15's and 16's) while under boost for any length of time is way too lean. I'm surprised that you haven't destroyed the engine by now. There is something wrong somewhere. There's a good chance it is not a malfunctioning gauge, but if you have access to another one, I'd try that first. Actually, I'd try an examination of the engine for vacuum leaks. (even though a leak would probably not allow you to see 14.7 at idle, but if it was running rich, the leak could balance that down to the 14.7 that you're seeing. Check the map sensor to make sure it hasn't popped out of the grommet as well as all the vacuum hoses. There has to be a reason for the engine to be running that lean and I would find the cause before riding it any longer. JMHO

    Nobody gets outta here ALIVE

    You’re sure those are afr numbers that you’re seeing under hard acceleration? What are the boost numbers that you’re seeing? If you’re in to the 20’s under hard throttle and haven’t blown the engine I would say there’s most likely something wrong with the gauges or the sensors.



    Sent from my iPhone using Polaris Slingshot Info

    I may have it in reverse! When I shift gears my gauge will be flashing a number normally in the low 20s. Thats when I get a chance to look at it. It may be in low numbers while I giving it gas and then spike up to the higher numbers once I engage the clutch? Then my gauge would flash the highest reading to let me know it just spiked there. Does that sound more like it?


    I dont know to view the boost numbers on my gauge. Its a snowmobile gauge (link on main post) and I just left it on the main settings it was on since I am unfamiliar with everything

    Quote from sgtklein

    I may have it in reverse! When I shift gears my gauge will be flashing a number normally in the low 20s. Thats when I get a chance to look at it. It may be in low numbers while I giving it gas and then spike up to the higher numbers once I engage the clutch? Then my gauge would flash the highest reading to let me know it just spiked there. Does that sound more like it?


    I dont know to view the boost numbers on my gauge. Its a snowmobile gauge (link on main post) and I just left it on the main settings it was on since I am unfamiliar with everything


    That’s perfect. Look at your numbers when you aren’t clutched. As soon as you cut the fuel it’ll spike up and show super lean. That’s what you want to see. Under hard acceleration you should see around eleven. That’s in gear, foot cramming down the pedal.



    Sent from my iPhone using Polaris Slingshot Forum mobile app

    Quote from sgtklein

    I may have it in reverse! When I shift gears my gauge will be flashing a number normally in the low 20s. Thats when I get a chance to look at it. It may be in low numbers while I giving it gas and then spike up to the higher numbers once I engage the clutch? Then my gauge would flash the highest reading to let me know it just spiked there. Does that sound more like it?


    I dont know to view the boost numbers on my gauge. Its a snowmobile gauge (link on main post) and I just left it on the main settings it was on since I am unfamiliar with everything

    I would find a back road where you can look at the gauge a little closer while driving. I'm running the same gauge on my sling and it works great. If you push the bottom right button it will change your main display from boost to A/F or vice versa. The other reading will go to the bottom right.

    Posted while driving with No Hands!

    Thank you everyone. I really appreciate the help.


    So the AFR should only be at the 14.7 at idle and then drop down between the 9-11 range with the pedal to the floor. Then it will spike up to the 20s when I engage the clutch and shift. Thats what I should be expecting? What should the AFR be when I am cruising around in 3rd but not mashing the gas? How about when I am in 5th pushing the triple digest?


    My bike seams to be running great and is incredibly fast, only problem is getting traction lol. Is there anything special I need to be doing with routine maintenance besides the normal oil changes? Im running Vr1 changing it every 2500 but thats really all I have done, dont know what special I should be keeping an eye out for.

    The tune you have is still has a "closed loop" idle. It will chase 14.7, so what you are seeing is correct.

    When you are cruising down the road with a consistent light pedal (lets just assume 60mph in 5th gear) you should see numbers in the middle 13s and 14s. Let off the gas and the number should rise to show leaner. Smash the gas in boost and the number should go lower (11s) to show that it is richer.

    An AFR gauge is mainly used to see fuel delivery under full pedal and full boost conditions. This is when the numbers are important. Most people should be seeing number between 10.5 - 11.5. 10 - 12 is also pretty common. Anything under 10 under full boost is way too rich and anything over 12.5 is too lean.


    DO

    Let your vehicle idle 30-60 seconds after really hard driving to let the oil cool the turbo. I let my fan come and and when it shuts off, I shut the vehicle off. I only do this after really hard driving when I know the turbo is really hot.


    DON'T

    Stray away from good 91 or 93 fuel.

    Build a bunch of boost at very low RPMs in 4th and 5th gear. You want to move faster, downshift so there is less unnecessary load on the engine.

    Owner of Slingshot #263 that has some stock parts left on it. :D

    Everyone on here is great, thank you so much.


    I tool her out last night and everything is right where it should be. Hanging around 12s on hard acceleration. My gauge only goes to 24 so when i let off the gas it spikes up to 24 and then my gauage flashes the 24 for a few seconds to tell me it went that high. Looks like everything is great.


    Now how do i read my boost? I was told that i was running 8.5lbs of boost. But my gauage shows -13 at idle. When i get on it goes down into lower numbers but it never got below -2. I didnt notice the boost go into the possitve at all. What does all this mean? What should i be watching out for there?

    Quote from MiM

    @sgtklein, I don't have a turbo and those numbers scare me... Likely going supercharger...


    But anyway, is it safe to say you purchased the Rev Dynamics Slingshot? That avatar and paint job look familiar... :00000436:

    Mim I did not buy the Rev Dynamics bike. But it is a complete replica of their paint job. Besides i have red instead of orange. I had an all red 2015 SS with nice prp seats and custom black/red rims. So i needed to leave some red in it to pull the seats and rims together.


    I sent the pics to Rev but they never respounded. They say imitation is the greatest form of flattery.

    Check out the Koso link and click on "download instructions" button. This should help you in understanding this gauge better.
    Gauge Info

    You would want to set up the gauge with a 15psi positive pressure scale and at 1psi increments. Warning should be set at 10psi.

    Vacuum numbers really don't mean much other than you are not in boost. It will be negative at idle and most light cruising. Once you start building boost, you should see the gauge start to display positive pressures. If you are not seeing over 8psi on long full pedal pulls (3rd gear probably works best), something isn't working right or hooked up right.

    Positive pressure mean that extra air (boost) is being pushed by the turbo into the motor. The higher the number, the more power potential.

    You could have a kinked vacuum line to the gauge if readings aren't correct.

    Owner of Slingshot #263 that has some stock parts left on it. :D