Throttlebody Mods and Tune

MAP based tuning uses absolute pressures. Thus, altitude has minimal impact (wave pulse tuning in the intake and exhaust do change some with decreased density with the greatest impact at WOT.) For example, to run at 50 mph on level ground or to accelerate at any given G rate takes X amount of power no matter which gear you are in or the altitude you are operating at (not counting the change in wind resistance.) If you are at higher altitude, you simply open the throttle further to achieve that power than you would at sea level. Both low and high altitude require the same absolute manifold pressure to achieve the same power (discounting the above changes in pulse tuning.)

You can run entirely on MAP tuning any where from sea level and up without any altitude compensation from a second air pressure sensor. I would suggest that the more one rides in quickly varying altitudes the greater the need for MAP tuning. Personally, I would have the change over from L-table to F-table set above 60% TB opening at the very least.

Attach an absolute pressure gauge to a TB port, ride or load on a dyno and correlate manifold pressure, load and rpm. F-table tuning is easier because you can run at 10 to 100% throttle openings at a constant load for each and interpolate in between. Not so easy with MAP values as you need variable loading.

Secondary air pressure sensors are essential for F-table tuning to work at various altitudes. Both fixed and load based operation need accurate and fast intake air temperature sensors (Ideal gas law.)
 
Got it! And no stepper motor, no tps, and no 2nd throttle shafts,
 
Last edited:
Hi Claviger, I have had nothing but trouble with my TPS and stepper motor for over 10 years. Replaced them both, tuned and re tuned but never perfect. I have tied them under seat but didn't like the clicking. If you are able to speak with Alain to remove these codes from my map I would be very grateful. I don't plan on having my TB bored out. I have attached my map. Please let me know how you go. Cheers in advance, Cruze Ryder
 

Attachments

  • Oct 23 dyno tuned AFR table adj.hex
    180 KB · Views: 3

this thread is almost 5 years old
search the threads and you probably won't find a fix
i have been dealing with mine for a few years not fixed but still have an idea to try.
reply to a stepper motor thread that is not to old