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Title: OBD Dyno Post by: nautica on March 09, 2012, 11:50:19 AM I think you have heard about OBD Dyno. Anyone help me please, i don't know what to write in Transmission ratio field.
Final drive ratio * 3rd gear ratio (data logging gear)? For example Mk4 GTI 3.684*1.308=4.818 i'm right? If not, correct me please. (http://s018.radikal.ru/i525/1203/28/d39de7c3fb9b.jpg) Title: Re: OBD Dyno Post by: Nottingham on March 09, 2012, 12:15:16 PM You can usually get more accurate estimations about power by logging the air-mass with VCDS or similar program.
4th gear WOT pull to the limiter or so -> air-mass in g/s /0,8 = hp (roughly). For accurate readings you need to put it on rollers. Title: Re: OBD Dyno Post by: nautica on March 09, 2012, 12:33:29 PM your method is not so accurate, for example stock passat 170hp measured 147g/s at 5600rpm -> 183hp.
Title: Re: OBD Dyno Post by: nyet on March 09, 2012, 01:31:28 PM ECUxPlot has a HP calculator. You enter gearing using rpm vs mph ratio, since sometimes its hard to figure out the gear ratio for tools like the one you're using.
For ECUxPlot, all you need is a gps unit to get accurate mph. Title: Re: OBD Dyno Post by: Nottingham on March 09, 2012, 02:07:28 PM your method is not so accurate, for example stock passat 170hp measured 147g/s at 5600rpm -> 183hp. It is not unusual that 1.8T develops more power at stock than the manufacturer specifies. Actually in most cases they are. Title: Re: OBD Dyno Post by: nautica on March 09, 2012, 02:33:05 PM ECUxPlot has a HP calculator. You enter gearing using rpm vs mph ratio, since sometimes its hard to figure out the gear ratio for tools like the one you're using. For ECUxPlot, all you need is a gps unit to get accurate mph. Which blocks i need to log with VCDS? It is not unusual that 1.8T develops more power at stock than the manufacturer specifies. Ok, another example: Jetta 1.8T 150hp stock - 114g/s at 5500 -> 142hp...another 8 has dead? ))Actually in most cases they are. Title: Re: OBD Dyno Post by: nyet on March 09, 2012, 02:44:02 PM RPM, gear, accelerator pedal position
for SAE, ambient pressure and temp it has been tested more with ECUx logs, so if you have problems, PLEASE email me your log and I will try to update ECUxPlot as needed. Title: Re: OBD Dyno Post by: whoopsie on March 16, 2012, 11:34:18 AM I think you have heard about OBD Dyno. Anyone help me please, i don't know what to write in Transmission ratio field. Final drive ratio * 3rd gear ratio (data logging gear)? For example Mk4 GTI 3.684*1.308=4.818 i'm right? If not, correct me please. Hi, you are right. Its final gear * gear ratio of logged gear. bye |