I bought obd2 interface and now i've got questions :)
by poland » Wed Apr 14, 2010 9:19 am
Hi,
My car is 2005 sle v6 completely stock. Few weeks ago I bought simple obd2 -> USB interface (less then 23$) and I’ve got proscan 5.5 software for reading data from it. Now I’m playing in “mini-telemetry” - I record drive data like speed, rpm, throttle position, intake temperature, airflow rate from MAF, calculated load value and oxygen sensors reading when I drive everyday to/from work. After analysis of collected data I've got few questions – maybe You will know answer
1. Why the hell throttle never opens more then 80%. First I thought that is some calculation mistake in Proscan software. But I remove air filter box and check real throttle change with obd2 readings. I record that when idling throttle is open ca 16%, when I push accelerator pedal to the max on P position – TP is ca 49%, on D position max TP is 39% - I checked that while watching throttle body and readings are OK. So when I’m driving and push acc pedal to the max for WOT max TP is only 80% - why not 100% ??????????
2. Airflow rate reading from MAF for WOT (but remember 80% not 100%) is ca 164 g/s (21,6 lb/m). Is it little to less for 3.3l engine ?? I found old (2005) post on another forum from user of lexus 400h (same engine like in solara) – he got obd2 interface and measured data like me So I will quote his post:
“The aiflow from the Lexus( 3.3l V6) is at most 160g/s. A quick estimate at STP gives that the airflow at WOT at 5500 rpm should be ca:195g/s for 100% Calculated Load Value. Another quick estimate gives that 160g/s means ca: 142 kW output assuming that Lambda is 1.00 and the efficiency of the engine is 30%. The engine is supposed to give 155kW at 5600 rpm. I.e. The output is 91% of max rated power. So that seems correct. So what is wrong?”
I’ve got same questions !!!! (but our engine supposed to give 165kW, and from my readings I never had lambda = 1.00 – max was 9.55)
3. If You want to know air intake temp in stock air intake (to compare with CAI): I recorded data for 7 days (mornings and afternoons), air temp was ca 9-16 deg C and air intake temp was from min: 12 deg C to max: 40 deg C and avg was 22,3 deg C.
very simple example
My car is 2005 sle v6 completely stock. Few weeks ago I bought simple obd2 -> USB interface (less then 23$) and I’ve got proscan 5.5 software for reading data from it. Now I’m playing in “mini-telemetry” - I record drive data like speed, rpm, throttle position, intake temperature, airflow rate from MAF, calculated load value and oxygen sensors reading when I drive everyday to/from work. After analysis of collected data I've got few questions – maybe You will know answer
1. Why the hell throttle never opens more then 80%. First I thought that is some calculation mistake in Proscan software. But I remove air filter box and check real throttle change with obd2 readings. I record that when idling throttle is open ca 16%, when I push accelerator pedal to the max on P position – TP is ca 49%, on D position max TP is 39% - I checked that while watching throttle body and readings are OK. So when I’m driving and push acc pedal to the max for WOT max TP is only 80% - why not 100% ??????????
2. Airflow rate reading from MAF for WOT (but remember 80% not 100%) is ca 164 g/s (21,6 lb/m). Is it little to less for 3.3l engine ?? I found old (2005) post on another forum from user of lexus 400h (same engine like in solara) – he got obd2 interface and measured data like me So I will quote his post:
“The aiflow from the Lexus( 3.3l V6) is at most 160g/s. A quick estimate at STP gives that the airflow at WOT at 5500 rpm should be ca:195g/s for 100% Calculated Load Value. Another quick estimate gives that 160g/s means ca: 142 kW output assuming that Lambda is 1.00 and the efficiency of the engine is 30%. The engine is supposed to give 155kW at 5600 rpm. I.e. The output is 91% of max rated power. So that seems correct. So what is wrong?”
I’ve got same questions !!!! (but our engine supposed to give 165kW, and from my readings I never had lambda = 1.00 – max was 9.55)
3. If You want to know air intake temp in stock air intake (to compare with CAI): I recorded data for 7 days (mornings and afternoons), air temp was ca 9-16 deg C and air intake temp was from min: 12 deg C to max: 40 deg C and avg was 22,3 deg C.
very simple example
- poland
- Just Licensed SolaraGuy
- Posts: 21
- Joined: Tue Feb 03, 2009 3:34 am
