Why A Model Report For The Auto, But Not Manual?

[IanF]

What are the differences between the two - the auto goes through without a problem, but the manual fails emmissions. If we could identify what the differences (and the similarities are) it may help in knowing what needs to be done.

To the best of my knowledge, both versions have the same intake, engine and exhaust - so these cannot be the reason for the higher emmissions on the manual.

How about these for suggestions:

* Different fuel map on the auto - the manual runs richer

* Slower cold idle speed on the manual, so less efficient running at startup (my car passed the warm MOT emmissons test, but failed the cold start ESVA test)

Any others? - any help or advice greatfully accepted.

Cheers

Ian

[OLI_EP3]

Probably not helpful but the first difference that sprung to mind is the power output difference. More for the manual.

Start from here?

[IanF]

Yes - but what is the root cause of the extra power from the manual?

There will be greater transmission losses from the auto, but I would guess the power figuers quoted from Totota / Lexus are flywheel figures rather than at-the-wheels figures.

If the 2 versions have the same engine - why does the auto have less power? - is it detuned somehow, or is something altered on the manual to free extra power?

Ian

[AltezzaScott]

Ian, i have told model reports to get ( or i would supply ) a HKS Super AFR i think this could help!...

Here is the write up on the item..

The HKS Super AFR is the very first airflow meter correctional device in the industry with a built in CPU. The advantage of having a built in CPU is that instead of making corrections to the airflow meter voltage, the characteristics of each airflow meter is inputted in the CPU so it can calculate the accurate amount of air flowing in. Since the correction will be made to this specific intake volume, the correction ratio of fuel will be precise and proportionally correct. The Super AFR is compatible with most Import and Domestic 12V, 2~12cylinder vehicles that utilize a hot wire, Karmen Vortex, or pressure sensor. The internal CPU allows it to be versatile and be utilized on many of the newer type airflow meters. Also incorporated in the Super AFR is the ability of idle air/fuel ratio corrections as modification progress and require further specific tuning levels. The response function, similar to the one in the VPC, allows for adjustments to the fuel settings upon throttle inputs to improve driveability and performance. The EIDS function is automatically programmed with the data from the initial self-learning calibration and automatically activated to correct sudden imbalances is air/ratios from discharge valves upon deceleration.

Air/Fuel Ratio Correction Function

Controls air/fuel ratios through airflow meter or pressure sensor

Range - 50% rich to 50% lean from the factory baseline settings

Output can be adjusted in 1% increments

Eleven points of adjustment between 650 and 8000 rpm, these points can be arbitrarily moved in 50 rpm increments

Response Correction Function

Engine response can be adjusted through airflow meter/pressure sensor

Range - 1m/sec to 100m/sec

Six points of adjustment between 650 and 5000 rpm, these points can be arbitrarily moved in 50 rpm increments.

First in the industry to offer this function in a simple airflow correction device

Idle Correction Function

Idle mixture can be adjusted 50% rich to 50% lean in 1% increments within the idle range (650 to 1500 rpm) from factory baseline setting

This adjustment is made independent of the other eleven points of mixture adjustments in the air/fuel correction function

Electronic Idle Stabilizer Function (EIDS)

This automatic function prevents engine stalling or stumbling in some airflow meter vehicles which use blow-off valves discharged to the atmosphere when throttle is released

Base of Adjustability and set-up

This device is very simple to set-up and adjust

The head unit is adjusted through three control knobs

HKS recommends tuning for this device be done on a chassis dynamometer with use of an accurate air/fuel ratio measuring device

[IanF]

I like the sound of that! What did they say - are they going for it?

[AltezzaScott]

I like the sound of that!  What did they say - are they going for it?

←

seem to be mate... think they want the report as much as us!!

fingers crossed it should do the trick.. will let you know as soon as i know something

[IanF]

So to relate this back to the original question - a possible difference between the auto & manual is that the manual runs slightly richer - meaning a bit more power, but also less complete combustion and higher emmissons.

The AFR will allow the mixture to be tweaked slightly without the expense of a fully programmable ECU - improving the efficiency of combustion and potentially dropping the emmissons into the bargain.

Does this sound about right?

Ian