DetroitSlim, thank you for sharing your info. I have an '05 JCW, and this is very interesting info. The a/f curve appears to indicate that you have a rich condition above 5,000 rpm that would yield more hp if leaned out. What do you think? Have you been able to share the a/f info with Tradiuz and MTH to see if they can lean it out? How was the a/f info gathered - do you have a header with a bung, or...?

 

I had the all my dyno data sent to the MTH guys in Germany, but haven't heard back yet.

The A/F was taking from the tail pipe.

Not sure what you mean by it running rich, the tuner file appears to run a bit leaner than the original JCW map above 4000 rpm.

I would have done back back runs, but the MTH guys on state you have to drive a few hundred miles for all the adaptive learning to kick in.

 

Problem with those same day dyno results is always the ECU. It needs to be re-set completely before you get accurate figures. I have to say it again – it can NOT be done through the speedo. You would need a dealer to do that for you. Otherwise it takes a few 100 miles in order for the ECU to fully adapt.

Btw, there is a new version of the tuner file available (vt_7). An official announcement should be posted by MTH-USA / Pat soon. Existing customers will get the update for free.

 

Accurate A/F figures can only be gathered by installing a LSU sensor right in front of the pre-cat. Everything else is fine for emission control, but does not provide detailed data to work with. Fiddling with A/F is tricky and can result in major engine problems (but I am sure you knew that already :smile: ) .

 

Does this new version fix our ongoing flat spot problem?

 

Thats the reason for the new version.

 

Is this a proven fix or a attempt? Can you share any details on what has been changed?

 

If we have a header installed where would we need the LSU sensor reading from? just in front of the cat?

John.

 

Thanks for the information. I will get with Simon to request a new version for my car.

John

 

Pre-Cat (where the first O2 sensor is). The post Cat O2 sensor is just for checking cat efficiency and emessions.

There was a great discussion on Wideband O2 sensors (LSU) and how some have a Wideband output with a narrowband so they could be put in place of a stock O2 without adding a bung.

 

This IS a proven fix....

 

See my dyno result here https://www.northamericanmotoring.co...ad.php?t=55696 , for before and after back to back runs.