Aussie Pete

In my previous days playing around with HSVs the Delco management used to sense road speed versus rpm and use this to adjust the idle speed steps.

So, when you changed the diff ratio some cars started to experience hunting idle and pig-rooting.

Now I guess I wanted to ask the same question related to the BA Boss engines running EEC7. If I change from a 3.23 to 3.75 or whatever diff ratio am I going to have driveability problems? If so, maybe the better option is to go for a 3.45 and download the GT ECU calibration?

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BA'1.5' Pursuit 290
Lightning Strike / Reflective Orange Stripes
'General' Dog - AP's German Shepherd and Best Mate - 02Dec1998-15Dec2003.
'Pepper' Dog - General's and My Little German Shepherd Sweetie - 1996?-02Apr2006.
'Sako' Dog - My Beautiful and Pretty German Shepherd - 2001?-23Aug2006.

WBT56

I'd go the 3.45, with GT program as you have suggested. Anything lower and you'll never use first gear. What you have now with 3.7 would have the same overall first gear as your old T5 with a 4.23 diff. Availibility of the 3.7, 4.1 gears are unknown at this time. EEC will need to be recalibrated, or the car will have serious issues.

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If you're not driving a manual you're really just steering.

Aussie Pete

I've lined up a 3.45 and it's available right away however I'm considering costs etc. It would be nice to know about the EEC thing for sure though.

__________________
BA'1.5' Pursuit 290
Lightning Strike / Reflective Orange Stripes
'General' Dog - AP's German Shepherd and Best Mate - 02Dec1998-15Dec2003.
'Pepper' Dog - General's and My Little German Shepherd Sweetie - 1996?-02Apr2006.
'Sako' Dog - My Beautiful and Pretty German Shepherd - 2001?-23Aug2006.