My wife is driving a 01 740i that we're using while I fix up her 850. After driving the 740i she realized that her 8 is slow as crap. She wants to know why?

You are comparing apples and oranges. The V8 has dual vanos engine management and all else that 10 years difference in development would bring, the weight is probably less, and the gearing of the transmission and rearend is different.

Yeah. 10 year difference is a lot.

The Wokke has answers , he has the cure.

Gearing -
To make it more of an apples to apples comparison you'd need to change the diff (as has been suggested)

Gearing -
To make it more of an apples to apples comparison you'd need to change the diff (as has been suggested)

+1. Among a host of other changes, the 01 740iS has a 3.15 final drive (in addition to electronic throttle and a high stall torque converter). The changes make the car much more lively then it would be otherwise.

Simply doing the same via adding a higher final drive WILL make your car much more lively. For 4 spd automatics, I suggest 3.91; for 5 spd automatics, I suggest one of the following:

3.15LS ex early 750iL (pre93) - cheap and easy to get a hold of; in fact I will have one for sale in 2-3 months.
3.23LS ex Euro M3 EVO. - Rare in the US and pricey but the best bet for all around driving IMHO, if you frequent the highway
3.45 gear set ex euro M gears - Very rare and pricy, fine for occasional highway driving
3.6x gear set - common, not recommended for highway use; very aggressive

Stock is a only 2.82!

You are comparing apples and oranges. The V8 has dual vanos engine management and all else that 10 years difference in development would bring, the weight is probably less, and the gearing of the transmission and rearend is different.
The transmission is the same 5HP22 as that found in very late 840Ci (M62). The gearing matches the more robust 5HP30, but the 740iS uses a higher stall torque converter. I had toyed with the idea of swaping it in my E31, but it is not worth the effort. I mean why go to all that work when you can instead swap a manual in there, but then this fellow I know is taking that very fascinating approach, and I can't wait to see his results! :D

The only tech improvement really is the electronic throttle. Much more lively then our cable based system, but I feel you can better modulate the cable based (at least IMHO). The rear end is indeed different, as mentioned above, at 3.15 (Open). I never weighted my E31 versus my E38. I am getting more curious to see how much they differ.

Why do I have the feeling when she drives the 8 you leave the automatic switch on manual.:stickoutt That's what I do when I leave it with the Valet.

Why do I have the feeling when she drives the 8 you leave the automatic switch on manual.:stickoutt That's what I do when I leave it with the Valet.


What switch?

By the gear selector

What switch?

Greg you really need to read up on what's on your car and what it does.......:stickoutt

By the gear selector(where you put it into drive :stickoutt) towards the bottom is a switch that has M & A on it....if you put it on M and put shifter in Drive. Try to race a Geo Metro and you WILL loose. :D

By the gear selector(where you put it into drive :stickoutt) towards the bottom is a switch that has M & A on it....if you put it on M and put shifter in Drive. Try to race a Geo Metro and you WILL loose. :D

That just locks t in 3rd gear. (If its a 4 speed-auto)