su27TT

First, I'm new to this forum, so hello everyone!
I'm seriosly considering 530xi or 545i and test driven both of them tonight. I found 530xi (auto) pretty spanky and generally liked it. When driving 2004 used 545i the feelings were very mixed. The shifts are very long (well, may be it's me coming from Supra TT), but I can live with it . What I didn't understand was the total engine irresponsiveness on down shifts. Every time I down shifted and let RPMs drop to less than 2.2-2.3K I'd need a throttle blip just before dropping the clutch. To my amusement the engine wouldn't respond to the blips at all . I had to either hold the gas pedal for a 2-3 secs or make 2-4 short blips, which both sucked. So, is something wrong with this particular car or this is a feature ?

thanks!

05E60Black545i

I have a 545 and I noticed the same thing, I love the car, maybe it's the electronic pedal, who knows, but yesterday I drove one of my relatives 1970 jaguar e-type and the throttle response was much better, quite odd seeing that theres 35 years in difference.

SteveHI

For every downshift, you should be blipping the throttle to match revs to alleviate stress on the transmission. If you didn't, you certainly should have on your Supra. I admit that some of my own downshifts are not silky-smooth, but that's just driver inattentiveness. It helps to start the blip sooner rather than later in the shift.

I agree that the throws are a little long. There are short-shifter kits out there to cure this if it's an issue. Also, some have modified/removed the clutch delay valve which is believed to be a culprit of accelerated clutch wear and poor shifts. I personally just want to get a clutch stop, which I think would improve the shifting experience.

su27TT

that's exactly right and that's what i tried to do and beleive me I did it quickly (it comes naturally after driving stick for long time) but as I said the engine wouldn't respond. Well, if that how the 545i behaves normally I'd be very much hesitant to get the MT.

hinckley

I think SteveHI is right - especially regarding the CDV. Removing it (very inexpensive) makes a big difference.

BTW, I also find the throws long and have added the short-throw shifter. It helps, but the throws are still longer than those on my last three 5ers.

su27TT

Would removing the CDV void the warranty? Is it a DYI thing or a got to be done by the dealer to keep the warranty?

hinckley

Most of us had an outside shop do it. I think it cost me somewhere between $100 - $150 including parts and labor.

It's not the removal of a part, but an exchange of a very small part. It's impossible to even notice, so I don't think that any of us worry about a warranty issue.

su27TT

thank you all guys for clarification!

SteveHI

I know what you're saying - there's a bit of delay if you are completely off throttle. Not really 2-3 seconds, but timing is critical down to fractions of a second if you want smooth downshifts. For the smoothest downshifts (and I'm not CDV-free yet), I barely let off the throttle when I depress the clutch pedal. That enables me to blip more quickly to match revs. Otherwise, it's a SLOW downshift. Hope this helps. Good luck!

EBMCS03

Ya its most likly due to the electronic throttle... there is a delay. I've driven several BMWs from the MINI Cooper S to 545 to E46 M3 to E39 M5 and the throttle behaviors are all the same... there is a lag... you really have to step into it rather than just bliping it. You'll get use to it. I know thats not what you want... but thats the problem with drive by wire. Its not bad once you get use to it, it'll actually be fine I think.... and CDV valve modification is almost a must... see here very good info.

http://www.zeckhausen.com/CDV.htm

The only problem with the "getting use it" stepping into the throttle for rev matching is if you drive a friends car that doesnt use drive by wire and thus the throttle reponds a lot faster you'll be over revving the engine for the first few miles before getting use to that again.