Dinan upgrades - woohoo! (i.e. subtle does not necessarily mean not impactful) - The Unofficial BMW M5 Messageboard (m5board.com)

Jacob Lee · 19th January 2002, 03:03

ok, so i've changed my mind and become a raving fanatic re: the Dinan mods, especially the Stage III, like the rest of you mod hounds.

i still think that the changes in handling (turn in, sharper line, decreased body roll, etc) and performance (chip + ff exhaust) is subtle to very subtle, BUT...having said that, and now put on about 150 miles cruising up and down Hwy 280 all night yesterday, including doing the little switchback streets going off 280 into San Carlos / San Carlos Hills, that little bit of "subtle" seems to make a big impact.

course, some of this could easily be the placebo effect of my own mind plus the hypnotic "beastly" sound of the new exhaust, but while everything feels only a little bit better/sharper/firmer taken as individual parts, the overall "impact" of them all added together really seems to make a substantial difference to driving pleasure if not the actual driving mechanics. does this make any sense? i mean, i always got a kick out of driving my M5 - you know, the 30 mile Starbucks run, an hour to go to Safeway to pick up milk, but it's like double that.

so even if you don't go all the way, i'd say at least just doing the stage III should make anyone who already enjoys driving their beast a whole lot more happy with it. in a way, i sorta wish now i had added on the dinan upgrades one by one just to see how each made a difference.

oh well, guess that's what the 3.45 diff is for now. still not sold on that - don't really know about this giving up top end speed and higher revs.

just how much higher are the revs with the 3.45 diff?

PaulMarin · 19th January 2002, 10:21

The 3.45 rocks. Has anybody had buyers remorse yet with the 3.45? Not that I've heard. I cruise at 80 mph (on the speedometer) in 6th at 3000 rpm. Stock is probably 2750. Figure aprox. 9% higher rpm at any speed/gear for the 3.45. Top speed is about 185 either way, an definite non issue for most of us. If I cruised at 150 regularly, I would probably want the 3.15 to keep rpms down. But for California driving its 3.45 all the way. No downside IMO, just more fun every day.

Jacob Lee · 19th January 2002, 10:37

is the 3.45 diff all about just the sense of "feeling" more acceleration/torque/oommmph!, or does the 0-60 time actually improve too?

more responsive to the throttle?

dinan description says something about how they wanted to be able to let you go up to 0-60 without having to shift out of 2nd to 3rd. i get the idea of the lower gear ratio translating to higher speeds in each gear, but what's the bottom line effect?

anyone know why BMW didn't just build in 3.45 as the final drive ratio since it sound so much superior to the stock?

Bart Carter · 19th January 2002, 21:17

IMO:

The M5 has so much torque/HP that the limiting factor to 60 is not gears. It is clutch and traction. In fact you have to be a better driver to get the same 0-60 times.

It is when you are in the higher gears that the gear ratio becomes effective.

tfung · 19th January 2002, 21:36

I agree with Bart here... definitely harder to launch the car 0-60... with the 3.45, the tires are laying down so much torque in 1st gear, that if I floor the car in 1st with DSC off, the car would fishtail all the way to 7300rpm... you really have to modulate the gas carefully... but having said that, it's definitely more FUN to drive the car now...

do a search on the messageboard, and you can see this topic on the 3.45 intensively debated before...