A good one for Ron...final drive ratios

[AC]

If anyone knows...

what are the final drive ratios of all the 6 cylinder Z3s that have been built?

I know S54M 3:15, S52M 3:23 but what about the 3.0, 2.8. 2.5 and 2.3?

:bigpimp:

[Ron Stygar]

If anyone knows...

what are the final drive ratios of all the 6 cylinder Z3s that have been built?

I know S54M 3:15, S52M 3:23 but what about the 3.0, 2.8. 2.5 and 2.3?

:bigpimp:

I have that info. Althiough the info is torsen or not related it will answer your question. Just have to find it in the multiple piles. Funny that you should ask, since I'm going through the same for another differential mod some will be doing.
Right now my car isn't working quite right. Once I get it working, I'll get back to the piles:).

[Randy Forbes]

If anyone knows...

what are the final drive ratios of all the 6 cylinder Z3s that have been built?

I know S54M 3:15, S52M 3:23 but what about the 3.0, 2.8. 2.5 and 2.3?

:bigpimp:

We also know that the 3.0 with an automatic transmission is 3.46:1

BTW, congratulations on getting the cheese (NE ASP title). I know you must've had some tough competition to get past. :thumbup:

[Ron Stygar]

If anyone knows...

what are the final drive ratios of all the 6 cylinder Z3s that have been built?

I know S54M 3:15, S52M 3:23 but what about the 3.0, 2.8. 2.5 and 2.3?

:bigpimp:
Here are the Torsen ones for all Z3's 4 and 6 cylinder :

33 10 1 428 753, 3.38, 1.9M43 Euro

33 10 1 428 609, 4.27, 2.5 NA

33 10 1 428 593, 4.44, 1.9 NA M44, 2.0 Euro

33 10 1 428 591, 3.46, 1.9 NA, 1.8,1.9 M44, 2.0 Euro

33 10 1 428 439, 3.15, 2.5,2.8 NA, 2.8 Euro

33 10 1 428 435, 2.93, 2.8 Euro

33 10 7 508 262, 3.46, 3.0 NA/Euro

Email me your home address and I'll send you something.

[AC]

FYI those are all the SCCA Street Prepared legal interchangable bits for the Z3....mix and match.

[rukman]

if i remember correctly...z3 3.0 5 speed has a 3.07...

[AC]

We also know that the 3.0 with an automatic transmission is 3.46:1

BTW, congratulations on getting the cheese (NE ASP title). I know you must've had some tough competition to get past. :thumbup:

My co-driver... but we both were among the only 5 drivers in the 77sec club (street cars that is)results (http://www.nedivsolo2.org/04divisional/NEDIV2004CLASS.txt) :thumbup:

[Pinecone]

Here are the Torsen ones for all Z3's 4 and 6 cylinder :

33 10 1 428 753, 3.38, 1.9M43 Euro

33 10 1 428 609, 4.27, 2.5 NA

33 10 1 428 593, 4.44, 1.9 NA M44, 2.0 Euro

33 10 1 428 591, 3.46, 1.9 NA, 1.8,1.9 M44, 2.0 Euro

33 10 1 428 439, 3.15, 2.5,2.8 NA, 2.8 Euro

33 10 1 428 435, 2.93, 2.8 Euro

33 10 7 508 262, 3.46, 3.0 NA/Euro

Email me your home address and I'll send you something.

Hmmm, talk about a launch. :)

[sthoma9]

if i remember correctly...z3 3.0 5 speed has a 3.07...

i think its a 3.17 in the 3.0i 5sp Z Coupe :dunno:

[AC]

i think its a 3.17 in the 3.0i 5sp Z Coupe :dunno:

3:17 doesn't sound right, since BMW makes and uses a 3:15 in a number of cars...

[mng]

Hmmm, talk about a launch. :)
i drove a 325i loaner once (step). that thing was wicked quick off the line....i'd be interested to see it's 0-30 or 40mph times compared to others (like the 330i).

rookie question of the day - anyone have a good link that explains how these drive ratios work? :dunno: :thumbup: . i can infer from Pinecone's comment, and my own experience, that the higher the number, the quicker off the line....what's the trade-off?

[Mpire]

Yeah, a past girlfriend had a 2.5 Z, and it was very peppy... I wouldnt mind having one of those....

[Randy Forbes]

rookie question of the day - anyone have a good link that explains how these drive ratios work? :dunno: :thumbup: . i can infer from Pinecone's comment, and my own experience, that the higher the number, the quicker off the line....what's the trade-off?

Trade off? Higher rpm for a given road speed and lower top speed potential.

I don't have a link to a road speed vs rpm driveline calculator. Can someone post one from the 368s site? Simple to use, enter ratios and (rear) tire size and you'll quickly see the results.

[sthoma9]

try this link-
http://www.368s.com/tools_rpm.phtml

AC-
i think ur right, i prob have the 3.15 in my Coupe

[Neil]

Andrea -

FWIW, I was regularly bumping against the rev limiter in 2nd gear while autoxing after I switched from stock 3.23 to 3.46. Much happier with my present 3.15 (but, of course, power to get off the line quickly is not an issue!).

Regards,

Neil

[Mpire]

If your really worried about top end cruising, I suggest you just add a .83 overdrive. That will drop your cruising speeds below the 5th gear stock rpms...

[AC]

Andrea -

FWIW, I was regularly bumping against the rev limiter in 2nd gear while autoxing after I switched from stock 3.23 to 3.46. Much happier with my present 3.15 (but, of course, power to get off the line quickly is not an issue!).

Regards,

Neil

according to the RPM calculator with 275/40/17 tires I would be good for 67mph in second, down 5mph from the 3:15. That should be good for most courses I think

[Ron Stygar]

try this link-
http://www.368s.com/tools_rpm.phtml

AC-
i think ur right, i prob have the 3.15 in my Coupe
Based on the parts data you have a 3.07.

[Pinecone]

i drove a 325i loaner once (step). that thing was wicked quick off the line....i'd be interested to see it's 0-30 or 40mph times compared to others (like the 330i).

rookie question of the day - anyone have a good link that explains how these drive ratios work? :dunno: :thumbup: . i can infer from Pinecone's comment, and my own experience, that the higher the number, the quicker off the line....what's the trade-off?

Basically gearing increases torque. So changing a rear ratio to increase by x% you increase torque delivered to the rear wheels by the same x%. And since torque accelerates the car, more torque is better.

The downside is that your cruising RPM will go up. And the max speed in each gear will go down.

I did an Excel spreadsheet that does speeds in gears for the M tranny gears, and does the RPM in 5th at 60 and 80. I can't send it out right now, since it is on my computer at home, an I am in Africa.

[mng]

Basically gearing increases torque. So changing a rear ratio to increase by x% you increase torque delivered to the rear wheels by the same x%. And since torque accelerates the car, more torque is better.

The downside is that your cruising RPM will go up. And the max speed in each gear will go down.

I did an Excel spreadsheet that does speeds in gears for the M tranny gears, and does the RPM in 5th at 60 and 80. I can't send it out right now, since it is on my computer at home, an I am in Africa.
i see....makes sense. thanks! enjoy Africa.....safe journey home.

[markd89]

I found the following spreadsheet interesting.

It allows you to enter in your final drive ratio, etc. and see what G-force you will see in each gear. I figure if the rear-end change makes third gear have the G-force of 2nd gear that this would be good to know.

You can also tweak your horsepower. i.e. I was thinking.. if I add a supercharger how will it change the feel of the car? This is one way of getting a feel of that.

http://www.lumenique.com/Cars/cargeneral/gforce%20Mcoupes.xls