How fast at 7000 rpm?

[M3Jimbo]

Can any of you boffs work out how fast (Actulal/mechanical) i would be
going in a 1989 M3 stanrd gearbox and diff on 16's 225/45 r16's
at 7000rpm and then another one at 8000rpm!

I did a run the other night and had it in Fith Gear at 7000rpm
its got a sport speedo and was reading off the clock at 150 but im thinking
thats maybe not true! Also it still need remaping at which point they'll
raise the limiter to 8250rpm so im wondering what sort of speed it will
be doing if it get up near that??

I think it might be worth while chaging the diff! As 145mph seem like
more than enough for road and track days?

[Martinaston]

Fast enough for an instant ban
Try this
http://www.unixnerd.demon.co.uk/bmw.html

[M3Jimbo]

cool do ya know where i can find the gear ratio's and stuff?

[Chaos]

u can up the rev limit m8 but it prob wont pull that high

e30 isnt that aerodynamic (think housebrick)

ive got a program called car test which u can input ratios and tyre sizes etc into, but im not at home till sunday so can send it u then if thats any good to ya?

[M3Jimbo]

i think fith gear is 1.00 and the diff is 3.35 does this ring any bells
with anyone??

[M3Jimbo]

Apperntly the more raked read window and higher boot level gives it
a lower co-eficient of drag(whatever that means)? and i think i heard
someone say that the touring where most aero dynamic????

My car has got some lairy shrick cams so it shold have power up there??

[Chaos]

My car has got some lairy shrick cams so it shold have power up there??

that helps, but if it wont pull the speed/gearing then its wasted (only in top tho obviously)

[Martinaston]

The gear ratios will depend on what gearbox you have and to find out the Diff ratio you have to crawl under the car.

[M3Jimbo]

To dark to crawl under the car now i'll leave it till tomorrow!
Cheers for ya help that website is cool!

It pulls to 7000 realy easy although acording to that conversion thing
7000rpm is 148 and 8000rpm is 170 not sure how that works but i know
iwould like to hit the limiter at that speed!!!

SCARY

[Andy335Touring]

The dif ratio is 3.25

[M3Jimbo]

Can ya tell me if im right thinking fith has a ratio of 1.00
and was that the only diff ratio they did?

[Andy335Touring]

I think it is 1:1 fith ?

3.25 is the euro M3 dif ratio,the US didn't get the dog leg box so they got some thing like a 4.1 dif ratio ?

[Richy325iTouring]

Apperntly the more raked read window and higher boot level gives it
a lower co-eficient of drag(whatever that means)? and i think i heard
someone say that the touring where most aero dynamic????

My car has got some lairy shrick cams so it shold have power up there??

touring shape certainly helps while towing a caravan

[twincamman]

Had my 325i sport on the limiter in fifth on a few occasions. Pulled to the limiter no problem. Was reading 150mph on the speedo but was probably well off the actual speed.

[Wilson]

Had my 325i sport on the limiter in fifth on a few occasions. Pulled to the limiter no problem. Was reading 150mph on the speedo but was probably well off the actual speed.

My '88 325i se, was only doing 80 at 4000rpm and 95 at 5000rpm.... Is this right???? surely that means at 6000 i'll be doing 110mph and at 7 i'll be doing 125mph...

Actually that can't be right!!!!, I'll have to do it again.. and check!

[E30Mark]

At 80mph your doing 1000rpm = 20mph per 1000rpm.

Therefore at 7000rpm you will be doing 140mph...