Max speed on gears 325i, 325Xi, 330i, 330Xi

[iradek]

Does anyone know what is the maximum speed on 1st, 2nd, 3rd and 4th gear in 325i, 325Xi, 330i, 330Xi?

Thanks
Radek

[marti5]

Quite simple really BMW's have a rev limiter, so once you reach the top revs for that gear, which is a very very bad thing to do it will sort of cut in cut out until you change up.

If you require the exact speeds for each model...search google for owners manuals on each, in the technical data it will specify the speeds per gear ratio.

[iradek]

That's the problem, they don't say it in the owners manual, only top speed. I tried to google it with no luck.
Thanks

[witeshark]

If you can find the gear ratios (and final drive), a calculation utility like this one can answer your question. Again as marti5 stated, running to top speed in each gear is not the best idea.

[Technikzauberer]

Might need tranny and diff ratios for each model:
BMW E46 Differential Info

[iradek]

The reason Im asking this is because I've just bought 325Xi 2002y, manual transmission and on every gear car goes slower than it should.
On 3rd gear the max speed is about 120km/h (75mph), on 5th gear 210km/h (130mph). It should be 150km/h(90mph) and 240km/h (150mph) respectively.

Does anyone know whether it's the gearbox, transmission box or the diffs?

Thanks for your help

[Technikzauberer]

Originally Posted by iradek

On 3rd gear the max speed is about 120km/h (75mph), on 5th gear 210km/h (130mph). It should be 150km/h(90mph) and 240km/h (150mph) respectively.

Does anyone know whether it's the gearbox, transmission box or the diffs?

Is that indicated speed [speedo]? @ what RPM? BMW E46 transmissions are are nearly identical in gearing. Diff has the largest impact to speed vs. engine RPM. Wheel size has largest impact to indicated vs. actual.

[iradek]

It's indicated speed at around 6000 rpm. Wheels are 225/45/17 front and 245/40/17 back.

[Technikzauberer]

Well those speeds don't look like they match for the stock 3.23 ratio's...more like a 3.46. Had someone swapped in rear diff and front final with 3.46's from and automatic? Not that it is a bad thing, for you will get a bit more accel/torque transfer to the ground. Common mod for E46 (like from 3.07 to 3.46) but a bit more tough and not so common on an 'x'.

BTW, have 3.46 in daily driver with 245/45-17's all around and yes, top speed is less (although limiter has been raised) yet get to speed quite a bit quicker.

[iradek]

I think you're right. Someone must've swapped diffs. I've already managed to buy second hand front today on ebay but there I can't find rear 3.23 diff for 325Xi.
Do you know if 3.23 diff from RWD cars (323, 325, some 316 and 318 here in Europe) would fit 325Xi?

[Technikzauberer]

yes they should...may have to pay attention to the input flanges though (4 bolt vs. 6 bolt, etc.).