max rpm ?

[sudds]

Hi all, first of all its a true pleasure to be in this forum hope you can answer some questions for me as im a new bimmer owner i just bought a 03 z4 2.5 and was wondering what the safe max rpm range is when shifting ? and what the heck is a buisness cd player ? does it do some kind of buisness im not aware of ?
ummm also need a name for my car, its a girl !!!!!!

 

[vlad]

Your tach should have a red line or area on the dial, you should shift before you go into the red area. Also, there should be a limiter that rather bumps, (sorta feels like the engine stalls for a sec.) when redline/max rpm is reached.

Tha business cd player is just a name that BMW came up with for the player. I believe that there was another early player that didn't have all of the features of the business cd, can't remember the name of it tho.

 

[Bryan330i]

Thanks Vlad. I was also interested in the "Business" CD, I was not sure what I ended up with for a CD. I thought that I must have just gotten their cheap one.

 

[PuShAkOv]

Say.. how safe would you think always shifting at 4K-5K RPM is for the engine?

 

[mikev]

as long as you have gone through the run in period then shift at the DAMN redliine just (and i mean tenths) other wise :

(a) you wont use all the power available
(b) you wont be at a high enough RPM when you shift to give you decent acceleration.

i know im being a little strong here but. i sick and tired of people on this damn forum saying blah blah ultimate driving machine then telling other people not to shift at the limit. come on people the fun only starts at 4000 in mine. if you want to track or get any sort of acceleration then listen to me. I know that some people like to cruise but you have to push it to the max otherwise sell the Bimmer and by a F***ing civic with an M3 body kit.

 

[brahtw8]

as long as you have gone through the run in period then shift at the DAMN redliine just (and i mean tenths) other wise :

(a) you wont use all the power available
(b) you wont be at a high enough RPM when you shift to give you decent acceleration.

i know im being a little strong here but. i sick and tired of people on this damn forum saying blah blah ultimate driving machine then telling other people not to shift at the limit. come on people the fun only starts at 4000 in mine. if you want to track or get any sort of acceleration then listen to me. I know that some people like to cruise but you have to push it to the max otherwise sell the Bimmer and by a F***ing civic with an M3 body kit.

I understand what you are saying, and I hit fuel cut-off in both of my cars on a regular basis.

However . . .

In most cases, shifting at the absolute redline will not give you the best acceleration. You want to shift at the RPM that gives you the greatest amount of the powerband. There are two considerations, the gear you are currently in and the gear you are shifting into. Most engines reach peak power before redline, and then the power starts to drop off. You want to use up the most power in the current gear, and then shift at a point that puts you into the powerband in the new gear. This will actually vary from gear to gear, as the ratio of each gear is different .

I figured it out once for my 325i. The redline on that car is 7000 rpm with the chip. The 1-2 shift should be made at 6500, and that rpm level drops a few hundred rpm with each successive shift. If you shift the car at redline, you miss out on a few hundred rpm of the powerband in the higher gear, and you aren't getting that much in the last few hundred rpms of the lower gear. You need to figure out where the powerband starts, in my car that is 4000 rpm, and shift at the spot that puts you at 4000 rpm in the higher gear.

If you can find a graph of the torque curve, you should be able to eyeball it. Otherwise you'll have to do some calculus.

As long as you let the engine warm up, you shouldn't do any damage to the engine revving it through the entire powerband. If you never revved the engine past 5000 rpm, it might last a little longer, but we are talking about the difference between getting 300k miles on an engine and 350k, so it matters not to me.

 

[mikev]

well said

 

[Wadula]

yup, that ia what i always said. hitting her hard (given the right treatment of course) does no harm. though, hitting her hard at each and every light every day kills her sooner and not later. doing it two or three times and not as the regular behaviour is just fine. the enigines are build to stand much higher revs that the limiter lets you go to. it is a security feature to enhance the lifetime of the engine. racing the car now and then is just what the car is build for anyway!

 

[Bryan330i]

I figured it out once for my 325i. The redline on that car is 7000 rpm with the chip.
[brahtw8]



So I have a question. To say that I am not a mechanic type person with that level of knowledge would be a big understatement. But how can you get such a large increase in red line from a chip? I thought that you would need to make engine modifications because the red line was the physical max the engine could withstand. Mine is 6800 a little more than the standard 330i, and I thought that was because of physical engine differences such as the cam and so on. Could I chip mine and then run the engine past the 6800 red line? Without damaging the engine? Just curious.

 

[vlad]

The chip alters what the computer engine management tells the engine to do. The engine alone would rev way past 7000 RPM, although that is not safe for things such as bearings and valves.

 

[brahtw8]

I figured it out once for my 325i. The redline on that car is 7000 rpm with the chip.
[brahtw8]



So I have a question. To say that I am not a mechanic type person with that level of knowledge would be a big understatement. But how can you get such a large increase in red line from a chip? I thought that you would need to make engine modifications because the red line was the physical max the engine could withstand. Mine is 6800 a little more than the standard 330i, and I thought that was because of physical engine differences such as the cam and so on. Could I chip mine and then run the engine past the 6800 red line? Without damaging the engine? Just curious.

I don't know if Dinan or others offer a software upgrade for the 330i PP. They probably will in the future, but it may or may not include an increase in the rev limiter. It would eliminate the top speed governor.

With no fuel cut-off, you could rev your engine until it blew up. At what rpm that happens depends on the kind of engine and the shape its in. If I were to hazard a guess, I would expect my 325i would blow up at 8500 rpm, but start to do damage at 7300-7500 or so. (Pure speculation on my part).

On a BMW, your greatest chance of doing that is on a downshift, as the transmission will let you into a lower gear without regard to what speed you are going. The typical 'money shift' is from 5th to 2nd, and will blow your engine if you shift into 2nd by mistake when you are doing 80 mph (in my car 2nd is good for about 63 mph at 7000 rpm).

The factory settings can be somewhat conservative. They make certain compromises in the name of fuel economy, emissions, longevity, etc. I would expect the 330i PP to be in a slightly higher state of tune from the factory, with less room for improvement, than a standard 330i.

1995 and older BMWs came with OBD I emissions and have much more flexibility in the aftermarket as a result. Since OBD II came out, software upgrades (instead of chips) don't provide the kind of gains that chips used to (for the most part, with some notable exceptions, turbocharged cars for one).

 

[Abdoman]

I read an article awhile back about the Porsche 911 turbo. The article stated that the tach actually lagged the engine in first gear. Is that common on sports cars/BMWs?

 

[brahtw8]

I read an article awhile back about the Porsche 911 turbo. The article stated that the tach actually lagged the engine in first gear. Is that common on sports cars/BMWs?

Do you mean that the tach can't keep up with how quickly the rpms are rising? I had not heard of that before.

 

[Abdoman]

Yes, that's what the article was discussing. It said that the tach lagged the engine by 200 rpm and you should shift earlier than expected (by 200 rpm).