RS4 & E90 M3

[replicat]

Ahh, I see. Well I thought that i'd add my input. Seeing as auto trannies new and old lose almost double the power train loss vs. manual, in most cars.

[JK42]

Not sure which cars you mean, but surely not BMWs. The automatic transmission on the E92 335i for example is the best that BMW has ever produced, with change times of 100 milliseconds it is close to the SMG boxes and only 0.2s less 0-62mph time than with the manual gearbox (and you have to be a really good driver with a manual to do that time, consistently.)

Best regards,

Jussi Attachment 15802

[Smoltz]

Originally Posted by JK42

Smoltz,

Actually they are not. In real life roto dynotests current BMWs lose between 4-8%. See www.rri.se. 130i loses 4% torque and 8% power, 335i Coupé loses 4% of torque and 6% of power. Hope this helps. (HTH.)

Best regards,

Jussi

I took a look at that website. Very interesting, lots of good information. However, with that being said. You're misinterpreting the data. Your statement is that the 335 has a drivetrain loss of 4% tq and 6% power. That is incorrect. On that website it is properly stated that 4% and 6% represent the discrepancy between stated engine performance and measured powertrain performance. The correct interpretation of the data is that the 335's hp & tq are underrated by BMW.

-Adam

edit: Here's what I'm talking about...

[Smoltz]

Originally Posted by replicat

Are we factoring in manual vs. auto trannies here? I think that smoltz' and Jussi's answers sound about right with the audis systems losing the power that it loses. I know that AWD/4WD vehicles lose an enormous amount of power and if thats also in an automatic car, thats even more power lost. I would guess that an auto awd audi would lose between 20-30% depending on the drivetrain. And a rwd manual bmw, losing less that 10% (HP)

Just my two cents.

My figures were both for manual transmissions.

-Adam

[replicat]

Well BMW always does everything better. But for the majority of cars (as I was refering to powertrain power loss and not speed) autos don't put nearly as much power to the ground as a manual.

-Pete

[JK42]

Originally Posted by Smoltz

I took a look at that website. Very interesting, lots of good information. However, with that being said. You're misinterpreting the data. Your statement is that the 335 has a drivetrain loss of 4% tq and 6% power. That is incorrect. On that website it is properly stated that 4% and 6% represent the discrepancy between stated engine performance and measured powertrain performance. The correct interpretation of the data is that the 335's hp & tq are underrated by BMW.

-Adam

edit: Here's what I'm talking about...

Sometimes it is, sometimes it's not. I've seen engine dynos of many BMW's, and they are not as over-powered as people usually think. The old 330Ci for example had 240hp instead of 231hp about 95% of the time, and about 305Nm instead of 300Nm on the engine. Seeing my own 130i on the dyno, it's engine had 272hp and 323Nm instead of the factory values of 265 hp and 315Nm, so the powertrain loss is still now very, very low.

This is because BMW has specifically stated that they have had huge success in decreasing the powertrain loss, and that RWD is the best technology to decrease it. BMW has added double-chain drives to the driveshaft on all N-series engines (such as N52B30) like they had on the S54B32 E46 M3 straight six, which is one of the biggest single areas of power loss of the whole transmission "chain". Also the driveshaft power distribution parts have been strenghtened with a totally new rear axle design beginning on the E90/E87.

Best regards,

Jussi

[Smoltz]

Originally Posted by JK42

Sometimes it is, sometimes it's not. I've seen engine dynos of many BMW's, and they are not as over-powered as people usually think. The old 330Ci for example had 240hp instead of 231hp about 95% of the time, and about 305Nm instead of 300Nm on the engine. Seeing my own 130i on the dyno, it's engine had 272hp and 323Nm instead of the factory values of 265 hp and 315Nm, so the powertrain loss is still now very, very low.

This is because BMW has specifically stated that they have had huge success in decreasing the powertrain loss, and that RWD is the best technology to decrease it. BMW has added double-chain drives to the driveshaft on all N-series engines (such as N52B30) like they had on the S54B32 E46 M3 straight six, which is one of the biggest single areas of power loss of the whole transmission "chain". Also the driveshaft power distribution parts have been strenghtened with a totally new rear axle design beginning on the E90/E87.

Best regards,

Jussi

It' interesting that you should bring up the E46 M3. Factory rated 333hp (here in the US). Most dyno around 275hp at the wheels. That's roughly 18% loss.

I'm not saying that the newer BMWs aren't more efficient or that they haven't made forward strides, but I can promise you that we pulled the engine out of your car and dynoed it. That you'd see more than 4% discrepancy between measured crank hp and measured whp using the same testing equipment.

-Adam

[JK42]

Yes,

There is more diffence, like I said, the engine had 272hp as standard and the rear wheels got 244hp. Before the ECU upgrade. The US E46 M3 engine is not a good example, since it was raped for emissions control reasons by plugging in catalysators straight into the engine and by few other tricks that were nasty for it's power. But remember you have to dyno the engine too before you compare it with what you have on the wheels before you can get the real difference. E46 M3 is over 8 years old design, and BMW has made giant leaps in improving the powertrain during those 8 years.

but I can promise you that we pulled the engine out of your car and dynoed it.

My god! You pulled the engine out of my car without my consent or knowledge. When did this happen?!?! How much did it show on your dyno?!

P.S. www.rri.se uses RON 95 octane fuel for all their tests, which definitely takes some power from the high-performance cars. I always run on Shell V-power which is 99+ octane fuel, improves hps of most cars and reduces fuel consumption signifcantly compared to 95E/98E fuels that are offered by other chains besides Shell. Shell sells this 99+ octane V-power all over Europe, and developed it with Ferrari.

Best regards,

Jussi

[meruyailir]

How much increase of hp using 99+ octane over 95? Approximately? I heard Shell is going to offer V-power next year here. I can't wait to try it out on my 325.

[Smoltz]

Originally Posted by JK42

Yes,

There is more diffence, like I said, the engine had 272hp as standard and the rear wheels got 244hp. Before the ECU upgrade. The US E46 M3 engine is not a good example, since it was raped for emissions control reasons by plugging in catalysators straight into the engine and by few other tricks that were nasty for it's power. But remember you have to dyno the engine too before you compare it with what you have on the wheels before you can get the real difference. E46 M3 is over 8 years old design, and BMW has made giant leaps in improving the powertrain during those 8 years.

The cat location defintely reduces power, but the car is rated for less here. Many US owners who are looking for performance move to Euro Headers, CSL Headers or an aftermarket setup.

That's been my claim since the get go, that you have to dyno both at the engine and at the wheels to determine drivetrain loss. Otherwise, you can't conclusively say if the drivetrain is highly efficient or of the engine is underrated.

Agreed. You cited design aspects in the E46 M3, so I was merely following your lead.

Originally Posted by JK42

My god! You pulled the engine out of my car without my consent or knowledge. When did this happen?!?! How much did it show on your dyno?!

LOL. Darn typos. There should be an 'If' in there. :-)



-Adam

[JK42]

Meruyailir:

Roto-dyno tests have shown that with the BMW N52B30 straight six V-power gasoline gives you an average of about ~+10hp and ~+10Nm compared to regular 98E RON fuels. Even higher if compared to 95E RON fuels, but those are not meant to be used in BMW's high-quality engines anyway, even though they can accept anything between 91 to 99+ RON and adjust themselves accordingly. You should always use a minimum of 98E on BMW's if better is not available.

Besides the added power, most BMW owners I know have noticed a marked decrease in consumption in highway driving, depending on the make and model of the BMW car and engine, anywhere between 5% to 13% less fuel consumption using the same average speed on the same route as with the compared 98E RON fuels.

Best regards,

Jussi

[cally_ive]

thx

[Paulb33]

I don't know how you can answer this question when the V8 M3 does not come out for another year. Here however is a video of the 2007 RS4 vs. the new M3 CS:

http://www.metacafe.com/watch/122116/2007_audi_rs4/

Here is what the experts at Top Gear have to say about the new RS4. They also talk about the RS4 vs the V8 M3 at the end of video 2:

Video 1:

Video 2:

I took delivery of the second RS4 in the US and have taken out many M3's and 911's. However I don't know how quick off the line the new V8 M3 will be, but I cant wait to find out!

[Seneca]

From an upcoming article comparing the RS4 and E46 M3 in Roundel magazine:

BMW Club Racing National Champion Ike Nielsen, who races an ex-works E36 M3 and has also owned and tracked an E46 M3, also took a turn in the RS4. “I really enjoyed driving it,” commented Nielsen. “It’s a lot nicer and more balanced than the E46 M3 I had. I had to put springs and track tires on my E46 M3 to get it to feel half as good. You really had to throw the E46 around to get it to move, but the RS4 just goes. I was hitting around 140mph on the back straight with the RS4 and the brakes were great. BMW really has their work cut out for them with the E92 M3.”

[replicat]

Yeah....about that. This is a brand new car compared to 7 year old technology. God would people stop comparing the new RS4 to the E46 M3...just wait till the E92 M3 comes out...I promise it will beat it in everyway possible. Interior, exterior, power, laptimes, you name it.

If not I will Paypal you US$100.

PS. RS4 = Old mans toy, too much saftey and no fun..(we'll fun that you get from the M3...RWD, lighter, etc..)

Just my two cents,

-Pete.

[Seneca]

Of course, you're right - and the age difference is stated in the article. But the M3 is still one of the best high-performance cars selling for under $75K on the market, so its still an interesting comparison. We also talked about what BMW needs to do with the E92 M3 to make it competitive with the RS4. NOT gaining any weight is on the top of the list.

[Romo]

Originally Posted by Seneca

Of course, you're right - and the age difference is stated in the article. But the M3 is still one of the best high-performance cars selling for under $75K on the market, so its still an interesting comparison. We also talked about what BMW needs to do with the E92 M3 to make it competitive with the RS4. NOT gaining any weight is on the top of the list.

Exactly..........................the weight will be the biggest issue................

[replicat]

Agreed, if the weight is kept down, (which it will) then it will be a slaughter. But even if it does weigh 3650lbs or more, it will still destroy the RS4, by a mile.

[Seneca]

Originally Posted by replicat

Agreed, if the weight is kept down, (which it will) then it will be a slaughter. But even if it does weigh 3650lbs or more, it will still destroy the RS4, by a mile.

Just curious, have you driven the RS4?