The new 335i vs. M3

[bimmerguy82]

Ok, so I went to the Seattle International Car show this weekend. Saw the new 335i and got to sit in it and look it over. I was talking to the BMW guy there and he had driven both the 335i and the E46 M3, and was saying that the 335i was only 1/10 sec behind the M3 on accel from 0-60. He was giving stats of the 335i and it has 300 ft.-lbs from 1400-5000 rpms a flat power band. Now my question is, if you have an M3 or whatever, how do you get that constant number of torque in a power band from 1400-5000 instead of peaking at like 6800 rpms? What kind of mods will do that? Because at this point the 335i will perform right up there close with the E46 M3.

[triggrhaapi]

You'd have to have boost my friend.

[bimmerguy82]

Originally Posted by triggrhaapi

You'd have to have boost my friend.

So Trigg, I know I would need boost, but my main point was being how to get the flat torque band and not a high rpm peak power. So your saying that just having boost will do that?

[thekid]

If I am understanding right, I really should go back and look at the stats for it but I'll just go off of memory instead. That is a fairly large engine compared to what we are used as far as it being stock and having a turbo. If they payed enough attention to the engine components, they could get it moving enough air (and the size of the turbo of course) to spool the turbo quickly (at lower rpms) meaning that it will get to full boost sooner than we are used to. As long as the exhaust and other considerations are not made just with full boost in mind you can still have good low end torque with a slight sacrifice to total hp. Typically a car with boost will have less torque and a hp band that just takes off after a few thousand rpms and the turbo spools. If the turbo spools low enough then you can get a much more linear delivery of power and better torque if you bother trying to tune it that way.

[bimmerguy82]

Originally Posted by thekid

If I am understanding right, I really should go back and look at the stats for it but I'll just go off of memory instead. That is a fairly large engine compared to what we are used as far as it being stock and having a turbo. If they payed enough attention to the engine components, they could get it moving enough air (and the size of the turbo of course) to spool the turbo quickly (at lower rpms) meaning that it will get to full boost sooner than we are used to. As long as the exhaust and other considerations are not made just with full boost in mind you can still have good low end torque with a slight sacrifice to total hp. Typically a car with boost will have less torque and a hp band that just takes off after a few thousand rpms and the turbo spools. If the turbo spools low enough then you can get a much more linear delivery of power and better torque if you bother trying to tune it that way.

So Kid, what you are saying is that with a larger displacement motor, moving a good amount of air, with a boosted setup you can get that linear power band at a sacrifce to total hp and torqe numbers?

[bimmerguy82]

anyone?

[CRTampa335i]

It's more the direct injection than the boost. Direct injection allows for the combustion process to be performed quicker and faster, thus creating a more efficient engine. Audi, VW and now GM have taken this not so new technology and have created some amazing numbers with direct injection. One common result of direct injection is the flat torque band. When boost is added to speed up the combustion process thru forced induction, you get the torque band at an even lower rpm and increased pounds of torque throughout. In addition, the process(direct injection) with or without boost provides better gas mileage. GM claims their Solstice GXP will generate 260/260 from a 2.0 direct inject single dual scroll turbo motor, while getting 22-32 mpg. That's more HP and torque than a 1989 corvette. The reason we are just now seeing direct injection on the seen, is that now engineers can control the extreme internal pressures and temperatures that direct injection brings. Now let me tell you, my new 335i sedan rocks. The torque band is present just has they claim. Pulls harder than my 1998 540i. I have v8 power, v8 torque and gas mileage of a standard inline 6. With 500 miles on the car, I'm getting just over 20mpg (a lot of city driving). It just don't get any better than that!!!!!

[ewohar]

I think the turbo on the 335i kicks in at about 1600 rpm, on a lot of other turbo cars, the turbo doesn't kick in until about 2400 or higher rpm.

[zisco]

i dont think that a good turbo kicks in about 1600rpm, it can also kit about 3200rpm

[94BMW325i]

It depends on the car, there are plenty of turbo vehicles out there nowadays that barely have any lag, and "kick in" at low rpm's.

[drz]

Holy thread bumpage