FI vs stroker

[Northern]

For example, the N54 appears to be the "top dawg" of turbo BMW platforms - but seriously, the heads flow about the same as an 885 M20. All it really has going for it is a stout bottom end and lots of aftermarket support.

Don't forget GDI, huge difference for how much boost you can slam into it. M52 has the same 10.2:1 CR, but you don't see much more than 400~450whp on stock CR+pump gas.

[nando]

Yes, no. The N54 ports are shorter and are cast "as is", while the N52 ports are CNC'd like the S54. I was shocked when I looked up N54 flow charts - even ported, it flows about as well as a ported 885. It also has smaller valves.

[The Dark Side of Will]

For example, the N54 appears to be the "top dawg" of turbo BMW platforms - but seriously, the heads flow about the same as an 885 M20.

Didn't the N52 has a port design more like the S54 than the M54? Did BMW not apply that port design to the N54 as well?

[nando]

I think what Nisse is saying - an engine with a higher N/A VE, will make more power for the same given boost level than an engine with a lower N/A VE. And I agree with that. :)

For example, the N54 appears to be the "top dawg" of turbo BMW platforms - but seriously, the heads flow about the same as an 885 M20. All it really has going for it is a stout bottom end and lots of aftermarket support - but those guys think that 500whp is the shit (on stock turbos, at 20+ PSI), but people have been doing that on turbo builds (M20, M50, S38, whatever) for ages with way less boost.

[Nisse Järnet]

I disagree with this.
A properly built high output NA motor will use completely different parts than a properly built high output boosted motor.



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It doesn't have to be a high output turbo motor, a low boost turbo on a S54 for example will have better low end, power band and top HP than a stock S54. Just an example.

When you have a good NA motor, you just can't help to think how much better it would be with a turbo :D

[Wolfman]

This thread is about a street driven IX... Neither 10k rpm S14's nor 700hp boosted S54's apply.

I stated my opinion, you guys are welcome to yours.


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.......then you remind us that's not what this thread is about...

[Wolfman]

Yes, but find a dyno graph of a high output boosted s54. You won't find a single one in a race car driven on the track. Remember, torque wins races, not HP.

Especially on a street car, a useable power band is WAY better than having 700+ HP.

Driveability people!


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First you bring up 700 hp s54s.........

[ACVC325ix]

Love the physics lesson! I defer to ya'lls mechanically/engineering knowledge that clearly dwarfs mine, that's why I love this site!
To tie back to original thread topic; the power I'm looking for is reliable, usable, non-track power. IMO I enjoy the IX more when I am tearing up twisty country roads; AND maybe teaching the occasional high school kid with a Subaru STI a lesson every now and then lol.
This thread's convo has me bouncing slightly back to FI with <10lbs of boost....

[nando]

that whole line (which is BS) ignores the fact that HP is just (torque * distance * time). Basically, torque is the force - HP is how much work (acceleration) you can do with that force. You can't have HP without torque.. Torque is useless without the distance and time factors. It makes no sense!

[iXguido]

Remember, torque wins races, not HP.

If this were true every racecar would be diesel.

Sounds like someone lives their life a 1/4 mile at a time

The BMW powered F1 car of the 80's won the championship in 1983 with the 1.5l 1350hp turbo. Also, what about motorcycles?

[berlow94]

This thread is about a street driven IX... Neither 10k rpm S14's nor 700hp boosted S54's apply.

I stated my opinion, you guys are welcome to yours.


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[Wolfman]

Because it had a useable power band!


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So now a "useable" power band is 7k-10k and constant shifting to keep it there?

[The Dark Side of Will]

Remember, torque wins races, not HP.

LoL.

[berlow94]

If torque and not HP is the only way to win races please explain to me how the e30 M3 managed to become the most successful touring car of all times?

Because it had a useable power band!


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[Wolfman]

Yes, but find a dyno graph of a high output boosted s54. You won't find a single one in a race car driven on the track. Remember, torque wins races, not HP.

Especially on a street car, a useable power band is WAY better than having 700+ HP.

Driveability people!


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If torque and not HP is the only way to win races please explain to me how the e30 M3 managed to become the most successful touring car of all times?