F30 320i vs 328i engines - Part number comparison

Originally Posted by namelessman

Is HP = torque x rpm? Since the torque specs on both are similar(at least for 8AT), so maybe the difference is to taper the engine rev on 320i N20 at 5000rpm to throttle at 181hp, but allows 328i N20 to keep pushing to 6000rpm and 240hp. I guess we would see dyno charts soon enough on this. For now, 328i does appear to be a $2k-3k(expensive) factory tune versus 320i.

As tim330i noted, the bmwusa data can be incorrect too, or else it would really be odd that 320i N20 MT only get 184 lb-ft@1250-4500rpm ....

Yeah, so much for being excited for my car to arrive. For me, the whole point in getting a 328 was its unrealized power. Now it seems the goal post has moved.

Originally Posted by tim330i

I have feeling the data on BMWUSA.com is wrong.

+1

Taking a look at the UK 320i engine specs, this is what I would expect:

Engine Cylinders/valves 4/4

Capacity (cc) 1997

Stroke/Bore (mm) 90.1/84.0
Stroke/Bore (inch) 3.50/3.30

Max output (kW/hp/rpm) 135 (184)/5000

Max torque (Nm/rpm) 270/1250-4500 (270Nm = ~200lb-ft)

Compression ratio : 11.0:1

Originally Posted by Ronin951

Yeah, so much for being excited for my car to arrive. For me, the whole point in getting a 328 was its unrealized power. Now it seems the goal post has moved.

Not really an expert on this, but I would think as long as newly built 328i still has the same N20 engine part number, it probably still has unrealized power to unleash(same as 2012 built ones). If the numbers are correct, the observation would be that BMW AG simply dial down the same US-spec N20 performance further for 320i. It would be a very smart move(no new parts, incremental emission qualification, just-in-time shift of production slots from troubled Europe to US/Asia, etc, etc). It is just that 320i owners would have even more headroom for unrealized power than 328i, given nearly all engine parts are identical as OP stated(even brakes are same part# in realoem).

What is unclear now is how to get the 120-lb weight reduction. Does the factory take out all the noise-insulation material to save weight and 320i is noisy as hell?

Originally Posted by namelessman

What is unclear now is how to get the 120-lb weight reduction. Does the factory take out all the noise-insulation material to save weight and 320i is noisy as hell?

No:

electric seats
rear fold-downs

Different:

Exhaust
Drive and axle shafts
Tranny

Here and there you could probably pick away 120-lb

Originally Posted by Ronin951

No:

electric seats
rear fold-downs

Different:

Exhaust
Drive and axle shafts
Tranny

Here and there you could probably pick away 120-lb

You could probably take away 100 lb from changing seats alone.

Originally Posted by Ronin951

No:
electric seats
rear fold-downs
Different:
Exhaust
Drive and axle shafts
Tranny
Here and there you could probably pick away 120-lb

That makes sense, $2-3k for a ECU tune plus additional beefed up drive+output shafts and such from the factory(with OEM warranty) is not bad.

its a different transmission?

Originally Posted by namelessman

That makes sense, $2-3k for a ECU tune plus additional beefed up drive+output shafts and such from the factory(with OEM warranty) is not bad.

So far the best ecu tunes for the n20 are below $500.

Originally Posted by justinnum1

its a different transmission?

From realoem the AT/MT replacement part numbers are different, can it be just different fitment into the engine bays, or different HP ratings do require reinforced components on the high HP engines?

(copy-paste data disclaimer )
rear axle output shafts -- 320i: 28mm; 328i: 31mm; 335i: 35mm
drive shafts for AT -- 320i: 1563mm; 328i: 1539mm; 335i:1508.5mm

335i AT:
Rmfd automatic transmission EH GA8HP45Z 1 09/2012 24008601194
328i AT:
Rmfd automatic transmission EH GA8HP45Z 1 09/2012 24008609706
320i AT:
Rmfd automatic transmission EH GA8HP45Z 1 09/2012 24008609707

335i MT:
Rmfd-6 speed gearbox GS6-45BZ - THY8 1 23007617492
328i MT:
Rmfd-6 speed gearbox GS6-17BG - TAU0 1 23007633990
328i MT:
Rmfd-6 speed gearbox GS6-17BG - TAY9 1 23007633989

Originally Posted by namelessman

From realoem the AT/MT replacement part numbers are different, can it be just different fitment into the engine bays, or different HP ratings do require reinforced components on the high HP engines?

(copy-paste data disclaimer )
rear axle output shafts -- 320i: 28mm; 328i: 31mm; 335i: 35mm
drive shafts for AT -- 320i: 1563mm; 328i: 1539mm; 335i:1508.5mm

335i AT:
Rmfd automatic transmission EH GA8HP45Z 1 09/2012 24008601194
328i AT:
Rmfd automatic transmission EH GA8HP45Z 1 09/2012 24008609706
320i AT:
Rmfd automatic transmission EH GA8HP45Z 1 09/2012 24008609707

335i MT:
Rmfd-6 speed gearbox GS6-45BZ - THY8 1 23007617492
328i MT:
Rmfd-6 speed gearbox GS6-17BG - TAU0 1 23007633990
328i MT:
Rmfd-6 speed gearbox GS6-17BG - TAY9 1 23007633989

the 335 and 328 share the same auto and the numbers are different on what you postes...

Originally Posted by justinnum1

the 335 and 328 share the same auto and the numbers are different on what you postes...

The numbers are the ones for 10/2012 production month(or from 9/2012?), it does look like different production months have different PN#s(e.g. 2/2012). This is complicated stuff.

Originally Posted by Jamesonsviggen

So far the best ecu tunes for the n20 are below $500.

I talked with one of the piggyback vendors about the impact of 11:1. Response was there will be lower boost with "similar" power compared to the 10:1's. Pretty much as expected.

Originally Posted by Ronin951

Are we sure it's 10:1. Here's the difference in the short block description
328i
Short Engine N20B20A 1 11002297079
only in conjunction with
320i
For vehicles with
Low compression engine
S858A=Yes <== what is this?
01 Short Engine N20B20A 1 11002297079

Some discussions on other forums mentioned that 320i in other countries can come with a low compression option S858A and 10:1 and same 7079 part# as above, or without option S8585A and 11:1(and a different engine part #). One possibility is that the bmwusa data sheets are correct, and US spec 320i N20 is with S8585A option.

Originally Posted by Ronin951

I talked with one of the piggyback vendors about the impact of 11:1. Response was there will be lower boost with "similar" power compared to the 10:1's. Pretty much as expected.

So does it mean piggyback solutions can do 240HP-ish, but not 300HP? I wonder how well the piggyback ones "compliment" the factory ECU, if the ECU does not like the modified readings, would it throw a fault code or CEL?

Anyone have the 0-60 time on the 320?

Sorry just saw the answer in the other thread.

Originally Posted by namelessman

So does it mean piggyback solutions can do 240HP-ish, but not 300HP? I wonder how well the piggyback ones "compliment" the factory ECU, if the ECU does not like the modified readings, would it throw a fault code or CEL?

My question was specifically 10:1 vs 11:1 on a 328 and I was told the gains would be similar and that there were 320 specific settings, which presumably just lowers boost. There is a different P/N for the exhaust on a 320, so an 11:1 328 vs 320 would probably have different dyno results. How much different I can only speculate.

I can't speak to CEL's, etc. That's probably better asked in a separate thread. I will say if the 2013+ 328's do have a different CR, the vendors will probably have to start asking customers the MY of their 328's.

I can 100% confirm that the compression ratio on the F30 320i is 10:1. That is the same 10:1 that the 328i has.

Tim

Originally Posted by tim330i

I can 100% confirm that the compression ratio on the F30 320i is 10:1. That is the same 10:1 that the 328i has.

Tim

Compression measured?

Originally Posted by Ronin951

Compression measured?

No, direct from BMW NA.

Tim

Sweet!

^

Any updates on the engine comparisons?

Originally Posted by namelessman

Any updates on the engine comparisons?

What other info are you looking for?

Tim

Originally Posted by tim330i

I can 100% confirm that the compression ratio on the F30 320i is 10:1. That is the same 10:1 that the 328i has.

Tim

Interesting I was told the 320 was 11:1 rather than 10:1. I've yet to see one at the office but we've tuned a few remotely using the Stage1.

N20 Stage2 tune development is underway now.

Originally Posted by Terry @ BMS

Interesting I was told the 320 was 11:1 rather than 10:1. I've yet to see one at the office but we've tuned a few remotely using the Stage1.

N20 Stage2 tune development is underway now.

There was a lot of conflicting reports. That's why I confirmed it directly with my contacts.

Tim