[combivan]

this is the weight differences.
Piston:
320i - 0.482 kg
328i - 0.470 kg

Rear Muffler
320i - 10.500 kg
328i - 12.610 kg

Automatic Transmission
320i - 78257.960 kg (prob typo and should be 78kg)
328i - 80642.460 kg (prob typo and should be 80kg)

Drive Shaft Automatic
320i - 8.975 kg
328i - 12.500 kg

Front Pipe & center muffler
320i - 2.290 kg + 3.600 kg
328i - 2.961 kg + 4.500 kg

Intercooler
320i - 2.930 kg
328i - 4.100 kg

[rjd_F30]

Originally Posted by combivan

I only said it was 30% heavier. If you click on each part then you can see the weight of each part

Never knew you could click on the PN for weight

And yah you did say heavier my bad. But I would think that's more or less synonymous with bigger... unless the 328i FMIC is denser, which I'd doubt. I have no reason to doubt because realoem doesn't really get things wrong, but I guess I'm surprised. Almost 2 years of keeping up with this subforum and this is the first I've heard of this.

[kobluna]

Interesting what differences there is for transmission as they are both rated for 450 Nm and similar transmission is used even for 335i. Maybe just different torgue converter or is that separate part and has different part number?

[CntryClub007]

Originally Posted by kobluna

Interesting what differences there is for transmission as they are both rated for 450 Nm and similar transmission is used even for 335i. Maybe just different torgue converter or is that separate part and has different part number?

I was also surprised with the weight difference on the transmission, I thought they were the same.

[kobluna]

Originally Posted by CntryClub007

I was also surprised with the weight difference on the transmission, I thought they were the same.

What is even more interesting is that RealOEM is listing multiple different part numbers for transmission. It seems like there has been multiple changes for the transmission along the productuction. Anyway there is exchange transmission for both with different part number but same listed weight of 79kg.

http://www.realoem.com/bmw/enUS/part...&q=24008601703 For 320i

http://www.realoem.com/bmw/enUS/part...&q=24008627132 For 328i

So hard to say if there really is any difference between transmission. Although they do have different part numbers

[rjd_F30]

Originally Posted by kobluna

What is even more interesting is that RealOEM is listing multiple different part numbers for transmission. It seems like there has been multiple changes for the transmission along the productuction. Anyway there is exchange transmission for both with different part number but same listed weight of 79kg.

http://www.realoem.com/bmw/enUS/part...&q=24008601703 For 320i

http://www.realoem.com/bmw/enUS/part...&q=24008627132 For 328i

So hard to say if there really is any difference between transmission. Although they do have different part numbers

I highly, highly doubt they're any different, though I can't explain why they use different part numbers.

[combivan]

Originally Posted by kobluna

What is even more interesting is that RealOEM is listing multiple different part numbers for transmission. It seems like there has been multiple changes for the transmission along the productuction. Anyway there is exchange transmission for both with different part number but same listed weight of 79kg.

http://www.realoem.com/bmw/enUS/part...&q=24008601703 For 320i

http://www.realoem.com/bmw/enUS/part...&q=24008627132 For 328i

So hard to say if there really is any difference between transmission. Although they do have different part numbers

Looks like theres identical weights for 2014 transmissions but f30 in 2012 has different weights for transmissions.

[Nomana]

Originally Posted by combivan

this is the weight differences.
Piston:
320i - 0.482 kg
328i - 0.470 kg

Rear Muffler
320i - 10.500 kg
328i - 12.610 kg

Automatic Transmission
320i - 78257.960 kg
328i - 80642.460 kg

Drive Shaft Automatic
320i - 8.975 kg
328i - 12.500 kg

Front Pipe & center muffler
320i - 2.290 kg + 3.600 kg
328i - 2.961 kg + 4.500 kg

Intercooler
320i - 2.930 kg
328i - 4.100 kg

Automatic Transmission
320i - 78257.960 kg
328i - 80642.460 kg


This is 80 tons

[rjd_F30]

Originally Posted by Nomana

Automatic Transmission
320i - 78257.960 kg
328i - 80642.460 kg


This is 80 tons

Yah I'm not quite buying the weight difference thing.

[nggrey]

Hey everyone, new to the forum, not a new owner.
I have a 2016 320i with a bms stage 1 piggyback tune. It's nice, made me fall in love with the car, but my ultimate goal with it is to hit 250 hp at minimum. I noticed a lot of discussion about the differences between the 320i and 328i, which seems to be mainly the compression ratios due to the pistons. Would it be too optimistic to change pistons in my 320i to achieve a better compression ratio? I'm not too knowledgeable with this aspect of cars, so I apologize if this is a dumb question.
Thanks!

[rjd_F30]

Originally Posted by nggrey

Hey everyone, new to the forum, not a new owner.
I have a 2016 320i with a bms stage 1 piggyback tune. It's nice, made me fall in love with the car, but my ultimate goal with it is to hit 250 hp at minimum. I noticed a lot of discussion about the differences between the 320i and 328i, which seems to be mainly the compression ratios due to the pistons. Would it be too optimistic to change pistons in my 320i to achieve a better compression ratio? I'm not too knowledgeable with this aspect of cars, so I apologize if this is a dumb question.
Thanks!

I'm sure it can be done, but it will not be very cost efficient. You're better off getting a flash tune, catless downpipe and upgraded intercooler to get closer to that number than you are getting different pistons.

[CandyRedRC46]

Originally Posted by nggrey

Hey everyone, new to the forum, not a new owner.
I have a 2016 320i with a bms stage 1 piggyback tune. It's nice, made me fall in love with the car, but my ultimate goal with it is to hit 250 hp at minimum. I noticed a lot of discussion about the differences between the 320i and 328i, which seems to be mainly the compression ratios due to the pistons. Would it be too optimistic to change pistons in my 320i to achieve a better compression ratio? I'm not too knowledgeable with this aspect of cars, so I apologize if this is a dumb question.
Thanks!

Changing pistons is a very very big job and realistically isn't happening.
But if I were you I would:
Upgrade intercooler
Upgrade charge pipes
Catless down pipe
Install full 3" cat back
Then stage 2 bm3 flash

[nggrey]

Originally Posted by CandyRedRC46

Changing pistons is a very very big job and realistically isn't happening.
But if I were you I would:
Upgrade intercooler
Upgrade charge pipes
Catless down pipe
Install full 3" cat back
Then stage 2 bm3 flash

How reliable would that setup be? I'm not very familiar with the emissions info around me (nyc), so I'm not certain that catless would work for me. I'm not too concerned about maintenance costs, I'm sure they're not that bad even with the extra push. Just wanna know if there would be something I should be aware of when getting these upgrades.

[CandyRedRC46]

I would think that it would be very reliable, but I am in Florida with zero emissions laws and I am not sure how that would work in New York. You would probably have to hold on to your stock down pipe and reinstall it every year or so, if they have testing up there. Or if that isn't for you, you could fork out some $$$$ for a catted high flow down pipe, which may pass.

[nggrey]

Originally Posted by CandyRedRC46

I would think that it would be very reliable, but I am in Florida with zero emissions laws and I am not sure how that would work in New York. You would probably have to hold on to your stock down pipe and reinstall it every year or so, if they have testing up there. Or if that isn't for you, you could fork out some $$$$ for a catted high flow down pipe, which may pass.

Just found out nyc passed a law that uses California's laws specifically for catalytic converters. fml

[F30VADOS]

Hey guys quick question, I've been trying to find this and no luck. I'm trying to shoot the gun and finally buy my catless DP from vrsf or that's the brand at least. It's only has the one option n20 downpipe. The 328 and 320 share the same motor but not the same piping. So my question is will this fit or will I have to change my midpipe aswell?

[rjd_F30]

Originally Posted by F30VADOS

Hey guys quick question, I've been trying to find this and no luck. I'm trying to shoot the gun and finally buy my catless DP from vrsf or that's the brand at least. It's only has the one option n20 downpipe. The 328 and 320 share the same motor but not the same piping. So my question is will this fit or will I have to change my midpipe aswell?

Downpipe is the same between the 320i and 328i. I do recall hearing that the mid pipe is smaller on the 320i than the 328i, but I'm not sure about that. I do know for certain that the downpipes are the same, at least according to realoem.com

[F30VADOS]

Originally Posted by rjdnyy224

Downpipe is the same between the 320i and 328i. I do recall hearing that the mid pipe is smaller on the 320i than the 328i, but I'm not sure about that. I do know for certain that the downpipes are the same, at least according to realoem.com

I kinda new that myself I just needed someone else to reconfirm it for me lol. Thanks

[CandyRedRC46]

328i has 75mm mid pipe
320i has 65mm mid pipe

I definitely wouldnt go stage 2 without the factory 320i 65mm piping upgraded to 75mm.

[F30VADOS]

Originally Posted by CandyRedRC46

328i has 75mm mid pipe
320i has 65mm mid pipe

I definitely wouldnt go stage 2 without the factory 320i 65mm piping upgraded to 75mm.

Why not? Even with upgrades fmic and dp?

[rjd_F30]

Originally Posted by F30VADOS

Why not? Even with upgrades fmic and dp?

Oh boy, don't get him started

Not to speak for him, but here's my take. Some believe in the merits of a freer flowing exhaust more than others. It is my personal opinion that there are little realizable gains to be had by widening/opening up the exhaust on these cars (other than getting rid of the cat). I think the stock exhaust flows just fine once the cat is gone. However, the aftermarket standard is bigger = better, so a bigger exhaust pipe, whether it be the mid pipe or whatever, should make more power. I don't think it would really make a difference on an engine like ours that doesn't really produce all that much exhaust by volume, but others disagree. It's a different story on bigger engines that flow more gas, those types of cars benefit from a bigger exhaust.

There are reasonable arguments on both sides of the coin. There is not, however, any dyno data to back up either side lol

[kobluna]

Originally Posted by rjdnyy224

Oh boy, don't get him started

Not to speak for him, but here's my take. Some believe in the merits of a freer flowing exhaust more than others. It is my personal opinion that there are little realizable gains to be had by widening/opening up the exhaust on these cars (other than getting rid of the cat). I think the stock exhaust flows just fine once the cat is gone. However, the aftermarket standard is bigger = better, so a bigger exhaust pipe, whether it be the mid pipe or whatever, should make more power. I don't think it would really make a difference on an engine like ours that doesn't really produce all that much exhaust by volume, but others disagree. It's a different story on bigger engines that flow more gas, those types of cars benefit from a bigger exhaust.

There are reasonable arguments on both sides of the coin. There is not, however, any dyno data to back up either side lol

I guess the reasoning being that because 328i has larger diameter midpipe, tuned 320i would need it as well. I'm not sure if it's really needed though as 65mm is not that narrow for 2 liter 4 banger either. And there is as well that 58mm narrower part at the end of DP which has also caused some debate if it matters or not.

Dyno results would be great but there are not too much results of stage 2 anyway from 320i. Actually I have not found any. But I know that some tuners claims to get 280hp out of stock 320i. I mean besides software mods.
https://en.bsr.se/tuning-kits/t/3015...20-b-n20-b20-d

However, I would not believe those claims nor would want to test how long engine would last if the tune really pushes that amount of power without upgraded DP and FMIC.