F30 320i vs f30 328i

R

Rolf

Guest
Any argument on that matter is nil and void as acssa has set his own goal posts by talking racing engines and racing fuel :blab:

end of story....
 

Julz

Member
To run boost on a high compression engine is highly impractical.First of all you run the risk of some serious detonation and secondly you are doomed to always running Methanol or high Octane fuel which doesn't make it a Street friendly setup.I agree that high compression will spool up the turbo quicker but it still makes more sense to match the right Turbo to a low compression setup for maximum boost.
The only reason they would run higher compression on the 320 is to limit its tuning potential.Not everybody is happy running high Octane fuel or Methanol on their daily drive.
 

acssa

New member
The 2JZ engines are port injection... direct injection is a hole new story. It also depend on the piston material that is used. Cast of forged.

The 2l N20 engine according to bmw is the 335 engine with 2 cyl chopped off... small differences. They usually get pistons supplied from Mahle(forged). I hope to get hand on a crashed 328 so we can check and play a bit... and then we will do the same on the 320 engine.

I heared that some piggy back company is looking into adding a flexfuel sensor to its box, so when you add ethanol to fueltank it will do automatic AFR compensation while increasing boost.

Methanol injection is also used by some to increase boost but its a pain to maintain.



Rommies said:
the lower the compression ratio = the more you can boost.

Lets take my car for example:
"The 2JZGE (N/A) is about 9.6:1 as compared to the 2JZGTE (Twin Turbo) at 8.5:1. The 2JZGE can run a turbo, but you won't be able to run as much boost because of the higher CR (compression ratio) pistons. Your effictive CR will climb faster. With about 9psi boost an 8.5:1 engine will have an effective CR of about 13.7:1 and a 9.6:1 motor will have an effective CR of about 15.5:1. In terms of how the engine will respond the higher compression NA motor will not like more boost. The NA motor will however make better low end TQ. Which in the real world of daily drivers is preferable to a laggy boosted to hell dyno queen"

So lets say for arguments sake:
F30 320i (11:1 CR) internals can handle 1 BAR of boost will make more power than a F30 328i (10:1 CR) boosted at one 1 BAR, BUT the 328i (10:1 CR) would be able to be boost 1.2 BAR where the 320i (11:1 CR) would not be able too. Because the compression ratio of the 320i is already too high and cannot handle anymore boost.

So in the end the F30 328i has more potential tuning than the F30 320i
Am I correct or am I talking shit?


no goal... my 320 stays stock as a daily drive and it has more than enough power for a JHB traffic. Weekends is for the toys to play with...

I am just adding some info to explain principles.



Rolf@PromotecAuto said:
Any argument on that matter is nil and void as acssa has set his own goal posts by talking racing engines and racing fuel :blab:

end of story....


As I mentioned before... first 8:1 was the rule on a turbo. Then came new ecu's with knock sensors and 8.5-9:1 became common. Then came direct injection so we can run 10-11:1.

Times and technologies change.

Julz said:
To run boost on a high compression engine is highly impractical.First of all you run the risk of some serious detonation and secondly you are doomed to always running Methanol or high Octane fuel which doesn't make it a Street friendly setup.I agree that high compression will spool up the turbo quicker but it still makes more sense to match the right Turbo to a low compression setup for maximum boost.
The only reason they would run higher compression on the 320 is to limit its tuning potential.Not everybody is happy running high Octane fuel or Methanol on their daily drive.
 
R

Rolf

Guest
We are still not discussing things on the original subject.

Standard production vehicles do not have water / meth injections and playing with piggyback system on fuel on the F30 320i might give you some gains but I can promise you that your economy will go down the drain :thumbdo:
 

acssa

New member
I agree 100%... if you want more horses you need to feed more horses.

On the circuit running ethanol fuel mix we get 1.5km/L on a 2L engine.

Rolf@PromotecAuto said:
We are still not discussing things on the original subject.

Standard production vehicles do not have water / meth injections and playing with piggyback system on fuel on the F30 320i might give you some gains but I can promise you that your economy will go down the drain :thumbdo:
 

A B

///Member
Quite an interesting topic.

Been to a dealer over the weekend to look at the F30 328i and this idiot tries to sell me a 320d because, and I quote:

"performance is the same"
"there is no need for the extra kw power"
"why spend the extra money on something that you not going to use"

And the more I trying to tell him this is what I want, the more he explains that he's trying to save me money.
 

skiet

Member
Promotec said:
We are still not discussing things on the original subject.

Standard production vehicles do not have water / meth injections and playing with piggyback system on fuel on the F30 320i might give you some gains but I can promise you that your economy will go down the drain :thumbdo:

I disagree, I just went to Durban for a week, average speed was 122km/h on the trip computer so was driving between 130 and 135km/h and averaged 6.4 litres per 100 with the ac schnitzer piggy back on 320i f30. :=):
 

phantom

Member
F30 cars are new generation so still on 5 year maintenance, no one in their right mind would want to void this.
If you buy a new car, buy the more powerful.
There is a big difference between a road car and a racing car.For the normal guy in the street he wants to stop at a filling station and carry on.You are your cars doctor.If you want to make more power it is your responsibility to give the engine the correct octane.
Want to make power go buy yourself a toy to use weekends.
Higher compression is more efficient (volumetric efficiency) but not allowable due to poor fuel quality.
The modern day car has ECU that will try and bring mixture to 14 to 1 mixture.
Biofuels (ethanol/ methanol) cannot produce the same energy per litre.Travelling at the same speed on the hiway the engine will consume far more fuel.
If you get 10l/100 with 95 you will go up to 11 or 12l/100 depending on mix.
My advice save till you can afford the F30 328i. Remember if you do your buying in steps you are going to lose a lot of money because the VAT on your car never comes back.
 

Mo35

Banned
bilal04 said:
What would be a better buy? Does the 320i and 328i have the same motor?

If one does software on the f30 320i would it be performing same as a 328i?

From the homework I have done and the buddies that I have spoken to at BMW Plant.

F30 320i and F30 328i is same platform , same pistons etc. (2013 onwards)

Loved the car so much that I went out and bought TWO F30 320i's

I have test driven a F30 320i pushing out some serious horse power with very subtle mods done to it , so yes to answer your question IMO 320i with map and you up onto 328i power.

Things to consider is 328i is detuned and car easily see more.

All depends on the POWER you after.

MAJOR component to ensure you have is the ZF 8 speed gearbox , this is where all the magic is IMO

:thumbs:
 

Dean ///M

Limited Profile
The pistons are different on both these cars. Terry posted a pic of it a few weeks ago but the 320i does make good power with the JB tune check out Burger Tuning, gains are really impressive and the same tune can be used on both engines (N20/N26). The 320 gets close to 328i power & 328i gets close to stock 335i power levels.
 

///M-Powered

New member
Hi guys

My buddy works for the bmw plant at Rosslyn. He did say that the twin scroll turbo on the 328 is slightly larger than a standard K04, whereas th 320 uses a smaller one. So i guess, besides th CR and a few other goodies, another practical explaination is the turbo. Yes, and the sports auto box
 

Naruto

///Member
"bilal04 Wrote: What would be a better buy? Does the 320i and 328i have the same motor?
If one does software on the f30 320i would it be performing same as a 328i?"

If you want more power then go for the 328i and keep your MP
If you want better consumption buy a 320i
 

Iceman007

Active member
Naruto said:
"bilal04 Wrote: What would be a better buy? Does the 320i and 328i have the same motor?
If one does software on the f30 320i would it be performing same as a 328i?"

If you want more power then go for the 328i and keep your MP
If you want better consumption buy a 320i

:thumbs:
I agree 100%
 

Gbmw

///Member
Naruto said:
"bilal04 Wrote: What would be a better buy? Does the 320i and 328i have the same motor?
If one does software on the f30 320i would it be performing same as a 328i?"

If you want more power then go for the 328i and keep your MP
If you want better consumption buy a 320i

Agree with Naruto, my F30 320i is slightly modded = Chip, DP and exhaust and he still moered me :cry:
But check my consumption on open road at 150

IMG-20131219-00450.jpg~c200
 
S

S1NGH 001

Guest
Chip logic is claiming to achieve 210kw from the 320i :thumbs:
 
S

S1NGH 001

Guest
Gbmw said:
S1NGH 001 said:
Chip logic is claiming to achieve 210kw from the 320i :thumbs:

whoa....that's tempting to investigate :=): Would love those figures !!

Would be nice to see one making that power :rollsmile:
 

Gbmw

///Member
Sirhan said:
buy a 320i and change the badge to a 328i :flyfun:

Well not so much rebadging but affordability at purchase and when pocket allows upping performance
 
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