R
Rolf
Guest
best advice ever :thumbs:
-
Read the WELCOME ALL BMWFANATICS post.
F30 320i vs f30 328i
- Thread starter bilal04
- Start date
R
Rolf
Guest
Really?
Now I understand why the same engine with 10:1 compression is sold as 328i
Now I understand why the same engine with 10:1 compression is sold as 328i
J
Josh-ZN
Guest
There is a big difference between a google expert and a real expert. I dont know much about the 2 cars in question but simple logic tells me to follow Rolf's advice.
Rolf@PromotecAuto said:Really?
Now I understand why the same engine with 10:1 compression is sold as 328i
yes Really!
The challange is to get fuel that will cope with the compression and boost. Evo's with 4g64 engines come with 8.8:1 and many people go to 10:1 and some even higher. Usually when they go higher they see major power increases.
And just by the way... I build a 406wkw subaru and then a 450 wkw evo 9.... and even help building the 335 race cars with ADF motorsports... all with the help of "Google"
11:1 is slow at 11000rpm in a 2L huh?
J
Jakkals_F30
Guest
So here comes a person with google advice against someone that really knows what he's doing...
Interesting and at 2 posts a big mouth... acssa !! Calm down dude :=):
Interesting and at 2 posts a big mouth... acssa !! Calm down dude :=):
Sabretooth tiger
///Member
babyboss said:
+1
J
Josh-ZN
Guest
opcorn:
DeoJor
New member
:joy: I is the season to be jolly... tra la la la laa...:joy:
cant we just all get along, to map or not to map will be the question for quite some time with the F30's but for what it's worth this 320 driver will be happy with either option. So to BMW: "that will do boys, that will do" :bravo:
cant we just all get along, to map or not to map will be the question for quite some time with the F30's but for what it's worth this 320 driver will be happy with either option. So to BMW: "that will do boys, that will do" :bravo:
S
SP33DYV
Guest
Josh-ZN said:
Please share your
opcorn:
assuming you have enough octane the higher compression ratio will make more power... but in the real world getting high enough octane is not always cost effective or practical...
Im sure BMW would now lower the CR on the 328i if it was not needed to make the higher boost level more stable... CR makes efficiency... If you want the 320i to boost high it will take more work because it will take more to get it stable than the 328i...
a car can make 1000kw on one day then get beaten by a 100kw car because its broken the next day...
Im sure BMW would now lower the CR on the 328i if it was not needed to make the higher boost level more stable... CR makes efficiency... If you want the 320i to boost high it will take more work because it will take more to get it stable than the 328i...
a car can make 1000kw on one day then get beaten by a 100kw car because its broken the next day...
I know SAV, Freddie/Donvan from ADF, Rob at BMWSA and many more.
Just for pure info... a Subaru STI comes with a 8,2:1 comp ratio and use port injection. Evo's used 8.8:1 with port inection... then came direct injection with the injector in the camber and the turbo cars could run comp ratios of 10+:1. Its got to do with det/pre ignition.
Hi compression also help to spool the turbo so you get less lag.
on 95 pump fuel on my toys I can boost 1.1 bar with no engine failures but on ethanol fuel mix I can run 2,2bar with no engine failure. So if you have high octane fuels you can run hi compression and hi boost... (note! dont just add ethanol to your stock engine as the stoic is different from normal pump fuel)
The problem comes what is available at the normal filling stations...
the 328 runs more boost to make the more power but the compression needs to dropped because of fuel octane levels. The 320 boost less so it is ok with a higher compression.
So what I am saying... if you have the same turbo at 1bar boost on the 320 and 328 and you can run 110+octane in both the 320 will make more power.
That evo 2l from extreme tuners run 13:1 ratio making stupid power.
Just for pure info... a Subaru STI comes with a 8,2:1 comp ratio and use port injection. Evo's used 8.8:1 with port inection... then came direct injection with the injector in the camber and the turbo cars could run comp ratios of 10+:1. Its got to do with det/pre ignition.
Hi compression also help to spool the turbo so you get less lag.
on 95 pump fuel on my toys I can boost 1.1 bar with no engine failures but on ethanol fuel mix I can run 2,2bar with no engine failure. So if you have high octane fuels you can run hi compression and hi boost... (note! dont just add ethanol to your stock engine as the stoic is different from normal pump fuel)
The problem comes what is available at the normal filling stations...
the 328 runs more boost to make the more power but the compression needs to dropped because of fuel octane levels. The 320 boost less so it is ok with a higher compression.
So what I am saying... if you have the same turbo at 1bar boost on the 320 and 328 and you can run 110+octane in both the 320 will make more power.
That evo 2l from extreme tuners run 13:1 ratio making stupid power.
Andy1GP said:
J
Josh-ZN
Guest
acssa, you seem to have made quite an entrance. 4 posts and you are already flying. you seem like a seasoned poster. you sure you not also running under another alias?
tell SAV, Freddie/Donvan from ADF, Rob at BMWSA and many more that I say hi :tease:
tell SAV, Freddie/Donvan from ADF, Rob at BMWSA and many more that I say hi :tease:
R
Rolf
Guest
acssa said:Rolf@PromotecAuto said:Really?
Now I understand why the same engine with 10:1 compression is sold as 328i
yes Really!
The challange is to get fuel that will cope with the compression and boost. Evo's with 4g64 engines come with 8.8:1 and many people go to 10:1 and some even higher. Usually when they go higher they see major power increases.
And just by the way... I build a 406wkw subaru and then a 450 wkw evo 9.... and even help building the 335 race cars with ADF motorsports... all with the help of "Google"
11:1 is slow at 11000rpm in a 2L huh?
All of the above is not comparing apples with apples! :argh:
Why didn't you state that in the first place but triggered the whole discussion as if it was valid for ANY car and pump fuel :flyfun:
Now it's a complete new tune
We can not read your mind.... :idea:
Rommies
Active member
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?
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?
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