E46 BMW Social Directory E46 FAQ 3-Series Discussion Forums BMW Photo Gallery BMW 3-Series Technical Information E46 Fanatics - The Ultimate BMW Resource BMW Vendors General E46 Forum The Tire Rack's Tire Wheel Forum Forced Induction Forum The Off-Topic The E46 BMW Showroom For Sale, For Trade or Wanting to Buy

Welcome to the E46Fanatics forums. E46Fanatics is the premiere website for BMW 3 series owners around the world with interactive forums, a geographical enthusiast directory, photo galleries, and technical information for BMW enthusiasts.

You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.

Go Back   E46Fanatics > E46 BMW > General E46 Forum

General E46 Forum
This is the place to get answers, opinions and everything you need related to your E46 (sedan, coupe, convertible and wagon) BMW!

Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 09-18-2004, 02:07 PM   #1
gmhl10
Resident CF Whore
 
Join Date: Mar 2003
Location: Honolulu, HI
Posts: 2,624
My Ride: '05 A08 M3
Send a message via AIM to gmhl10 Send a message via MSN to gmhl10
What's the Compression Ratio for Our Engines?

I guess to be specific... the 2.5L M54 engine.
But if you know the ratio for others, please list.
I always hear that BMW engines are high compression so I'm just curious what it is.
__________________
'05 Silbergrau M3 - mfg date: May '05
Modifications: WAY too much to list

gmhl10 is offline   Reply With Quote
Ads by Google

Guests, get your FREE E46Fanatics.com membership to remove this ad.
Old 09-18-2004, 02:30 PM   #2
BWMguy206
Registered User
 
Join Date: Aug 2002
Location: Glendale
Posts: 792
My Ride: '98 M3 and '07 335i
compression ratio is 10.5:1

Thats the same compression ratio as the 1995-1999 E36 M3 S52 engines.
BWMguy206 is offline   Reply With Quote
Old 09-18-2004, 04:12 PM   #3
vaio76109
Registered User
 
Join Date: Nov 2003
Location: Fort Worth, TX
Posts: 8,831
My Ride: Race Cars
The 3.0 is 10.2:1. Neither the 2.5 or 3.0 is very high, but not low either. The new M5 is 12.0:1, thats high.
vaio76109 is offline   Reply With Quote
Old 09-18-2004, 04:37 PM   #4
BWMguy206
Registered User
 
Join Date: Aug 2002
Location: Glendale
Posts: 792
My Ride: '98 M3 and '07 335i
E46 M3 S54 engine is 11.5:1

E39 M5 S62 engine is 11:1
BWMguy206 is offline   Reply With Quote
Old 09-21-2004, 11:45 AM   #5
gmhl10
Resident CF Whore
 
Join Date: Mar 2003
Location: Honolulu, HI
Posts: 2,624
My Ride: '05 A08 M3
Send a message via AIM to gmhl10 Send a message via MSN to gmhl10
My cousin says his RSX type S has an 11:1 compression ratio on his car.
That's quite similar to the 3.0L at 10.5:1.
Why is it that his car can easily fit a turbocharger when our cars can't?

BTW.. anyone know what it is for the 2.5L M54?
__________________
'05 Silbergrau M3 - mfg date: May '05
Modifications: WAY too much to list

gmhl10 is offline   Reply With Quote
Old 09-21-2004, 12:46 PM   #6
vaio76109
Registered User
 
Join Date: Nov 2003
Location: Fort Worth, TX
Posts: 8,831
My Ride: Race Cars
Quote:
Originally Posted by gmhl10
My cousin says his RSX type S has an 11:1 compression ratio on his car.
That's quite similar to the 3.0L at 10.5:1.
Why is it that his car can easily fit a turbocharger when our cars can't?

BTW.. anyone know what it is for the 2.5L M54?
I wouldnt say you can easily fit a turbo on a rsx-s. If u plan to run over prob 8-9psi youd need internals.

The main reason why there are no turbos yet is due to ecu tuning i beleive.
vaio76109 is offline   Reply With Quote
Old 09-21-2004, 01:54 PM   #7
gmhl10
Resident CF Whore
 
Join Date: Mar 2003
Location: Honolulu, HI
Posts: 2,624
My Ride: '05 A08 M3
Send a message via AIM to gmhl10 Send a message via MSN to gmhl10
Quote:
Originally Posted by vaio76109
I wouldnt say you can easily fit a turbo on a rsx-s. If u plan to run over prob 8-9psi youd need internals.

The main reason why there are no turbos yet is due to ecu tuning i beleive.
Oh.. ic...
Yea, my cousin is running only around 8psi of boost right now until he can get more stuff on his DC5.
And yea, now that I think about it, I do remember people on the forum saying that our ECUs are hard to program for.
__________________
'05 Silbergrau M3 - mfg date: May '05
Modifications: WAY too much to list

gmhl10 is offline   Reply With Quote
Old 09-21-2004, 03:38 PM   #8
Jspeed
Registered User
 
Join Date: Dec 1969
Location: Vancouver, BC, Canada
Posts: 1,990
My Ride: '01 330i
Quote:
Originally Posted by gmhl10
My cousin says his RSX type S has an 11:1 compression ratio on his car.
That's quite similar to the 3.0L at 10.5:1.
Why is it that his car can easily fit a turbocharger when our cars can't?
11:1 is hardly an optimal compression ratio for forced induction. You'll notice that most FI engines from the factory come with 8:1~9:1 CR's.
__________________
Jspeed is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Censor is ON





All times are GMT -5. The time now is 03:09 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
(c) 1999 - 2011 performanceIX Inc - privacy policy - terms of use