Fordmods Logo

Higher Compression? 


Page 1 of 1 [ 3 posts ] 

 Post subject: Higher Compression?
Posted: Thu Jan 08, 2009 10:35 pm 
Tyre Shredder

Age: 31

Posts: 347

Joined: 10th Jan 2005

Ride: 2002 Mustang Cobra

Location: Broadmeadows (Melb. North)
VIC, Australia

Been hearing abit about compression and realised I have no idea about it. If it makes a difference, it was referred to when talking about the popping sound coming from the exhaust while decelerating while in gear (like a manual.. backing off accelerator without pushing in the clutch pedal)...

What is compression about? What are the benefits of having more/less compression? How do you get more/less compression?



Red 2002 Mustang Cobra

Posted: Thu Jan 08, 2009 10:46 pm 
Getting Side Ways
User avatar

Age: 29

Posts: 2517

Joined: 27th Mar 2006

Gallery: 1 images

Ride: FG MkII Xr6t Ute

Location: Brisbane
QLD, Australia

compression is how much the piston in your engine compresses the air/fuel mixture once its in the cylinder.

I feel really lame for putting this here, but wiki is your friend and even has a moving diagram lol.

With reference to static compression it is a measure of what the volume of your cylinder (including head and piston crown) is at BDC and TDC. So for a compression ratio of 9.5:1 it means the ratio between the pressure at TDC (when compressed) is 9.5 times that of at BDC (ie atmospheric). However this is in a perfect situation; in reality it doesn't quite work this well.

Dynamic compression takes into account overlap of cam etc.

To increase compression you can run a thinner gasket, get metal taken out of the head (although this can play havoc with timing) or better yet, get a bottom end rebuild with higher compression pistons. You will most likely either have to run better fuel or get a tune.



EVL098 wrote:
Cramping in the hand from having it on your Wang for an excessive period of time is a definate con.
Seriously do people google "f**k up modifications for Fords owned by Jews" and get linked straight to this site nowadays?

AU,factory fitted tickford kit/IRS, t5,Sports ryder/KYB: gone.

Posted: Fri Jan 09, 2009 12:03 am 
Fordmods Junkie
User avatar

Posts: 3083

Joined: 22nd Sep 2005

Gallery: 13 images

Ride: EF

Location: Melbourne
VIC, Australia

the popping your talking about is just unspent fuel igniting in the exhaust, im not sure if that is directly related to a higher compression ratio. some people call this engine braking "compression braking", possibly this causes some confusion.



latest mod: A Service

Display posts from previous:
Sort by  
 Page 1 of 1  [ 3 posts ] 

Who is online

Users browsing this forum: No registered users and 22 guests

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum



It is currently Thu May 24, 2018 12:36 am All times are UTC + 11 hours



(c)2014 Total Web Solutions Australia - Australian Web Hosting and Domain Names