Power Adders Getting a Supercharger or Turbocharger? Thinking about using Nitrous? All forced induction and N2O topics discussed here.

how much compression will a supercharger add?

Thread Tools
 
Search this Thread
 
Old Mar 12, 2011 | 09:44 PM
  #1  
snowboardgod869's Avatar
Thread Starter
Junior Member
 
Joined: Oct 2008
Posts: 36
Likes: 0
From: Sussex, Wisconsin
Car: 1991 RS Camaro
Engine: 305
Transmission: T5
Axle/Gears: 9 bolt 3.27
how much compression will a supercharger add?

im building a 350 bored 40 over i have Keith black forged pistons stock 350 rods and crank and a splayed 4 bolt main i have some 416 heads with 64 cc combustion chambers which 62cc combustion chambers put me a 10.6 compression my question is how much compression with what supercharger will add i was thinking of picking up some afr heads with maybe 76cc heads to bring my compression down to maybe 9 to 1 and have the super charger but how much compression will it increase with it?
Reply
Old Mar 12, 2011 | 11:55 PM
  #2  
daverr's Avatar
Senior Member
iTrader: (1)
 
Joined: Dec 2000
Posts: 689
Likes: 0
From: chicago
Re: how much compression will a supercharger add?

forced induction does not increase compression ratio.
Reply
Old Mar 13, 2011 | 12:18 PM
  #3  
blackbmagic's Avatar
Senior Member
10 Year Member
 
Joined: Mar 2010
Posts: 865
Likes: 2
From: LI, NY
Car: 1985 IROC-Z
Engine: 355
Transmission: T5
Axle/Gears: 3.42 10 Bolt Posi
Re: how much compression will a supercharger add?

While it doesn't add to the acctually dynamic compression ratio, It does increase internal pressure. This is why generally low dynamic compression ration is used with a forced induction application, it allows for a higher pressure without knocking. The higher the compression the more pressure in the combustion chamber.

You do not HAVE to lower you compression although the afr heads might flow better. Just make sure you have the coolest possible intake charge, have the correct cam, and are running the right octane. 10.6:1 is fairly high and you should venture lower than 93oct.

Just remember your engines compression ratio stays the same when adding forced induction, but the pressure in the combustion chamber increases.
ie.
The combustion chamber pressure of 10.6:1CR and 10lbs of boost pressure > 9.1:1 and 10lbs of boost pressure

The real question comes down to your setup and how much boost you want to effectively produce without detonation.
Reply
Old Mar 13, 2011 | 01:07 PM
  #4  
snowboardgod869's Avatar
Thread Starter
Junior Member
 
Joined: Oct 2008
Posts: 36
Likes: 0
From: Sussex, Wisconsin
Car: 1991 RS Camaro
Engine: 305
Transmission: T5
Axle/Gears: 9 bolt 3.27
Re: how much compression will a supercharger add?

so what is a good compression ratio to run with what size super charger if i am running stock rods and a crank but i have forged pistons and what kind of camshaft but i would also like to get my hp over 500 if possible
Reply
Old Mar 13, 2011 | 01:57 PM
  #5  
blackbmagic's Avatar
Senior Member
10 Year Member
 
Joined: Mar 2010
Posts: 865
Likes: 2
From: LI, NY
Car: 1985 IROC-Z
Engine: 355
Transmission: T5
Axle/Gears: 3.42 10 Bolt Posi
Re: how much compression will a supercharger add?

Well I wouldn't recommend doing anything near 500+ with stock rods first off. You need to do a little bit more research about super chargers and forced induction before asking about sizes and specs. You need to have a budget and a price range as well as time range and mechanical ability.

As for the cam, you should talk to your dealer or if you want to go with Comp Cams they have some pretty accurate software called cam-quest to help you find the specs of the cam that will best suit your application.

It all comes down to how your motor is built, before you can start asking questions about what size pulleys and how much boost.

I myself would stay below 9:1 for a boosted application. Maybe even as low as 7.5:1.

Originally Posted by snowboardgod869
i have some 416 heads with 64 cc combustion chambers which 62cc combustion chambers
what do you mean by that?

I'm sure there are others that can get more specific for you. Search the archives for other users builds and projects for info. Make sure you can not find your info before you ask to many questions. Value peoples help and only ask questions if you need to.

Last edited by blackbmagic; Mar 13, 2011 at 02:00 PM.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
MoJoe
Members Camaros
33
Feb 6, 2025 09:47 PM
InfernalVortex
Electronics
10
Apr 20, 2021 11:31 AM
FormulasOnly
TPI
95
Jul 23, 2018 08:47 AM
mrbird
Electronics
5
Oct 20, 2015 03:43 AM
gord327
Transmissions and Drivetrain
19
Oct 3, 2015 01:25 PM




All times are GMT -5. The time now is 10:51 PM.