Quick Question
2nd Gear Member
Joined: Jan 2007
Posts: 386
From: doylestown, pa
RE: Quick Question
supercharged = dished pistons for lower compression ratio which doesnt matter because boost will make up for the low ratio
Naturaly aspirated = flat top pistons for high compression so that you can get as much bang for your buck.
if you are staying under 500 hp than hyperutectic pistons should be fine. anymore and you should get forged steel
Naturaly aspirated = flat top pistons for high compression so that you can get as much bang for your buck.
if you are staying under 500 hp than hyperutectic pistons should be fine. anymore and you should get forged steel
Thread Starter
3rd Gear Member
Joined: Apr 2005
Posts: 837
From:
RE: Quick Question
ORIGINAL: POISND U
Your friend isn't very scared of sounding like a schmuck, is he?
Your friend isn't very scared of sounding like a schmuck, is he?
6th Gear Member
Joined: Oct 2006
Posts: 10,551
From: Texas
RE: Quick Question
you want low compresion when u got f/i becuase your forcing more air n fuel in the combustion chamber. when ur n/a u can use flat pistons to raise your compression ecause ur not going to put slamming all the air in. i hope that helps??
, it makes perfect sense. Lol glad I got this site with lots of smart car guys to give info instead of listening to my friend.
2nd Gear Member
Joined: Jan 2007
Posts: 386
From: doylestown, pa
RE: Quick Question
the ONLY way to make more power is to smash as much air and fuel as possible into the combustion chamber. the reason you want low compression ratio with F/I is because you do not want to much compression. your engine will start to diesel and detonate if the compression ratio is to high. for instance. 4.6 mustangs have about 9.3:1 compression ratio. in the 70's when cars sucked, they had about 8:1 ratio. Some Hondas today have over 11:1 ratio. Crotch rockets have about 12.5:1 the highest you can go is about 13.8:1. Diesel engines have 20:1 because they dont have spark plugs and use compression to ignite the fuel and air instead which is what your engine will do with to much compression.
lets explain what compression ratio is. It is the ratio between the volume of the cylinder, when the piston is at the bottom of its stroke, and the volume when the piston is at the top of its stroke.
basicly when you are supercharging or doing a turbo, you are making your car have a high compression ratio when you are making boost. thus making a f/i car more streetable and controlable.
lets explain what compression ratio is. It is the ratio between the volume of the cylinder, when the piston is at the bottom of its stroke, and the volume when the piston is at the top of its stroke.
basicly when you are supercharging or doing a turbo, you are making your car have a high compression ratio when you are making boost. thus making a f/i car more streetable and controlable.
6th Gear Member
Joined: Oct 2006
Posts: 10,551
From: Texas
RE: Quick Question
ORIGINAL: incubus1275
the ONLY way to make more power is to smash as much air and fuel as possible into the combustion chamber. the reason you want low compression ratio with F/I is because you do not want to much compression. your engine will start to diesel and detonate if the compression ratio is to high. for instance. 4.6 mustangs have about 9.3:1 compression ratio. in the 70's when cars sucked, they had about 8:1 ratio. Some Hondas today have over 11:1 ratio. Crotch rockets have about 12.5:1 the highest you can go is about 13.8:1. Diesel engines have 20:1 because they dont have spark plugs and use compression to ignite the fuel and air instead which is what your engine will do with to much compression.
lets explain what compression ratio is. It is the ratio between the volume of the cylinder, when the piston is at the bottom of its stroke, and the volume when the piston is at the top of its stroke.
basicly when you are supercharging or doing a turbo, you are making your car have a high compression ratio when you are making boost. thus making a f/i car more streetable and controlable.
the ONLY way to make more power is to smash as much air and fuel as possible into the combustion chamber. the reason you want low compression ratio with F/I is because you do not want to much compression. your engine will start to diesel and detonate if the compression ratio is to high. for instance. 4.6 mustangs have about 9.3:1 compression ratio. in the 70's when cars sucked, they had about 8:1 ratio. Some Hondas today have over 11:1 ratio. Crotch rockets have about 12.5:1 the highest you can go is about 13.8:1. Diesel engines have 20:1 because they dont have spark plugs and use compression to ignite the fuel and air instead which is what your engine will do with to much compression.
lets explain what compression ratio is. It is the ratio between the volume of the cylinder, when the piston is at the bottom of its stroke, and the volume when the piston is at the top of its stroke.
basicly when you are supercharging or doing a turbo, you are making your car have a high compression ratio when you are making boost. thus making a f/i car more streetable and controlable.
6th Gear Member
Joined: May 2006
Posts: 6,448
From: Ohio
RE: Quick Question
I forged my motor and added nothing else and still NA and lost power (that I can feel) But I also dropped the compression to 8.8:1 because I will be slapping on a couple of turbos. The forged parts did feel lighter but I didn't weigh them.