when i go kat, ill be rebuilding the bottom end. i was wanting to ask some experienced people which compression would be best for the set up.gt35 turbo I was thinking about 10psi daily but when i race set it at about 18-20.is that really high boost?i know the higher the boost you go the lower the compression should be.im trying to deside between8.5:18.8:19.1:19.5:1any help?thanks
Modified by 1991h9 at 8:54 PM 7/10/2008
which compression
Re: which compression (1991h9)
a solid tune and it will not matter, except for power output personally I wouldnt go lower then 8.8:1 just dont skimp on the fuel/timing and you should be golden, a nico member makes over 500 on a stock internal motor 30psi I think
Re: which compression (neverlift)
ok cool thanks. just a really technial question.what would be the technical difference between 9.1:1 and 9.5:1i know its 4 more compression and a little better horse power butwhere and when does it have its advantages.Example:effect the power band?etc...
Re: which compression (1991h9)
like i know it effects the hp and tqbut i mean like does it effect the power band?where the hp or tq kick in. and where in the rpms it kicks in.
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DevilMB3017
- Posts: 1639
- Joined: Thu Sep 14, 2006 7:25 am
http://auto.howstuffworks.com/engine.htm
That website is AWESOME.
Basically, compression happens when the piston moves up and spark is about to happen. The compression ratio is how much it compresses, and is affected by pistons and some other things, like your headgasket.
So let's say your stuffing 8.8 units into 1 volume...your gasoline/air mixture is under pressure. And even more considering you're talking turbocharged compressed air already going into the cylinder. This makes it more likely for the mixture to combust before spark.
More compression is more power because there is more air/fuel.
It is also more likely to combust before spark, causing detenation (knock) and damanging your motor. Most KA-Ts I've seen use 8.8:1 or 9:1.
That website is AWESOME.
Basically, compression happens when the piston moves up and spark is about to happen. The compression ratio is how much it compresses, and is affected by pistons and some other things, like your headgasket.
So let's say your stuffing 8.8 units into 1 volume...your gasoline/air mixture is under pressure. And even more considering you're talking turbocharged compressed air already going into the cylinder. This makes it more likely for the mixture to combust before spark.
More compression is more power because there is more air/fuel.
It is also more likely to combust before spark, causing detenation (knock) and damanging your motor. Most KA-Ts I've seen use 8.8:1 or 9:1.