[J Mill]

Ok, this has probably been discussed but i'm just wondering, if i want to build up the KA, and get the compression down to 9:1 or 8.5:1 how would be the best way to go about doing that? and if i do get the compression down around there am i gonna be stuck with a gutless car till i turbo it?

 

[Nismo240]

i think the best way would to be to get aftermarket pistons, so i would go ahead and just build the bottom end.

 

[J Mill]

alright, what other options are there for lowering the compression?

 

[J Mill]

and if i would be to get a 3inch exhaust but was running it on the stock lower compression engine, would it end up scavenging and sucking away my power?

 

[Nismo240]

a thicker headgasket will also lower compression. a 3in. exhaust will give you power while you're still NA, but you'll lose a lot of your low end power.

 

[Asleep]

not entirely true. my brother had all bolt-ons and 3" exhaust on his s13 and it would keep up with my altima no problem. he lost no power anywhere in the powerband.

 

[Nismo240]

well i'm going with other people (that i know personally) and personal experience. when i got my exhaust done (only 2.5"), it lost a lot of torque, making the low end seem weak, but the top end improved greatly.

 

[rogoman]

Ok, this has probably been discussed but i'm just wondering, if i want to build up the KA, and get the compression down to 9:1 or 8.5:1 how would be the best way to go about doing that? and if i do get the compression down around there am i gonna be stuck with a gutless car till i turbo it?

Since you'll be going turbo, the smart way to lower the CR is to go with forged custom pistons. It turns out that OEM KA pistons have a habit of breaking the upper ring lands with turbo charging so there's a good reason to go with forged..

With 8.5:1 CR, you'll be down a bit in HP but you should still have a good performing car. Why don't you hold off on the 3" exhaust until you install the turbo.

 

[J Mill]

ok, so there's some Arias pistons i'm lookin at for 8.8:1 CR, has anyone used these, and if so, how well did they work?

 

[rogoman]

Jim Wolf Technologies is a well respected company. JWT uses Arias pistons, which is high silicon content so tighter tolerance can be used. No piston slap. Arias is a well respected company and has been around for many years.

 

[Trippen]

I have a KA-t and you can run it on stock internals. We have quite a few guys running stock internals up to 14PSi some higher but it all goes to what engine management your using. A engine will only last if your tune is good. I run a JWT on my 95 it is awsome. I run 14-18psi buttt...and a big butttt...I have a fully built motor. I have Eagle rods, Aris 8.9 pistons. You can do around 300-350HP with stock lower ends if your compression is good.

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