High Vs. Low Compression. . . Pros and cons

[KA-T_CVC-ETR]

My Ka24et has a 9.1:1 Compression and im thinking about running a thicker head gasket to bring my compression down for the turbo (as advised by peers) would this be a good move on my part or no because i dont fully understand compression ratios and how they affect the motor.

[-RJ-]

I though a thicker head gasket will bring up compression. You want lower compression if you want to turbo and you want higher compression if your Formula 1 car. How much horsepower are you trying to get?

also you could use the search button

[480sx]

If you already have 9:1 comp you dont need to lower it. Thats plenty low for most any street turbo setup. Lowering the compression will lower your HP but allow you to run more boost with a bigger safety margin.

[Warped161]

a thicker head gasket would lower your compression, increasing the space between the head and the piston's tdc position means less compression, it was only the very early 89 240's that had a 9:1 compression all others had a 8.6:1, but unless you are pushing more than 18 lbs of boost i wouldn't change the compression ratio at all.

[KA-T_CVC-ETR]

Im lookin for about 25 LBS

[Warped161]

do more than just the head gasket, new pistons and rods as well. and you can def lower your compression by getting diff pistons.

[nismoracingsx]

say what? 25 psi of boost?? gl i suppose...would like to hear more about your supposed 25psi monster motor..

[KA-T_CVC-ETR]

Well its going to be full forged internals, Balanced Crank, Titanium Valves, Stage 3 cam, motor sleves, thicker head gasket(maybe), Ported and polished head, Top mount T3 turbo, Front Mount intercooler with spray bar, Stand alone fuel management system, HKS Turbo Timer, 300zx twin turbo injectors, walboro 255 fuel pump, Custom upgraded SR20 intake manifold, 300zx throttle body, thicker head studs, 3 inch down pipe into a custom 3 inch HKS HI-Power Exhaust.

[coop356]

Well if you want to see 25psi, you have some problems with your list. First I would say have a shop do it for you. Nothing like a warranty when stuff breaks and it will. I had to redo my head because a 5/8 water hose had a kink in it. Now the block. You dont sleeve a ka it's steal. You forgot ARP head studs and main. At 25psi you will stretch and break everything. Stage 3 cams are good and valves to, but dont forget springs, and 3 deg valve job. On the engine management do it right go Jim wolf or AEM the have the best support. Injectors 300zx is only 330cc. You will need atleast 720cc. And dont buy them from ebay. Also a topfeed fuel rail Aeromotive fuel regulator " Make sure its for boost". Gauges you need airfuel, boost, and pyro gauge. That helps alot with tunning. And thats just the start to 25psi good luck and have a secound car to drive or a lot of bus tokens lol. I've been fighting mine for almost 3 years and there is always a new problem. P.s. dont forget AAA... Everyone else nows what I mean..