a friend of mine had a turbo but the turbo is broke and he dont have the money to get a new one and he was wondering if he could put back on his stock parts and run his car but he has low comp pistons in it its at 8 5 1 ratio is it safe or no i dont think so but dont know any help

 

U can run low comp pistons on a na car but it will be very sluggish, better to use the stock pistons for na and out of $

 

8.5 to 1 is enough to get the engine running. Probably only making about 110 at the crank (Assuming 2.0) with them... so about 90 or less at the wheels.

Both of my Italian cars run 8 to 1 compression on a 1.8 with an 8 valve DOHC engine. They produce 80 hp in the Lancia and 90 in the spider. I am mentioning this as a baseline. These cars are carbed. When fiat went to injection in 1981, the 2.0 jumped from 80 hp (yes, the carbed 2.0 had LESS hp than the 1.8) to 102. Being a 16 valve design and a slight bump higher in compression, the Hyundai beta engine should do a little better.

Not great performance, but doable. Trust me, the dark days of emissions were truely dark days for performance.

 

you can run with 8.5:1 compression ratio. It will be safe. Only problem - hp loss and bigger fuel consumption.

With lower compression ratio you can run lower octan gas.

 

Why 8.5? Unless you're gonna run 500+whp, just go with 9:1's. You'll get better streetability.

 

It's not like it's THAT noticeable. I got 8.8:1 pistons, and running no boost currently (breaking in the clutch/pistons/flywheel/KaaZ). I got a little less power than stock, but certainly not 20% (30hp) less.

 

i am getting to but some pistions from crower and the cp is 8.8:1 is that to high for a turbo? :unsure: :unsure: i was under the impression that the lower the comppression the better. Shine some light on me.

 

youll do just fine with 8.8:1

 

Mad_John, just make sure you stay on top of your fuel ratio to make sure you don't go lean and you'll be fine. You will prolly run a little bit more power with a lower Max Boost. Lower compression just allows higher boost, plus the rods and pistons are better suited to handle the power.

And yes 8.5:1 will run but poorly without boost.