How to lower the compression on a st170
#1
15000
Thread Starter
How to lower the compression on a st170
Can anyone tell me the what size head gasket or decompression plate would be needed to lower the cr on a focus st170 to create a st170 turbo. There's a guy on ebay selling a st170 turbo with stock pistons and he says he used a 3layer head gasket to lower cr and its running 14 psi. But I thought the st170 head gasket was already 4 layers thick and the stock zetec was 3 layers? Also the Americans seem to be safely turbo charging stock st170s ( svt turbo in America) but I can find how they are doing it Wether it's a cometic head gasket or decompression plate? Any help or advice much appreciated cheers
#4
Regular Contributor
as above i am in the middle of doing the same thing....burton sell a cometic gasket 1.78mm but its on a 3-4 delivery as of yesterday, going to phone ford later.
#5
15000
Thread Starter
All I could find was a Pec Athena head gasket that was 1.6 thick I will ring ford and find out if the 1.8 frs one is still available.let me know if anyone finds out the part number for it cheers
#6
I've found that life I needed.. It's HERE!!
I got one a few months back for mine. Do a search for the part number as Ford's will have no idea what you're on about. There system doesn't show the thickness.
Not cheap though. ..around £142
It drops the cr a little more when you use a blacktop head. No need for the st170 head with a turbo. You will run out of luck before you run out of gas flow.
Not cheap though. ..around £142
It drops the cr a little more when you use a blacktop head. No need for the st170 head with a turbo. You will run out of luck before you run out of gas flow.
Last edited by big_wasa; 25-02-2017 at 05:19 PM.