I have done extensive research in the archives, but I have not found the exact answers I am looking for. I am rebuilding my motor because I have most likely blown two piston rings.

- I am using Darton sleeves (I called Darton and they said the H22A4 is a solid closed deck, but I read someones thread in the archieve, and they said the A1 is closed and the A4 is closed). What's right?

- I have a turbo application and would like to run between 12-15 psi with a T3/T04 (320-350whp). I have been auto crossing but would like to get into road course racing. What would be the best compression ratio when looking for forged pistons? I want low end and top end power.

- I don't want to create a lot of work for the machine shop and create a bigger hole in my pocket. Is it worth getting larger bore pistons or longer connecting rods to increase the stroke? I don't want to mess with the crank. I am just planning on replacing the connecting rods and pistons and adding sleeves. Do I need anything else besides replacing OEM gaskets if I am just building the bottom end?

Sorry this was long - I appreciate any feedback


Modified by rags00prelude22 at 5:24 PM 11/12/2008


Modified by rags00prelude22 at 9:16 PM 11/12/2008

 

have done extensive research in the archives, but I have not found the exact answers I am looking for. I am rebuilding my motor because I have most likely blown two piston rings.

- I am using Darton sleeves (I called Darton and they said the H22A4 is a solid closed deck, but I read someones thread in the archieve, and they said the A1 is closed and the A4 is closed). What's right?

- I have a turbo application and would like to run between 12-15 psi with a T3/T04 (320-350whp). I have been auto crossing but would like to get into road course racing. What would be the best compression ratio when looking for forged pistons? I want low end and top end power.

- I don't want to create a lot of work for the machine shop and create a bigger hole in my pocket. Is it worth getting larger bore pistons or longer connecting rods to increase the stroke? I don't want to mess with the crank. I am just planning on replacing the connecting rods and pistons and adding sleeves. Do I need anything else besides replacing OEM gaskets if I am just building the bottom end?

Sorry this was long - I appreciate any feedback

 

-a1 is closed, a4 is open

-350whp is waay too much power for tracking in a fwd car. 300whp is way to high on street tires too.

-You'd do yourself a lot of good to put the money towards seat time before you start modifying the car a lot. Starting out with that much power will tremendously slow your progress in becoming a good driver.

-Sleeving is a waste of money for only 300whp(which is too much power anyway). Use the Mahle Goldseries pistons. They're forged and will work in FRM.

 

I have to sleeve it because I have 140k miles on the block. The machinist said that the block would most likely not meet the correct clearance standards, and I would have blow by thus loss of compression. I have been making 300 whp for the past 4 years with stock internals, and I have been successful on the track. I understand the value of track time, and I will be running conservative boost while learning on the track.

I don't think the Mahle Goldseries will work well with sleeves.

So what piston ratio would be good to use?

 

Overbore and use .25 OS pistons. Make sure your machinist knows how to hone FRM. More often than not, they screw it up.

 

I will check with the machine shop and compare the price differences between sleeving and just machining the FRM.

Thank you for your help - what compression pistons should I use? Should I lower the compression ratio using a thicker cosmetic head gasket too?

 

Use stock size headgasket. Go with a properly sized turbo and 10:1.