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Old 04-09-2002, 12:43 PM   #1
Impreza25RS
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Default what to buy? low compression pistons or short block?

I was thinking about this on my way back from class today because Im turboing my RS and seeing that my kit is not doing much good sitting on my couch I wanted to see what the better route would be. I have a 98RS so keep that it mind. Would it be a better idea to get low compression pistons or just I just go the whole nine yards and bolt the 2.2 block to the 2.5 heads. What would be the better plan both cost wise and effectiveness? I dont want to blow up my car so Im taking all the precautions BEFORE my turbo kit goes on! Thanks for the help guys like always
Kyle
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Old 04-09-2002, 04:14 PM   #2
Graham
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Remember that your engine is a little better for turbocharging due to the fact that your engine comes from the factory with 9.7:1 Compression pistons. This will be better to handle boost. Although, the Phase I blocks didn't have the best head gaskets, and this seems the most common problem with MY98 turbo owners having troubles.

As far as cost effectiveness, the pistons will run you anywhere from $700 and up. Not many (if any at all) places stock pistons for our cars due to the low amount of purchases, so plan on waiting a while for them. You can also tack on a pretty penny for the install of these things, and if it was me, I would do rods while I was in there.

You won't absolutely need low CR pistons to run boost, just don't go crazy. I say keep it conservative and you won't run into any major problems. One thing though, you MUST have some sort of timing control.

Graham
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Old 04-09-2002, 07:16 PM   #3
adamsrs
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I have a set of JE 8.5:1 compression pistons, rings, and pins for sale. BRAND NEW!
adamsrs
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Old 04-09-2002, 09:36 PM   #4
Impreza25RS
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would the Apex-i ITC be suffcient for timing control?
Kyle
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Old 04-10-2002, 02:15 AM   #5
kaos200
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Quote:
Originally posted by adamsrs
I have a set of JE 8.5:1 compression pistons, rings, and pins for sale. BRAND NEW!
adamsrs
Adam your pistons will Not work on his motor. Why are you selling?

Last edited by kaos200; 04-10-2002 at 02:20 AM.
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Old 04-10-2002, 02:31 AM   #6
ac_gohan
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there is a very wide price gap between the two also. Pistons go for around 800 and i think a block would go intot he thousands. I would go for the pistons since you have the 98 block. They seem to handle boost better than the my00 plus

Andy
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Old 04-10-2002, 11:09 AM   #7
AaronB
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I think blocks are somewhere around $1200-1400. Since you have to pull the engine either way, you will pay the same labor for that side of it. With new pistons you have to pay to have the old pistons pulled, the block bored for the new size pistons, and then the pistons installed. If you do rods as well there will be more costs for machining, balancing the crank etc.

The cost is pretty close in my opinion.

Keep in mind almost everyone who has aftermarket pistons complains about how loud they are, so if that will bother you may be better off with a 2.2 motor.

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Aaron
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Old 04-10-2002, 11:31 AM   #8
crash
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Quote:
Originally posted by AaronB
[b]
Keep in mind almost everyone who has aftermarket pistons complains about how loud they are, so if that will bother you may be better off with a 2.2 motor.
Excuse my ignorance, but what makes them loud?

-Nathan
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