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Is anyone going to try a low compression ratio? 6.5?

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Old 04-08-2003, 06:53 PM
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Default Is anyone going to try a low compression ratio? 6.5?
Our compression ratio is 9.3:1. We can only stuff so much fuel and air in that 2.9 cu inches at TDC at some temperature and pressure with a given octane. With a 6.5:1 compression ratio we'd have 4.2 cu inches to play with, over 40% more. I know some of those 3 liter 944s are running low 6.X:1 ratios. Why doesn't someone with way more money than me change pistons, put on some big turbos, and provide AW with something more fun to argue about than 400whp KO4s!
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Old 04-08-2003, 06:55 PM
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How much would pistons cost to change?
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Old 04-08-2003, 06:57 PM
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few points lower YA, but NOttttttttt 6.5!!!
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Old 04-08-2003, 07:05 PM
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Default RS4 heads.
But there are disadvantages to lowering the compression ratio.
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Old 04-08-2003, 07:06 PM
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a few hundred bucks for JE pistons.. but lots more for labor.
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Old 04-08-2003, 07:09 PM
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It's only 9.1:1 I think...
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Old 04-08-2003, 07:28 PM
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I thought it was an 8.6:1, but your probably right.
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Old 04-08-2003, 08:13 PM
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****, if we're going to go that low, why not 2:1? Why not 0:1? Oh, no off boost power? Oh ok.
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Old 04-08-2003, 08:28 PM
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Default Using compression to raise the size of the motor is just not going to work.
The lower your compression the more boost you need to run to make up for it. I lowered my 1.8t down to 8:1 but I am looking at running 30psi out of a bigger turbo.
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Old 04-08-2003, 08:41 PM
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Default The content of your message is what I was suggesting...
Any info on how much hp or how drivable a 1.8t w/ 8:1 and 30 psi would be?
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