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If someone wanted to lower compression to run more boost, could we just install a thicker head gasket? It would be interesting to know how much more power from extra boost you could make doing this while sticking to 93 octane.
 

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I see on the website that the 10.0-1 pistons are good for 450hp or 25psi made of 4032 and the 11.1 are made of 2618 but says no rating or psi it can handle.. I believe 2618 is a stronger piston material but why aluminum?? I want fricken forged steel that will last and is stronger
 

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Id take 11:1 comp with 20 lbs making 400wheel over 8.5:1 with 27lbs making 400wheel anyday.

Higher compression, more responsive. Nobody is every really below 3k rpms unless cruising anyway. And if you are, just down shift.

Higher compression is just as safe with boost, you just need the octane to support it.
 

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Id take 11:1 comp with 20 lbs making 400wheel over 8.5:1 with 27lbs making 400wheel anyday.

Higher compression, more responsive. Nobody is every really below 3k rpms unless cruising anyway. And if you are, just down shift.

Higher compression is just as safe with boost, you just need the octane to support it.
So much this. Unless you plan to go 30+psi, theres no reason to lower the compression
 

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So if i wanted to run 11.1 compression and 30+ psi on a 7163efr im screwed? Im running 50/50 watermeth..
Probably not a good idea. We would run 8th gen civics at 8-10 psi with 11:1 all day and make 400whp. Not very much timing though. Add race gas and we could make another 25-30 whp with some timing and a couple more pounds of boost. They were ticking time bombs at that point. Stock block of course
 

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2618 forged aluminum pistons are very strong and are usually used in boosted applications where extra ductility is needed. 4032 aluminum alloy pistons are more brittle much like hypereutectics and are much more sensitive to detonation and high cylinder pressures. 2618 pistons are usually produced to allow a larger piston to wall clearance for a given bore size since they expand to a greater degree once up to temperature.

I am using a set of 2618 JE grand national pistons in my turbo Buick v8 build. I've done quite a bit of research on the subject.

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2618 forged aluminum pistons are very strong and are usually used in boosted applications where extra ductility is needed. 4032 aluminum alloy pistons are more brittle much like hypereutectics and are much more sensitive to detonation and high cylinder pressures. 2618 pistons are usually produced to allow a larger piston to wall clearance for a given bore size since they expand to a greater degree once up to temperature. I am using a set of 2618 JE grand national pistons in my turbo Buick v8 build. I've done quite a bit of research on the subject. Sent from my SM-N900V using Tapatalk
there's a give and take on this one isn't nessarly better then the other when u compare the 2. 2618 is initially stronger then 4032 but suffers fatigue from heat cycling much more rapid then 4032 so they have a lot less of a life span then 4032. 4032 will wear much better and over a long period of time will outlast 2618. Personally unless u plan on rebuilding it often like u would a race motor 4032 is a much better option. The inly real advantage in the end is 2618 ability to withstand a bit more detenation but with how advanced the knock control is. Unless your a total bone head it shouldn't be a problem.
 

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Yes, I forgot to get into the con side of the 2618 piston. It should be said that 2618 is best for an all out performance limited use build. If you want to run race gas in order to have a high boost high compression engine chances are you won't be driving enough to require frequent engine rebuilds. To use 2618 pistons in a relatively low power build would not be ideal.

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2618 forged aluminum pistons are very strong and are usually used in boosted applications where extra ductility is needed. 4032 aluminum alloy pistons are more brittle much like hypereutectics and are much more sensitive to detonation and high cylinder pressures. 2618 pistons are usually produced to allow a larger piston to wall clearance for a given bore size since they expand to a greater degree once up to temperature.

I am using a set of 2618 JE grand national pistons in my turbo Buick v8 build. I've done quite a bit of research on the subject.

Sent from my SM-N900V using Tapatalk
Got picks of this buick?
 

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Sorry last off topic post. Not trying to derail the thread here. I'm just waiting on my connecting rods before I can send the block and heads out for machine work and rotating assy balance.



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Discussion Starter · #39 ·
Mahle's had these out for a while now. 9.3, 10 and 11:1. I talked to them a couple days ago.

http://www.us.mahle.com/media/motorsports/2015-app-guide-final-compressed.pdf
Slstomper, these pistons have been "added to the catalog" for a little while now, yes that is correct. As for actually being available to where you can physically have a set, that's now just a reality. SPEEDPERF6RMANC3 have worked step by step with Mahle to design & create the piston line up for the Ford ST. We hoped to help provide a line up the suits everyone's build needs from mild to wild

As you can see below the first drawing it.
Clip art Illustration Fictional character
 

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Discussion Starter · #40 ·
I have read over some people comments and question about running high CP.
Running High compression is they way to go on boost engines and NA the technology and fuel have got in way better over the years and with DI it made it more easier.

Here is the list of car with High compression.
Ford focus NA with DI and the Compression ratio is 12.1. If this was a PI car back then the Compression will be min 10.1 or so.

Ford Fiesta NA With DI and the Compression ratio is 11.0:1

Ford Fiesta st turbo With DI and the Compression ratio is 10.0:1 .Which isn't that off from 11.0:1

Mazda SKYACTIV NA with DI and the Compression ratio is 13.0:1

With the list above you can see how car manufactures are going high compression but you must understand when tuning high compression min room for errors.
 
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