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      10-04-2019, 06:46 PM   #1
Rhys22gnt
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hi so after recently blowing my piston rings in cylinder 3 I've taken the plunge into forged pistons. my question is I've gone from the high compression 320i piston at 11:1 cp ratio, to Carrillo 9.5:1 compression, will the OTS bm3 maps still work without any issues?

other engine mods
mst inlet/intake
decat
charge pipes
dv+
arp rod bolts

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forged pistons 9.5:1
arp rod bolts
mst inlet/intake
dv
bm3 stage 2
decat
ftp charge pipes
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      10-05-2019, 03:33 PM   #2
rjd_F30
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I would definitely talk to a tuner about that. Changing the compression ratio is a pretty substantial modification that I would assume should be tuned for.
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      10-09-2019, 07:29 PM   #3
Gen13 F36
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Quote:
Originally Posted by Rhys22gnt View Post
hi so after recently blowing my piston rings in cylinder 3 I've taken the plunge into forged pistons. my question is I've gone from the high compression 320i piston at 11:1 cp ratio, to Carrillo 9.5:1 compression, will the OTS bm3 maps still work without any issues?

other engine mods
mst inlet/intake
decat
charge pipes
dv+
arp rod bolts

thanks
Just the piston? How about the rods and the deck/ sleeves?
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      10-10-2019, 11:48 AM   #4
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Quote:
Originally Posted by Rhys22gnt View Post
hi so after recently blowing my piston rings in cylinder 3 I've taken the plunge into forged pistons. my question is I've gone from the high compression 320i piston at 11:1 cp ratio, to Carrillo 9.5:1 compression, will the OTS bm3 maps still work without any issues?

other engine mods
mst inlet/intake
decat
charge pipes
dv+
arp rod bolts

thanks
No.

Maybe.

Not recommended. Call up BM3 about a custom tune if you are going there. I wouldn't, even stock it would probably be a nightmare.

Is this them or just a "shop"? Seems like them:
BM3 Tuning NYC/NJ
639 East 31st Paterson,NJ Call/Text: 646.907.9439 or or (862) 823-2370 | 2890 Shell Road, Brooklyn NY
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      10-10-2019, 11:49 AM   #5
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Quote:
Originally Posted by Gen13 F36 View Post
Just the piston? How about the rods and the deck/ sleeves?

Why does that even matter? Going 11:1 to 9.5:1 is not trivial. I can make some assumptions, but not going there.
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      10-10-2019, 12:17 PM   #6
Gen13 F36
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Quote:
Originally Posted by deviantspeed View Post
Why does that even matter? Going 11:1 to 9.5:1 is not trivial. I can make some assumptions, but not going there.
Well... I was thinking the OP is going for more power in the future. Why do piston if you can install more forged internal while the engine is open.

Just saying
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      10-10-2019, 12:32 PM   #7
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Quote:
Originally Posted by Gen13 F36 View Post
Well... I was thinking the OP is going for more power in the future. Why do piston if you can install more forged internal while the engine is open.

Just saying
Didn't see any of that assumption. Just saying.

will still need a custom tune.
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      10-16-2019, 08:08 AM   #8
CandyRedRC46
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A compression of 9.5:1 will require considerably more timing and or boost/cfm to make the same hp as an 11:1 compression ratio (all other things equal). I wouldn't even think of doing this upgrade with out a much larger turbo that can support more more boost and cfm, rods as strong as the Pistons, sleeves as strong as the rods/ pistons and an auxiliary port fuel injection that could keep up.
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      10-16-2019, 09:13 PM   #9
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Quote:
Originally Posted by CandyRedRC46 View Post
A compression of 9.5:1 will require considerably more timing and or boost/cfm to make the same hp as an 11:1 compression ratio (all other things equal). I wouldn't even think of doing this upgrade with out a much larger turbo that can support more more boost and cfm, rods as strong as the Pistons, sleeves as strong as the rods/ pistons and an auxiliary port fuel injection that could keep up.
Yah, you don't just upgrade the pistons. Pistons are typically just a piece to a much larger upgrade puzzle.
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      10-21-2019, 02:41 PM   #10
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Def stick with 10:1 compression and get the rods while you are there. No sense in doing just pistons.... Rods are weak link with this engine above 360 Wheel Torque. If you just do the rods and pistons you can run about 450-500 HP safely with the open deck on supportive turbo and fueling upgrades.
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