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Discussion Starter #1
Just talked to a buddy of mine. He is saying if you go turbo you want lower compression pisonts and if you just go with a N/A engine with a nitrous setup you should go with a higher compression ratio piston. Thinking about going with the Supertech 11.2:1 Pistons with direct port nitrous injection. What's everyones take on this topic? [race]
 

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nos loves compression..................
 

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Discussion Starter #4
Like.

Now what if I am not using the N20 every day? Will my engine like more compression and will I have to switch octanes?
 

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boost loves compression as well, you just have to keep deto from happening which requires higher octane than your NA and nitrous.

Most of the guys running 400+whp on zetecs (yes, apples to oranges) are at stock compression (which is 9.7 iirc...)

tune, tune, tune! You will need higher octane to run these pistons and when spraying you may even need more.

But why tear down the motor to add pistons when a stock d20 hatch with a 75 shot, bolt ons (sans IM), and slicks with some gutting went into the high 12s? He's currently tuning for the Cosworth IM now and hopes to hit low to mid 12s :)
 

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Discussion Starter #7
I had a 75 shot in there before. Changing the pistons because I am getting missfire #1 cylinder and I am burning oil quick (getting fuel in my crankcase and oil out my exhaust) leading me to believe i fryed a ring. So while I have it apart might as well put some upgraded stuff in there. Gonna have the stage one Excedy clutch and CMA TB with opened up exhaust and gonna have the head P&P while its apart. Lightweight flywheel and a good tune I think I should be able to reach mid 12's if not better. When i was pushing it before with the basics I was getting mid 13's.
 

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Discussion Starter #11
Right around 60k. Ran the nitrous on and off from about 20k-60k. Weekly track use, a lot of street abuse but didnt really spray on the street. Started noticing white smoke coming out of the exhaust during rev up and it progressivley got worse. Then one day it popped a check engine. Got it read and they said it was missfire cylinder number one. Took the plug out and it was covered in oil. Started taking intake and all that fun stuff off and noticed a yellow foamy like substance that smelt of oil and fuel= faulty piston rings, cylinder number one
 

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How big of a shot were you running and did you have it tuned for nitrous? Also what octane fuel did you use when spraying?
 

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if you didnt have it tuned for nitrous i have found your problem lol especiallyyyyyy if you have it tuned but not tuned for nitrous!
 

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Discussion Starter #14
I was running a 75hp shot, single nozzle on stock engine with FWS CAI and CBE. No tune. Using just regular octane.
 

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Discussion Starter #15
It lasted a long time and ran just fine with the nitrous. After the build I will have it tuned, be running higher octane and prob about an 80hp shot/ direct port (20hp ea. port)
 

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Discussion Starter #16
Kinda think maybe we got off topic, but keep the convo going. Still wondering what I should do for higher compression pistons (what CR I should run) and still have a solid running motor on a 90's octane gas? Anyone ever use the supertech higher compression pistons before?
 

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I would just get in contact with Tom from Focus-Power. He can tell you what you need to know. Or he may just chime in.
 

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yea i had the same problem running the 75 shot but number 3 i broke the ring landings..... ran it at the track everyweekend 2 years ago ran good 6 months after then well yea boom.. but decide to build ultra low compression for a goal of 450..... hope to have the dyno sheet in the next month or 2... got to change the heads out on mine figured a good cnc head is what imma need.. by the way with fswerks intake and a home made exhaust i was in 13.3's on stock wheels and tires... 91 octane
 
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