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Enjoy the GTR Matt!
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Will I have any problems running a JWT computer programmed for 8.5:1 compression, cobra MAF, and 50lb setup on a stock DE (9.5:1) block with the same injectors and MAF?

Can a SAFC or Emanage correct for the compression difference between the JWT and what is actually there?

Thanks!
 

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utahnissans.com
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I am not postitve about the 8:5 ECU working well on the DE,but I think I can remember people saying it works. If you search I am sure you can find other threads with the same question.

An SAFC or Emanage can't correct the compression difference, but a metal head gasket can. :)
 

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No soup for you
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IKnowNothings said:
what size head gasket would you need to run to change a sr20de 9.5:1 to 8.5:1
allso do you need now head bolts as well ?

Not sure about the head gasket thickness, but even if you can, I wouldn't recommend it. As far as the head bolts go, they should be replaced everytime the head is removed, as per the FSM.

John
 

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I am also running a 8.5:1 ECU on my DE motor and it is fine. Witout it tuned I would say just change the timing to about 17 degrees to compensate for teh agressive timing of the 8.5:1 cr.

Now at 15 degress with the JWT it sounds fine, idles fine, and hauls serious ass.

Hope this helps.
 

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The only difference between 8.5:1 and 9.5:1 JWT programs... is the timing. The 8.5:1 program runs a little bit hotter timing map. The lower compression ratio allows you to get away with more timing. The DE program has less timing, because of the higher compression ratio. Just be careful if/when you turn the boost up. It's a good idea to leave your timing at 15* too.. I wouldn't go any higher.
Travis
 

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I turned my timing up to 17* daily driving, up to 15psi no knock whatsoever. At the track with 110octane, turned up timing to about 22* nothing wrong there either.

Justin
 

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So what base timing do you guys run with DET 8.5:1 and a JWT? 15 degrees? I ran my car up to 14 psi last year on the STOCK ecu. I imagine that has more timing than a turbo program. No problems at all. Base was set to 16 degrees.
 

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You won't "hear" mild detonation usually.. However, with cast pistons.. why risk it? I'm just going by what I was told by the person who makes the ECU's.. I would set it at 15* and leave it be.
Travis
 

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Well, there reccomendation is considering 91 octane. We get 93 here, or 94 if I want to drive 15 minutes out of my way. SO do you think 16-17 degrees would be ok with the JWT? Thanks travis.
 

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R0b_ said:
back to the thread question.. is 15* ok with 9.5:1 compression and the ECU is set to 8.5:1?
No problem on 92/3 octane, I was running 16.5 degrees w/ 112 octane on the 424 run, just fyi.

John
 
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