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Old 10-18-2009, 08:00 PM   #1
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Default Rattling noise only after ~7psi

I know I've been sort of a post ***** lately with starting new threads but it seems like one stupid problem after another. Now after installing the supra 305cc injectors and upping the boost I get this rattling noise above ~7psi. While driving it almost sounds like its the turbo, could 7-10psi make the greddy kit turbo make noises like that? The turbo is not even a year old but does have a little side to side shaft play when you wiggle it on the cold side.
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Old 10-18-2009, 08:13 PM   #2
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wait, when you get into boost it rattles? or does it rattle all the time?

the reason i ask is because detonation kind of sounds like a rattling if youre not familiar with the sound
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Old 10-18-2009, 08:14 PM   #3
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High or low frequency rattle?
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Old 10-18-2009, 08:17 PM   #4
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Only when I boost, at like 7+ psi, I run 93 octane and have the timing retarded to 6 degrees. it sounds more low frequency.. I'm not expert so it could be detonation but 7psi seems sort of low to get detonation with the timing back so far and 93 octane, right?
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Old 10-18-2009, 08:21 PM   #5
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Quote:
Originally Posted by linuxbox View Post
Only when I boost, at like 7+ psi, I run 93 octane and have the timing retarded to 6 degrees. it sounds more low frequency.. I'm not expert so it could be detonation but 7psi seems sort of low to get detonation with the timing back so far and 93 octane, right?
What does your wideband say?
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Old 10-18-2009, 08:21 PM   #6
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Well there's your problem you have No MEGASQUIRT!!!!
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Old 10-18-2009, 08:24 PM   #7
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Can't afford a megasquirt yet, and the wideband is ordered but not here yet. btw I know a guy that can get aem analog widebands kits for 190 shipped if anyone is interested just pm me.

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Old 10-18-2009, 08:27 PM   #8
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my narrowband says borderline stoich/rich, should it be real rich? When I adjust the afm richer two notches it idles up and down.
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Old 10-18-2009, 08:45 PM   #9
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my narrowband says borderline stoich/rich, should it be real rich? When I adjust the afm richer two notches it idles up and down.
when youre in boost?

that means you are too lean

a Narrow Band says rich when youre anywhere from 14:1 up, if youre on the border you are likely in the high 13's, which is too lean for boost
that narrow band should be way into the rich part of the guage under boost, even maxed out
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Old 10-18-2009, 08:48 PM   #10
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1. Turn boost back down
2. Get a wideband
3. Install wideband
4. TUNE
5. TUNE
6. TUNE SOME MORE
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Old 10-18-2009, 08:51 PM   #11
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Alright will do. I'll try to post an update here after I throw it on.
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Old 10-18-2009, 09:35 PM   #12
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How do I make it idle decent after making it more rich by adjusting the afm? (besides megasquirt)
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Old 10-18-2009, 09:52 PM   #13
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Quote:
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How do I make it idle decent after making it more rich by adjusting the afm? (besides megasquirt)
you dont

what are you using for fuel enrichment?
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Old 10-18-2009, 10:00 PM   #14
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I don't have any engine management but I have the walbro 255 and 305cc's.
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Old 10-18-2009, 10:01 PM   #15
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So no fuel pressure regulator?
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Old 10-18-2009, 10:01 PM   #16
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yah, do you have a vortec FMU or something?
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Old 10-18-2009, 10:02 PM   #17
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Yeah the stock greddy one sorry
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Old 10-18-2009, 10:04 PM   #18
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oh okay, well basically the only way to add fuel is to get a different ratio diaphram for the vortec FMU, it will basically add more fuel per psi, but a better option would be to find a BEGi adjustable FMU used (ppl sell then on here all the time), or better yet, get a PNP megasquirt, haha.
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Old 10-18-2009, 10:09 PM   #19
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K i'll look for that fmu, thanks man
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Old 10-18-2009, 10:11 PM   #20
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always a pleasure to help out a fellow linux junkie
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