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Discussion Starter · #1 ·
well i've run Tbird hybrids on all 3 of my mx6 gt's.

ran the first two with no issues whatsoever.

well this last one i've never been able to go past 10psi without hearing detonation.

havent done MUCH to figure out why because the car's a daily driver and i just havent cared that much.

thought might be timing related so i pulled the timing back. didnt help.

months have gone by since. then today, i decided i'd mess with it some more.

i took the vaf out of my last GT (current parts car) and put it on this one.

problem solved.

neither vaf's were modified in any way shape or form.
 

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what do you have done for mods? just wondering as ill be getting my tbird installed hopefully within the next couple months or so. Glad to hear how you solved the problem though in case i run into it.
 

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Discussion Starter · #3 ·
engine mods:

tbird turbo, exhaust, HKS SSQV BOV, zombie chip, magnecore wires.

other mods:

HKS EVC, boost gauge, 2g front springs.

note i have done nothing to intake system, fuel, tuning etc (except messing with timing + chip).

i'm still on the stock IC piping, stock IC, stock air box. stock down pipe. the exhaust is 2.25" after the downpipe into a 3" megan racing muffler.

i HAVE 2.25" aluminum hardpipes sitting in a box along with an EVO8 IC that i should probably have fixed sometime....but i just dont care to mod the mx6 until i finish the rx7.
 

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i made some custom aluminum 2" hardpipes with stock IC. I really need to buy a wideband to be safe but im just trying to get a good idea of what people are running. I have 2.5" turbo back with nothing but a muffler on the end and zombie chip. I take it you use higher grade gas also? I only fill my car up with 93 octane all the time.
 

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Discussion Starter · #5 ·
yeah 91 or 92 depending on which pump i go to.

hooked it up to a wideband tonight and its pegged rich at WOT under 14psi now. AEB the fuel smoke that rolls out of my tail pipe now :lol:
 

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Jester...you do know that the VAF meddles in the timing as well, right?

If there is something wrong with the VAF electronics, it could effect your timing enough to not retard enough under boost, causing you to have pre-ignition.
 

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Discussion Starter · #7 ·
yeah i know.
i had pulled timing back manually (grounded test pin, with a timing light, blah blah)

so i'm going to need to ground the test lead and set it again i'm sure.
 

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yeah 91 or 92 depending on which pump i go to.

hooked it up to a wideband tonight and its pegged rich at WOT under 14psi now. AEB the fuel smoke that rolls out of my tail pipe now :lol:

so is that on the stock fuel system you are rich at wot? If so thats pretty sweet haha. I was gonna try like 11 or 12 psi but maybe i can push 14 then.
 

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Discussion Starter · #9 ·
yeah stock fuel. runs nice and rich.

just make sure u hook a wideband up. dont do what i did and just turn the boost up til it starts pinging. :lol:
 

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I turned mine up until I heard lifter noise...then I backed it down a couple psi :lol:
 

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Discussion Starter · #11 ·
lifter noise? how is that related??
 

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turn it up to about 19psi...you'll hear lifter noise ;)
 

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Discussion Starter · #13 ·
yeah...i've run past 20psi and there was no lifter noise...i'm not understanding why there would be to begin with.
 

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i thought tbird was good till about 18 psi?
 

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Discussion Starter · #15 ·
it is. i was having wastegate issues and it was unhooked.
 

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haha ok..that explains that. Im having wastegate issues with my stocker. The nipple on the vacuum side of the wastegate is loose and can spin freely, thus leaking vacuum. If i floor it in 5th gear doing about 55 mph i have hit 23 psi without a boost controller installed. Of course when i saw it hit that high i let off instantly though.
 

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Discussion Starter · #17 ·
thats similar to what happened...ecept the nipple just came off.

i'm still curious as to how high boost causes lifter tick.
 

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thats similar to what happened...ecept the nipple just came off.

i'm still curious as to how high boost causes lifter tick.
It's not really lifter tick...it's hard to explain, and it wasn't engine knock. The sound was coming from the head.
 

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Discussion Starter · #19 ·
hmm. can't say i've ever experienced that.

at the most i've experienced some valve float but i shimmed my valve springs pretty tight and got that to go away.
 
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