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Old Feb 17, 2017 | 10:19 PM
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Interesting. I have a cutout right after the downpipe, too. What are you using for an air filter?
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Old Feb 18, 2017 | 08:24 AM
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Originally Posted by gixxer9
Interesting. I have a cutout right after the downpipe, too. What are you using for an air filter?
i was using a 5.5" long filter on a 3.5" stainless pipe that ran from my front bumper to the compressor housing (3 feet of piping). I now run a turbo screen only.
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Old Feb 19, 2017 | 11:53 AM
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Taking the differences of the two engines out of the equation, isn't the "problem" presented here par for the course with MBC's? A pressure peak then settles to slightly below? Where, if you want constant 20psi, it'll probably crack the MBC open at 22-24 then settle at the desired setting?
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Old Feb 19, 2017 | 11:53 AM
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I may have some extra back pressure, but I was still able to make more power with the larger motor and same hot/cold side. We are going to be looking for a leak on Monday.
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Old Feb 19, 2017 | 11:56 AM
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Originally Posted by SethU
Taking the differences of the two engines out of the equation, isn't the "problem" presented here par for the course with MBC's? A pressure peak then settles to slightly below? Where, if you want constant 20psi, it'll probably crack the MBC open at 22-24 then settle at the desired setting?
Quite possibly, but the MBC didn't have as dramatic settling on the 383. It hit 15-16 psi and held at 15.
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Old Feb 19, 2017 | 01:44 PM
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Originally Posted by gixxer9
Quite possibly, but the MBC didn't have as dramatic settling on the 383. It hit 15-16 psi and held at 15.
you have boost drop issues with just wastegate too though, right?
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Old Feb 19, 2017 | 04:53 PM
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Originally Posted by RealQuick
you have boost drop issues with just wastegate too though, right?
Yes, I do.
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Old Feb 19, 2017 | 05:04 PM
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Originally Posted by gixxer9
Yes, I do.
that rules out boost controller as a cause.

what air filter you running?
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Old Feb 19, 2017 | 05:14 PM
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Originally Posted by RealQuick
that rules out boost controller as a cause.

what air filter you running?
A large cone type right on the inlet of the turbo.
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Old Feb 19, 2017 | 07:57 PM
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Originally Posted by gixxer9
A large cone type right on the inlet of the turbo.
what dimensions?
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Old Feb 20, 2017 | 03:32 PM
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Originally Posted by RealQuick
what dimensions?
Approximately 6" at the base and 4" at the top and about 10" long.
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Old Feb 20, 2017 | 04:22 PM
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Originally Posted by gixxer9
Approximately 6" at the base and 4" at the top and about 10" long.
can you log a 2nd gear pull on the street with and without the filter?
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Old Mar 5, 2017 | 11:12 AM
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We have resolved the boost taper by again replacing the wastegate spring with a new 18 lb spring from Precision. It holds 17-18 psi on gate alone, but all is not well....

We turned up the boost and then my ignition was breaking up. New plugs with a tighter gap and new wires fixed this breaking-up, but..

It will not make any more power than 680ish regardless of boost pressure. It is not showing any knock or pulling timing. There is no way that this turbo is maxed out on a 346, right?
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Old Mar 5, 2017 | 12:06 PM
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Originally Posted by gixxer9
We have resolved the boost taper by again replacing the wastegate spring with a new 18 lb spring from Precision. It holds 17-18 psi on gate alone, but all is not well....

We turned up the boost and then my ignition was breaking up. New plugs with a tighter gap and new wires fixed this breaking-up, but..

It will not make any more power than 680ish regardless of boost pressure. It is not showing any knock or pulling timing. There is no way that this turbo is maxed out on a 346, right?
The tuner has total control over timing. The tuner has to determine whether there is any knock or not.

So the tuner has all the information to hand to test whether the turbo will make any more power than that. Boost pressure is only one aspect
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Old Mar 5, 2017 | 12:10 PM
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Originally Posted by gixxer9
We have resolved the boost taper by again replacing the wastegate spring with a new 18 lb spring from Precision. It holds 17-18 psi on gate alone, but all is not well....

We turned up the boost and then my ignition was breaking up. New plugs with a tighter gap and new wires fixed this breaking-up, but..

It will not make any more power than 680ish regardless of boost pressure. It is not showing any knock or pulling timing. There is no way that this turbo is maxed out on a 346, right?
Could be maxed, especially if it's through an unlocked automatic. That's not a lot of turbo. Didn't see how much timing, or what injectors you are using.
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Old Mar 5, 2017 | 03:01 PM
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Originally Posted by Game ova
Could be maxed, especially if it's through an unlocked automatic. That's not a lot of turbo. Didn't see how much timing, or what injectors you are using.
It's a t56. Not sure what timing is set at, but injectors are 80 lb, with twin 340 pumps. I am running 96 octane mix with meth.
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Old Mar 5, 2017 | 03:36 PM
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Originally Posted by gixxer9
It's a t56. Not sure what timing is set at, but injectors are 80 lb, with twin 340 pumps. I am running 96 octane mix with meth.
can u post the dyno sheet?
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Old Mar 5, 2017 | 06:59 PM
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Originally Posted by RealQuick
can u post the dyno sheet?

I'll talk to the shop to see if they can email it to me.
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Old Mar 7, 2017 | 10:11 AM
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Old Mar 7, 2017 | 10:35 AM
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What fear were you in on this pull? Looks like 2nd
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