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      05-20-2012, 02:25 PM   #1
jpsimon
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Any reason why I shouldn't push further? 20psi?

So I'm currently running ~18.5psi with meth. WGDC maxes out at 60-65%. Fuel trims and AFR look good.

Is there any reason why I shouldn't push these snails a bit further? to say 19.5-20psi? As long as WGDC isn't maxed out at 100% is there any reason to NOT raise boost a little more? Assuming I do make more power with more boost. Does running a higher WGDC (as long as it's not maxed) have any negative impact on turbo life? or is it negligible?
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Last edited by jpsimon; 05-20-2012 at 04:12 PM.
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      05-20-2012, 02:52 PM   #2
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you can probably run more boost low - midrange and keep the high rpm the same.
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      05-20-2012, 03:10 PM   #3
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You are running clipped turbine wheels, so you could and should run more boost to make both the power and back pressure to match the unclipped upgrades.

Edit: the aerodynamics is not as good, as unclipped, so you'll never actually match the power...
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      05-20-2012, 03:30 PM   #4
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Quote:
Originally Posted by jpsimon View Post
So I'm currently running ~18.5psi with meth. WGDC maxes out at 60-65%. Fuel trims and AFR look good.

Is there any reason why I shouldn't push these snails a bit further? to say 19.5-20psi? As long as WGDC isn't maxed out at 100% is there any reason to NOT raise boost a little more?
You should dyno increased boost up top to see if it gains you any power. If it does not, all you're doing is flowing hot air with no benefit.
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      05-20-2012, 03:36 PM   #5
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Quote:
Originally Posted by jippii ensio View Post
You are running clipped turbine wheels, so you could and should run more boost to make both the power and back pressure to match the unclipped upgrades.

Edit: the aerodynamics is not as good, as unclipped, so you'll never actually match the power...
All things equal clipping a turbine wheel does not reduce power. What it does is potentially reduce exhaust back pressure at the expense of turbine efficiency (which has a negative impact on boost response).
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      05-20-2012, 03:47 PM   #6
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I guess a better question... assuming I do make more power with more boost. Does running a higher WGDC (as long as it's not maxed) have any negative impact on turbo life? or is it negligible?
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      05-20-2012, 09:50 PM   #7
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I prefer to cap WGDC at 80% since the wastegate is nearly closed at that point. There's a point of diminishing returns when you crank up the boost with small turbos. Backpressure in the exhaust manifold can rise quickly with little added boost. It's still beneficial to crank up the boost just after spoolup to get a nice torque hit, as long as you can balance the boost spike with good fuel and timing. Just make sure the boost tapers down as rpm climbs so the engine doesn't choke with extreme exh backpressure.
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      05-20-2012, 10:11 PM   #8
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I'm thinking of going with a turbo setup very similar to the EPL's with a couple extra things added to try get them working better. I would be very interested in seeing the results of how they respond to more boost and how well they can hold the boost.
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      05-20-2012, 10:19 PM   #9
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Ill post up the results when i get back on the dyno. Waiting on a trunk-mount meth tank to come then I'll run a higher % meth mixture when doing this
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      05-20-2012, 10:24 PM   #10
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Quote:
Originally Posted by Dave W. View Post
I prefer to cap WGDC at 80% since the wastegate is nearly closed at that point. There's a point of diminishing returns when you crank up the boost with small turbos. Backpressure in the exhaust manifold can rise quickly with little added boost. It's still beneficial to crank up the boost just after spoolup to get a nice torque hit, as long as you can balance the boost spike with good fuel and timing. Just make sure the boost tapers down as rpm climbs so the engine doesn't choke with extreme exh backpressure.
This is solid advice.
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      05-20-2012, 10:39 PM   #11
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Here's a question- Is there any worry of bending a rod from the massive torque at 3500rpm?

I haven't seen any rod failures due to too much torque, and the Vishnu single turbo is capping torque around 500, so it's unknown at this point what tq level the rods will let go at. Because of that I'm a bit weary of cranking it up farther than my current 440whp/503wtq level.
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