Turbo 5.3 laggy spool
06-17-2015, 02:00 PM
#21
Sure that gate is staying closed?
06-18-2015, 05:27 AM
#22
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pretty sure the wastegate is staying closed i did do a boost leek test as well i pressurized the intake to 37 psi before i could even hear any leeks so i know the intake is sealed.do you guys thing it could be week valve springs.
06-18-2015, 05:32 AM
#23
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ya you can just barely feel i little bit of exhaust leaking from one of the welds on the exhaust. i did however find another little pin hole in the other side and my flange for the driver side manifold was a little loos and leaking. but they were all minor leeks not even big enough to tick. do you think that would cause my lack of spool. also do you guys think i could be getting valve float with some week valve springs the motor does have 120000 miles on it with not even a freshen up.
06-18-2015, 08:41 AM
#24
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here is a pic of my setup and don't worry the hose clamps have since been replaced with T bolt clamps i just didnt have enough at the time that i took that picture and the coils have been relocated to below the manifolds as to keep the spark plug wires clear of the manifolds.
06-18-2015, 08:56 AM
#25
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Well placement isnt really ideal, that will slow stuff down but doesnt answer the boost loss. Also I have to ask since I have seen flipped UP mani's on a few cars with issues. I would check all the wires and make sure you are not burning any up.
Also it looks like the gate is completely 90 degrees to the pipe. I would cut that off and put it on as much angle as possible so exhaust is flowing INTO the wastegate.
Jay
Also it looks like the gate is completely 90 degrees to the pipe. I would cut that off and put it on as much angle as possible so exhaust is flowing INTO the wastegate.
Jay
06-18-2015, 11:07 AM
#29
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i would think that hotside being as big as it is could effect spool time some, i have a 5.3/gt45 and went with 2in for my hotside.that doesnt explain the power numbers being low though.
06-18-2015, 11:40 AM
#30
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i think that has something to do with the lack of fuel pump it was going a little lean around 4000 rpms not too bad only like 15 or 15.3 to 1 but the tuner was able to compensate most of that with trim and we got it back down to safe levels. we were also getting some knock retard at 10 deg of timing so he bumped it back to 8 and that went away i think thats because the plugs are gapped to .030 and they should be like half that.
06-18-2015, 12:02 PM
#33
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the really weird thing is that it's not like it's at 7 lbs as soon as the turbo spools. it makes 2 or 3 lbs at 3200 when the turbo spools then gradually builds to 7 maybe 8 by 6000 and the waste gate starts to open around 5800 ish
06-18-2015, 12:04 PM
#34
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i'm at a complete loss the only thing that i could think of is it's a rather big turbo for a stock motor and the cam doesn't have much lobe separation. and my fuel pump may not be big enough to supply fuel to 80 lb injectors like i'm asking it to. i'm gonna try and fix those things and bring it back to the tuner and see if i can get any better results. i found you can pick up a Z06 cam for around 250 and a set of matching springs for 60 and i'm gonna go to a 2 pump setup and see if that helps.
06-18-2015, 12:09 PM
#35
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does anybody know of a way to verify what i have for a spring in the waste gate, the description says i have a 12 or maybe even a 10 lb spring (i don't actually remember which one i had them put in) and the tuner said he put a 5 in while we were tuning, so if anyone knows how i can check them it would help.
06-18-2015, 01:03 PM
#36
Blow compressor air into the bottom port of the wastegate. Whatever pressure opens it, divide that in half and thats the "rating" of the spring.
Where is your boost reference coming from that goes into the wastegate bottom port? It should be between the IC outlet and throttle body.
Where is your boost reference coming from that goes into the wastegate bottom port? It should be between the IC outlet and throttle body.
06-18-2015, 01:24 PM
#39
Congratulations. If someone is having a problem making steady boost, or much boost at all, between the IC outlet and TB is better than the compressor outlet. Ive used the compressor before too but it opens the gate sooner because the pressure is higher pre-IC.
06-18-2015, 01:42 PM
#40
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I usually run a vacuum block off of the intake manifold. From there I line-out to the boost gauge, MAP sensor, wastegate, Hobbs switch, and regulator.