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Discussion Starter · #1 ·
I have a s300/ ht3b setup and i have a boost gauge in the intake and in the pipe between the two turbos. I am needing to know what is a good number to have on boost on the one in the pipe beween the two turbos. i am only getting 15 psi there and i am getting 50 at the intake just wanted to make sure they are working porperly
 

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i would play with the waste gate on the top turbo and try for around 20-25 psi

20-25psi top charger and around 30-35psi for the bottom....but you will also want to check the drive pressures.....run a gage in the exhaust manifold to read that and waste gate it as close as you can to 1:1....i would guess around 65 psi should get you close 1:1
 

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Discussion Starter · #3 ·
top turbo boost

i would play with the waste gate on the top turbo and try for around 20-25 psi

20-25psi top charger and around 30-35psi for the bottom....but you will also want to check the drive pressures.....run a gage in the exhaust manifold to read that and waste gate it as close as you can to 1:1....i would guess around 65 psi should get you close 1:1
How do i figure what the top charger is making? do i take intake manifold boost-Bottom turbo boost and that will give me top turbo boost
 

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you said your getting 15psi now?.....from where you have it hooked up that is what the top charger is putting out...the one in the intake would be total of both chargers

keep in mine that it takes fuel to make boost so i am not sure how hard you are fueling it
 

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Discussion Starter · #5 ·
Clairfy

To Clairfy the bottom one is making 15 and the top and bottom compine is making 40+ psi
 

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To Clairfy the bottom one is making 15 and the top and bottom compine is making 40+ psi
ok if thats the case it sounds like you don't have enough fuel to push the bottom charger...you may want to look into some injectors


bottom should be at around 35psi and the top (small turbo) should be around 25psi + or - to get you close to 1:1 drive pressures

some will run a little more depending on mods,....ex. ported head..etc

do you know the size of the exhaust housing on the HT3B ?
 

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Correct me if I'm wrong. Drive pressure should be 1-1 (Exhaust manifold - Intake manifold)
And the bottom charger should be putting out 1/2 of your total boost reading at the intake?



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Correct me if I'm wrong. Drive pressure should be 1-1 (Exhaust manifold - Intake manifold)
And the bottom charger should be putting out 1/2 of your total boost reading at the intake?
correct....but from what i was told the bottom turbo should be a little more then 1/2 60/40 + or - ...to lower drive pressures.....and that what i found with my set-up....about 60/40 gave me the lowest drive pressures with the highest boost pressures
 
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