boost questions!
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Junior User
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boost questions!
ok Ive got my 6 pos. in now but in the high and extreme settings i get a over boost light and can only push about 28 psi? questions is, how much boost will a stock turbo handle and does the computer defuel the truck if you over boost it because it sure feels like it to me?
Lead Driver
Joined: Oct 2004
Posts: 7,413
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From: Columbia, MO
It will defuel at about 24 psi. The way around that is a MAP line regulator, so the MAP sensor won't see the extra boost. However, much above 25 psi and you are out of the efficiency range of the stock turbo and you begin to just super heat the air. Plus, the stock turbo won't live long at those boost levels.
Post Fiend
Joined: Jul 2005
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From: 21791
the van turbo has been tested up to 39psi (by Mech2161) and with that boost he was still only getting 39psi of backpressure.
as long as the boost and the drivepressure ratio is close to 1:1 or only a few pounds apart, then it's unlimited on what boost to run, because there is virtually no side loading on the bearings, as opposed to the stock exhaust housing creating a 2:1 drivepressure to boost ratio. so at 28psi of boost, you were probably making 55-60 psi of backpressure, which is extremely inefficient for the boost you were making.
i could see 28psi or so with my stock turbo, but now with the 1.15 van housing and the WW (soon to be ATS this week) i can produce 25psi, but i know it is alot more efficient, it's moving more air with less restriction, and its not way out of the compressor efficiency map. lowers cylinder pressures which extends longevity.
as long as the boost and the drivepressure ratio is close to 1:1 or only a few pounds apart, then it's unlimited on what boost to run, because there is virtually no side loading on the bearings, as opposed to the stock exhaust housing creating a 2:1 drivepressure to boost ratio. so at 28psi of boost, you were probably making 55-60 psi of backpressure, which is extremely inefficient for the boost you were making.
i could see 28psi or so with my stock turbo, but now with the 1.15 van housing and the WW (soon to be ATS this week) i can produce 25psi, but i know it is alot more efficient, it's moving more air with less restriction, and its not way out of the compressor efficiency map. lowers cylinder pressures which extends longevity.
Lead Driver
Joined: Oct 2004
Posts: 7,413
Likes: 1
From: Columbia, MO
Van turbo's have been pushed up to around 40 psi. But, it takes a lot of fuel to get there. The van turbo actually runs less boost than the stock one, but it's more efficient and actually moves more air & cooler air at lower boost numbers. For example, right before I changed my turbo over, I could hit 34 psi on the stock turbo. Swap to the van-like setup and now it can sometimes push 27 psi, but typically 25-26. However, I'm making more power than I was with the stock turbo because the new setup is more efficient.
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locknload223
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Jul 21, 2009 06:48 AM
