vacuum/Boost
#1
vacuum/Boost
This question is just out of curiosity. If an intake usually works off vacuum and a blower adds boost, what is going on when you go part throttle and the gauge reads “0”? No vacuum, no boost, wouldn’t this mean no airflow? Or is this the happy medium whre air is being pushed in just enough to not be a vacuum but not quite enough to boost air levels? And if so, wouldn't this be the most efficient level for the engine?
#2
14 Second Truck Club
iTrader: (31)
Originally Posted by 1SlowHoe
This question is just out of curiosity. If an intake usually works off vacuum and a blower adds boost, what is going on when you go part throttle and the gauge reads “0”? No vacuum, no boost, wouldn’t this mean no airflow? Or is this the happy medium whre air is being pushed in just enough to not be a vacuum but not quite enough to boost air levels? And if so, wouldn't this be the most efficient level for the engine?
#3
single digit dreamer
iTrader: (6)
yes it is the happy medium where the intake presure is the same as atmospheric presure. normaly on a NA set up there will always be a little vacume so you are geting some extra hp from the blower even at 0psi.
often people see great gains from very low boost levels. something like 50hp from 2psi kind of thing but you are really seeing more of a diference that 2psi because there was some vacume that was overcome too.
i dont really know when the max efficency would be but i dont see any reason why it would be right at 0psi. it has more to do with the compresor, heads, cam, stuff like that.
often people see great gains from very low boost levels. something like 50hp from 2psi kind of thing but you are really seeing more of a diference that 2psi because there was some vacume that was overcome too.
i dont really know when the max efficency would be but i dont see any reason why it would be right at 0psi. it has more to do with the compresor, heads, cam, stuff like that.
#4
Thanks guys. That's kinda of what I was thinking but wanted some other ideas. Heres a question for ya that is sure to have people arguing.
What is the most boost I can run on stock internals with a good/dyno tune? I'm wanting to go down from a 3.4" pulley to, say...a 3.25" and try to get 9 pounds or so. I know 10 pounds would be pushing my luck. What is the limiting factor? Rockers, springs, push rods?
What is the most boost I can run on stock internals with a good/dyno tune? I'm wanting to go down from a 3.4" pulley to, say...a 3.25" and try to get 9 pounds or so. I know 10 pounds would be pushing my luck. What is the limiting factor? Rockers, springs, push rods?
#6
14 Second Truck Club
iTrader: (31)
Originally Posted by parish8
yes it is the happy medium where the intake presure is the same as atmospheric presure. normaly on a NA set up there will always be a little vacume so you are geting some extra hp from the blower even at 0psi.
#7
14 Second Truck Club
iTrader: (31)
Originally Posted by 1SlowHoe
Thanks guys. That's kinda of what I was thinking but wanted some other ideas. Heres a question for ya that is sure to have people arguing.
What is the most boost I can run on stock internals with a good/dyno tune? I'm wanting to go down from a 3.4" pulley to, say...a 3.25" and try to get 9 pounds or so. I know 10 pounds would be pushing my luck. What is the limiting factor? Rockers, springs, push rods?
What is the most boost I can run on stock internals with a good/dyno tune? I'm wanting to go down from a 3.4" pulley to, say...a 3.25" and try to get 9 pounds or so. I know 10 pounds would be pushing my luck. What is the limiting factor? Rockers, springs, push rods?
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#8
single digit dreamer
iTrader: (6)
Originally Posted by 1SlowHoe
Thanks guys. That's kinda of what I was thinking but wanted some other ideas. Heres a question for ya that is sure to have people arguing.
What is the most boost I can run on stock internals with a good/dyno tune? I'm wanting to go down from a 3.4" pulley to, say...a 3.25" and try to get 9 pounds or so. I know 10 pounds would be pushing my luck. What is the limiting factor? Rockers, springs, push rods?
What is the most boost I can run on stock internals with a good/dyno tune? I'm wanting to go down from a 3.4" pulley to, say...a 3.25" and try to get 9 pounds or so. I know 10 pounds would be pushing my luck. What is the limiting factor? Rockers, springs, push rods?
the limit is your fuel and tuning. tranny wont be happy either.
about 6-7psi seems to be the limit on non intercooled set ups with pump gas, i would think an intercooler would add 2psi or so but i am not up on what the limit for a radix on pump gas is. there is a point when you have to run it soo rich and pull so much timing to run the higher boost and stay out of knock that you end up gaining no power.
#9
single digit dreamer
iTrader: (6)
Originally Posted by mzoomora
I dont think 10-11 PSI is all that much if you are not beating on the truck constantlyand have a safe tune. I might try 13-14, I am at 10 now. Its still under warranty anyway.
#10
From what you guys are saying I think I could run 9 #'s safely. I have an intercooler, I run 93 octane fuel and plan on getting a dyno tune when I go with the smaller pulley. I just wanted to make sure my rods, springs and etc...would take 9 #'s. I see about 7 at wot right now. Mine however is Not under warranty. Actually it is under extended warranty but the dealership won't even look at my truck with the Radix on it. I haven't fought that battle yet.