Horsepower gains from pounds of boost.Weird question
09-24-2007, 07:43 AM
#22
just shows how nieve the import crowd is to turbo domestics. my buddys GT67 rearmount gto picked up about 110-120whp on just 4psi- 420-430whp with a formata tune. his car is strong as hell
thats closer to 25-30whp per lbs of boost.
i picked up 110whp on 9psi on my turbo blazer.
and yeah +1 on the new friends.
also my buddy threw his kit together for about $3300. that was a used STS set-up for $2000 + GT67 $700 + 42lbs injectors(200) + formata tune (~$300)
he got the kit cheap because the sts turbo was fubard so he bought a bigger one
thats closer to 25-30whp per lbs of boost.
i picked up 110whp on 9psi on my turbo blazer.
and yeah +1 on the new friends.
also my buddy threw his kit together for about $3300. that was a used STS set-up for $2000 + GT67 $700 + 42lbs injectors(200) + formata tune (~$300)
he got the kit cheap because the sts turbo was fubard so he bought a bigger one
Last edited by 02Vortech; 09-24-2007 at 07:53 AM.
09-24-2007, 09:40 AM
#23
Originally Posted by SStolen
Update: LS1Chris, your friends are holding you back. Find new car buddies.
show them a few dyno sheets that list the numbr of pounds they are running in the title.
09-24-2007, 10:34 AM
#24
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Said before but just to reiterate, there is no simple equation that dictates hp/psi. There are sooooooooooo many other factors to account for to see how an engine would perform and the graph would likely look like a shallow bell curve rather than a linear
09-24-2007, 10:52 AM
#25
Originally Posted by SStolen
Stock LS1 = 300rwhp /14.7 = 20.4hp x 18psi = 367 + 300 = 667. But an APS kit on a forged stock cube LS1 should make 850rwhp on 18psi which would equal over 30rwhp per lb of boost, which completely bothces this formula.
09-24-2007, 11:16 AM
#26
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Dont forget also a big part of how much power the turbo makes is where in the effiecient range its in too... if you run 4 lbs on a ginormous turbo, you might make 25hp/lb... where as if you run 15lbs you will make 30-40... at least from my experience.
09-24-2007, 02:23 PM
#27
my T/A went from 344 RWHP NA to 454 RWHP with NOTHING changed besides the addition of a P1SC at about 6psi. So that is 18.3 RWhp per psi of boost with stock exhaust manifolds on a completely stock shortblock... (When I added headers, it got 489RWHP.)
Your friends are wrong.
Your friends are wrong.
Last edited by ChevyChad; 09-26-2007 at 07:36 AM.
09-24-2007, 02:36 PM
#29
Has nothing to do with the amount of boost. It is strictly CFM flow. Boost is only restriction to flow. For example, take a car that is making 500 hp at 5 psi of boost/restriction, Now put better flowing intake/heads/cam and that car may make the same 500 hp on only 3 psi of boost/restriction. It is all about CFM flow.
09-24-2007, 04:34 PM
#31
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Some very good info here guys thanks for some insight.i admit i am thinking my friends have watched The fast and the curious one to many times .But Dont worry guys tonight im going to have some fun i will send them this post so they can read up and just sit back and look at their face lol
09-24-2007, 05:46 PM
#34
Originally Posted by ls1chris
well after talking with a few friends that have nissian 240sx with a sr20 det they say that you will gain 7 horsepower for every pound of boost you have .I was telling them how i seen some Turbo setups running 6-7 psi and putting down 400-415 hp at the wheels ,They said their is no way that is possiable on a bolt on car with that little boost .So is that about the goin rate of hp gain for each pound of boost you bolt on ls1s guys see. they said i was full of it when i told them i seen a ls1 put down 300rwhp then put a turbo kit on and hit 400+ with around 6-7 psi .
ls1's in general gain 25 rwhp per lb of boost.
09-24-2007, 06:21 PM
#35
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Tech Adddict you are just about right on.
Every one is forgetting engine size.
1 lb boost on a 1 liter motor is not going to produce the same HP gain as 1 lb boost on a 6 liter motor.
According to Gale Banks: "1 lb boost is equal to 7% increase in Hp"
I think he is more close to it than anyone.
Bob
Every one is forgetting engine size.
1 lb boost on a 1 liter motor is not going to produce the same HP gain as 1 lb boost on a 6 liter motor.
According to Gale Banks: "1 lb boost is equal to 7% increase in Hp"
I think he is more close to it than anyone.
Bob
09-24-2007, 07:45 PM
#37
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you are not going to gain hp numbers per lb of boost guys! you are gaining a percentage of your n/a power levels.
besides you dont even gain hp you are gaining torque. hp is just an equation of the relationship between torque and rpm. you dont measure horse power, you calculate it.
besides you dont even gain hp you are gaining torque. hp is just an equation of the relationship between torque and rpm. you dont measure horse power, you calculate it.
09-24-2007, 08:30 PM
#38
Originally Posted by uncle ray
you are not going to gain hp numbers per lb of boost guys! you are gaining a percentage of your n/a power levels.
besides you dont even gain hp you are gaining torque. hp is just an equation of the relationship between torque and rpm. you dont measure horse power, you calculate it.
besides you dont even gain hp you are gaining torque. hp is just an equation of the relationship between torque and rpm. you dont measure horse power, you calculate it.
I can agree with that!
09-25-2007, 07:56 PM
#39
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i think topend is right how do you explain indy-f1 cars of the past running 6-7 psi making 800hp. its really restriction and flow ....even wher you read the boost from makes a difference. on a huge turbo in the upper reaches of boosted applications size of the turbo(s) matter, example on a 88mm vs a 106mm turbos running the same boost levels you wont net the same HP at same psi . as levels are pushed and ALL the factors come into play the larger turbo will win hp per pound of boost but it might not be the same case if the smaller turbo was the "right" choice for the motor
too many factors to figure that one out ive seen from 12 to 30 hp per pound of boost depending on cars heads mods etc. etc plus varying factors...... go figure
too many factors to figure that one out ive seen from 12 to 30 hp per pound of boost depending on cars heads mods etc. etc plus varying factors...... go figure
09-25-2007, 09:01 PM
#40
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my old Z put down 488rwhp on only 6-7 lbs with just a cam and bolt ons. It made 370 before the turbo. so thats about 120 off of 6-7 lbs. around 20 per lb. roughly....