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boost hp calculation

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Old Apr 5, 2009 | 03:46 PM
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Default boost hp calculation

Hey,

I have an equation to figure hp from boost. It's 6% of base hp x lbs of boost.
example: 98 GT=195hp
6% = 11.7
Boost = 10lbs 11.7 x 10 + 195 = 312hp

Is this correct? Also I would think that 10lbs of boost on ported heads would produce more hp than non ported heads. What is the way most of you figure out what yourr end results will be when adding boost? I need to buy a pulley so I need to know what boost I need for my hp goal. Also what bolt ons I need.

Any help appreciated
Old Apr 5, 2009 | 04:41 PM
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I would get it dyno tuned and then you'll know for sure.
Old Apr 5, 2009 | 06:06 PM
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Originally Posted by Obsequious1
I would get it dyno tuned and then you'll know for sure.


Thanks, I plan on getting it Dyno tuned, however I am not trying to make max hp. I have a goal of 350rwhp. I would like to be able to calculate approx hp before that, so I am not grossly under or above my stated number. I have many add on parts, so I want to pick the right combo to get 350.
Old Apr 6, 2009 | 02:41 PM
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Do you have cams and headers? If not then you should go with 8 lbs of boost to hit your mark. Ported heads, cams and headers will drop the peak amount of boost you see but will pick up rwhp. If your not stock as far as cams, headers and heads are concerned then you can't go by boost. If your running a P-1 and have a stock bottom end just go with a 3.4 pulley. No matter what boost it makes it'll hit your mark.
Old Apr 6, 2009 | 06:11 PM
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Originally Posted by contentsunderpressur
Do you have cams and headers? If not then you should go with 8 lbs of boost to hit your mark. Ported heads, cams and headers will drop the peak amount of boost you see but will pick up rwhp. If your not stock as far as cams, headers and heads are concerned then you can't go by boost. If your running a P-1 and have a stock bottom end just go with a 3.4 pulley. No matter what boost it makes it'll hit your mark.
Cool info, unfortunately you lost me. Yes I have cams, a pi manifold, shorty headers,75mmTB/plenum, catted x, catback, none of it is installed. Bottom end is stock.

I want 350-380rwhp. I need to buy a pulley. I am trying to figure out what parts to use to get to that hp. There are a couple of combinations.

Are you saying that there is not a way to figure hp if the car is not stock, due to the difference in flow?. Is the boost number a product of the resrictiveness of the motor?


Thanks
Old Apr 7, 2009 | 04:50 AM
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You can install all the parts you have and run 8 psi of boost and make 380 even more to the back tires. You can get it dyno tuned for 400 rwhp if applicable or you can get it tuned at 350 rwhp. Its all in the tune.
Old Apr 7, 2009 | 04:58 AM
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Which blower are you running? When I was all stock I ran a 3.6 pulley on a P-1. I made 353 rwhp and 8 lbs of boost. After that I swaped to a 3.4 pulley but never got it dynoed again. I did make 10 lbs of boost though. After I built my motor, added stage 2 ported heads and blower cams, I had to drop to a 3.2 pulley to keep my 10 lbs of boost but picked up 87 rwhp.
Old Apr 7, 2009 | 09:22 AM
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I have a Vortech V1 kit.
Old Apr 7, 2009 | 09:25 AM
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Originally Posted by Obsequious1
You can install all the parts you have and run 8 psi of boost and make 380 even more to the back tires. You can get it dyno tuned for 400 rwhp if applicable or you can get it tuned at 350 rwhp. Its all in the tune.


I was wondering that last night, if they could dumb down the hp via the tune. So if I install all my parts and make 420hp, they can change the tune to limit to around 380 ? That would solve all my issues. I was afraid of going over 400 and blowing up my bottom end. Is there a limit on how much they can shave?

Last edited by Armydad; Apr 7, 2009 at 09:27 AM. Reason: spelling
Old Apr 7, 2009 | 09:41 AM
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They can take timing out to lower your hp to a certain extent. You'll lose gas milage like that too though. If you run a 3.6 pulley with that blower it should make about what your looking for tuning it all out.



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