how many psis to run

shttygtstang

New Member
Jun 2, 2004
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i have a 89 gt 5.0 simple mods xpipe 70mm throttlle boddie bmm headers i just bought a paxton sn93 and a bennet rcaing headgsket 65 thousands over compresion willl be dropped to 8.5 any ideas how many pounds of boost to run
 
did u just pluralize PSI to PSIS??? LOL... You didnt need to spend the extra money on those .065 thick headgaskets. That is huge for a headgasket. Theres alot of guys on here with stock block motors running 10-12psi and doing no harm. I recommend doing a compression check to check the integrity of the piston rings too see if their up for the job of holding boost.
 
shttygtstang said:
hey im new here and new to the hole v8 world ... ya i plured it but to my piont i wasnt thinking of runnig 12 psi more like 16 18 maybe a turbo combo to

Welcome to the club..

What are your goals? 16-18 psi is ALOT...more like unheard of, im making 600hp with 10 psi on a 331, so what are you aiming at? :shrug:
 
like i said new to the whole v8 thing ..i have a eclipse gsx rummig at 19 psis with 8.5 compression. thats why i purchased a thicker head gasket to run high boost 15 18 psi with low compression could be done i know that much if you can help or give me some theorys that would be great
 
shttygtstang said:
10 psis ? with a 8.5 compression i know i dont know about stangs buti know about adding boost you can boost alot more pressure than that


14.7 psi is the atmospheric pressure, SO, if you boost a motor with 14.7 psi, you will technically DOUBLE the output of power, as long as you have the supporting parts, ie: fuel, spark managment, intake, exhaust ect ect ect...SO, for example, a 302 (225hp stock)with well flowing heads and intake, with high flowing injectors, boosted to 14.7 psi, should in theory make somewhere around 450- 500 FLYWHEEL horsepower, which translates to approx 400 rear wheels hp, WHICH the majority of guys on this sight have, by doing the above combination. My engine in particular, flows REALLY well. The heads are stage 3 ported twisted wedge with off the chart flow numbers, and iv got an unrestricted exhaust(long tube headers, no cats). I have a 14lb pulley on my supercharger, and as we know PSI stands for Pressure per Square Inch, so...Since my motor flows so well, ( good heads and intake) I will never actually see 14 psi on my boost guage, becuase the motor is using that air before it has time to build PRESSURE(per sqaure inch). However, I am still injesting the same amount to CFM, or, volumetric air into the motor. So in conclusion, I only see about 7-10psi on my guage, but the power output is the same as someone who would be squeezing 14psi into the restrictive combination causing more stress on the motor. any questions?
 
Youre eclipse and mustang are 2 different worlds. For one I guarantee you dont have the fuel system to handle 15psi, id be sceptical of enough fuel for 6psi. The eclipse was built from the factory to handle boost and the ECU is able to compensate for that better. The mustang is not in the same boat. The 5.0l engine is robust, but not 19 psi from the factory. Also one thing to remember is your efficiency. What turbo are you running on your Eclipse? Stock i bet...News flash, run that T-25 at 15psi and you be just as fast and your turbo will last years longer.

-Dallas J
 
no actuly im running a 20g with alot of mods ESTAMATED 350-400hp...got bored with it though any more with that car an its would be a drag car that couldnt be driven on the street ***** that car though ..and no at this current point in time i dont have a fuel system to handel that i dont even have the sc on the car but im willing to get the stuff needed to see high boost numers.F.I is the best set up for cars i think .wut sc are you runing
 
shttygtstang said:
i wanna do an sc turbo combo thats my goal

Thats unrealistic and uneffecient, been tried and proven to be a waste of money, just good for looks. You dont need to worry about turbo lag with a 5.0, its virtually unheard of. Im running an Water to Air intercooler on my supercharger, its not needed, but good to have. Air to Air would be the way to go without a doubt.