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Stock psi?

S

Slopar00

New member
I just installed a auto gage boost gauge in my car and says the boost is around 6-8 psi is that right? Figured for as good as the car goes it was higher then that.
 


my car stock didnt see 7 psi till the shift. most of the time 6 at the most.

unless it was 5 degrees out, then id see 8 psi easy.
 
Doesnt matter, boost level is still the same.

The M90 is not a very efficent supercharger and mega big stock pulley size give you the avg boost numbers. Any more on the stock motor and it would be slower and can easily damage the engine.
 


Fivefingerdeathpunch said:
Doesnt matter, boost level is still the same.

The M90 is not a very efficent supercharger and mega big stock pulley size give you the avg boost numbers. Any more on the stock motor and it would be slower and can easily damage the engine.
Click to expand...

So If I put a 3.6 pulley on my car it will be slower?? How does that make any sense obviously with a tune. Right now I have a 3" catless dp Autolite 104s msd plug wires and home made intake.
 
Slopar00 said:
So If I put a 3.6 pulley on my car it will be slower?? How does that make any sense obviously with a tune. Right now I have a 3" catless dp Autolite 104s msd plug wires and home made intake.
Click to expand...

Not necessarily. And if you have a catless downpipe and better intake you are not stock :p . With those you are probably actually seeing "less boost" than stock. More boost on a supercharger just means the supercharger is working more harder, not necessarily that you're going faster.

What people mean by the smaller pulleys making you slower is that they can cause KR which will reduce your timing and make you slower. If you can run a scan on your car right now and see no KR at all then you are probably fine with a 3.6 but not all cars are the same so you never really know until you scan for KR.
 


I ran a 3.6 on my monte, with the Ubend delete (your down pipe is a better solution) gutted factory air box, and autolite 104s, and a 180tstat i didnt have KR until the shift from second, i timed my car with a good launch at 6.2 to 60 from about 6.6 before, granted the launch is important but it did definitely add a little power (my guess was about 20hp overall)
stock i saw 7psi stock, with the pulley i hit 9psi when it was cold out (sub freezing), 3.6 is alright, but IMO the 3.4 and its mods are the way to go, you'll notice it more
 
I'm going to ro all maintenance work and make sure that my kr is real low before I go dropping a pulley.

I did hit 8.5psi on my auto lite boost gauge. It was about 60-70 degrees out.
 
if your stock your kr is real lol they all knock stock, bad. up to 8* of KR. what i had.

you need headers to drop a pulley. or a plog and down pipe.
 
Skip the plog and get some speed daddy headers for $217 shipped on fleabay. That will solve both the restrictive front manifold and the even more restrictive U-bend. That alone will kill any KR you have
 


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