need help on greddy bov adjustment

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djfalcon10
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need help on greddy bov adjustment

Post #1 by djfalcon10 » Thu May 04, 2017 8:23 pm

Ok guys i need your help on this. Have a 300 6 with a paxton supercharger novi gss. It is pushing 7 psi. And i have running a intercooler on it. I got myself a greddy rs 35mm blow off valve. Now at first i set it to soft setting. When i rev the motor and let off the throttle. A little bit was coming off the blow off valve.. But it was coming out of the air filter on the supercharger. So i went to hard and it did the same thing..it has 2 springs in the blow off valve. Do you think it has to much pressure with the 2 springs?And i should take the inter spring out and with that help with the pressure.plus i have a vac/boost gauge. When i rev the motor. Should it go on the boost side? Cause when i rev it. It give me 20 inch of vacuum. At idle it at 7. Any help would be appreciated.

pmuller9
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Re: need help on greddy bov adjustment

Post #2 by pmuller9 » Fri May 05, 2017 12:18 am

Do you have the hose from the BOV diaphragm connected to the intake manifold vacuum?
I wasn't aware that it came with 2 springs on the top side of the diaphragm.

Where or who did you buy this BOV from?

djfalcon10
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Re: need help on greddy bov adjustment

Post #3 by djfalcon10 » Fri May 05, 2017 8:27 am

Yes i do have it hook up to the intake manifold vacuum. I bought the blow off valve from greddy. Here's what my setup looks like

djfalcon10
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Re: need help on greddy bov adjustment

Post #4 by djfalcon10 » Fri May 05, 2017 8:41 am

20170416_135843.jpg

Here a pic of my setup
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pmuller9
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Location: Columbus, Indiana

Re: need help on greddy bov adjustment

Post #5 by pmuller9 » Fri May 05, 2017 9:56 am

Thanks for the picture. clean looking setup.

The Vacuum/pressure gauge should read pressure (or at least less vacuum) when you rev the engine.

Try removing the inner spring

djfalcon10
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Re: need help on greddy bov adjustment

Post #6 by djfalcon10 » Fri May 05, 2017 10:51 am

Ok. I took off the inner spring. And try it. And now.lol when the blow off valve open. I hear a little whoosh but alot more coming out of the supercharger filter. Now i dont know know what going on. Now just to let you guys know. I am doing this in park.now should i go out and drive it and put a load on it and see where it whooshes?

pmuller9
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Location: Columbus, Indiana

Re: need help on greddy bov adjustment

Post #7 by pmuller9 » Fri May 05, 2017 1:26 pm

One of the reasons it blows out the supercharger is because the intercooler is filled with pressurized air and blows out both ends when the pressure is released.
Drive it and see if how much the boost gauge reads when you let off the gas pedal.

djfalcon10
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Re: need help on greddy bov adjustment

Post #8 by djfalcon10 » Sat May 06, 2017 10:22 am

ok took the car out today. When i give the car. Part throttle i hear a little whoosh. Got on the car and it gave me 4 pounds of boost. I am guessing if i tighten it up. The bov will hold more pressure and give me a higher boost. If that is correct

djfalcon10
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Re: need help on greddy bov adjustment

Post #9 by djfalcon10 » Sat May 06, 2017 4:20 pm

Ok i tighten it up a little more. It still just giving me 4 psi of boost. When i bought the supercharger. I got a rebuild sheet with it. and it suppose to have 7psi . but i did change the pulleys over from serpentine to dual pulley.i got it from paradise wheels. Woundering if the pulley is a little bigger then the old one. Going to measures it soon. And let you know.

djfalcon10
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Re: need help on greddy bov adjustment

Post #10 by djfalcon10 » Sun May 07, 2017 11:57 am

Ok. I check the old pulley and its 4 3/4.the new one is 5". So with the bigger pulley i got less boost? Hopefully you guys can help on this. Can a 1/4 difference make me lose 3 pounds of boost?

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