Ya my car idles 11.5 to 12.0 rich at idle my giant carb doesn't like much leaner the curb screws don't have much turn left to go in either.

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For some reason I can't adjust the idle to be rich at all. It seems to be 22 or nothing. At one point I had it at 13, and it ran great, but now I can't get it back there. you were right about the whole tuning part not being fun. Once I get 5 psi stable, then I'm taking it to 8 where it will probably stay till I get some better components. It's best not to press my luck with some of the Chinese parts while it's a daily driver.

my 650 doesnt like a lean idle either.

do your mix screws do anything? thats a pretty small carb, you should be able to get a good mix at idle. might be time to pull the bowl and blow out the passages. only takes a tiny piece of crap to fall down the vent tube to mess things up.

the tuning isnt fun but the test drives are most of the time. not saying it will get easier but you will get used to it. lol. ive been in my carb more times that i really wanna think about and ill be in there a bunch more. but its worth it every time.

dont give up at 8, get at least 10 out of it. its still pretty safe and its the tipping point into the really fun numbers.

Not sure about 10, this is still a stock motor, in-fact I just rolled over the first 100k miles on it. The car now only has 26 miles on it. Practically brand new. Both mixture screws are turned out about 3 full turns. Before that it likes to stall out. The curb speed screw is in about 1 full turn.

my car held 14 for a while, completly stock motor. now im pushing 20 and everything is still good. not saying go crazy but 10 is fun and pretty safe.

sounds like you need to go into the carb and give it a good cleaning. there has to be something in there.

little update. worked on my brpv a little today. went a proven route this time. drilled the carb to use turbine pressure instead of boost pressure to open the power valve. turbine pressure is usually 2:1 boost pressure. so for 5psi boost i should see 10psi back pressure before the impeller.

<img src="http://i125.photobucket.com/albums/p79/weesers1/Mobile%20Uploads/20141130_154920_zps11hsatnd.jpg" border="0" alt=" photo 20141130_154920_zps11hsatnd.jpg"/>
the top hole is through to the power valve cavity. the bottom one has a drill bit snapped off in it. didnt make i all the way through thankfully. the brake line with the first half of a double flare done to it to hold the hose. tapered end to use with an interference fit on the hole.

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pipe fitted.

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managed to get through without hitting any passages. you can see the raised portion in the cavity where the whole comes out.

<img src="http://i125.photobucket.com/albums/p79/weesers1/Mobile%20Uploads/20141130_155126_zpsz4tfm3iz.jpg" border="0" alt=" photo 20141130_155126_zpsz4tfm3iz.jpg"/>

<img src="http://i125.photobucket.com/albums/p79/weesers1/Mobile%20Uploads/20141130_160244_zpslwbqsep7.jpg" border="0" alt=" photo 20141130_160244_zpslwbqsep7.jpg"/>
put some epoxy in the hole and smacked the pipe in with a hammer. epoxied the outside. tried to get it close to the flange for a little extra strength.

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this is the brpv i was using. the drilling and added pressure is to compliment this setup. just to make sure it opens every time and all the way isntead of just letting it do what it wants too. given the extra pressure from the turbine i put a 6.5 spring back in.

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copper line im going to sue for my reference. going to use the whole length to dissapate any heat that might try to make its way twards the power valve. there isnt really any flow in this setup so it shouldnt be an issue but better safe then sorry.

<img src="http://i125.photobucket.com/albums/p79/weesers1/Mobile%20Uploads/20141130_162210_zpsmicrrpq3.jpg" border="0" alt=" photo 20141130_162210_zpsmicrrpq3.jpg"/>
used a post off of a buick electra script that i stole the 225 off of to plug the port where the power valve cavity would normally get its signal from. epoxied the hole and smacked it in with a hammer. nice tight fit. covered with epoxy though its not in this pic.

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coudnt remember if i had taken a picture of this before but the brass fitting at the base of the carb is where i get my boost vacuum signal from for the gauge. just pulled the pipe that was in there out and tapped it. was already the right size. works well.

thats all for now. waiting for the epoxy to setup and still trying to figure out where to tap into the turbine housing. not sure if i need it close to the flange or if i can go a little further up the snail. if it has to be near the flange i have to take the turbo off and im not looking forward to that.

For sure tuned into this portion. I'm just gonna have standard brpv for now and see where that gets me. Hopefully this works out, only down side is drilling the snail

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225, Offenhauser, Holley 350, A833OD, 3:55, GM HEI,99 Durango starter
BOOSTED! WH1C, BIG FMIC, 10#
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No reason to drill directly into the turbine housing. You can pick up the drive pressure from any point in the exhaust manifold between the head and the turbo.

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i know. but the easiest thing to do would be to drill the snail. im gonna have to take the turbo off to do it. im pretty sure i can rig something up on my drill press to get a good straight hole. im not taking my manifold off. its a pain in the butt. i dont trust the j-pipe enough to drill that so it kinda only leaves me one option. for some reason i have trouble drilling holes straight enough to tap them and have the fittings fit well enough to seal so i think taking the tubo off is the way to go for me. if i had thought to do this sooner i would have drilled the manifold last time i had it off.

the standard brpv like the one i have pictured does work. but i think it could be better. the afr drops down to where it should be a little slower then i like. i would prefer it to get there a lot quicker and know that its going to happen every time. im pretty sure a stock motor will hold 25+psi of boost, but thats only gonna happen with a good tune. that is something i want to test. im also doing this to be able to cruise with it again. once i know the brpv is opening when its supposed to then i can jet it back down in the primaries and open up the pvcr's a little more to make up the difference.

I would probably weld a threaded bung onto the J-pipe instead.

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--> Check out my FI Turbo build <--
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--> The Diesel Corvette <--

i would like to do that but i dont see it happening. money is tight right now. i have a drill bit and a tap. i bought the copper line kit a while ago. its been raining so i havent gotten the chance to pull the turbo yet. i might be able to scrounge up some money and hit the hardware store. gonna see what happens.

I was going to suggest that would be the perfect use for the egr port, but I believe your intake doesn't have that. I like the idea of leaving the tube long. Just coil it up so it looks like mad science.

So now there is no longer boost able to reach the cavity? Or does it also hit there and the exhaust pressure is overcoming it?

manifold doesnt have the egr. mad scientist was what im going for right after function.

no more boost to the cavity. only using the exhaust pressure. its higher then the boost pressure at any given point.

So the idea simplified - is you have a spring with a valve that is held closed by said spring, then when exhaust pressure overcomes it, the passage for the valve opens, and allows fuel through to the bores?

Correct?

I'm just thinking if that's the case, maybe the power valve can be avoided all-together and a spring setup like what you have and utilize a homemade valve to close the opening.