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Discussion Starter #1
I have been doing searches and can't find an answer to my question. I am going to built my own grainger style valve and i want to know what size nipples to use. The wastegate can has a 1/4 inch nipple on it. The ones I see for sale all seem to use a smaller nipple size then that. I plan on cutting the brake booster line to supply the line to keep the hose short. Would using the smaller nipples create a restriction slowing the wastegate to open causing a spike? Or would the added volume of a bigger diameter line create a spike? Second question. On the wastegate side of the valve I know it needs to vent the wastegate can when not in boost. What size hole needs to be there or would an adjustable bleed there allow me to fine tune my set up?
Thanks for all imput. :thumb:
Tim
 

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i purchased 9/64" black rubber nipple ends at Autozone ($1.69 ea) and they seem to work well, using ny-ties as well. i use hard plastic 5/32" vacuum line (exactly like the OEM stuff dodge uses on the TD engines, available thru McMaster-Carr for like 20 cents/foot) with these nipples, no soft tubing, to give a more reliable signal. from my engine to the wastegate can there is no soft tubing at all.

stock tubing has an ID of .093" (on my glhs) going to the various vacuum devices and i have found no noticable probs/spiking with using slightly larger ID tubing which i had on before this year but like i said, i switched to use the smaller, hard plastic stuff cause i am bumping the engine from 16 psi to 20.

stock setup on our engines uses a small orifice in the wastegate can line to modulate the can's movement under boost, but your grainger valve will eliminate the need for this orifice and it should be removed if its in the line, the gv acts as an adjustable orifice of sorts. no need for an adjustable bleed, you can fine tune the boost using the adjustments in the gv itself (ie: spring tension and pre-load on the ball/seat).

yes, you will need a small vent hole on the wastegate side of your GV to vent the boost signal away from the can as boost drops, so the can will be able to move the puck closed again (this is what the stock wastegate solenoid does), i beleive the hole size is .015", thats what my brass gv has drilled into it.

good luck.
 

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Discussion Starter #3
To expand more on my thinking pnumatic systems and hydraulic systems can be related to electrical systems. On an electrical system if you took the battery and put it in the trunk you would increase the cable size because of how long the cable needs to be because of resistance. The same things happen in air and hydraulic systems. Trucks with air brakes use relay valves because when you hit the brake pedal the rear wheels of the truck are to far from the treadle valve (foot valve) to flow enough air to them from the front it would take too long to get there because of resistance. So on a truck the treadle valve (foot valve) just sends a signal (low volumn) to the relay valve telling it to open the big lines from the tanks near by to supply the large amount of air the can needs to work. In hydraulic systems its the same I was just in a class and the intructor showed this. The pressure at the the pressure relief is higher then the pressure at the work it drops as the lines get longer. The fix if the pressure drops too much is the same as the battery in the trunk bigger diameter lines.

In a lot of posts I have seen everybodys answer is the same don't just pop off the lines off the wastegate solinoid and install the grainger. Get it close and use shorter lines. This removes some of the resistance and decreases spiking. A larger line run in the same location should do the same thing but why run 15 foot of hose when you can just move it closer. My thoughts have been to do both move it close and use a larger line. The lines most have been using are small compared to the volumn needed for a large can. In some of Wallace's posts I found he used the brake line to tap (large line near the turbo) http://www.turbododge.com/forums/showthread.php?t=34863&highlight=boost+brake+booster He did not say his line size he used but to install a "T" with a 1/4" nipple is easy and clean. Then a 1/4 inch hose to the wastegate. In his post he also said he put in another "T" to provide the bleed needed to vent it. I saw a site that the guy selling his grainger style valve he had 2 adjustments on it one was the usual adjusment and the second was so that you can adjust that bleed hole size. He claims you can fine tune the total setting with it.
Tim
 

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my gv used to be located about 6" from the wastegate can and plumbed with larger soft vacuum line.....this year, i moved the gv to the wastegate solenoid and plumbed it with small hard plastic line and i havent found any noticeable difference in boost behavior. no spiking at all. (spiking is the result of the wastegate can not receiving an accurate MAP signal correct?)

since the factory does use an restrictor orifice between manifold pressure and the can, there must be some reason for this.....and most agree it is to regulate the volume of the signal the can sees...in a stock 2.2L turbo engine there is very little large soft vacuum tubing, rather, an abundance of the small hard plastic tubing...but, i have to admit it might not make any difference one way or the other.

keep in mind that the bleed hole in the gv will leak manifold pressure, reducing the signal to the can, so i can see where adjusting the size of the bleed hole could effect can response.

testing/experimenting is the best way to ensure all is working correctly.
 

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Marcus86GLHS said:
no soft tubing, to give a more reliable signal. from my engine to the wastegate can there is no soft tubing at all.
:bang head I just changed every inch of my vaccuum lines to silicone. Now you tell me I need hard lines. :bang head
 

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Discussion Starter #7
Thanks for all the imput Marcus. It gave me things to ponder. I started to work on my valve at work today. I'm going to start with the 1/4 inch hose set up and see how it goes. I was looking at springs in my old "bag O trans springs" and the selection is thin. The brass is plentiful as is the balls. I guess I'll do what you said experiment/test.
Tim
 

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As I recall, McMaster Carr has 1/8" id aluminum tubing that would make a good hard line setup for those so inclined.
 
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