Author Topic: yea...i know...another boost question (Read 5158 times)

boosted_diesel_84 · « **on:** April 12, 2007, 04:15:13 pm »

ok, so, i have been trying to turn up the boost a little bit on my 84 1.6 TD jetta,i turned up the pump a few turns to get a little more fuel, IP timing is fully advanced, i installed a boost gauge, and it makes 8-9psi, i pulled the spring on the BOV and shimmed it from opening, after i did this is able to make boost from just revving, w/o a load, i wanted to move peak boost up to around 12-13 for the time being, so, from what i gathered on here, i backed out the shaft on the wastegate, but when i went to tighten the nut, it threaded the shaft back in, so i unthreaded the whole shaft, took it out, moved the nut from where it was originally and moved it closer to the wastegate by maby 1/4 inch, and put it back in and tightened it, i drove it, and its still making only 9 psi, why? the shaft is noticiably further out, what am i doing wrong? shouldnt it make even slightly more boost? the turbo has no endplay and very minimal axial play, and spools very quickly from 4-9 psi, and i dont think the boost is leaking off, because i can hold it at peak boost and it never changes. please help

jtanguay · « **Reply #1 on:** April 12, 2007, 04:59:07 pm »

maybe your wastegate is stuck?

boosted_diesel_84 · « **Reply #2 on:** April 12, 2007, 05:46:03 pm »

i dont know about that, because when i build boost and shift, the wastegate opens, and you can definitly hear it, here are some pics, if it would help anyone, i hope i can get the pics to work, never posted on this site before, oh yea, its a KKK by the way

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jimfoo · « **Reply #3 on:** April 12, 2007, 05:56:15 pm »

Maybe I'm wrong, but don't you screw the shaft IN to raise boost? If all else fails, put a bleed in and bleed some boost off. Just don't use a plastic tee. They don't last long before they melt. :oops:

RabbitJockey · « **Reply #4 on:** April 12, 2007, 05:59:13 pm »

you need to completely disable it, not just shim it. and then to turn boost up you do in fact turn the pin thingy in

boosted_diesel_84 · « **Reply #5 on:** April 12, 2007, 06:06:16 pm »

well i put a post up asking how to raise it and xud9te said to "Always shorten the shaft to increase boost. This will increase the pre-load on the diaphragm spring and make it require more load to start moving!" so i just did as was stated, what do u mean by put a bleed in? where does it go? what is a bleed? i understand that bleeding it would make the wastegate think its not seeing the high boost it really is, but how do i accually go about doing this? and to Trev0rbr "you need to completely disable it, not just shim it." i have it so it cannot open but is not pushing thru the diaphram, i just didnt have anything else to plug the hole with, is the only reason the BOV is still there, i am gonna go outside now, and turn it in, and il be back with the results

jimfoo · « **Reply #6 on:** April 12, 2007, 06:12:19 pm »

Bleed. Cut the metal line midway to the wastegate. Get a metal tee and some silicone tubing. Run it to a valve, either an adjustable one in the car if you want to play with it, or under the hood. You could probably also experiment with a small piece of metal line held in place with silicone tubing spliced in the turbo/wastegate line. Just drill a small hole in it, making it bigger or smaller until the desired boost is achieved. For a cheap in the car valve, an aquarium air valve works good.

boosted_diesel_84 · « **Reply #7 on:** April 12, 2007, 06:43:29 pm »

ok, just got back, HOLY TURBO, i am up to 15 psi, didnt expect that, but sweet, the weird thing though, is in 1st gear 0-5psi is slow as usualy 5-10 is fast as usual, but then it slows down and holds at around 11-12, but in 2-3 gears it does the same but does not taper off at 11-12psi it then gradually makes it up to 15 psi, why is this? and should i be worried about egt's? im getting the gauge and probe just dont have it yet, it smokes a little less than usual, oh and the line you are referring to is the metal line going from the wastegate to the turbo housing that really looks like a oil line? even though i know the oil line is on the other side that comes from the filter housing. just making sure before i do something i will regret, and that line just has air running thru it? and can i get this aquarium valve at like walmart or something? sorry for so many questions i am kind of new to TD's, but i am very familiar w/ VW/Audis as i work at a machine shop that focus' on these cars,(not many TD's though)

jtanguay · « **Reply #8 on:** April 12, 2007, 06:56:01 pm »

i can build 20 psi in 2nd gear no sweat... the more boost you build in the upper gears, the more EGT's you will make.

essentially high egt = lots of black smoke. i've even turned down my fueling quite a bit... once 10 psi kicks in, i cannot get my car to smoke.

my wastegate is completely disabled... i like it that way! but a wastegate is good for the highway, as 5th gear going uphill creates too much boost for my liking.

xud9te · « **Reply #9 on:** April 12, 2007, 07:23:53 pm »

Hi,

Yes, sorry, if you have a wastegate actuator with a rod and fulcrum, shortening the rod increases load on the spring. Like garrett turbo. On the KKK style wastegate the diapraghm adjustment is from the other side of the spring so you need to turn it in!! Its not a common setup though. It is on yours!!

Yes, the metal line is just the boost line from compressor to wastegate actuator. If you can get hold of some similarly threaded, barbed connectors you can remove the metal pipe and replace, use a rubber hose and your bleed valve. I think the diameter of the metal tube is a bit small to cut and get hose to clamp over the top of.

The cheap man trick might be to drill a (very) samll hole in the metal line and check boost, then if its not enough, drill another!! carefull you don get chaff in your turbo though.

boosted_diesel_84 · « **Reply #10 on:** April 12, 2007, 07:39:03 pm »

i just returned from my local walmart supercenter with no luck finding a aquarium air valve, i couldnt find it, so after a while i gave up and asked the guy working there, (who happined to be wearing a honda racing shirt) told him what i needed, he had no clue, told him kinda what it did, still no clue, then i finally told him, i was gonna use it for a turbo boost controller, figuring that he might be a car nut since he was wearing a honda racing shirt, bad idea, he got even more confused, so moral is dont ask a honda guy, lol, but what exactly does a aquarium air valve look like, so i can go back and find one, pics would help too,lol, im trying not to be helpless, ive just never done this type of thing before. thats for all the help though!!

boosted_diesel_84 · « **Reply #11 on:** April 12, 2007, 07:47:40 pm »

just googled aquarium air valve and found this, is it what i need? its 2 way,sounds right, just want to verify. thanks!

jtanguay · « **Reply #12 on:** April 12, 2007, 08:11:37 pm »

Quote from: "boosted_diesel_84"

i just returned from my local walmart supercenter with no luck finding a aquarium air valve, i couldnt find it, so after a while i gave up and asked the guy working there, (who happined to be wearing a honda racing shirt) told him what i needed, he had no clue, told him kinda what it did, still no clue, then i finally told him, i was gonna use it for a turbo boost controller, figuring that he might be a car nut since he was wearing a honda racing shirt, bad idea, he got even more confused, so moral is dont ask a honda guy, lol, but what exactly does a aquarium air valve look like, so i can go back and find one, pics would help too,lol, im trying not to be helpless, ive just never done this type of thing before. thats for all the help though!!

usually honda drivers are pretty lame... k&n filter & a loud exhaust! +10HP!! :roll:

go to home depot, and get a grainger valve. that's all you need man. i think that is what they are called... mainly something with a valve so you can control the boost (you will need to buy some hose & clamps though)

boosted_diesel_84 · « **Reply #13 on:** April 12, 2007, 08:42:17 pm »

ok, lets say i get the valve, drill a hole in the middle of the line, put a brass firtting in with the line and run it in the car to hook it up to the aquarium air valve on one end, what do i hook the other end of the valve to? or do i need to?

jtanguay · « **Reply #14 on:** April 12, 2007, 10:22:26 pm »

words from the wise libbybapa! i agree that the best boost controller is my foot too...

i can easily peg 20 psi in 2nd... the thing you have to know, is when your motor is being overloaded. if you slam into 3rd gear too soon, and just floor it, and you're not really moving, then the EGT's will skyrocket, the turbo will probably start to creep up slowly, and eventually reach the boost you want, but that kind of loading is bad for everything.

so just remember, if you're launching from 1st all the way through and rev up to 4500 rpm or so, then you can pretty much nail it through. if you're nailing it in 2nd or 3rd, wait till your turbo is at least going at 5 or 10 psi... that way your EGT's won't spike too much.

do you have an intercooler?