Anyone shim there 14B, 16G, 20G wastegate?

[truwarrior]

Saw this on www.3si.org. Apperently they take washers and stick them some where, on the wastegate arm I'm guessing... Anyone done this before? How do you do/how does it work?



Forgive my ignorance but when you are shimming the wastegates all you are doing is putting washers inbetween the actuator and where it bolts to the turbo? I have never heard of this before but I seem to be having a similar problem with my 14b's where as I have a very low peak boost.

 

[truwarrior]

I'd assume you would put the shims on the wastegate spring but how does it come apart?

 

[90blacktsiawd]

Ive tried what your talking about. I read about it somewhere on this site. Basically i took 2 washers maybe 1-2 mm thick and stuck one in between the turbo and wastegate actuator on each bolt that holds them together. I had read that it will put alitle more pressure on the wastegate actuator so it would help keep the wastgate closed for a quicker spool. To tell you the truth i didnt notice a difference. Maybe i didnt use enough washers. Id say go ahead and give it a try. Its free and i dont see how it could really hurt anything. Although i will say it was a pain in the a$$ to get those washer in there while the turbo was on the car. If it works out let me know ill go ahead and try it again on my new turbo.

 

[Mike1992]

Ive tried what your talking about. I read about it somewhere on this site. Basically i took 2 washers maybe 1-2 mm thick and stuck one in between the turbo and wastegate actuator on each bolt that holds them together. I had read that it will put alitle more pressure on the wastegate actuator so it would help keep the wastgate closed for a quicker spool. To tell you the truth i didnt notice a difference. Maybe i didnt use enough washers. Id say go ahead and give it a try. Its free and i dont see how it could really hurt anything. Although i will say it was a pain in the a$$ to get those washer in there while the turbo was on the car. If it works out let me know ill go ahead and try it again on my new turbo.

I did this because my actuater didnt fit tight after i installed my 18g into my ported 7cm housing. I used two thick washers, one on each bolt inbetween the turbo and the actuator. Doing this and cleaning my intercooler made full boost at 3200 rather than 3800

 

[oldman]

Why are you doing this? Are you having problems? This is done when either the actuator spring doesn't return the arm all the way, making it to long to shut the flapper, or the spring isn't strong enough to hold the flapper shut against the exhaust flow. In both cases the right way to deal with them is a replacement actuator. The major draw back to shimming is that the arm can no logger open the flapper all the way which may cause boost creep.

 

[92 AWD ECLIPSE]

That is true. I had to install washers on my wastegate because the rod was bent. It helped hold it shut, but at 15psi of boost it would creep to 19 or 20.

 

[Mike1992]

Im only running 12 psi but I dont creep at all

 

[beat90tsi]

Ok, I shimmed my Evo3 last year and it made a huge diff in spoolup. Until recently it was trouble-free.

This thread seems to be most closely related to my problem. Recently I've been having trouble building boost. Both times I found the WG actuator to be the culprit. I sprayed the sucker down with WD, trying to get some down in where the rod goes into the housing, then grabbed it with pliers and jerked it in and out. It does not move smoothly all the time, and sometimes binds up halfway and gives me awful spoolup (4k). When I take the pin out, and the rod off the flapper, I can get it to move and fully close, but it's just a matter of time when driving until this happens again, as it has happened a few times already.

Has anyone else encountered this? Is it safe to take it off and soak it in some type of oil to help free up the action?

 

[Mellon]

the reason us 3000/stealth twint turbo guys do this is because the wastegate tends to crack open under high back pressure. being twin turbo we don't have a boost creep issue.

shimming the wastegate brings the minimum boost up and makes it much less likely to crack open prematurely slowing spoolup and limiting maximum boost.

I put 4 washers in between the compressor housing and wastegate actuator on my twin e16g setup.

you can see exactly where they go in this pic and yes, it's a complete biatch to put them in after the turbo is on the car.. especially on the 3/S where the rear turbo is between the plenum and firewall.

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[Stapl3]

Did this on my 16g. The o2 dump made a sound at idle and normal driving, so I knew the flapper wasn't closing well.

Put 2 washers about the size pictured above in on each bolt. Sound went away and the boost still held rock solid at 12psi.

 

[daren_p]

I added a couple shims under my evoIII wg because without them I was initially seeing 8 psi with the boost controller disconnected & it would creep up to about 11 psi by redline. After the washers it spooled to 12 psi with no boost controller & stayed there. I needed to this because I wasn't able to raise the boost to where I wanted it to be with my ebc. After it was done the car seemed to pull harder, I don't know if it was just my imagination or maybe the extra pressure on the flapper held it closed longer and the turbo didn't have to work as hard to make the same boost level, therefore giving me a cooler intake charge.

 

[truwarrior]

I added a couple shims under my evoIII wg because without them I was initially seeing 8 psi with the boost controller disconnected & it would creep up to about 11 psi by redline. After the washers it spooled to 12 psi with no boost controller & stayed there. I needed to this because I wasn't able to raise the boost to where I wanted it to be with my ebc. After it was done the car seemed to pull harder, I don't know if it was just my imagination or maybe the extra pressure on the flapper held it closed longer and the turbo didn't have to work as hard to make the same boost level, therefore giving me a cooler intake charge.

Well looks like adding washers increase the min boost level and also helps decrease flapper blow open under high exhaust pressure.

8-11psi wastegate just seem to light especially if you running the turbo at 18-20psi. Seems like a decent mod, maybe not 4 washers but just a couple should help some what too, specially with a ebc which usually has spool already then a mbc.

 

[Stapl3]

If the mbc doesn't allow the WG to see boost unitl 18-20 and the flapper is held shut, I don't see how it would matter.

 

[dsm-onster]

After it was done the car seemed to pull harder, I don't know if it was just my imagination or maybe the extra pressure on the flapper held it closed longer and the turbo didn't have to work as hard to make the same boost level, therefore giving me a cooler intake charge.

The turbine/compressor wheel accelerates slower when you have less pressure on the flapper to keep it shut. So your turbo spins slower and does less work. If you disconnect the wastegate actuator arm all together the turbo would hardly spool at all and spin very slow relatively.

Your gains are most likely because you keep the flapper shut longer which GREATLY increses spool up. Keeping the flapper shut for longer forces more exhaust gases to do work on the turbine wheel longer. Even with a MBC, the wastegate opens up slightly and more and more as you get to the target boost where it stays open to meter out just enough exhaust gas flow to spin the wheels at the speed to maintane your desired boost.

This shim trick is used by turboford guys to increase spool up as we have 4-banges with 8-valve heads . Also many of us have t3s with stage1 wheels and .48 a/r housings (prime candidate for cracking open under higher boost levels). We have to run high boost because we have very poor flowing heads. Also this makes for a cheap bost controller as more pressure on the flapper means more boost pressure needed (from the boost source) to open the flapper to the same angle. The shimming no doubt does the samething here......