Bought my Greddy kit used. Installed the turbo without messing with the wastegate settings. I was getting 3 psi on my boost gauge so I went to tighten the actuator rod to get closer to 5. I noticed that the actuator bracket had two washers betwen it and the compressor housing... interesting. I tightened the end of the rod down to where there were only maybe 3 more threads left unused on the rod, went for a drive and I wasn't even getting a solid 4 psi. So then I removed the washers - for some reason I was thinking they were setting the boost lower... went for a drive and I was at 2 psi. Obviously, the washers push the actuator farther away from the wastegate, so it tightens the wastegate actuator even more... so I found another washer and put it in between the bracket and the compressor housing, and I got 5 psi. The threaded rod is tightened down almost completely.
This seems odd since I thought you could adjust the Greddy wastegate up to ~8 psi by itself, and I've got ~1/4" of washers tightening the actuator down beyond what the rod can tighten down to and I'm only getting 5 psi max...
What gives? Could the actuator be leaky/bad? 4.5 doesn't come on until 4k rpms, but that's probably dur to the greddy downpipe and crap piping.
I'm installing my intercooler this weekend and will want to run 6 psi - as is, I don't think I can even adjust the actuator to get 6 psi.... what should I do?
-Ryan

 

How much vacuum are you reading? I thought I had a similar problem until I realized that my vacuum was reading low -- something is wrong with my boost gauge or how it's hooked up.

 

Eh, 8psi on the stock greddy wastegate isnt happening. 5-6 at the most is more like it. (if even, i get like almost 5 max).

Also peak boost at 4k is normal with stock dp and exhaust, get a MBC off ebay- then you can up your boost to 6 and have quicker spoolup.

 

Thanks fireindc - sounds like mine is operating normally... any recommendations on which mbc to go with from ebay?
-Ryan

 

Hmm, they are all pretty good from what ive seen.


This was my frist one, worked great and i sold it to my friend with a talon. Then i bought another one that was different but same basic design.

http://cgi.ebay.com/ebaymotors/NXS-M...em260224678655

this one is simple and works well.- cheap too. If you want one with more bling, there are others of the same style in diff colors.

I bought this one but have yet to install it.
http://cgi.ebay.com/ebaymotors/R-TUR...em170204442327

I like how the adjustment notches on it- but cant actually vouch for its performance.

Eh, any simple ball and spring MBC is ftw.

 

I used this one and love it! http://cgi.ebay.com/ebaymotors/Manua...em300210378861

 

I got 8psi with just my greddy WG. Added a spring and boost cut got me at 16psi

 

im sitting pretty at 6psi with my stock wastegate, and it looks like i can tighten it more

take some pics of the waste gate actuator <-- that a long effin part name

 

I'll take a picture of the wastegate actuator today to show you what I've got goinng on. I'll get a mbc but I've heard mention of a 300zx actuator supposedly being a lot better in some way? I can't find anything on that... would that be a good thing to upgrade too as well? Seems like it'd be inexpensive so if it helps, I'm all for it.

 

MBC is less then 20 bucks.. how much more inexpensive could you get

 

or go to home depot/ace hardware and buy a helper spring. **** you could make yourself a boost controller while your at it- but honestly the parts cost more than you can buy one for off ebay(at least thats what i found).

 

I'm going to fit an FM1 WGA on mine after I get MS sorted out and feel comfortable in my ability to redo EBC tables.

 

8 psi is possible with the stock Greddy wastegate actuator. Hell, 12 psi is possible. The problem, and why you need a helper spring, is that it won't hold boost through the powerband. I'll dig up a couple of dynoplots with the Greddy wastegate, with and without the helper.