I was hoping it wouldn't have to be this type of solution.
You're referring to the O2 housing right? And porting the area that the wg flow meets with the turbine flow?
Well since it seems as if the problem is boost creep related, do you think going with the 84mm cover would help the cause?

 

Mikey previously ran the same exact turbo/WGA setup that you have. I am currently running a 64mm Red with the FP 18 PSI actuator. Both .ikey and I have had had to take a hacksaw to the actuator rod on the 18# FP WGA to reach optimal spring tension with that setup. So, you probably not experiencing excessive preload with a stock length actuator rod. So the source of your creep is something other than actuator rod length.

 

Actually, I was referring to the turbine housing. But, yeah you could try porting the merge hole on the O2 housing first. A lot of guys have successfully controlled creep by enlarging the merge hole. You are right.

 

Hey Sparky thanks for the help so far...I have absolutely no knowledge in porting stuff so I might just be better off finding a already ported O2 housing. Any recommendations?
I just want to understand something here, I can clearly see the "creeping" going on in the last set of logs I posted running off wg pressure, but do you still consider it to be creeping in the first post (that was with the mbc connected?) I probably should have posted the rest of that log because right after what looks like fluctuation in the peak area, it actually holds relatively steady to redline.
Let me grab the end of that log and post it.

 

Ok here's the tail part of the 2 logs I have in the first post:





Do you still consider it to be creeping?
In those 2 logs the surging was pretty pronounced just like in the 2nd video R/TErnie posted here:
https://www.evolutionm.net/forums/ev...0mm-cover.html

never mind the excessive knocking, I took care of that...lol

 

Enlarging the merge, or crossover hole in the O2 housing's divider wall is really simple. I think that the job can be done w/o pulling the housing off the turbo while it is still on the car. Just remove the DP. Enlarge the opening to golfball size. Really simple

 

Yeah. The data in your most recent post shows good steady boost levels. No creep. What was the target boost? Was the MBC set to full soft?

 

Another possible option for you to consider might be a well designed O2 dump.

 

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I have the s ame FP HD 18 PSI actuator and I can adjust mine down to 14# base. So, go figure.

 

Like Sparky said, I had to cut 3-4 threads off my wastegate arm and take that gay nutt off just so I could turn the turnbuckle down far enough to get proper preload. If you follow the arm of the wastegate down to the actuator you will see what looks like a "thimble" at the base of the actuator... You should have enough preload that the thimble is sitting about a 1/3 of an inch off the base of the actuator. That may make you creep a bit, which is why I had to open up my wastegate ports but your boost wont fluctuate anymore and you will hold more boost out the top You then get the best of both worlds but requires some work on your part.

If you are confused on what I'm talking about take the wastegate off the car and pull on the wastegate arm and you the see the thimble separate from the actuator.

Mikey

 

Sounds relatively easy, I think I'll give that a shot over the weekend but knowing my luck I'm better off taking it off the turbo.

That's what I was thinking too, it doesn't creep up top just the fluctuation at peak area...the target boost was about 24psi...no the mbc had a couple turns on it.
When I had it to full soft it would do just like what was shown when I just ran wg pressure, hit like 16psi and gradually creep up to 22-23psi (this is when I had the wg preloaded 1 full turn back from max)
So what I did was increased the mbc until it hit 23-24psi at peak area instead of 16psi. When I did that, it produced the results I posted in my last log (no creeping), but had the fluctuation at peak which I started to wonder if that was a result of the comp surging.

I also considered this option, but I'm not really a fan of the added noise and would opt for a well designed (ported) O2 housing instead.

 

Yea I was wondering how come I was only getting like 15-16psi so I went and did a boost leak test (which I didn't find anything since I had done one not too long before I put on the Red)...got it now.

 

Oh I got ya, well I definitely don't think my problem is too much wg preload then because I still had that gay nut on when I preloaded mine. I'm almost convinced now that it's the comp surging that's causing the fluctuation (were you on the 64mm cover when you had your red? Did it surge hard?)
When I get back home from work I'll go take a proper look at the actuator to see what you're referring to, but I understand what you're saying.
Looks like I should have opted for the ported Red instead, while I'm comfortable enough to try and port the O2 housing, porting the turbo is a out of my league.
I'm going to try a couple things and compare the results, because when I have less preload on the wg the car doesn't surge as hard as when I have lots of preload, which I'm going to assume means less fluctuating (I didn't get to log the pull but gonna do that later and compare) but I figure that also that means I'm not going to be able to hold as much boost out the top.
I'll then try and remove the nut and preload as far as it can go and see how that goes.
I won't be able to port the O2 housing till this weekend but at least I'll have some data to compare once I do.
Thanks for the advice Mikey

 

I never had much of a problem with comp surging... some guys I know had a lot of problems but I never did. Guess I got lucky. One thought, you can actually get the comp cover from Robert. That is what I did, all holding it on is a VERY large snap right. Also I never ported my turbo housing, I just ported the wastegate ports so it flows a bit better. The housing that I am testing today is the first ported housing I have ever used. And when I say ported, I mean gutted to a single scroll.

Not a problem man. Let me know how things go

Mikey

 

Yea it looks like the 64mm cover is a hit and miss in regards to surging.
I'm definitely going to get the 84mm cover, I'm not too comfortable with the amount of surging I'm having. For now I'm just going to port the O2 housing and keep the wg preload conservative so as to reduce the surging. When I get the cover I'll probably just take the turbo off at the same time and have the wg ports opened up a bit like you and sparky suggested.
Yes I saw your thread about the single scroll housing, very interesting...I'll be following it to see your results