Set-up:
B16 head(stock)
b18c1 block(stock)
je pistons 9:1 & je rods
rc1000cc
gt30r
afi ramhorn with 3in downpipe
tial 50mm bov
tial 38mm w/g with big yellow spring(0.7 bar)
hondata s300 on 91 pump

now, as we try a little street tune before hitting the dyno the car wont stay at spring rate. Every time the turbo spools up the more boost it goes, we were planning on using boost by gear but its boosting by rpm. Lol? We have checked for leaks on the wastegate and vacuum thinking it might be leaking causing faulty pressure. This is not the only car with this problem. I was thinking the wastegate wasnt holding because of the size but 2 other cars with the same issue using 44mm w/g. Running off the wastegate it will creep to 21 psi of boost! & going. We stop at 21 psi cause it seems like it didnt want to stop! Now, any help would help! Let me know what my honda techs my have to say on behalf of my issue here. Thank you very much for the help. i have read some forms about boost creep but everyone seems to not figured it out yet. for those who did can u please share with members of the honda community :D

 

It's pretty simple. . . . And very complex. LOL.

You need to get more exhaust gas to choose to go through the wastegate instead of through the turbine. This means you need to:

1) Add wastegate flow capacity, or

2) Give the flow priority to the wastegate pipe, or

3) Restrict the exhaust flow out of the main exhaust that comes through the turbine, and/or

4) Ensure that the wastegate dump tube is very free flowing

I think after those things, there isn't much left. . . I ended up putting a 2.5" Dynomax superturbo muffler on my exhaust to keep my boost creep down until I finally get around to building my new bottom end that can handle the boost this setup wants to creep to.

I'm sure there are people on here who will be able to provide you some pretty specific advice, especially if you can put up all of the necessary info like pics of the setup or whatever to see what might be easiest to change.

 

bump!

 

show us the manifold and wastegate placement. post a pic

 

Wow. That's a lot of creep even for a ramhorn.

Are you sure it's .7 bar spring? lol Are the vacuum hoses on the wastegate run properly? And if they are, are they run to an appropriate vacuum source? Is the vacuum hose too small? Is the wastegate run on its own individual vacuum line?

Definitely put up a pic of the manifold. I've seen the AFI manifolds, so I can't imagine the placement of the WG would creep THAT much. But ya never know.

 

 

Perfect. Preferably to where the hose for the PCV goes.

1/4 - 3/8" probably. Can't think of it off of the top of my head. I just know it when I see it.

Hmm. Well, I honestly have no experience with a dual wastegate setup, but if the vacuum hose and source is good enough, then it 'should' work. I have my BOV and WG on the same line. So the large hoses and a good source should be able to handle both WGs but don't hold me to it. lol

 

I'll try to get a picture of my set-up as well. we swap the w/g and put it on another turbo car and it works perfect! it has a little bit of creep to about 12ish but not like my 21psi+