helpdabraddaout

I have a B18c GSR
Topmount twin tial 38mm waste gates
Precision 6169 ar70 .82 hotside
3" down pipe
JG intake
Water to air intercooler
Water meth stage 2*
Blox C cams*
Port and polish head with ti valve train
Non sleeved 81mm CP pistons 9:1 Manley rods
1200cc RC*Aeromotive 340 pump
My problem: I'm having boost creep. While adjusting for boost by gear using a EBC MAC solenoid at 44% duty cycle I have boost stable at 18psi. When I set the duty cycle to 45% my boost will creep all the way past 25psi. Thats only 1% change. I'm trying to achieve 22psi. Is my solenoid to sensitive? I have 2 38mm waste gates with 9psi springs. I checked all my pipes and hoses they are all tight and no leaks what so ever. My tuner suggested using 4 psi springs in each waste gate. But i will have boost lag. I need some help bad! What should I do? *What would you sugggest?Thanks Rockman

Muckman

iTrader: (2)

Standard EBC questions - which solenoid? how do you have it plumbed? what are you using to drive the solenoid? Try playing with the frequency. And the 4psi spring is a good suggestion to try also. Lets see if it solves the problem and then we can work on the quick spool.

helpdabraddaout

Thanks Muckman. It's a Mac solenoid which is the same as the Hondata. I have it plumb according to the instructions port 1 turbo and waste gate bottom. Port 2 waste gate bottom. I test the EBC and at 0 duty cycle I have 9psi boost which is my spring pressure. Any suggestion? I would really apreciate it

wantboost

iTrader: (2)

so both ports go to the bottom of the wastegate? thats a problem

helpdabraddaout

Wantboost, Sorry my bad. Port 2 waste gate top. Port 3 open to air.

helpdabraddaout

Any suggestions? Need help!

wantboost

iTrader: (2)

you won't have lag with 4psi springs... you'd be running whatever you want with the solenoid.... just because the spring has changed doesn't mean response will... the solenoid keeps the wastegate closed until target boost is reached...

extremeracer

Frequency of the solenoid should usually be a 31hz - check that

My_EFsedan

3 ports open to air? should those be closed?

helpdabraddaout

Wantboost, thanks i will purchase the small yellow 3.6 psi springs and give it a try. Extremeracer, i will check that frequency and see what its at. My_EFsedan, port number 3 is a vent. Thanks guys any other suggestions? Anything mechanical I should look at?

kbouchard1092

i had creep issues....ended up relocating one reference to the charge pipe coming out of the turbo a Bung was welded on. Playing with the frequency should def help. Factory default from hondata i think is 78....Way too high! shoudl be 31hz like mentioned earlier. This will effect youre previous settings as well....So the Duty cylce that made 18psi will most likely be different now.

My_EFsedan

lol i completely read that wrong. my fault.

wantboost

iTrader: (2)

yea the softer springs actually mean the wastegate will respond quicker, since there's less seat pressure on the valve. it also means you will have a lot of valve travel to control boost levels so creep shouldn't be an issue

helpdabraddaout

Wantboost you are absolutely correct with the soft springs it will pulsate quicker that means it will release boost sooner. I guess that's what I gotta do install lighter springs. Thanks everyone. If anybody out there have 2 small yellow(3.6psi) tial sport springs let me know and I'll buy em or trade u for 2 small blues or 2 large blues. Also I'm up for more suggestions

wantboost

iTrader: (2)

ebay is your best bet...
pictures of how the wastegates are plumbed? that could have something to do with the creep

helpdabraddaout

Wantboost, I just checked my frequency setting and it's at default 78hz. You think I should put 31hz? Do u think that's why I'm having creep past 18 psi? It creeps past 25psi with 1% increase in duty cycle from 44 to 45.

wantboost

iTrader: (2)

31hz is what it should be at... but the whole duty cycle map will have to be changed since changing the frequency changes everything else

helpdabraddaout

By lowering the frequency this will give me a wider margin to adjust duty cycle right? So 1% increase shouldn't be 7psi or more increasements. If I can get it to 1 or 2psi adjustability that will be my goal. 22 psi is all I want. Thanks

ef92b

i agree to this.

to the OP, aren't you suppose to boost 2-3x your wg spring?

i haven't tried past 3x the wg spring rate though.

so with a 4lbs spring, max = 12lbs.

helpdabraddaout

That's only with a MBC. EBC puts pressure on the top of the waste gate to keep it from opening but the goal for me is to open it sooner because the turbo is in it's happy effeciency zone and creating so much boost.

ef92b

regardless if it's MBC/EBC.

https://honda-tech.com/forums/showth...+boost+by+gear

helpdabraddaout

Muckman

iTrader: (2)

I have a 5.5 to 30psi range with my 4port mac solenoid. The downside is you dont get very good resolution. Ie 1% duty may give you 3psi

helpdabraddaout

I gotta get this right I'm a slightly confused. So if my frequency is at 78hz will that cause my duty cycle to be real sensitive? Like I said going up 1% duty cycle I'm creeping from 18psi to over 25psi. By lowering my Hz to 31 will I see a more finer adjustment? Does this make sense?

Muckman

iTrader: (2)

Yes try it at 31-35hz if that doesnt change the resolution then go lower like 20-25hz.