svt_lightning01

iTrader: (1)

Okay so i have had issues with boost creep on my car since i have purchased it. Its a 2005 MR and ive posted about the problem before and tried a few things. The car has a Forge UNOS mbc on it stock 02 housing turbo xs TBE cams intake etc. It was tuned before hand for 23 psi on 93 octane.

Originally the car was creeping boost out of control. So i bypassed the MBC by running a line straight from the WG to the tubro outlet nipple. Still had crazy boost around 25 psi before i let out. the gauge is hooked up correctly into the intake manifold. It shows 15 or so vacuum at idle and 22 ish on a down throttle. So i think it is correctly installed.

So then people said it had to be a WG problem so i bought a stock actuator and changed out my old one. Sure enough, the old one had a rattle in it and i was sure this was the issue. So i swapped out the actuators and i have the gate with no pre load at all. The flapper has tension but just barely enough to keep it in place so i know it isnt pre loaded.

I left the MBC out of the equation and still i have high boost. I will say the creep is drastically reduced. Still around 25 psi if you stay in the boost which i am not doing to save face obviously im just trying to get it right. WG pressure should be 12-14 psi and its still high.

So my first question. The line that i have ran from the turbo outlet to the WG is quite long (probably 3-4 feet) because i just unhooked MBC lines and tubed them into each other. Could this long hose somehow cause the high boost?? Seems kind of dumb but idk.

Okay so since i figured that the problem wasn't the WG since i just replaced it i hooked the MBC back up turned all the way down. Its about 65* outside when i do this. BOOM i see 21 psi all day long no creep or anything. So i think the problem is fixed. Then weather turns cooler around 45-50* and i see 23-25 on same setting. however this is turned all the way down so i have no way to turn it down further.

Second question. Could it be possible that i have the stiff spring installed on the MBC? I didnt originally install the MBC. If this could be the case where can i get a soft spring to try out this as the issue.

thanks in advance for the help. the only thing i can come up with is an issue with the line being too long or a spring in the mbc because the WG is fine with no pre load. I have a stock 02 housing with no leaks in boost or exhaust. Any other ideas aside from the line or the mbc? Im getting the car tuned soon also but i would like to get this under control first.

awdordie

iTrader: (1)

Possibly be from having the stock 02 housing with an upgraded exhaust? I know many dsms run into this when they do an upgraded exhaust before the 02 housing.

svt_lightning01

iTrader: (1)

i thought the same thing too but with so many people seeing creep from the aftermarket ones i thought the stock one may have been the way to go. Ive just gotten the car a few months ago and ive got most of the issues ironed out but this one have been a pain in the @$$!!!!! haha. I thought maybe the spring and he line issue would be a cheap quick fix. But any other ideas would be appreciated!! Ive just heard the o2 housing is a pain also to change and the aftermarkets are high. You think that is just a restricting point in the flow? With aftermarket TBE maybe the flow isn't large enough? How can you port the stock 02?

boostedmkiii

iTrader: (3)

May be too simple, but could also be just a easily overlooked - MBC hooked up correctly?

Also, are the IC pipes stock?

Other than that, double-triple check for leaks... Just thinking outloud.

svt_lightning01

iTrader: (1)

yes sir mbc is hooked up with on line from mbc to turbo outlet and other line from mbc to WG. all lines are zip tied or tight clamped. No cuts in any lines most lines are brand new with the installation of the mbc. stock solenoid is capped, intake is capped, bov to intake manifold hardline is clamped also no apparent leaks.

The lines are stock to my knowledge. the IC is stock and it was aftermarket at some point in its life. but all the pipes have stock brackets on it and they are stock im 90% sure. All the connections to the IC are clamped tight i double checked it all when i replaced the radiator and other things.

The only other possible thing that has even crossed my mind :
I live in Kentucky. The evo was tuned in Florida in 2005 with all the mods that are currently on it with a few exceptions. The car had aftermarket IC and stock radiator when it was tuned, it not has stock IC and mishimoto radiator now. It had hallaman MBC then and has Forge UNOS now. is it possible that the location change combined with the minor mod changes could cause the problem? Just a thought.

Anyone know where i can get the soft spring? I have no clue which one is installed. Just call Forge?

Boosted Tuning

iTrader: (12)

WGA has too much preload maybe. Trying loosening it.

svt_lightning01

iTrader: (1)

the WG is loosened with zero pre load i triple checked that part because it was such a pain to get to. It has just enough tension to keep the flapper from moving freely. Im 99% sure thats not the problem but i did think that may have been before i checked/adjusted it.

JDM_MR

iTrader: (1)

Had a similar issue, your WG needs to pre-loaded, its like a trial an error until you get it satisfactory. I had the Forge actuator which got busted, bought the Force Performance 18psi, configured the pre-load along with the Hallman MBC and WALLA, only tapers now like 1.5lbs up top.
Hope this helps...

svt_lightning01

iTrader: (1)

Currently it has just enough tension to pull on the flapper how much tension does it need?

awdordie

iTrader: (1)

I would think that it is restricting the flow out of the wastegate. Im assuming u have the dual flapper 9.8 hotside correct? There are plenty of how tos on the dsm forums and a few scattered in evom on how to port the o2 housing if it turns out to be a problem. Im not sure how hard they are to change out I've read that its not hard and some say its a pain. Im changing mine and a cracked manifold this coming week so I will know first hand lol. On all of the how tos it says not only to port the o2 housing but also port the hotside to help exhaust flow to the gates as well as after the gate. I have also heard that the 10.5 hotside flows better so this could also be an option since its a single flap design and the gate is larger. Just my .02.

svt_lightning01

iTrader: (1)

im not sure i think that its a 10.5 hotside and im almost positive its a single flapper. Its an 05 mr evo 8 car. Im just really lost on what to try ive tried about anything any one has told me to. The only things im left with is the spring in the MBC which i dont think is the issue, the o2 housing restricting flow, or the WG not being correctly adjusted which i dont get because it has virtually no tension on it currently, unless i read wrong that should release the most boost through the WG is when the tension is at the least?

Also i know its not a MBC issue because when you run a loop it still boost 23-25 lbs on a WG loop. If the loop is fairly lengthy could this be the issue compounded also with a faulty MBC? Its just really annoying haha summer is here and i want it under control asap. lol