justchil

iTrader: (44)

I'm going to try to lay this out as simple as possible. I'm pretty ticked right now from this and personal stuff but I'm not here to bash anyone or any products. I just want this fixed so I can enjoy the car. Sometimes you need to back away and get input from others

Here is some background:

I had a 20G-9-5, Forge WGA (red spring), Forge DV (blue spring) and Hallman MBC stiff spring. Worked great for around 7 months. Boost started getting iffy... found a major problem with the WGA. pic: http://www.justchil.net/gallery2/d/69951-9/100_3008.JPG

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Ok so no big deal I'm upgrading to the LT soon and will have the FP WGA. I clean this WGA out.. it's spotless. I buy a Forge MBC because I've heard good things and wanted a change. Well I was getting a lot of taper with the soft spring so I jump up to the stiff spring.

Works great right! Wrong. Next day on a 300 mile trip the ball "gets stuck" and my boost is stuck at WGA pressure which was about 18psi. I reseat the spring be very careful and quadruple checking my work. Works great for a while... doesn't get stuck again but sometimes when I would shift fast from 3rd after hitting 26psi I would get 18-19psi in 4th gear just like when the ball would stick.

At this point I'm pretty frustrated. I start second guessing the Forge WGA as the problems it had before. This is all over a week so there wasn't really much time for it to get in this condition again (no rain etc..)

Stay calm Daniel son the new stuff will arrive any day.....
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I get my 20G-LT, FP High Boost WGA, tons of new bolts seals.. everything is pretty much new other than the mani/o2 housing. I'm excited. I double check and second guess all of my work and 99.9% it's always right. I take pride in working on my evo.

Everything is together! Idle is damn near perfect... daily driving in no boost is perfect.

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Changes in this setup related would be NOT T'ing the DV as a boost source for the MBC. I noticed when this was T'd the MBC would see negative pressure and suck in air through the bleed hole. I had FP put me a nipple on this turbo so I the best source possible.
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Now it's time to boost. I set the Force MBC (still stiff spring) about 5-8 clicks from the lowest setting. I hit 28psi about 1-2 seconds it's starts falling drastically. Dropping to 19-20psi by 7300RPM. I've adjusted it up and down, checked for leaks.. you name it same crap. It does not gradually taper... it holds for a second then blam its down 7-9psi.

Giving up on thinking the MBC was the problem I put the red spring in the DV. Well that didn't help same crap. I could have swore looking at the gauge it held a little more boost but my logs said otherwise.

MBC being the only thing left in my mind I unhook it and connect the lines together. I needed to see what my WGA was preloaded to anyways. Well it hits 21 psi and holds 20.something psi until redline. It actually pulls harder with less boost than it did before.
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I'm waiting for the car to cool down now and I will preload the WGA 1 more turn (4 turns is the highest recommended setting) Which should put me at around 24-25psi. If that holds true and boost holds like it is now I'll hookup the Forge MBC with the soft spring which worked before but tapered down the WGA pressure. That would mean in theory I'd have almost 30psi tapering to 24. That seems to be fairly normal for this turbo and my setup.
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So what do you guys think? Again I'm not trying to down any products as I only buy the best.. or the best I can afford.

I'm really hoping this works out like i'm thinking.. but I could be totally wrong here. I'm no mechanic but like I said I take pride in what I do

sparky

iTrader: (1)

Have you experienced the characteristic boost spike which the FP HP WGA is known for yet? FWIW, I personally would only increase the preload by 1/2 turn at a time once you get over 20# of preload. Sometimes the solenoids don´t react in a linear fashion over 20# with respect to increasing preload. Also, use caution since you are holding the WG puck on the seat longer and at preload levels over 20-22 PSI you may increase the likelihood of an overboost condition given a turbine housing with an unported WG bypass port. Just my $02.

justchil

iTrader: (44)

Which solenoid(s) are you talking about?

justchil

iTrader: (44)

PROBLEM FIXED


Just as I had assumed the problem is now taken car of.

Forge MBC heavy spring just doesn't like me. I could see an indentation of where the spring was seated on the ball. Almost looked like a lil rust on the ball itself.

1. Forge MBC fully cleaned, ball lubed with a light amount of grease as well as the spring on both sides. I'm not using the soft spring. I started at 20 clicks from the lowest setting.

2. FP High Boost WGA now has 1-1.5 more turns of repload.

It's been raining all day and I have RT-615's so I couldn't pull to 7500 even in 2nd gear. The car is insane now I can't wait to get the tune fixed up.

Here is the after.. granted it's 900rpm less but the curve is nice and flat... and yes she's too rich... I'm playing it super safe til I worked out the boost issues

Before:



After:

sparky

iTrader: (1)

[quote=justchil;4210142]Which solenoid(s) are you talking about?[/quote]

Sorry for the confusion, I meant actuator, not solenoid. I´m glad that you fixed your boost problem.

justchil

iTrader: (44)

No problem. After spending so much time typing this out in such a way NOT to cause bs drama... I'm surprised by the lack of responses but glad I solved the problem.

Hopefully this will in some way be useful to others.

patty AT forge

justchil,

I just started to visit this site so forgive the lack of a more timely response. Glad to see that you have resolved the issue, it would seem to me that debris from the WGA may have made its way to the MBC. So cleaning it would go a long way towards fixing the problem. As always we back our products for life so give me a call or send me an email and I will make this right. Right off the bat I'm thinking new internals for the UNOS are in order.

407.447.5363
pat@forgemotorsport.com

justchil

iTrader: (44)

The MBC's were added after the WGA was cleaned out and now I have the FP WGA. I have two UNOS's right now due to losing a stiff spring and needing one right away. Both would stick with the stiff spring no matter what I did. Both would work for a day or so then start sticking

Both work perfect with the soft spring. With my FP WGA preloaded I can now use the soft spring and it works perfect. I've also ditched the "T" on the bov as a boost source and have a nipple on the turbo. I noticed that during idle and such the UNOS would suck in air through the bleed hole.

The WGA is a lost cause tho... I really don't wanna pay to fix it or anything and will probably lose a lot of the resell value due to the finding of these problems
It was only used with an UNOS for a day or two... I was using a hallman before.

I'm happy to have the car holding boost perfectly... What I've spent to achieve this hasn't really kicked in yet lol

dubbleugly01

iTrader: (24)

seems like the intial thought was to blame the hallman. Then you found a bad wga?

I'd try the hallman again. I know, I know...... sounds like you've already solved the problem, but the hallman could be worth another try?????

justchil

iTrader: (44)

I'm really not sure on the WGA. I don't really blame it cause any number of factors could have come into play. The MBC is my main issue... I had planned on ditching the Forge WGA for the FP unit anyways.

The only reason for change from the hallman was I wanted something new. I never had any problems out of it in the 2 years I had it. Unfortunately many of its pieces were lost in the quest to find normal boost

C6C6CH3vo

iTrader: (9)

Yes, controlling boost is more about MBC and WGA settings, the plumbing network, static/dynamic psi, rocket engineering, volume, flow and so forth, not really the parts used


Is that the A:F you usually run up there with 50/50, what timing peak and redline?

justchil

iTrader: (44)

Totally agree.

No, Thats extremely rich as to what I would normally run. This is a new setup so I'm still getting the turn in order (running 100% alky btw). Not even sure right off what peak timing is I'm thinking 17-18ish and my redline is 7800 although I normally shift around 7300.. but this is a new setup so all this may change. The log above was just a quick pull to see if the boost was right!

cfdfireman1

iTrader: (11)

Andy,

A wastegate is essentially a device that bypasses some exhaust flow around the turbine section of a turbocharger to control maximum boost. The evo wastegate is controlled by a pressure actuator that is connected to manifold pressure via a MBC. The wastegate is normally closed, held shut by a spring inside the actuator canister. When preset pressure limits are exceeded the MBC ball is pushed off the seat allowing pressure to the actuator progressively opening the wastegate, allowing exhaust flow to bypass the turbine, thus regulating manifold boost pressure. The wastegate spring is the only thing holding the flapper closed. If the MBC ball is not opening the pressure will not be regulated “too much boost” if it opens too soon “too little boost”. The MBC only allows the wastegate to open it doesn’t hold it closed in any way. Somebody correct me if I’m wrong.

justchil

iTrader: (44)

I think you're right but I don't know if the ball was stuck open or closed. It wouldn't boost past the WGA pressure when it would stick. No matter what I did with the stiff spring after a day or two it would stick.

Alot of other people are having or had this problem. It's been said if you compress the spring in your fingers 100 times it helps prevent this.. but not in my case.

patty AT forge

Email me at pat@forgemotorsport and I will get you squared away.