Help me understand why my MBC does not function properly
May 1, 2007, 11:18 AM
#46
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Well I busted my stock radiator taking a WGA out so rather than make that 300-400 $ mistake any more I play it safe. I can adjust it no problem being in the car... I just put cardboard in the way of the radiator.
I preloaded it a full 4 turns and it would hold almost 25psi to 7000rpm. Shortly after that a vac line popped off and I found a couple other little leaks... after fixing all this the WGA is now only holding 18-20psi which made me wonder what else could be wrong.
If I preload the WGA more it should bring the boost back up where I need it but with 4 full turns it was VERY difficult getting the pin in the hole.
I've tried everything with the stiff spring tho.. I would clean it out reseat it and it would work great for a few minutes then start sticking. I have bought 2 Forge MBC's and both do this.
I'm about to the point of having someone else look at it... Maybe I'm overlooking something or making it more difficult than it really is.
I preloaded it a full 4 turns and it would hold almost 25psi to 7000rpm. Shortly after that a vac line popped off and I found a couple other little leaks... after fixing all this the WGA is now only holding 18-20psi which made me wonder what else could be wrong.
If I preload the WGA more it should bring the boost back up where I need it but with 4 full turns it was VERY difficult getting the pin in the hole.
I've tried everything with the stiff spring tho.. I would clean it out reseat it and it would work great for a few minutes then start sticking. I have bought 2 Forge MBC's and both do this.
I'm about to the point of having someone else look at it... Maybe I'm overlooking something or making it more difficult than it really is.
May 1, 2007, 02:37 PM
#48
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I guess I'm gonna have to.
Eh? You mean a gasket? Yes and I used a little RTV so it should never leak... I had a nipple put on the compressor housing which I'm using as a boost source.
Eh? You mean a gasket? Yes and I used a little RTV so it should never leak... I had a nipple put on the compressor housing which I'm using as a boost source.
May 1, 2007, 02:50 PM
#49
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Just give the turnbuckle on the end of the actuator rod one more full 360* rotation. This should get you up to about 21# of preload. From there on up, dial in the last few PSI with your MBC.
May 1, 2007, 03:01 PM
#50
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That's what the plan is after I check for exhaust leaks. I had it dialed in perfect..rather than just crank the wga up more I wanted to investigate... It's a learning experience although frustrating.
I see you have the green... can you comment on any "different" sounds you hear during very light spool/acceleration? I have this weird kinda noise I didn't have with the 20G-9-5 which has kept me paranoid about leaks.
I see you have the green... can you comment on any "different" sounds you hear during very light spool/acceleration? I have this weird kinda noise I didn't have with the 20G-9-5 which has kept me paranoid about leaks.
May 1, 2007, 03:19 PM
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That's what the plan is after I check for exhaust leaks. I had it dialed in perfect..rather than just crank the wga up more I wanted to investigate... It's a learning experience although frustrating....I see you have the green... can you comment on any "different" sounds you hear during very light spool/acceleration? I have this weird kinda noise I didn't have with the 20G-9-5 which has kept me paranoid about leaks.
Yeah there is a sound kinda like a dry shaking sound like certain percussion instruments. Like when you tighten the screen lever on a snare drum or the sound of maracas but continuous. It is more noticeable with a cutout top on the stock airbox.
Sort of a dry, raspy, whispering intake sound. Also it seems to make a more noticeable high-pitched whistling sound in comparison to my TME when spooling up. Is this the noise that you're refering to? Obviously, I really have difficulty articulating turbo noise nuances.
Last edited by sparky; May 1, 2007 at 03:50 PM.
May 1, 2007, 04:03 PM
#52
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Yes that's exactly it.. and you can understand why I didn't try to explain it 
That makes me feel a lot better.
Here is where I'm at right now. It's almost cooled down enough to work on so I'm about to get busy
This is what I need back (minus the afr's) lol
That makes me feel a lot better.Here is where I'm at right now. It's almost cooled down enough to work on so I'm about to get busy
This is what I need back (minus the afr's) lol
May 1, 2007, 04:13 PM
#53
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Is your Green equipped with the FP HD actuator or the stock IX actuator?
Once you get preload up to 21#, then approach it with more caution. From 21# on up, you can try to add a bit more preload but do it in 1/2 turn 180* increments as the WG actuator seems to lose linearity above 21# of preload and it's easy to overboost.
I wouldn't personally go much over 21.5# of preload as you want to leave a bit of adjustability to dial in with the MBC just to leave some room for variances in climactic conditons and elevation etc.
Once you get preload up to 21#, then approach it with more caution. From 21# on up, you can try to add a bit more preload but do it in 1/2 turn 180* increments as the WG actuator seems to lose linearity above 21# of preload and it's easy to overboost.
I wouldn't personally go much over 21.5# of preload as you want to leave a bit of adjustability to dial in with the MBC just to leave some room for variances in climactic conditons and elevation etc.
May 1, 2007, 06:11 PM
#54
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Yes it is.
I will give that a try. I just "unloaded" it back to point "0" where it slides on easy. It was 4.5 full turns from "0". I'm going to set it on 3 turns and give it a try with and without the MBC.
Edit: Ok I'm back with some 3rd gear logs. It's actually worse now but before I change anything I want to get a log with just the WGA. I'm trying to find someone local with another brand MBC to try out.
Weather is a little cooler than it was in my last logs.
I will give that a try. I just "unloaded" it back to point "0" where it slides on easy. It was 4.5 full turns from "0". I'm going to set it on 3 turns and give it a try with and without the MBC.
Edit: Ok I'm back with some 3rd gear logs. It's actually worse now but before I change anything I want to get a log with just the WGA. I'm trying to find someone local with another brand MBC to try out.
Weather is a little cooler than it was in my last logs.
May 1, 2007, 06:22 PM
#55
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Ok. Stiff spring installed on the Forge UNOS. 1 click just like the soft spring.
One thing I had/have with the stiff spring is when I shift gears moderately fast and go WOT 3-4th it only builds about 22psi in 4th gear. This one was on my reasons i went to the soft spring. Noticed it again tonight (will post that log snippet tomorrow)
That's all for now. I'll get a log of just the WGA tomorrow.
One thing I had/have with the stiff spring is when I shift gears moderately fast and go WOT 3-4th it only builds about 22psi in 4th gear. This one was on my reasons i went to the soft spring. Noticed it again tonight (will post that log snippet tomorrow)
That's all for now. I'll get a log of just the WGA tomorrow.
Last edited by justchil; May 1, 2007 at 07:15 PM.
May 2, 2007, 08:43 PM
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I am just no good at reading graphs. How many PSI is 3 full turns of the turnbuckle on your Green w/ HP WGA and no MBC? Is it like 19#? Since you´ll be running over 25# peak boost, then you´ll probably want 21-22# of preload. It´s probably somewhere close to 4 full turns. Wow, that´s a lot. Good luck 