new turbo + mbc = overboost

[optional187]

just finished installing a b16g, forge mbc, type rs knockoff, and piping to make it all work. now i'm boosting way too much. for my first run with the new turbo i left the stock bov on and it held at 12 psi, i was assuming that was because...well, its the stock bov. i bolted on the type rs knockoff and my boost jumped (let it go up to almost 20 psi just to see how high it would go.) i've adjusted the forge bov all the way to + and all the way to - and it has NO effect on the level of boost what so ever.

the vac line coming off the bottom is running down to the nipple on the 90* elbow from rre, and the vac line coming off the side is running to the wastegate. the stock vac line i left disconnected from the solenoid completely. now that i think about it i havent plugged the hole yet, could that have any effect on this? have i got the mbc hooked up wrong? or am i about to have to pull some stuff apart again to adjust the wastegate?

 

[imagine3163]

i've adjusted the forge bov all the way to + and all the way to - and it has NO effect on the level of boost what so ever.

I am assuming that you meant "forge mbc"? Have you tried running just off the wastegate and the new bov?

 

[98gst14b]

If the mbc you got is a ebay one or real cheap you may have to cut the spring. I got one off ebay once and the spring was too long, the knob all the way out would give me 22psi. Also make sure the line going to the wastegate is the nipple closest to the knob on your mbc.

 

[optional187]

I am assuming that you meant "forge mbc"? Have you tried running just off the wastegate and the new bov?

yeah, meant to say forge mbc...sorry.

i read somewhere on here that tapping the bov was actually the bad way to install a mbc. are you saying i should connect a vac line tapped from the bov line directly to the wastegate and not hook up the mbc at all?

 

[pwayzjellyroll]

If your MBC is not functioning correctly you should connect a line from the wastegate to a nipple on the compressor housing or j-pipe. Have you re-done a boost leak test after the ebay rs install? Usually they are big pieces of junk that leak like hell and that's something you should keep an eye on.

 

[viperlp01]

I made my mbc with brass fittings and i tapped it off my vac line from intake mani to bov. Works perfect that way. 18lbs solid.

 

[optional187]

If your MBC is not functioning correctly you should connect a line from the wastegate to a nipple on the compressor housing or j-pipe. Have you re-done a boost leak test after the ebay rs install? Usually they are big pieces of junk that leak like hell and that's something you should keep an eye on.

connected a vac line from the nipple on my rre 90* to the wastegate and it didnt change anything at all. ok then, wastegate's not opening. i hooked a air compressor to the wastegate and watched it move, hardly moved at all. adjusted the wastegate arm a bit, retried the air compressor trick and viola. running a solid ~8psi, boost needle moves around a bit from 7-9psi but i'll take it.

gonna hook up the mbc to get it running about 10-12psi then start saving for fuel/fmic stuff that way i dont mess anything up with the new turbo.

oh, and about the ebay rs. i did a lot of searching and found that A LOT of people actually prefer it to the greddy rs. i actually found more problem threads concerning the greddy rs as compared to the ebay rs. only negative things i've found were that they are super quiet when recirc'd (both greddy and ebay rs.) but thats why i'm on the hunt for a old school type s now.

 

[turbo_punk]

I would say find the Greddy Type S I had one on my turbo civic and I loved it! It worked perfect and sounded great, but to tell the truth a 1st gen bov is a lot cheaper and works just as good it just don't look as good but they can be painted...

 

[optional187]

I would say find the Greddy Type S I had one on my turbo civic and I loved it! It worked perfect and sounded great, but to tell the truth a 1st gen bov is a lot cheaper and works just as good it just don't look as good but they can be painted...

got one sitting on my floor, just need a flange

authentic type-s bov's are super hard to come by it seems...when i do find one thats new its about $300 bucks. got a list of other things to get before i have to worry about that though.