InTeGrA B18b1

Mbc install on the turbo compressor or manifold vacuum source? im just curious what would be the best one to use because i have heard people say that both its good. its a t3/t4oe.

DLOTYPER

i heard going off the turbo was good, until i put the vacuum source to the intake mani!! when you go to the compressor, your not taking into account the pressure drop from an intercooler,,,, my turbo seemed less laggy after i put it to the mani,, almost seemed quicker,,, i dont know though,, everybody ive heard from always says to go from the mani,,, thats where the pressure is accurate,,,,,if im wrong somebody chime in>>>>

lazerus

Your engines intake manifold is the best source to use for the wastegate, because that is what boost pressure your engine sees.

InTeGrA B18b1

wastegate line to mbc then to vacuum source right.. i guess ill use my brake booster than or anyone say otherwise

Sprockets

iTrader: (6)

I have a Hallman MBC that was hooked up to the FPR and I got spiking, so I switched to the brake booster...same thing. I e-mailed Hallman and he suggested I try the lighter spring with the ceramic ball...still spiked. I just recently had my turbo tapped so I could use that as a boost source for the MBC. I found a diagram online somewhere that this was the best way to prevent spiking with an MBC, although I haven't had a chance to confirm this yet since I'm breaking in a new clutch. Although your true boost levels are measured at the manifold, it doesn't make a difference that the MBC is "seeing" different boost levels from the turbo compared to the manifold. Boost levels will be higher at the turbo, then pressure will drop after the intercooler, so I think I'll have the option to run lower boost levels than before because the wastegate will open sooner with this setup. The only difference is that I'll have to tighten the MBC more than before to run the same boost levels. Someone correct me if I'm wrong.

omahaturbocivic

If you have the boost controller at the same setting it will equal more boost off the intake manifold because of the pressure drop but what diffence does that make? You gonna set it at whatever psi you want either way with reference to the boost controller which will always be hooked up at the intake manifold so 8psi(or whatever your set at) is 8psi. The only difference I can see is that while you are in vaccuum during shifts it might suck the wastegate closed which may help spool between shifts but I doubt it makes any diffence. Anyone else have an opinion?

evil93evo

If you want less boost spike you need to make the hole that vents the air from the hose leading from the hallman to the wastegate actuater smaller, it will also lower your min boost a litlle.
If you eliminate the hole completely you will have slow boost response between gears, the hole lets the air trapped between the ball/spring controller and the wategate escape and that lets the wastegate close again so you get back to full boost sooner after the shift or letting off the throttle.

Tom