legacycentral bbs

well i just picked up a TurboXS MBc, sells for $135 new, i paid $50, ran once for about 30 minutes, then taken off and car was put back to stock.

hooked it up the other day and set it at 10psi. im loving how the car is, it has the ajustable bleed valve and i changed the lag time slightly higher then stock to help with gas milage.

i just cant wait until i have the money to get my cat-back or atleast a new axelback exhaust on and maybe a sabb TMIC.

I was wondering how you set it up because i could not get mine to work properly, and i followed the directions from TurboXS website. How does the weather effect the boost. Have you taken it up altitude before? Thanks
-max

basically i just hooked up the side with the brass fitting from the manifold source, then the blue nipple goes to the wastegate actuator, plug the fittings on the stock boost control solnoid and the fitting on the inlet of the compressor housing and your done.

then ajust the allen screw that is in the aluminum part, that is the corce ajustment, then play with the other one on the brass side, that is the fine ajustment to set the boost exactally where you want it. also you can kind of play with the turbo lagg with that also like i did so the turbo fully boosts at 3k instead of the stock 2200. only so i can try to get better MPG.

if you want a MBC, just build one for $2.50 I even set mine right up near the sterio so I have cockpit adjustable boost

sammydafish wrote:if you want a MBC, just build one for $2.50 I even set mine right up near the sterio so I have cockpit adjustable boost

How did you swing 2.50?

I tried getting the parts at the local Home Depot and it was coming to $40+

Forty dollars? Were you gonna make it out of gold?

$2.50 is a little low, but it all depends on how cool your local hardware store is. You need:

1 1/4" FPT tee
2 1/4" MPT - to - 1/4" hose barb adapters
1 5/16" ball bearing
1 spring of an appropriate diameter to cup the BB and length to fit in the tee
2 3/8" nuts
1 3/8" bolt

Most of those things were sold in two packs, plus I had to buy the tap bit and the tap tool

yeah, I actualy probably used like $5 on it all but I only had to buy a ball and spring and one 90 degree barb, the rest I had in my tool box so I only spent like $1.75 to make it. Ts are like $1.50 though and barbs are like $0.75 ... still, I dunno where you got off spending $40 .. even with a tap, a good tap isn't more than $10 and you can get a whole kit, albeit a crappy quality one for $40

Tap + correct bit = $18
T's and barbs = $10
Misc other bits and pieces = ~$10

You don't need a tap. Just solder a nut onto the end of the tee.

An actual hardware store would have the parts individually and more cheaply than at Home Depot.

Im actually gonna check at LordCo, I just got an account with them so I get a decent discount

The Scooby wrote:basically i just hooked up the side with the brass fitting from the manifold source, then the blue nipple goes to the wastegate actuator...

Doesn't connecting it the manifold cause part-throttle-full-boost? Why wouldn't you just connect the MBC to the same lines already used by the stock boost control solenoid? (which utlizes the compressor outlet)

sorry for the highjack but is full boost at partial throttle such a bad thing. I had my ebc set in my silver wagon such that anywhere over 3k it would be able to produce 15lbs. I never had any probs with the engine and it pulled like a mofo. I always thought it would make it run lean but I never experienced any probs.

I'd hazard a guess that it might wear out the throttle mechanism (15psi * whatever crossection of the throttlebody is in the air flow)

Mike, don't confuse "part throttle" with "mid-range RPMs."

Full boost in the manifold at part throttle implies more-than-full-boost at the compressor outlet and in the turbo. That means more heat.

Also, the ECU tends to run closed loop at part throttle. You want to avoid being on (much) boost in closed loop if possible, since air/fuel mixtures will not be as rich as they ought to be.

Exactly - with your boost controller's input pressure coming from behind the throttle plate, how much pressure is seen by the MBC is directly affected by the throttle position.

Generally, the recommended place to connect a boost controller's input pressure is the compressor itself, right on that convenient nipple they've provided for you by the outlet. This allows the boost controller to see exactly how much pressure is being generated by the turbo.

When this input is instead read from behind the throttle plate in the intake manifold, when the throttle plate is partially closed, the turbo will have to work harder to create the target boost level in the manifold, generating more pressure than necessary. Much more wear and tear on the turbo this way.

magicmike wrote:sorry for the highjack but is full boost at partial throttle such a bad thing. I had my ebc set in my silver wagon such that anywhere over 3k it would be able to produce 15lbs. I never had any probs with the engine and it pulled like a mofo. I always thought it would make it run lean but I never experienced any probs.

Yeah, it is. Your boost controller has no idea what the turbo is doing. All it knows is that it's going to try to do whatever it takes to get full boost inside the intake manifold at ALL times. So, if you lift the throttle, it's just going to try harder by blowing higher and higher pressures.

Let's simplify and say you set your boost controller to 15psi and your throttle is halfway closed. The throttle is cutting the pressure in the manifold to half of what the turbo is blowing. But, your boost controller *by definition* is going to tell your turbo to keep spooling until it sees 15 psi in the intake manifold. But the intake manifold is being choked off by the throttle. That means that it's going to tell your turbo spool up to 30 psi.

That'll be some hot air, and it'll be some bizarre response to the throttle.

It's an oversimplification, but I'm making a point.

I understand what all of you are saying but the cars perfomance increased significantly after setting it up like this.

At what throttle percentage does the computer switch to open loop?

Magicmike - is your performance increase measured by a dropped quarter mile time? AWD dyno results? Or just the plain old butt dyno? Because I'm sure it would feel "faster" at partial throttle than it did before due to the overspool and potential lean conditions - it's just not the best idea if longevity and reliability are factors.

Not sure exactly, Dan... You could spend a little time with my scantool and figure it out, though.