Boost controller question - PeachParts Mercedes-Benz Forum

rcounts · #1 11-02-2008, 02:04 AM

May seem like a noob question, but then I am pretty new to turbos...

Anyway, I was looking at this one on eBay

http://cgi.ebay.com/ebaymotors/B-TURBO-BOOST-CONTROLLER-350Z-G35-240SX-S13-S14-MR2-GTI_W0QQcmdZViewItemQQ_trksidZp1742Q2em153Q2el1262QQcategoryZ33742QQihZ006QQitemZ160294446980

and I'm wondering what the little 3-port cube thing is for.

My understanding of a turbo boost controller is that you install a pressure regulator between the intake manifold and the wastegate actuator to make sure the wastegate stays fully closed until the pressure reaches the psi level you've set on the controller - then it starts bleeding pressure through to the wastegate actuator.

So since all you are trying to do is regulate the pressure to the wastegate actuator, what is the 3-port piece for - is it even needed for a system like the one on our Mercedes?

compress ignite · #2 11-02-2008, 02:22 AM

Damn,

The "Auction" has ended! (Price was too good to be true)

The little box with the blue nipple pointing 90 degrees to the other two nipples
is the "TakeOff" for your "Boost" Gauge.

IF you're gonna install an EASILY adjustable Boost Controller
(Or a Bost Controller at all) I would HIGHLY RECOMMEND installing a Boost Gauge also [A Pyrometer ('Measures EGT [EXHAUST] Temperatures) would
also be a must!]

rcounts · #3 11-02-2008, 04:31 PM

Quote:

Originally Posted by compress ignite

Damn,

The "Auction" has ended! (Price was too good to be true)

The little box with the blue nipple pointing 90 degrees to the other two nipples
is the "TakeOff" for your "Boost" Gauge.

IF you're gonna install an EASILY adjustable Boost Controller
(Or a Bost Controller at all) I would HIGHLY RECOMMEND installing a Boost Gauge also [A Pyrometer ('Measures EGT [EXHAUST] Temperatures) would
also be a must!]

Actually, check his ebay "store" - last time I looked he had dozens of them at that price - different colors even!

Yeah I wouldn't even think of messing with the wastegate without a pyro and boost gauge - no way I want to blow head gaskets on my freshly installed motor!

Here's a question for you. What would be wrong with installing one of these...
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90590

It has both a pressure regulator and a built in gauge. They have them in lower pressure range models as well - I've seen 'em at their store...

LUVMBDiesels · #4 11-02-2008, 07:19 PM

Quote:

Originally Posted by rcounts

...

Here's a question for you. What would be wrong with installing one of these...
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90590

It has both a pressure regulator and a built in gauge. They have them in lower pressure range models as well - I've seen 'em at their store...

I think that would not do the job. It regulates pressure to keep pressures higher than what you set from going through the regulator. The boost controller is a simple ball check valve and a spring that is adjustable so that it does not open until a certain pressure is reached. I got one and set it to 14 psi using my mitivac. I installed it and a boost gauge and a pyro in my 300SDL and it worked fine.Before I installed it, I was lucky to get 6 psi before the wastegate opened. the difference in performance was very noticeable. The EGTs were not bad either topping at about 800 degrees with the amount of fuel available. I never set the IP for more fuel.

I am going to duplicate this setup in the SDL.

rcounts · #5 11-02-2008, 08:38 PM

Quote:

Originally Posted by LUVMBDiesels

I think that would not do the job. It regulates pressure to keep pressures higher than what you set from going through the regulator. The boost controller is a simple ball check valve and a spring that is adjustable so that it does not open until a certain pressure is reached.

OK, I get it, now that I think about it, you're right, these two devices basically work opposite each other - one only lets pressure through UP TO a set pressure, and the other lets NO pressure through UNTIL the set pressure is reached. Makes perfect sense.

Quote:

Originally Posted by LUVMBDiesels

I got one and set it to 14 psi using my mitivac. I installed it and a boost gauge and a pyro in my 300SDL and it worked fine. Before I installed it, I was lucky to get 6 psi before the wastegate opened. the difference in performance was very noticeable. The EGTs were not bad either topping at about 800 degrees with the amount of fuel available. I never set the IP for more fuel.

I am going to duplicate this setup in the SDL.

Now THAT's what I'm looking for. I'm not looking to make mine a tire-smoking fire-breathing dragster, but if a little more performance is readily available at a small cost with no major economy hit, I'm all for it. It didn't ruin your fuel, economy, did it? Did it improve your boost at lower RPMs? Make the boost come on any earlier?

I have a air pressure gauge that will work well for a boost gauge, and a dual pillar gauge pod, now I just have to get a pyro, and one of these controllers and I'm all set. Thanks for the feedback!