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After my tmic/td05 swap, I never turned the boost up past ~9psi because I didn't have any tools to make sure I wasn't leaning out the engine, maxing the maf/injectors, etc. I finally got my wideband and now feel somewhat more comfortable cranking up the boost a few more PSI.

I've cranked down my hallman rbx MBC all the way, yet the boost level remains at ~9 PSI -- which I know is the wastegate boost for the TD05. I've got the Hallman hooked up the same way as I had with the VF11 (and it worked there). Side nipple to the wastegate, end nipple to the turbo compressor. Autometer boost gauge is teed off the #1 runner and holds steady whatever the boost is (unlike others who describe constant shaking).

Searching the forum, there have been several other users who have td05 wastegate boost issue -- none really resolved it.

Reading in the hallman manual, one finds the following:

If you purchased the RX option your kit came with a ceramic ball and two different springs, one light and one heavy. The light spring came already installed in the controller and the heavy spring is included in a marked bag. The light spring is good for adding up to 5 pounds of boost over the stock boost level. If your stock level is 10 psi then the light spring could add up to an additional 5 psi for a total of 15 pounds of boost. The heavy spring can add much more than that. The light spring will allow you to adjust boost in very small increments.

1. Do you think I need to switch out the heavier spring?
2. I don't believe I have any leaks (well nothing obvious sounds of rushing air during WOT) in the intake/tmic tubing. One can look over my TD05 install pics here. What else would cause this problem?

You don't need to switch springs.

I would question whether your wastegate actuator is working properly. Get a vacuum/pressure pump kit used to bleed brakes. They're cheap and have a gauge on them. You should be able to determine when the wastegate actuator starts to move, and if it's moving when you think it is.

Hmm alright, I'll pick one up. I assume I attach the tool to the wastegate port.

If it opens before 9 psi, then.... ?
If it opens after 9 psi, then.... ?

The wastegate actuator will start to open before 9 psi. What you're looking for is what pressure it starts to open, and what pressure is it fully open.

Play with the acuator level to get a feel for the full travel/movement of the actuator.

When actuators go bad do they typically cause underboosting? i guess i always figured it would be the other way around,why would it become more sensitive rather than harder to move?

gijonas wrote:When actuators go bad do they typically cause underboosting? i guess i always figured it would be the other way around,why would it become more sensitive rather than harder to move?

The spring loses its strength over time, thus making it easier to open? Just a guess.

Now i need to see a cutaway of a wastegate actuator hmm...old crappy turbos in shop + sawzall.

gijonas wrote:Now i need to see a cutaway of a wastegate actuator hmm...old crappy turbos in shop + sawzall.

I went out and tried moving the actuator arm -- it moves, but sure isn't easy at all compared to the VF11. Got a vacuum/pressure pump and will test it tomorrow.

I think you said the actuator boost level was 9psi & the MBC was not increasing boost.
If so I'd think something was wrong with the MBC connections if the actuator was boosting properly on its own.

I just double-checked the connections yesterday when I looked over things. Per the picture below, they are hooked up properly.

So you don't have anything else teed into your lines to the wastegate or from the compressor outlet? I vote for bad MBC or boost leak.

You took off all the lines and inspected them right? When was the last time you replaced every single seal in your intake track? Have you ever smoke tested your intake?

Did you have that 07 WRX TMIC installed with the VF11 or is that new?

I was just looking at your install and it looks like you have FOUR lines coming off of that vacuum nipple on the cylinder #1 intake runner. That is a bad idea for a boost gauge install. I did that with my VF11 and it was reading like 5 PSI. I hooked it up to the vacuum nipple on top of the throttle body by itself and I was really getting 22 PSI! So yeah teeing your boost gauge in is a bad idea, it needs it's own line. You might be boosting a lot more than you think.

It looks like you reused a lot of old lines, hoses, and connections which is just prone to give you leaks.

One of your pics even had this comment:

"Brittle wires, noticed after the install. Sure to cause future problems..."

Mmmmmhhhmmmm and hoses will do the same thing.

You've got a lot of heater hose installed where you really need silicone. My suggestion is to go order yourself a pile of silicone hoses from ebay or summit racing, take apart what you got, and re do it with something that will last. Heater hose can work yeah, but it doesn't last.

You don't have to keep the stock setup for the PVC or the F-tube block breathers too. They have a crazy setup from the factory. I re-engineered mine and it wasn't that hard. I won't say what I did here because people are going to complain about the environment but it isn't that hard to think up a better setup.

I read in Sport Compact Car where they did a test on catch cans and if they actually add power. It turns out they do but only if they are hooked up to vacuum. Removing the pressure from the crank case and the heads allows the engine work better. I wish I had a link to the article but basically just putting a little K&N breather filter on your breather is a bad idea. When they hooked it up to a real catch can that was hooked up to the intake to provide vacuum it added power, minimal but noticeable on the dyno.

GodSquadMandrake wrote:So you don't have anything else teed into your lines to the wastegate or from the compressor outlet? I vote for bad MBC or boost leak.

Nope.

I hooked up that vacuum pump to the wastegate line and sucked 25 inHg -- it held steady and nothing moved. The pump I got is a Equus 3660 Hand Vacuum Pump & Brake Bleeding Kit. Umm, don't I want to be pushing/boosting air into the wastegate, not sucking? At least the kit I got, I don't think I can...

Anyways, since I was under the hood, I decided to swap out the soft spring for the hard spring in the Hallman. Put everything back together, left the MBC about half way screwed in and went for a drive. 2nd gear, WOT. I see the boost gauge immediatly jump past 15 psi! woohoo. Quickly let off the throttle since I dont have a FCD installed (opting for the Rev chip and use software in time). Pull over and keep adjusting the MBC so I'm around 11 psi.

So... since the harder spring 'fixed' it, does that just mean the soft spring has gotten too soft from time I've had it (bought 6/26/2008)? Or too hard to tell w/o me getting really testing the wastegate?

I knew that Actuator was fine, enjoy the boost.

Cool! Congrats on getting more than 9 PSI. How does it drive?

The ~1.5 psi isn't super noticeable -- not like the 15 psi I had it for a little bit. THATS the real kick in the pants. Now I'm starting to get impatient for that stage 3 revtronix chip cause I'm ready to go faster now, lol.

I'm still wondering if its the wastegate or mbc which was the reason for my boosting problem...

These damn wastegate issues continue (no, haven't gotten a pressure tester yet). A day or two after I got things working, I noticed that I was back to making 9psi. Figured it was just the spring and thus, cranked the MBC a half-turn higher. Next day, after driving it was still 9psi so I cranked it a half-turn higher again.

This little cycle went on all week, with the boost still stuck at 9spi. Yesterday, I cranked it up a half-turn again and went driving. Right away, I was back to crazy 17+psi boost levels. WTF. Pull over on the Interstate, crank it down a few turns. Go driving again, still too high, get off, turn it down more, etc. After about 30min of this process, I had it back to ~11psi again.

1) WTF is with my boost levels not increasing as I increase the MBC, but then jumping way too damn high after I've cranked it up a lot? I can partially move the wastegate by hand, so it's not stuck. I assume I can't move it all the way due to the higher wastegate psi level.

2) As a little experiment, I went WOT when my boost was ~17psi (no FCD installed) and doing 70mph. I heard the engine start to ping/knock bad and let off after a second. No, I didn't hit fuel cut during that time. Once I get larger injectors, MAF, and the chip -- whats going to stop me from having these detonation problems still?

The larger injectors and the chip will help solve the detonation problems so don't worry. They'll have the chip tuned to dump more fuel when the boost reaches those levels.

Sounds like your MBC is not working properly. You may want to look for a new one.