Alright, some of you may have remembered a few weeks ago I posted about not being to turn up the boost with my profec b boost controller. There was a few variables in the mix namely a leak in my charge system (piping, intercooler, etc), boost controller not working properly or wastegate-to-manifold gasket not sealing. Since this time I ordered the turbonetics fire ring gaskets to eliminate the gasket sealing problem. I have eliminated the boost controller as malfunctioning when i have used two different manual boost controllers, as well as putting the bottom port vaccum line for the wastegate to the top port and leaving nothing on the bottom port to try and hit above .5bar. This did not work at all, even in that dangerous configuration i boosted a steady .5bar. Now here is exactly what happens with my car:

Changed the wastegate gasket, car just coming up to full temperature. Mash the throttle hit .65bar immediatly at my preset profec b setting that i would normally only hit .5bar. I can HEAR the wastegate opening like it should. Turn up the **** a bit more, hit .7bar still hear the wastegate opening properly. Turn up the **** again back down to .5bar, keep turning the **** all the way till its full tilt and only .5bar and I cannot hear the wastegate anymore. Now the wastegate has a .3bar spring in it, so the boost controller is turning it up from .3bar to .5bar spring, but nothing more than that no matter what. Its like a proportional amount of boost is lost from a leak when i turn it up.

Here are some things that I thought could be wrong:

Turbo is bad: cant be since the shaft spins freely, seals arent leaking and turbos basically either work or dont

Leak in the charge piping: I went over every single piece of intercooler piping and examined it, and put it back on. I have went super extreme with welding beads around the ends of every single piping and intercooler ends, as well as using t-bolt clamps. Its highly unlikely that there is a leak.

Cracked manifold: I would have figured to limit the amount of boost through the wastegate, you would need to be bleeding that exhaust gases off before the wastegate. This could only mean that my max-rev log manifold would have a crack in it to leak the cfm from my exhaust gases and not give enough flow to the wastegate. This isnt happening, manifold looks perfect.

The profec b: There is a problem with my profec, it doenst work on channel 1 or "low boost". I have had the controller for less than 6 months and right off the bat it didnt work properly. I have been meaning to call greddy to get an answer or have a new controller since this doesnt seem to be working properly. The balance works super and "high boost" works great, although it doesnt turn up the boost anymore. The vaccum lines are all hooked up properly:

Bottom port: Brake booster vaccum line.
Profec b black box: In from brake booster vaccum line (tee'd at a different location),
Top port: The "out" nipple on the black box feed into the top port on the Tial.

The tial 35mm gate: I thought that this could be the culprit. The design is very basic and doesnt seem like it could fail. Took the wastegate apart, everything inside seem perfect. The diaphram looked perfect, no rips in the material. Tested the wastegate with pressure and the valve opened and closed when air was applied to the bottom and top ports. Switched my Tial 35mm gate with a friends known working one, same situatoin occurs.

Everything worked properly on my last swap, I spun a rod bearing and pulled that swap out and put a completely different swap back into the car. I hooked up everything per last swap. The first two nights after the swap was done and i was out tuning the boost would have steady at .65bar, and i had plenty left on the profec to turn up the boost.

Summary: Did the engine swap, hooked everything backed up the way it was beforehand when it worked. Tuned the car for 2 nights, boost held steady at .65bar, heard the wastegate opening. Next day could only hit .5bar. Changed wastegate-to-manifold gasket, checked for leaking in charge piping system, ran vaccum lines to wastegate in order to boost dangerous pressure, changed my tial 35mm with a friends working 35mm tial and checked everything else that was discussed. The car will not hit above .5bar, but when cold it can hit .6bar at the same profec setting. Please help!

 

bump for u

 

yah, bump for jeff

 

Alright, just did a quick test. Went out while the car was 1/2 warmed up, got on the highway, nailed it and hit .7bar. Did this again, same result. Traffic got heavy, waited a bit and did it again, back down to .5bar. Whatever my problem is, is based upon temperature. I am convinced that the greddy profec b is bad, but i dont know to point the finger at it as the source of my problem since it is turning up the boost. I rechecked all the piping and ran pressure with a compressor through the charge piping from the throttle body (have a bung welded on my charge piping for my water injection, good spot to run the air to test!) and there isnt a single leak. Also this wouldnt make any sense as a source of the problem, if there was a leak somewhere it wouldnt be temperature dependent. The profec is probably shot for whatever reason, but i dont know if the boost solenoid box is that temperature dependent. I have it mounted directly behind the intake manifold, which is a cool part of the engine bay.

 

what spring rate do u have in ur tial? try using a bigger spring and using just the wastegate without the boost controller and c what happens. then u can know for sure if the boost controller is bad. where is ur boost gauge signal pick up at?

 

we have tried different springs a .35 & .45 no dice. damn this is frustrating
good suggestion though

 

ohh and
BUMP!

 

Ed is in the house! I didnt even know that you were on this site.

Anyway, I am at the end of the road right now. I have no idea what to do. There are to many components in a turbo system.

 

try swapping out the boost controller for a new one.

 

damn jeff, that's annoying as hell. so when you tried the diffeent wastegate springs did you disconnect the boost controller?

 

I havent actually tried swapping in the .45bar spring since i have changed the wastegates out completely. This coming weekend when i have sometime i will be swapping them out to see what effects it has on boost pressure. I am guessing that it wont matter, since the boost's behavior is still the same as what it was before i changed the gasket (spring didnt have any effect). Its really pissing me off, i have my entire partial throttle map tuned and my boost maps up till right now. I want more boost!!!!

 

but have you tried boosting without the boost controller hooked up at all? to se if you can maintain proper boost with tjus the wastegate?

 

The pressure line from the turbo to the waste gate is cut, and the boost controller is installed. Once this is done, the spring really doesn't mean squat. The boost controller works by "bleeding" the pressure signal to the waste gate by switching it open and closed quickly.

Without the manifold pressure->waste gate line connected, the waste gate will never open, and boost will be limitied by the flow restrictions in the exhaust pipng. Juging from some other exploded Honda blocks, you should have no trouble exceeding 1 bar. Removing all tubing from the waste gate will tell you if there is a problem somewhere else (like a leak) but you must watch the gauge if you start to build boost- it goes faster the higher it gets.

If you really think it's the controller:

1) Put a tee in the [pressure] line that goes to the waste gate, between the waste gate and the boost controller.

2) Connect a needle valve, and close the valve all the way.

3) Open the valve 1/4 turn at a time. And take a run.

This will bleed off pressure going to the waste gate, and allow you build more boost. It should cost you like $5 to try it.

This method has been around loger than me. Be careful, it works. If it dosen't work, you have a leak in the i/c piping on the pressure side where you are loosing boost.

Hope this helps
Sean


[Modified by hybridsol, 10:30 PM 11/3/2002]