I am currently spiking over 15psi. I thought that maybe the Profec B was causing some issues, so I removed it and re-piped the hoses and installed 2 valves using Rob Robinette's site. No difference. I pulled the valve out of the boost feed to the wastegate. My understanding is this should produce around 7psi. Still 15psi. I checked the hoses for obstructiuon. They are clear. I tried to blow air thru the wastegate and couldn't. I disconnected the discharge hose from the wastegate and was able to blow air thru the wastegate.

Should this line be obstructed with the car shut off?

Does this line feed to one of the solenoids in the rats nest?

Any idea of what my problem might be?

Mods are :

Intake, catback, hi flo cat, downpipe, ecu, 2x radiator, upgraded fuel pump, street ported motor, j-spec turbos.

Thanks for any help you can give!!!!!

 

Damn Greg, we're still having problems. My boost is 4-0-4, and you're spiking at 15 psi!

That Rx8 is looking better and better

 

As a daily driver

 

Did you verify that you plugged the nipple on the WG completely and fully? I know I spiked to 15 psi because I didn't completely seal the WG nipple that went to the stock solenoid. Even if you can't blow threw it, it may not hold the pressure it sees.

 

I had similar problem way back when I first moved to Bham..

I found out that my lines for precontrol and wastegate connected to the AVC-R were burned.. So, my AVC-R wasn't controlling the boost.. I hit upto 1.3 bars.. Luckily my engine didn't blow..

I would check what engberg said.. I don't remember how profec b is set up.. but could be that some of the lines aren't capped..

 

The Profec B is not installed. The piping is back to it's original form except no pills and a valve in the pre-control. No vavle in the boost control.

 

Still stock sequential turbos, right? Is the boost spiking on the primary before transition? If so you have a either a leaking vac line on the precontrol solenoid or perhaps a bad precontrol solenoid. If it's spiking that high before transition it is definitely the precontrol.

 

They are sequential twins, but they are J-Specs that I had installed last year. The boost is high before and after transition.

 

so you have no way of controlling boost with all of your mods? (Profec B not installed and no valve in WG line) Or can you control with the PC? I'm not to familiar with the manual boost control but I figure you'd need to valve the WG line, could be wrong. Cause it is high boost throughout the power band on both turbos I'd figure it's more than the PC.

 

Has to be a wastegate issue then. I would verify the proper operation of the wastegate with a hand operated vacuum pump.

 

I am also experiencing the same issue... lately, it seems that its been pretty nasty... at first it would spike at about 13-14psi max, now, Ive seen it as high as 16psi... the other day, my wife wanted to be stupid and loose in our S2000 against me, and I launched out of a light and when the spike came in, there was such a surge of power that I broke the tires loose all through first AFTER the start got rolling...

So needless to say, I am kinda worried about going past 4k or so since I can get one NASTY spike...

 

The way I understand it, the more air flow on the wastegate, the less boost. With no valve, I should be running 7psi.

 

I am gonna try that tonight.

 

That is correct. But since you had a boost controller on there did you remember to uncap the other nipple on the wastegate actuator and replace it with the vacuum line that runs from there to the wastegate solenoid? If the other side of the wastegate actuator is still capped the wastegate will not be able to open.

 

Yes. I caught that little bugger and put a hose on it.

The questions I have is should the pre-control valve be mostly open?

 

Well,

I tried opening both the boost and the pre-control valves all the way open, still going past 15psi.

 

Borch,

Try this, with all of the stock plumbing in place, simp[ly disconnect the electrical connector off the waste gate solenoid (of the double solenoid mounted on the UIM it the one on the driver side). This should default the boost pattern to 7psi with wastegate going full open. Let me know the results of that.

This will verify if the problem is actuator or solenoid related.

 

I'll try this at lunch. Thanks Pauly!

 

I ran this test at lunch I am now running a 7-5-7 pattern. I didn't expect that it would make transition, but it did.

 

Well Borch, you have proved that the wastegate actuator and all the associated pluming is good. 7-5-7 is the perfect baseline pattern. Now the only ting to rule out is the wastegate solenoid and the ECU. I would be more suspicious of the wastegate solenoid. See if you can borrow on from of of the Cincy Guys, and see what the results are.

 

Good call PaulyDee!

 

Will do. I replaced both of them about a year and a half ago.

I was thinking that maybe I should try to re-install the ProfecB which would by-pass the solenoid, but I would actually like to keep from having it in the cockpit.

Thanks for the help. I'll let you know what happens when I get to test it.

At least I am running safe now.

Thanks Dr. Pauly!

 

Greg,

My low boost problem was due to a clogged high-flow Bonez cat. It was 5 years old, and 74,000 miles. Still planning on getting an Rx8 as daily driver (with S-plan yippee )

 

Glad to hear you figured it out.

 

Installed the PRofec B this morning and I am now runnign a nice 12-9-12.

Thanks for all your help!!!!!!!