First off, here are my mods -

HKS DP, resonated MP with magnaflow muffler, RB exhaust, Greddy intake, PFC, non-sequential twins.


Here's the first vid -

http://home.satx.rr.com/mr3plus1/rx7turbonoise.WMV (The server is kinda slow, so right click -> save as)

Okay, my car is usually pretty quiet. You hear very little from the exhaust. Notice that when I made full boost it started making a deep hum, like it had a louder exhaust. Thats new. I used to get spoolup that can best be described as sounding like my BOV was venting a little when it shouldnt. Even then, that was a problem, but now its loud and obvious. It still has the factory BOV, which I thought was the problem, but I used r0gu3's and it continued to make the same noise.

Here's the second vid -

http://home.satx.rr.com/mr3plus1/rx7bovnoise.WMV

This one is a little harder to hear. See if you can hear the BOV trying to act like its a sequential one. The last of the 3 clips should show it the best. In person its much more noticable. r0gu3 went for a ride with me and heard it too. Now, if I floor it and left off completely it just hisses like it should, but if I go from 100% throttle strait to something like 50% then 30% then 0% (gradualy letting off the pedal) I can get it to make this weird sequential BOV noise. In the last clip you can hear the first big hiss, followed by a low longer hiss. WTF is that.

Now, if I start up the car and drive around, no smoke. It runs rich as hell, so you get a very very light haze, but nothing you can see unless you catch it at just the right light and are looking strait in the muffler. After I make boost the first time it will smoke lightly during boost, then for a couple minutes afterwards. Then I can drive around all day and the only time it smokes is during boost. The smoke is a hazy white with a slight tint of blue. Its light enough that I cant see it behind me in any of my mirrors but it can be seen from people behind me. Its a light haze that stays low to the ground and dissipates pretty fast. Nothing close to the big clouds of smoke common with major turbo failure. The best explination I have is that a combo of the turbos leakin a little oil and the car running rather rich.

I bought the car with no receipts (guy didnt have any). The engine looks rebuilt. He said it had 10k miles on it (about 12k now) and the turbos had 8k on their rebuild (10k now). I cant tell the age of the turbos. The car makes full boost just before 4k. I have it set at .7 bars. It'll spike to like .73 then drop to .7 and hold it. No creep. The boost controller is some home depot ball and spring one.

Does anyone have any idea what could be my problem?

 

Might want to double-check for boost leaks, or maybe the factory BOV is leaking a bit.

How does the power on the car feel?

Dale

 

I have a similar problem with my boost. I still have the sequentials. Most of the time my car is pretty quiet (HKS DP, stock cat, Greddy CB) but every once in a while the exhaust changes tone and the car feels slower. Looking at the boost gauge, I can see that I dont have as much boost as I should. While its doing this, the power kicks in all of a sudden and the exhaust tone goes back to normal along with my boost (10psi). To me it sounds like something isnt opening and makes the exhaust force its way out. Could it be some solenoid or a messed up checkvalve? Otherwise, the car has very good power and a good boost pattern.

 

Car doesnt seem to be any slower. Makes perfect psi still. Checked all along the line for boost leaks from the turbo all the way to the intake manifold. Couldnt find anything.

I thought it might have been my BOV leaking, but I swapped r0gu3's bov into my car and it continued to do the same thing. Might the vaccum line to the BOV be colapsing under boost and causing the BOV to creep open a bit?

Also - what might be the explination for hte smoke?

 

what you guys are experiencing is probably the same thing i am. The problem is that somehow it's getting stuck in non-sequential mode, and therefore the car is louder and you have lag=less boost to begin with. It happens on my car every time i redline it and then let it settle down to like 2-3k, It just get's stuck there and it takes 2-3 min to get back in.

I think my problem is stupid TCA solenoid, the one that's bolted on the ACV under manifold.
I'll have to look into replacing it when i get some time.

 

that sounds alot like a vacuum leak. when you're on boost, you lose vacuum and because of your leak your vacuum tank(s) don't hold reserve vacuum, thus, when you need vacuum to get the turbos working again after winding down, you don't have it. you can test your tanks using a simple pump and gauge, but you may want to wait for the seq. experts to chime in first. this is exactly why i went non-seq. once i started chasing these kind of problems and couldn't solve them easily.

 

hmm.well guys I would highly suggest you check the actuator rods and actuators underneath the car.When my wastegate actuator rod came off the door latch the exhaust got a hell of a lot louder.When my pre spool actuator became loose I started to get some bad lag and of course a much louder exhaust note.Check these 4 actuator rods out and their corresponding solenoids.The charge control actuator is controled by the charge control solenoid and so forth.The pre control solenoid controls the actuator.Im pretty sure you know where im going with this.The turbo control actuator is controled by two solenoids and of course the wastegate solenoid controls the wastegate actuator.Good luck.Im pretty sure your troubles have something to do with these 4 valves opening and closing correctly and at the right time.

 

Im non-sequential already, so its not related to any of the sequential controls. I'll check for the actuators. It probably isnt a line loose (I checked for ANYTHING that could have come loose). Chances are if its one of those actuators, it failed.

 

Everything seems to be connected correctly. Might my turbine housing be cracked somewhere and I'm either leaking to atmoshphere or leaking to exhaust when I shouldnt (I've seen a lot of cracked housing around the wastegate). Might mine have developed a large enough crack that exhaust is getting by when it shouldnt?