I've read many posts on this board referring to a 10-8-10 boost pattern as healthy, however I had my car in the shop last week to fix a secondary turbo whistle and they told me it was boosting properly (10-8-8-7...) and that it wouldn't be worth finding the whistle since it wasn't causing a problem. The car is mostly stock and has been doing it since I bought it 4 years ago without getting worse or better.

Anybody know for sure which pattern is healthy for a stock car?

 

I am 100% absolutely sure the correct pattern is 10-8-10. I would go back to that shop and tell them they don't know ****. That whistle you hear might be the boost leak.

 

Yes, and the '8' at 4500rpm should last only a fraction of second. You should see 10psi nearly the whole way (in 3rd gear, WOT) from 3k-8k. A little dropoff at the high end (say, 8-9 psi at 6k+) is normal, but indicates a clogging cat or other restriction. Exhaust leak does sound likely.

Dave

 

A stock FD will not hold 10 PSI until redline. So the boost pattern will looks something like 10-8-10-8 --> redline.

If you never see 10 PSI after 4500 rpms, then there is a problem. If it just doesn't hold 10 PSI until redline, that may be normal depending on mods to the car.

 

CRV not closing all the way? It has to be something related to the sec turbo system. Sorry, but I stopped takeing mine to shop after I reliezed that 9 years of exp working on cars applied to these as well(they aren't that complicated).

 

^ That's a good place to start. I would also check to make sure the Y-Pipe flange nuts (2-10mm) are screwed tight onto the Secondary Turbo Housing.

 

I would pop off the actuator arms (wastegate, turbo control, and turbo precontrol) and make sure all of them have a half-pin width of pre-stretch in the arms. Easy to do and very important.

Dave

 

Thanks for the input, I tend to agree with everyone here. They're good guys but I don't think they understand that even though its still boosting and fast as hell, I want that extra two psi... They're probably also right though that I wouldn't want to pay for them to search for it.

So, Klar, any easy way to check that the CRV is closing all the way? A while ago somebody suggested switching the crv with the blow off valve and nothing changed when I tried it. I've been looking myself for ~2 years and have no real mechanic experience or I probably wouldn't have taken it in.

areXseven, I also tried looking for the y-pipe flange nuts the other day but couldn't find them in the mess from the top. Do I have to be under the car?

And finally, dgeesaman, can you describe more specifically or point to a pic/drawing that illustrates what you're talking about? I can only imagine what a "half-pin width of pre-stretch" means.

Again, thanks for the responses. I'm taking it to the track for the first time in november and don't want to lose out on that extra boost...

 

Go to www.autosportracetech.com to find turbo troubleshooting guide. Study it, as well as the colored vacuum hose diagram, until your eyes bleed. I solved my secondary problem this way. After a while you will develop an understanding of the seq. system and you should be able to zero in on the problem.

 

I pretty much get about 11-8-11. I'm running dp, cb, intake, efini y-pipe, and pfc.

A few weeks ago I was only getting about 10-8-7. I replaced my main cat, and now it's boosting perfectly.

 

Each of the actuators is spring-loaded. In order to get a good seal on their corresponding valves, the spring should be pulled a little bit to keep the valve doors tightly shut - the proper amount is travel of about 1/2 the width of the connecting pin. If it's not right, you just use some sturdy pliers and twist the threaded arm end until it's right. Then you stretch the actuator arm that little bit to fit over the valve lever put the e-clip back on.

 

They are not accesible form the under the vehicle. You best bet is to disconnect the secondary intake hose. You should be able to get to nuts it by using a 1/4" socket (10mm) with a long extension. Make sure the Flange Gasket is in place.

 

Props to areXseven, turns out it was the connection between the y-pipe and turbo, there was no bolt on it at all! i pulled one off something less important and no more whistle... 4 years of trying to get dealers and specialty shops to fix it and something so simple. Anyway, for anybody else that might read this, you can't actually see the bolts holding the y-pipe to the secondary turbo, just the bolts for the primary. I had to squeeze my hand down there and feel around blind. In fact I could only get to one of the bolts, I still don't know if the other is on there at all. I still need to check the boost pattern though, I did a couple pulls and it looked like it was pegged at 8 past about 6.5k rpms, I missed whether it went back to 10.

 

^ Congrats. Glad I could help.