sorry tapper... so u think it's only a tapper thing .. and not a boost leak thing?

 

Dammit, it's TAPER, not tapper. TAY-PURR, not TAP-UHR. I said it 5 times already.

You may have a boost leak, but a 3psi taper is not an indication of a boost leak.

 

Clayton, if you are hiting 28 psi and then going down to 16 psi, you got a problem some where. Find it. It is there. That exact problem have happened to several well known people around here, including me. Leak test your car again. And check your Forge WGA. I had to cut my rod a little over 1/4 inch and tighten the 8 allen bolts on the neck. I found it by turning the EBC off and with the 20 psi spring, the WGA was opening at 12.5 psi. Now is perfect, holds near 22 psi on its own. No way is normal to drop that much on your mods. You don't even have 280 cams. Check for cracks in the exhaust manifold and turbo area too.
Or may be your turbo is on its last days. Check for play. You know the rutine. Good luck.

 

It's because I came to Colorado. I was tapering to 22.5psi at redline at sea level, then it changed to 16psi up here. The turbo just can't flow as much with this thin air. All the stock turbo'd Evos that Al tuned showed a taper to 16psi on the MAP sensor. It just seems to be the limitation of the stock turbo up here.

 

16 psi seems too low on a modified car??
Actally I remember stock it was 19, and would taper to 16 but after I got my dynoflash and boost controller that went away.
Yes it would still slightly taper, but my car used to hold 22 or whatever I would set it to and then maybe taper to 21 or possibly 20.5. Not all the way to 16 tho.

This was an '03 evo with a greddy profec b spec 1 boost controller and dynoflash.

 

tapper? beer time?

 

^ The reason you are leaking air is because when you put pressure on the throttle body butterfly air will flow by it. If there is some overlap in a cylinder where both valves are open you will find yourself with a bigger leak.

When doing a pressure test you are supposed to take off the pipe that goes to the TB and cap it off, that way you can see if your pipes are actually leaking.

 

Use soapy water to help find the leak(s) when presure testing to be for sure where its coming from .

 

x2

If you didn't do this, you really didn't do a pressure test because you could not locate the leak.

 

take and cap off which pipe?... the upperintercooler piping???


p.s.
i did try soapy water... and nothing...

also
my boost used to hold perfect 21-20 the whole time during WOT... after i got my 272cams headbolts and new reflash when i started taper/leaking... i figured it was taper... but after dynoing the car and finding really low tq numbers... there's something up with my car.. and i figured boost leak would be the best place to look

 

Some cars dont do well at holding presure when leak testing (ie "sounds like it going right through the motor") So you take the UICP off at the the T-body and plup the uicp (ive used a empty spray paint can before) that way you know that the motor is not bleeding off the psi your useing to presure test with . But you cant use the boost gauge in the car you have to rig up a psi gauge on just the pipes and the bov is going to need the same presure sourse as the ic pipes .

pss . i dont understand how the soapy water didnt work , it did bubble up ?

 

noo i didnt find any bubbles through out my pipping