Im having a problem with boost in 1st gear. under WOT it boosts to about 9 initially then bleeds off to about 6 at redline. After shifting into 2nd (and higher gears) it boosts normally to about 12.

After the last run I popped the hood and while I was looking at the vacuum lines one of the lines running into the black plastic box popped off right before my eyes and pressure was released. whats going on?

Thanks for any info.

 

check all the hose in front of the UIM. I had a similar problem last year, no 2nd turbo in first gear... it was a hose that popped near the vacuum plastic chamber. should be pretty evident.

good luck,

Max

 

1st gear is a tough one to notice as redline comes up Damn fast. Sounds like you may have a boost leak, but you'd be better off testing your boost in 3rd gear frome 3k to redline (aprox. 35mph) to see what your primary boost actually is and what your transition looks like with yiur secondary boost perssure. You don't mention any of your mods. so we'll assume stock and tell you 12 psi is too much on a stock system (ecu).

 

So are suppose to use either spring clamps or tie wrap all pressurised hoses as one of the main safety mods!

 

This is a staement or a question ?

 

my mods are shown in my signature.

im traveling now but when i get back i will check my primary and secondary boost when i get back and post it. thanks for the help.

 

Sounds like your only problem may be crappy hose clamps. If you have to good ones then you'll need to remove the coupler that's coming off and see if it's got oil residue in it. If this is the case clean both the pipe nad coupling with soap and water and then wipe with denatured alcohol and then reinstall it. This should help it stay seated better. I have also seen where the coupler will expand and push the clamps away from each other and require aircraft (mechanics) wire to keep the hose clamps from from doing this. I'll see if I can find a picture example of the wire I'm talking about and how it's used.

 

That box is the pressure chamber. Most of the rats nest lines carry vacuum, but the ones leading to/from this chamber carry pressure only. So as the lines get old, tired, oily, etc they tend to pop off or leak.

Like chuck said, you want to install small spring clamps or zip-ties on these lines and replace any line that looks suspect. I'm going to guess that you get pretty full boost in 1st from that point on.

Dave