Well I used to be boosting like 4-5 PSI. I then added a 3in. catback but still left on the stock cat and downpipe and then it creeped up to 7 but I never seen it go past that. A week after I put on the catback I added a 2.5in. downpipe and testpipe and I took it out today and I saw it hit 10 PSI. I got off the gas right when I saw it get that high. I dunno what the wastegate spring is supposted to be set at but I dunno if somethings wrong with that or whats going on. I've never really heard of this happening to our cars before unless they had a boost controler. I have no intercooler or boost controler I can tune it for 7 PSI but that is probably the highest I want to go untill I get a intercooler. Does anyone know how I can get this to go down? Should I get replace the wastegate spring or something or just stick a boost controler on there and turn it down with the controler? Thanks in advance.

Also a buddy of mine has a 3in. turboback and 3in. highflow cat and pretty much the same set up as me and he didn't creep at all. I think my car just hate me or something. Someone please help. ;(

thats weird. dont think it has anything to do with after the turbo exhaust.make sure your conection to the wastegate is good.

Woah dude! 10 psi NON intercooled! Did you hear any knock? I would suggest a compression test to make sure you're still okay. I would also recommend 7 psi MAX, preferable 5-6 until you throw any kind of intercooler on it. Just my .02

As for the boost creep, I have two buddies who have had boost creep after adding an aftermarket exhaust. Unfortunately, they don't have them on 420a's but I'm sure there's stuff we can learn from them. One of them is thinking about porting out the wastegate hole to make more of a flow. Before doing that, you might want to make sure the flapper is opening all the way. If it's partially opening, it might not have been sufficient, and not a big deal with a small exhaust and thus more restriction, but with the easier flowing exhaust, it magnifies it. Check to make sure the wastegaste is opening all the way and you have a GOOD vacuum/boost line to it.

Brian

Dude go with an external dump = bye bye boost creep (also try porting your 02 housing, other solutions making sure you have the least restriction on the wastegate out......

this is the reaso im running a tial 44mm :)

Try finding another source for the WG boost signal. Instead of the turbo compressor , try the intake mani and cap off the line from the compressor.

whats your wastegate/manifold setup like? take sandmans advice and find a better boost signal, like the intake manifold

his is the hahn stage 1. actuator to compressor for signal

What he said ^^^ From what I know I thought the best place for the signal is at the compressor because it is reading almost exactly what your boosting and not at the intake manifold because it might have signal that could be a little off. I think I might call Hahn on Thurs. (it's next day off that I have) and see if they have had a problem like this before and if they can help me out in solving mine.

thats happened to me before and it ended up being a vaccum line that was crimped a bit coming off a tee...

Do what Sandman told you. I had that problem. I used to spike to 11ish psi. I ran a vac. like to my manifold and boost gauge signal and it solved the spiking. As an added benefit I also had more boost lower in the rpm range but I lost boost up top (holding at 8ish psi).

Try it. Its worth a shot.

Yeah I'm gunna try the manifold as a source and probably call Hahn if that doesn't work.

Originally posted by BlueMoonEclipse
Dude go with an external dump = bye bye boost creep (also try porting your 02 housing, other solutions making sure you have the least restriction on the wastegate out...... this is the reaso im running a tial 44mm :)

02 housing......? I'd didn't know we had one.

Originally posted by eclipsekaiser

Originally posted by BlueMoonEclipse Dude go with an external dump = bye bye boost creep (also try porting your 02 housing, other solutions making sure you have the least restriction on the wastegate out...... this is the reaso im running a tial 44mm :)

02 housing......? I'd didn't know we had one.

Well you do if you use a rebuilt turbo w/ one like i had...

well I tried rerouting the vac line that goes to the wastegate actuator. I took it off of the compressor and routed it up to where the vac line for the BOV connects into the intake manifold and it still hits 10PSI. I called Hahn and left them a message. I have taken off the downpipe to inspect the flapper but I'm not quite sure how far it really should be open when it's open all the way.

I'm tempted to say it's something with the actuator/flapper after you tried a stronger signal. Bill might have a little more insight though.


PS, bet taking out the DP was a heck of alot easier than before ;) HAHAH

Originally posted by SANDMAN
I'm tempted to say it's something with the actuator/flapper after you tried a stronger signal. Bill might have a little more insight though. PS, bet taking out the DP was a heck of alot easier than before ;) HAHAH

Heck yeah it was! I didn't even shout obsenities at it when removing that downpipe. Thanks ERT guys!

I called Hahn and left a message but they never called back. Is there a better way to actually speak with someone at Hahn because now I have to wait tell freakin Mon. to possibly talk to them. Anyone know how far the flapper should open so I know if mine is bad?

Nobody knows how far the flapper should open on a normal turbo?

Originally posted by QC DSM ESiT
Nobody knows how far the flapper should open on a normal turbo?

the hahn turbo isnt what id call a "normal" turbo lol. The no o2 housing/no wastgate port is quite unique.

Yeah but considering half the people on here have that turbo I would think someone would know. Oh well one of the ERT guys is going to check for me on a HRC turbo they have there. If anyone knows or can check on there turbo it would still be greatly appreciated.

Jordan(QC DSM Esi-T) I got the same thing happening to me.
Did anyone ever find out what it was?
I checked all my vac lines and connections. Everything seems fine.
Except I hit 10 psi the other day and shit myself.
I don't hear any knocking whatsoever.

Another thing that I thought was weird is that my boost guage shows an unusually high vacuum reading at cruising. Normally I would cruise at like 10 psi vaccuum. Now it cruises at like 5 psi vaccuum.
It seems like it is much easier to make it boost but it doesn't respond to the same amount of boost like it used to. My fuel pressure guage also is showing lower fuel pressures for the same amounts of boost. Like 40-50 psi fuel pressure for 2-3 psi of boost. Normally my fuel pressure would be reading like 70-80 psi in for this amount of boost. I'm just confused.

I've got the Hahn stage I and full 3" inch exhaust. The rest is stock