Boost creep is out of control!!

[95DSMTurbo]

I have had my brand-new big 16g turbo on my car for 2 days now and I'm itching to see what it can do. One problem: I can't get my boost to stay put!!

Here is my exhaust set up:
RNR 2.5" external-dump o2 housing
2.5" downpipe, expanding to 3" after the flex section
3" catback

Right now, I have the boost controller backed out all the way. The boost comes on at about 14 psi. By the time I reach 4000rpm, the turbo is about to hit 20 psi, and I have to let off (or else I hit massive fuel-cut).

There is no way I should be creeping this bad with a dump tube. Does anyone know what the problem could be? Also, would it help if I just connected the wastegate actuator directly to a boost source without the boost controller?

If anyone with a big 16g could help me out (I know there are plenty of you guys out there!), it would be greatly appreciated.

 

[quest49s]

I would first do what you suggested and hook the actuator to a direct boost source(like off the turbo elbow) just to eliminate the fact that the boost controller is malfuctioning. check all of your boost lines(to and from the boost controller) for spliting or cracking.

You are right there is no way you should be creaping that bad.

Hope this helps,
Jon Hebbeln

 

[95DSMTurbo]

Here is what I did today:

- Disconnected my 3" intake pipe to discover the hose connected to the wastegate actuator had a hole worn through it. I replaced the hose and put my stock intake pipe back on. This only made a minor improvement, and made my BOV sound funny (TiAL BOV now sounds like an owl). Boost still crept up to 20 psi before I let off.

- Eliminated the boost controller from the equation completely. The wastegate actuator is now connected directly to a boost source. Now, instead of hitting 14 psi and creeping up to 20, the boost hits 10 psi and creeps from there.

Any other suggestions??

 

[92awddsm]

My big 16g boosted at 14 psi then crept to 19 psi and stay steady from there. I installed my mbc and set to 17 psi. Now it is rock solid with no creep. My turbo is also ported along with o2 housing.

 

[95DSMTurbo]

Ok, so today I worked up enough courage to stay on the throttle after the turbo hits 20 psi. It seems that the boost levels off at 21 psi. Then, less than one second later....BAM! Massive fuel cut! I'm thinking about hooking my boost controller back up and setting the boost to 17 psi or so. I'm hoping that I can get it to hold somewhere in that area.

Anyone else have any suggestions? I want to play with my new toy already!

 

[PieTSI]

Port out the wastegate flapper on the turbo. This is the easiest way to stop boost creep.

 

[Coldandafraid]

what size flapper is it? My big 16 doesnt creep with a 34 mm.

 

[aggietsi]

I'm having your problem, and I feel your pain... I just installed (tonight) a 16g, ported with a big flapper. From Forced Performance, and the most beautiful port I've ever seen, btw. I hold at 1.1 bar till about 5.5k, then I just creep and hit cut. So annoying.

 

[95DSMTurbo]

Tonight I tried hooking my boost controller back up and turning the boost higher. It seems that no matter where I set it, the boost creeps to 20-21 psi before I hit fuel cut.

I don't really know what else to try. I really don't want to take the turbo back off after less than a week, pay to ship it off, and shell out even more money for wastgate porting and a 34mm flapper.

By the way, anyone know why putting the stock intake pipe back on made my TiAL BOV sound like a cricket? It sounds stupid!!

 

[PieTSI]

Try zip-tieing all your lines to your mbc and to your wastegate. Sometimes these will leak. Also did you port out your wastegate hole, this is the easiest way to stop creep?

To do this get a die grinder from any hardware store. Make sure its the kind that connect to the air compressor. These cost around $20-$25. Then buy some bits $5-$10.

Disconnect all the exhaust bolts from the turbo, and then disconnect a clamp that hold the hot side of the turbo to the cold side. With this clamp off you can seperate the turbo. Be careful when u slide it off, to not damage the turbine wheel. Then port out the wastegate runner and hole, to as big as you can with the stock flapper. Put it all back together, making sure the dowel pin on the turbo lines up with the two sides, and your creep should be gone.

Overall this should take you about 1-2 hours to do, depending on how fast you work.

Consult www.vfaq.com for more info on this.