Turbo Boost Creep Creeping T25 14B 16G [Merged]

[9!'clipseDOHC]

Your stock intercooler was most likely clogged with oil and now that you have a clean intercooler you are creeping.

Same thing happened to me; stock intercooler, 14b, 3" exhaust, hitting 13-14 psi solid, no creeping. Cleaned out my stock intercooler from my previous blown 14b, nothing else changed, now it creeps to 17+.

So if you want to stop the creeping, pour some oil in your intercooler. (that is a joke, please do not put oil in your intercooler!)

I have a stock 2g unported o2 housing, usually porting the wastegate passage of the o2 housing or switching to a tubular is supposed to help. If you don't mind the noise, an atmosphere dump o2 housing is supposed to cure boost creep. Other than that an external wastegate is your only other option.

Hope this helps!

 

[dsmdeliveryboy]

14b's are notorious are creeping and there isn't a whole lot you can do it about it except, hit up kidtsi or jusmx and they can make you a custom actuator so you don't creep. Or go external gated..

 

[ryan90tsiawd]

Bep makes a bolt on housing for the tdo5 turbo. It comes with a 34 or 38 mm flapper I believe, and if you ever decide to upgrade to a larger turbo, it will also fit the 16g style turbos as well. My uncle had this problem with the 14b, and he did this. Fixed him right up.

 

[4g63oncrack]

is your exhaust leaking?

 

[rocafellafw]

This solved my boost creep issue:
http://www.dsmtuners.com/forums/art...oler/186525-how-cure-boost-creep-porting.html
Good luck.

 

[wkmitsu]

i checked them all and replaced the one from my waste gate to my boost control solenoid. when i installed the FMIC i did eliminate the boost line that came off the stock j-pipe and teed into the waste gate line could that be a problem?

Yes, you need that line so your wastegate actuator can read the boost pressure in the system. I'm surprised that your boost isn't going even higher. Put that back and it should fix your problem.

 

[toyotagt1]

Yes, you need that line so your wastegate actuator can read the boost pressure in the system. I'm surprised that your boost isn't going even higher. Put that back and it should fix your problem.

i cant connect it to the j-pipe because i have the new j-pipe for the fmic and it doesn't have a nipple for a vacuum line

Agreed, just a better header would make it worse, but if he got a manifold flanged for an exeternal wastegate and got either a 38 or 44mm external w/g, it should help control the boost greatly... might be a little overkill for his current setup though

i don't want to go the external waste gate route if i dont have to i mean its the stock turbo for crying out loud

is your exhaust leaking?

i have a small exhaust leak where the down pipe connects to the o2 housing but iv asked around and they said that would not be a boost creep problem

 

[U8NTRDY]

You need to get that vacuum line situation straightened out. Its looking like your wastegate is causing your problem due to its inability to read boost pressure. Right now without that line, the actuator is, in theory, trying to give the wastegate directions to somplace that doesn't exist.

 

[endeffect0]

Originally Posted by toyotagt1
i checked them all and replaced the one from my waste gate to my boost control solenoid. when i installed the FMIC i did eliminate the boost line that came off the stock j-pipe and teed into the waste gate line could that be a problem?

Yes, you need that line so your wastegate actuator can read the boost pressure in the system. I'm surprised that your boost isn't going even higher. Put that back and it should fix your problem.

^there is the answer to your question.

The waistgate needs to see the pressure form the outlet of your turbo housing. its that pressure that determines when your wastegate opens and closes. If you have no boost source going to the WG then the actuator thinks your not making any boost and will keep the valve shut. You dont have boost creep, your actually just running at full pressure.

You ma need to have a stem welded on to your new J pipe if that was the only boost source on the turbo. for now try to find any boost source before the TB and hook up a vacuum line from that directly to your WG. The closer to you turbo the better, but anywhere before the TB will work better than nothing.


It seems only a few people actually read the users post before making suggestions...

 

[toyotagt1]

^there is the answer to your question.

The waistgate needs to see the pressure form the outlet of your turbo housing. its that pressure that determines when your wastegate opens and closes. If you have no boost source going to the WG then the actuator thinks your not making any boost and will keep the valve shut. You dont have boost creep, your actually just running at full pressure.

You ma need to have a stem welded on to your new J pipe if that was the only boost source on the turbo. for now try to find any boost source before the TB and hook up a vacuum line from that directly to your WG. The closer to you turbo the better, but anywhere before the TB will work better than nothing.


It seems only a few people actually read the users post before making suggestions...

i will have a nipple welded on to the j pipe. hopefully this fixes my problem thanks alot i appreciate the feedback

 

[91mitsuman]

You could also drill a hole into the j-pipe tap the hole and thread in the nipple. I had lock with that on a car. Use lock tite this is if you don't have access to a welded of course. Getting that vacuum line back on should take care of your problem though.

 

[92DSM89]

i will have a nipple welded on to the j pipe. hopefully this fixes my problem thanks alot i appreciate the feedback

yes. have one welded i wouldn't drill a hole and tap it. but thats just me.

 

[toyotagt1]

You could also drill a hole into the j-pipe tap the hole and thread in the nipple. I had lock with that on a car. Use lock tite this is if you don't have access to a welded of course. Getting that vacuum line back on should take care of your problem though.

ok thanks im going to try that before i pay a welder to weld one on thanks for the tip

 

[91mitsuman]

yes. have one welded i wouldn't drill a hole and tap it. but thats just me.

Well even if it pops out you can retap, thread it in again and have that welded in. Just need to have a steel nipple. I believe my buddy's car that I did this to has not had any issues.

 

[toyotagt1]

Well even if it pops out you can retap, thread it in again and have that welded in. Just need to have a steel nipple. I believe my buddy's car that I did this to has not had any issues.

i was going to use the stock j-pipe nipple(which is steel) and just cut it off and install it on my new j-pipe

 

[TheGreatGSX]

I searched this issue but couldn't find any specific enough to my situation. Never had this issue with this setup before. Quick rundown:

Recently upgraded the exhaust system from a homemade to a megan racing 3" all the way except where it bottle necks to the O2 housing. I did not get to run the car much after this installation because there was an oil leak I was unaware of and the turbo blew literally 2 days after.

Got the turbo shipped out to get it rebuilt (Thanks Jus!), got the turbo back. Wal lah! Boost creep like a mofo. I did get get a chance to run it a little after the exhaust and didn't experience no boost creep, now, like I said before creeps very badly.

No matter what the MBC is set on, it creeps to about 22psi. I had it set to 12psi today for testing purposes and it still crept to 22psi. Now I am aware of an exhaust leak where the flex pipe connects the the O2 housing (because the megan racing exhaust is at a weird angle and doesn't want to line up). Will a leak there cause boost creep?

I was confused by this because the leak is where it would be dumped if it had a dump tube. What confuses me more, is I didn't have this issue right before I shipped turbo out to get rebuilt and have changed nothing. I've had this setup for 7 months now with no experience with boost creep and have changed nothing except the exhaust which the old exhaust was 3" then bottle necked at the cat then back to 3" to O2 Housing.

Wanted to also note, that I DID get a chance to run the car after the exhaust installation BEFORE the turbo rebuild and didn't experience boost creep, that it was AFTER I got the turbo rebuilt and put back on. Wanted to clarify this since after reading my initial post, I don't think I did a good job with the explanation.

Also, the old exhaust was VERY leaky, it leaked just about everywhere (Bad winter), could you have boost creep with the same exhaust with little to no leaks vs no boost creep with same exhaust with several big leaks?

Someone please reply, trying to get this resolved before it starts getting too cold outside.

 

[AlaskanDsm]

I wouldn't think that a post-turbo exhaust leak would have any reason to cause boost-creep outside of an increased exhaust flow rate...

One thing that I would check is that the wastegate is opening fully without the actuator arm attached. If the wastegate appears to be opening fully, I would re-attach the actuator arm and use a compressor to pressurize the actuator arm. Then verify that the arm is opening the wastegate fully.

 

[TheGreatGSX]

I wouldn't think that a post-turbo exhaust leak would have any reason to cause boost-creep outside of an increased exhaust flow rate...

One thing that I would check is that the wastegate is opening fully without the actuator arm attached. If the wastegate appears to be opening fully, I would re-attach the actuator arm and use a compressor to pressurize the actuator arm. Then verify that the arm is opening the wastegate fully.

I wouldn't think so either, but I'm still new to all this and wanted to double check. How do I check to see if the wastegate is opening fully? Once I detach the actuator arm, what do I do?

When we took the turbo off to get sent off, we broke the pin for the arm and replaced it, could that be the problem?

 

[JusMX141]

The actuator was working properly when the turbo left my shop. Of course, MHI actuators only open about 3/8", so I'm blaming the free-flowing exhaust system on this one. Not much you can do unless you're willing to add restriction to the exhaust system....most guys just do the appropriate mods to run 22psi and call it a day.

 

[TheGreatGSX]

The actuator was working properly when the turbo left my shop. Of course, MHI actuators only open about 3/8", so I'm blaming the free-flowing exhaust system on this one. Not much you can do unless you're willing to add restriction to the exhaust system....most guys just do the appropriate mods to run 22psi and call it a day.

, that means I need a FMIC which I do not have the funds quite yet to get

I didn't have this issue right before I sent the turbo out though, and the new exhaust is the same dimensions as the old one, would the cat-delete make that much of a difference in the flow?

Edit: Also, I liked the fact that I could drop the boost during daily driving to work. I usually always dropped the boost down to stock during the week then upped it during the weekend or at the strip.

 

[JusMX141]

I didn't have this issue right before I sent the turbo out though, and the new exhaust is the same dimensions as the old one, would the cat-delete make that much of a difference in the flow?

Absolutely....think of the restriction that the cat itself can add, especially under 22psi of boost.

 

[AlaskanDsm]

The actuator was working properly when the turbo left my shop. Of course, MHI actuators only open about 3/8", so I'm blaming the free-flowing exhaust system on this one. Not much you can do unless you're willing to add restriction to the exhaust system....most guys just do the appropriate mods to run 22psi and call it a day.

True, would the Mr. Peepers actuator arm help at all in this situation? Also, I know that if the turbo for whatever reason gets dropped, and the spring in the actuator can be knocked around a bit, it would only effect the PSI at which the wastegate would open at stock boost correct? this problem could also be solved with an O2 dump or an external wastegate setup correct?

 

[JusMX141]

would the Mr. Peepers actuator arm help at all in this situation?

Possibly, but even the creator had his own issues:

http://www.dsmtuners.com/forums/blogs/mr-peepers/455-boost-creep.html

Also, I know that if the turbo for whatever reason gets dropped, and the spring in the actuator can be knocked around a bit, it would only effect the PSI at which the wastegate would open at stock boost correct?

I've only seen this become an issue if the actuator was crushed enough that the flapper hangs open a bit and causes slow boost or no boost at all.

this problem could also be solved with an O2 dump or an external wastegate setup correct?

External dump o2 housing or external gate would be other possible solutions, sure.

 

[TheGreatGSX]

Eh, not wanted to go external dump (Not a fan of the sound). Also not wanting to go external WG at the time so I'd like to solve the issue without these solutions (if possible).

I have one final question before doing the "Getting the mods to handle the boost creep" solution. After a few more runs, it creeps to 20psi, so I set the MBC at 20psi. Ran much smoother but I did get SOME knock. I got the knock on the first run (So no possible chance of heatsoak?) would this be a symptom of heatsoak (even though it was the first run) and could be solved with a FMIC or do you think the knock could be caused from something else? I only get knock at exactly 20psi, BEFORE the creep I boosted at 18-19psi steady and never got any knock but for some reason 20psi is the lucky knock number...

Thoughts? I'd hate to get a FMIC to support the boost creep just to find out I start getting knock and have another issue on my hands ><

Thanks for the help/advice.

 

[JusMX141]

It's easy to heat soak a stock 2G intercooler. I'd suspect this to be the issue if you're seeing knock after your first hard pull is complete. You can also try to combat this with a good octane booster, or by adding Meth injection if you're not ready to go to a FMIC.