excessive boost creep

[kandt]

all of a sudden when i get to about 4,000 rpms my boost starts to creep and gets to about 21psi from setting it at 13psi. i'm thinking its something with the waste gate.

any help please

 

[blackawdturbo]

Originally posted by kandt
all of a sudden when i get to about 4,000 rpms my boost starts to creep and gets to about 21psi from setting it at 13psi. i'm thinking its something with the waste gate.

any help please

What size wastegate flapper??

 

[kandt]

whatever comes with a big 16g. i haven't changed it

 

[Enigma_Man]

That sounds like something is broken. Check to make sure that your wastegate actuator is working correctly, and the arm that comes out of it is still attached.

Especially since it just started happening and didn't happen before. Make sure your boost controller is still working correctly, and isn't clogged, or has a split hose or something.

-Jesse

 

[blackawdturbo]

Originally posted by kandt
whatever comes with a big 16g. i haven't changed it

Any well tuned car will creep on a 16g without a larger flapper. Heck, even with my 34mm flapper I creep from 16 to 20 psi although my o2 is ported much less than it should be.

 

[Phoenix_RsX]

yeah I got that prob too, but not THAT bad. my boost is set to 15psi, and I've crept up to 17 in 3rd and forth. I'm not gonna look that much into until I get my L2R with supporting mods in first tho.

 

[tsi_turboawd]

I installed a 2.5" downpipe and my boost creeps to 19-20psi from 15psi
..wat next porting 02, manifold, then turbo?? $$$$

 

[Tevenor]

Porting the exhaust manfold will increase the effeciency of the exhaust turbine side and only increase creep. You need to flow more out the wastegate and/or make it easier for the excess exhaust to flow on the wastegate side.

 

[92tsiawd84]

would a o2 dump work?

 

[tsi_turboawd]

i just ported the $hit out of everything. helped a bit, but there still a slight creep from 15psi 2-4 more lbs... ARGHH! maybe i shouldnt have ported the manifold, wat the hell

 

[McGruffAWD]

Originally posted by 92tsiawd84
would a o2 dump work?

I wouldnt think it would because you are still limited to the amount of boost coming out of the wastegate.

 

[Tevenor]

Originally posted by McGruffAWD


I wouldnt think it would because you are still limited to the amount of boost coming out of the wastegate.

The dumped o2 will inrease the pressure differential across the wastegate, promoting better flow. However you are still limited by the passages of the exhaust housing. And don't forget, by dumping the excess exhaust to the atmosphere, you have increased the efficiency of the exhaust system so it will flow even better. It's a double edged sword.

 

[tsi_turboawd]

sounds good enough to me!

 

[Mr96GSX408]

i have a big t28 killer and it creeps like hell also. i have nothing ported and just the setup that turbochargers.com gave me. i plan on getting a ahp o2 housing to help with the problem but i'm not sure if that will eliminate most of the problem. should i go with the upgraded o2 housing or an o2 eliminating downpipe?

 

[Mr96GSX408]

i have a big t28 killer and it creeps like hell also. i have nothing ported and just the setup that turbochargers.com gave me. i plan on getting a ahp o2 housing to help with the problem but i'm not sure if that will eliminate most of the problem. should i go with the upgraded o2 housing or an o2 eliminating downpipe?

 

[tsi_turboawd]

AHP would probably that long to ship. You can check out RnR as they make about the same custom o2 housings for about the same price!

 

[UltraImports]

keep in mind that you usually get creep because you're not flowing enough out of the wastegate. Porting and the o2 dump both help increase the flow out.

I think I'll be going to RNR for my exhaust parts from now on. Prices are killer!

 

[Mr96GSX408]

upgraded o2 housing or an o2 eliminating downpipe - which helps more? or do they have the same effectiveness.

 

[whitegst97]

If you ahve done all the previous recommendations and still creep i think maybe if it doesn't interfere with your personal wants you should raise the boost maybe 1 or 2 psi's and there fore since the wastegate has to release less boost pressure it will creep less, maybe it won't at all.

 

[tsi_turboawd]

In my case, i have ported the WG hole, o2 housing etc. and i still creep on 3rd from 15 lbs. now im getting a fuel pump, pump up the boost and see what happens at 18 lbs DO IT

 

[TheHater]

There are very simple reason for boost creep.

The most common is not enough wastegate flow, aka restriction. I had the same problem. I'd set it to 15psi and it would start to creep ~5k rpm and boost would creep to 20psi everytime.

1st thing I did was port the hell out of the o2,especially the wg passage on both the turbo and o2, that I'm currently selling in the classifieds. It is sold, pending payment from Mr96GSX408. This almost solved my problem, but still in colder weather would creep to 17 and rarely 18psi.

I then installed a 34mm flapper from FP and hogged out the o2 even more. This completly solved ALL creep from my small 16g. A well ported o2 will also help spool because it rids you of a lot of backpressure.

I then went on and made my own 2.5" tubular o2 w/a 1:7/8 dump tube. This takes care of all creep issues. Plus better spool, boost control, power and scares the living #### out of people your racing.

Getting a dp will just make things worse until you get some more WG flow.

You can see pictures of my ported o2, and of my tubular 2.5" o2 w/a wg dump in My Gallery

 

[TheHater]

There are very simple reason for boost creep.

The most common is not enough wastegate flow, aka restriction. I had the same problem. I'd set it to 15psi and it would start to creep ~5k rpm and boost would creep to 20psi everytime.

1st thing I did was port the hell out of the o2,especially the wg passage on both the turbo and o2, that I'm currently selling in the classifieds. It is sold, pending payment from Mr96GSX408. This almost solved my problem, but still in colder weather would creep to 17 and rarely 18psi.

I then installed a 34mm flapper from FP and hogged out the o2 even more. This completly solved ALL creep from my small 16g. A well ported o2 will also help spool because it rids you of a lot of backpressure.

I then went on and made my own 2.5" tubular o2 w/a 1:7/8 dump tube. This takes care of all creep issues. Plus better spool, boost control, power and scares the living #### out of people your racing.

Getting a dp will just make things worse until you get some more WG flow.

You can see pictures of my ported o2, and of my tubular 2.5" o2 w/a wg dump in My Gallery

 

[Mr96GSX408]

I was told from Road Race that you cannot replace the original wastegate flapper with a bigger flapper on a Garrett turbo. Since I have a Big t28Killer which uses a Garrett housing, I'm screwed. What do you guys think? Also, DSS said that they could do it but it would cost me $150 alone just to port the WG passage and install a 34mm flapper. Please reply.

EDIT: These are the prices I have to play with and I only have ~$400 dollars.

--- DSS ---

150 wastegate pro: quick, no hassle
150 labor con: f**king expensive, don't get exh. mani ported
100 turbo port
________________
400 bux



-- SLOBOY RACING ---

install/remove free pro: install/remove hassle + exhaust manifold ported
shipping - 100 con: cheaper
porting+flapper - 230
gaskets - oil return - 2.00
turbo housing - 20.00
exhaust manifold - 30.00
_________________________________
382 bux





--- DSS/SloBoy ---

150 labor
50 gaskets con: a bit more expensive for everything
230 port exh mani + turbo flapper pro: easy, quick, get everything done
shipping one way?
________________
430 bux - 530 bux