Broost Creep Issue (Not a Nubie TO DSM's)

[Brett99GST]

Ok, heres the deal. I just put my exhaust on tonight thanks to Kenny (Props). Heres my setup. Ported 2G mani, Ported Evo 16G, O2 dump, full 3 inche turbo back, Hallman MBC. I have 2 exhaust leaks because of missing gaskets. First one is the O2 housing gasket and it is a pretty bad leak, second one is where the muffler bolts to the axle. and im not sure how bad that one is, probably just as bad. Car is runninhg super rich. Have walbro fuel pump, stock 450's and no AFC on yet. I had no creep at all on stock exhaust. Put the 3 inche on and my boost is running away past 20 PSI. Its boosts 13 till i hit 4 grand then just runs away. I set the MBC all the way as low as it would go and I know it was working cause i had it set to 15 right before I did the exhaust. I double checked all my BC lines. Have a first gen blow off valve, have the boost source tapped to the vaccum line between the BOV and Intake mani. Other line runs to the wastegate. All lines are on and didnt pop off. I am stumped. Jess has the same setup as me and doesnt creep. Same turbo and all. Is there anyway that my exhaust leaks could be causing creep?? Im am bummed that now I cant get tunned tommorow. Any help would be appreciated. Thanks!!!

 

[NewB2dsm]

am bummed that now I cant get tunned tommorow. Any help would be appreciated. Thanks!!!

how are you going to tune a car without injectors or a afc anyway?


And here are your choices to fix the creep. Port the hell out of the o2 housing, buy a evo 3 o2 housing and port the hell out of it. Put on your stock exhuast. Or my personal favorite, buy injectors and an afc and turn the boost up.

 

[Dub_C]

another solution you missed is porting the turbo more

if you pull ff just the exhaust side and work on wastegate area u can get it to flow much better, i've done this to many 14bs that have had the same severity of boost creep, solid to 4000 then as high as it'll go, and it has ALWAYS fixed the p[roblem and been able to hold boost to 15psi to redline

 

[Steve Hebert]

Well between the leaks and the 3" all the way - they can contribute 'some' to your boost creep. But I doubt that just fixing the leaks would change much, maybe it would hold till 4500 or 5 grand before creeping.

 

[andymoraitis]

The problem, which has been outlined by some of the above posters, is that your 3" is flowing better than your wastegate area. As a byproduct, the wastegate isn't functioning the way it should due to the flow issues and creep is your result. What you will find, is that the more you want to turn the boost down, the more it'll want to creep. Options are as follows.

1. Port the wastegate and the 02 housing.
2. Add larger injectors, some of form of fuel control and set the MBC to the point at which it creeps (provided the rest of your system can handle that amount of boost).
3. Fix your exhaust leaks! They will likely not fix creep, but they will make your car run poorly.
4. Install a high flow 3" cat. The slight backpressure may help with creep.

Finally, you mentioned that you're running rich. If you're on stock injectors you shouldn't be, even with a pump as large as a 190. If you installed a 255 and have no AFPR, or have one and haven't dialed the fuel pressure down, you're going to run pig rich, induce rich knock and once again make the car run poorly. I'd really start by fixing the nagging issues like leaks and fuel and then work on the creep situation.

Hope that helps,

Andy

P.S. PLEASE fill out your profile. We can't help diagnose anything if we don't know what you have.

 

[Eastwood95]

I wanted to throw in my .02 cents,
That kind of creep you're describing is like said above. Your turbo, and wastegate area need to be ported. I'm guessing you still are running an internal wastegate. If porting doesnt fix it, you should also install a new wastegate flapper, which would without a doubt fix your creeping problem. Go to Team Rip Engineering's website if you decide to go with a bigger 34mm flapper.

 

[99gst_racer]

Wow, I'm surprised nobody mentioned an external wastegate as a fix. It is afterall, the easiest and only garunteed way to fix creep.....

Or a new turbine housing from bullseye-power.com. They flow better and use a 38mm flapper on the internal gate.

Small leaks arent really going to affect creep much at all. You will need LOTS of porting or one of the two I mentioned above.

 

[oldman]

Wow, I'm surprised nobody mentioned an external wastegate as a fix. It is afterall, the easiest and only garunteed way to fix creep.....

Paul, you and your external wastegate.

I suggest porting the turbine housing first like many have suggested then go external if that doesn't work. So far I have not seen failure in porting yet as long as it's done right.

 

[90CherryTSI]

shoulda taken pics!! Last weekend I took off the exhaust housing and ported the wastegate area so the flapper opens all the way and no more creep. This on a full 3', 2.5' o2 housing. I had creep to 20+ when I put on the 3' DP so I had to just watch it, now it's rock solid since I've ported it. On a side note I got the PR 2.5 tubular o2 housing and that made my boost very smooth vs very sudden. Take off the mani, unbolt the dp, pull out the a/c fan if you have one, and unclamp the housing, slide it off, port it and be done with it. It took me 15 mins to take everything off, and 20 mins to port and 15 to bolt it all back up. This is easy and free if you have a die grinder and bits. The bits I got on ebay (9 in the set plus a few freebies) were such a good investment. Paid 45 for the 9 different iron porting bits, and 15 for the grinder and I can do it all myself now. Make sure you keep test fitting as it took me about 20 minutes to get the door to open all the way and there is absolutely not 1 lb of creep anymore. Good luck!

 

[Eastwood95]

hmmmmm, external is definately a fix. I was saying that the porting and flapper mod could fix it for a lot cheaper, thats what I meant anyways. External is very nice, but a little expensive. Good point though..............

 

[99gst_racer]

Paul, you and your external wastegate.

haha, I was waiting for you to say that.
I used to creep horribly with my old 14b. Nothing ever worked and I was sick of trying one little thing after another. I spent $210 on my 38mm Tial and have been happy ever since. One thing I really like about it, is it's mounted on the manifold, so no matter which turbo I decide to use, I will still have full use of the WG w/o any further modifications. Whereas, if you port your turbo to stop creep and then 5 months later you decide to switch to a different turbo, you would have to do that porting all over again (that is is the new turbo creeps also). And same with O2 mounted external gates. You always have to modify the turbo by porting the WG passage. I just love my external!!!

So far I have not seen failure in porting yet as long as it's done right.

Unfortuntely, most people dont do it right... (at least not the first time)

 

[oldman]

Unfortuntely, most people dont do it right... (at least not the first time)

Very true.

 

[cfisher]

I love my boost control with my external gate but the noise just plain sounds like shit. I'm in the works of re-routing back into my DP.

 

[90blacktsiawd]

Something else i noticed nobody saying. The more you turn down the boost the more it will creep. If you turn it up closer to what it is creeping too it will tend to equalized to an extent. Not a guaranteed fix by any means though. A high flow cat fixed my problem temporarily though.

 

[daren_p]

I just finished installing my evoIII which has the 34 mm flapper mod and I also gave it a proper port job & I can hold 15 psi to the redline. Remove the material on the turbine inlet that covers the top of the wg passage so that when you look straight down into the turbine inlet the bottom lip sticks out slightly further then the top (from the factory the wg hole is completly covered). Then port the huge lip on the wg outlet and make it a nice smooth transition to the outlet. If you look at the turbo the area of the wg passage that has the biggest lip is the area where most of your exhaust is going to want to flow, smooth it out so it will flow alot better. Then port your O2 sensor housing really well. I aslo took some of the divider out where the wg passage meets the normal exhaust route (just before the outlet) since its pretty small & another restriction.

 

[beat90tsi]

Unfortuntely, most people dont do it right... (at least not the first time)

I didn't....it's better, but still creeps. However since it stays around 20-21 at redline now, I haven't gotten motivated enough to take it off again.