Pretty serious if I do say... Did a simple downsift from 5th to 4k rpm and a nice pull to 6,250 with 4 people in the car and the heat on. Around 6k, the engine jumped, CEL blew and cruise started flashing on and off. Car is obviously still drivable, and Im almost 100% certain its from the boost creep. Going to see if I can swing by SoG sometime soon (tomorrow perhaps) and have Siegel take a peek as well as arrange for some ecutek (about damn time). Until then,
Yes, Chris, it is because of the colder weather and more importantly the change in pressure. Im experiencing this much more now due to the full 3" tbe, rather than just the dp which I had last time we ran into cold weather. I'm sure my review will be include a lot of testing and chipotle lunches (And this time I'll invite you Kris, not like those other guys).
I guess I'm lucky, we were having creep issues with my turbo while tuning but I was ripping it around last night with no problems in the 40 degree weather. You'll love the Ecutek.
I just got my first P0244 (Wastegate malfunction) CEL this past weekend. I hit 1.4 bar in 3rd gear. That's 20 psi! This is with the new protune I just had done. I hadn't previously experienced this with my AP 1.15 map.
Doug should be able to turn down the Air temp wastegate duty compensation and fix your cold weather creep. Just give him a call, I'm sure he'd be happy to fix it. SS
I just pulled the same p0244 with my new Cobb AP. Should i be worried? maybe clear it and just see if it does it again? when i uploaded the new map from the ap i'm assuming it cleared everything then so it couldn't have been from before...
Will a DWG Downpipe relief some of this issue What really causes boost creep ? --< trying to educate myself so to prevent it from happening to my car
Flip, I was wondering what kind of exhaust are you running from headers to to tailpipe? I guess I need to go ahead and get a boost gauge, since it will be getting colder soon and I just went to stage 2.
I have been reading a bit on this issue and to me if you plan on WOT this should be a concern. I hope Ive done enough to prevent this but of course tuning and porting the turbo will certainly eliminate it. But those two is $$$ Ive got 3 of the prevention pills so I may be ok 1. DWG DP 2. Hi Flow 3rd Cat 3. STi catback They say one will do but i think 3 is better
This was long before his AP. Almost a year ago, Nov 2005. Oh, and even porting your wastegate will not completely eliminate boost creep. Although it will probably for your application, the internal wastegate is flawed by design and will have creep at some level no matter what. The only way to completely eliminate boost creep is with a external wastegate.
Alrighty, alright. With a stock WRX turbo on the 2L you will be hard pressed to see creep. Some background on boost creep (STi). The creep is notorious on the 2004 STis. A bit of history lesson, IHI cast these turbos smaller and more thin than any other previous turbo and thus they are prone to cracking and creep. Consider boost creep as a room filling up with water at a rate larger than the water can exit the door in the room. You are floating in this room and you'd much prefer to be able to exit the door however you are coming dangerously close to the ceiling. What's your only option? Pull the drain plug in the floor, however, you know that this plug is marked "IN CASE OF EMERGENCY PULL". Your parents always told you, do not never pull this plug. So, you pull the plug, the room surges and begins to drain. Now, apply this to the car. Your car will cut fuel, you will have a dry fire and run extremely lean for just a tic until the ECU registers that the boost is back within an optimal operating range. DWG were once originally thought to help prevent creep, but what we've seen lately is that they are actually creating additional turbulance. When the WG opens, it is now blowing straight into a wall rather than the open bellmouth. The cars apparently futher dissaproves of this technique. I cannot stress this point enough, boost creep is 100% mechanical. If you wish to remove it, you MUST port your turbo. Tuning only moves the problem to a different spot within your powerband. Of course, Brett is correct about the ewg, but for some this is not an option. An STi axelback on a WRX is one of the best cheap investments you can make. They're nearly straight through and will improve your 60-90 time substantially. I am not, however, attributing the addition of the axelback to the removal of creep. The pressure issue is within the turbo / wg itself. A dremel, one beer and 20 mins will allow you to port your turbo lickity split. 2 hours, three beers and some bloody knuckes will allow you to install your new turbo Cheers,
Yeah, what Alex said. Also, I dont think I have heard of a stock wrx turbo (td04) creeping. As a matter of fact, after the 04 STi's, I havent heard much about creeping at all.
my 06 crept the morning before i went to get it tuned... luckily it was not a problem to tune around it
As far as I know, the 05's used the same casting of the 04 vf39, evident by the cracking issues. Not sure on the 06s, god only knows, they keep changing shit up on us :rofl:
I thought the DWG DP has a separate path for the WG gasses hence less turbulence hence allowing the WG to function more efficiently. So why is DWG more prone to Boost Creep ?
Right, but as I said, the ones Ive seen actually had the WG blowing straight onto the wall. Basic fluid dynamics tells me that moving air into a flat wall is not nearly as efficient as a moderatly open space.
Can you describe or get a pic of one? Other than the stocker and some other cheap shit downpipe I haven't seen any that 'blow into a wall'. Unless the wastegate is misaligned with the divorced pipe, it should flow well, maybe even better than a bellmouth since the main pipe might contribute some vacuum/sucking flow for the smaller wastegate pipe.
I thought DWG means individual exhaust and wastegate paths. In fact most of the new DWG has a tongue in between the two paths to separate further the air flow paths. Of course the perfect way is to have EWG (external) but a poor mans solution i would think is a DWG. without having to change UP and DP and weld shut the WG. As for Bellmouth i have mix signals but i think its fine but it would be better if th e WG arm(hinge) is on the other side (nearer to the exhaust turbine side) so when it opens the door is directiung the WG gasses away from the main paths hence causing less turbulence
Yeah, that's not a divorced wastegate pipe but it sounds like that's what Alex is talking about. I can't see how a divorced WG one would not help, it ought to create a scavenging effect on the wastegate side similar to the way headers work; creating a negative pressure that will pull more gas through the wastegate than a bellmouth would.
your logic is correct... thats exactly what i thought too but then i had another thought... does anyone know how much the wastegate flapper opens? is it >90 degrees when fully open?
If I am remembering this correctly from a few nasioc posts which i will try to look up for you, it isnt that the exhaust gasses are flowing into a "wall" but instead, they flow into the exhaust at a different speed than the other exhaust gasses, therefore disrupting flow. Goes off to nasioc to search Heres a good info thread on boost creep...still searching for the downpipe thing http://forums.nasioc.com/forums/showthread.php?t=477715&highlight=boost+creep+divorced+wastegate Here is Unabomber's Downpipe FAQ, another good read for boost creep and downpipes http://forums.nasioc.com/forums/showthread.php?s=&threadid=445812 Basically he says that there is no proof either way that one is better than the other, but that they both creep.
OK, maybe SS can chime in here.. but I'm looking at a stock STi map, and have some questions. Max WGDC is set to 65%. Taking into account turbo dynamics and WG intake temp compensation, does that still not leave a crapton of room for adjusting it? I'm no expert at reading these maps, but nowhere do I see WGDC compensations/adjustment adding up to anything NEAR the limits of what you could adjust... edit: just having a hard time with the 100% mechanical thing...
ok, here's an idea... i could be wrong as hell so correct me if im wrong i believe if u run close to stock boost, then a tune could open up the WG more to compensate for the lack of air bypassing the wheel... but most people who get tuned run much higher boost... at that time, it could be possible that even with the WG locked open, enough air can not pass through it... that excess air passes over the wheel and u get creep... in this case, porting the WG might be the only way to get enough air through it... thoughts?
Yep, I have the Invidia V2 catless bellmouth also with the Nur Spec R exhaust, and haven't had any issues yet...but I bet I will once I upgrade some things...hehehehe.. Mark
im curious to see if the 06 WRX creeps any... i doubt it would because i never heard of any forrester creeping
As long as the tune ALLOWS the ECU to hang the WG wide open... but unless a certain % WGDC does in reality have it fully open I haven't seen any modified maps that push it to the limit. Edit: though I admit I might not be looking at the right shit.
HAHA, Ok, update. I ran my car today with the AP attached to monitor boost. Ran around for about 15 minuts got some good pulls and the max boost I saw was around 18psi which is perfect since the map that i'm running is set to 17.5 +/- .5. My check engine light is gone but the AP still pulls the same code. If the check engine light is not on does that mean there are no codes? or just no NEW codes? Wondering if i need to erase all that my ECU has learned just to rid myself of that code or not...
I'll 'splain it when I get to work (gotta roll so I miss the traffic). Basically a divorced wastegate WOULD work well *IF* a wastegate opened 90 degrees from closed. Unfortunately it's more like 25 to MAYBE 30 degrees from closed. So the wastegate flow is going right into a wall... It's RARELY a problem on the 2.0 liters. If you are not hitting boost cut, I wouldn't worry about it. There are 2 things going on here, wastegate settings that might allow "overshoot" on boost (more boost than desired) and true mechanical "creep" (as in terminal, mechanical (not tune-outable) creep) which is ONLY the case if the ecu is hitting 0% wastegate duty. If the car is not going to 0% and still overshooting target boost, then it IS tune-outable. However, if it does hit 0%, it's game-off on tuning it out, at that point the only guaranteed solution is porting. I'll explain why increasing exhaust flow "causes creep" when I get to work. SS
Would it help if the WG when trigerred to open, opens wider ? How much is it worth ? or waste of energy or braincells if current opening is 25% I can easily change it to 40-50%. MOre if desired but concern there actuator is not strong enough to close it