Boost Creep (oldman read this)

[~laser_craver~]

This is to show how far the flapper opens and the litle bit of opening that up i did.

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This is the turbo inlet.

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[larsrya8]

Have you applied pressure to your wastegate to see if it opens all the way? My flapper has the ability to open 90 degrees, but I don't think the actuator rod moves that far. I think it opens to 45 degrees... maybe less.

 

[~laser_craver~]

Ill go try that right now... BRB

 

[gSx_r1der]

This is to show how far the flapper opens and the litle bit of opening that up i did.

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This is the turbo inlet.

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Wow you just made me feel so much better that I'm getting a full garrett .82a/r housing setup in a few days...

 

[daren_p]

Well judging from those pics I don't think your turbine housing is the culprit. You have the larger flapper & WG hole, you have removed more then enough material above the WG entrance and looks like you have also removed the lip on WG outlet. Like I mentioned above I would test the WG actuator & make sure its functioning correctly and also look towards the O2 housing. A proper functioning mitsu actuator will only travel enough to open the flapper around 45 deg, that is why there is no need to remove material from behind the flapper so that it opens a full 90 deg.

Have you ported the WG passage on the O2 sensor housing? Have you tried running the car yet with the WG actuator disconnected, if so what boost did you get?

 

[~laser_craver~]

Someone told me to ditch the dump tube because that is ###### working against me.... True or false?

 

[Ryan95tsiAWD]

FALSE...unless there is something in the way of the flow from the wastegate hole. The flapper does not open very much when attached to the actuator (try it yourself and see). I am a firm believer in porting is the ONLY way to fix creep. Like darren said, take the WG actuator arm off and see how high boost goes. If you are still creeping higher than the level you want to run (good luck getting it below 15psi with no CAT) then porting or sending it to someone to port it correctly is your only option (or go external). If it does NOT boost too high, then you most likely need a replacement actuator.

I have done just about everything under the sun in combating creep with b16gs.

 

[daren_p]

I know I can hold 14 psi no problem with my evoIII but I have a 3" HF cat. Now I also ported my buddies evoIII & O2 housing the same way as mine and he run's 3" from O2 sensor housing back, no cat & he to can hold 14 psi no problem. Both of us are using the 2g O2 housing, just did lots of porting, especially on the WG passage side, such as matching the gaskets, enlarging the WG passage as far as we could, taking out some of the divider wall where the WG passage joins back to the main exhaust and just smoothing out that general area to get the best flow without turbulance.

Test the actuator to make sure its moving like its supposed to & run it with the actuator disconnected & get back to us.

 

[dsmsucks]

Someone told me to ditch the dump tube because that is ###### working against me.... True or false?

False!!!!

 

[~laser_craver~]

ok i tested my wg actuator and at 10 psi itll open all the way but it only opens like 30* barely enough to jam my pinky finger between the flapper and the turbine housing... so i was told to ditch my old flapper and port the hole way bigger and then use a exhaust valve outta a honda for the falpper instead... so i think ill try this...

 

[WatchItExplode]

you read the other thread right? http://www.dsmtuners.com/forums/showthread.php?p=1863786#post1863786

on the Evo III it's only supposed to open partially. You can buy a larger wastegate flapper, I don't know how the hell you would use a valve from a honda.

edit: like this one that Slowboy makes http://www.slowboyracing.com/more.php?id=108&

 

[daren_p]

Ryan, did you test the car out with the wg actuator disconnected yet? I'm not sure that your creep is turbine housing related. You shouldn't have to port the WG hole even larger as its already 34 mm correct?

 

[bastarddsm]

Neither was I, they were two seperate statements, just put in the same paragraph. Like I said fuel cut has nothing to do with fuel or stock injectors. It happens when the MAF see's too much airflow & thats why I origionally said to check again for boost leaks. Boost leaks casue you to hit fuel cut before you should as some of the metered air is leaking out.

So are you still running the stock WG fapper size & hole? How did you turn your O2 housing into an external dump? ie does the exhaust gas still have to pass through most of the housing, if so has it been ported?

Dumbass he isn't hitting fuel cut b/c he has a boost leak it's because his turbo is creaping to 19psi. if he had a boost leak he'd fuel cut at like 10 psi. go play with ## tinker toys till you get a clue.

 

[Ryan95tsiAWD]

Dumbass he isn't hitting fuel cut b/c he has a boost leak it's because his turbo is creaping to 19psi. if he had a boost leak he'd fuel cut at like 10 psi. go play with ## tinker toys till you get a clue.

Uncalled for man...

If you read the whole thread, not only was he trying to help the guy out with his creep problem, he was explaining the CONCEPT of fuel cut too someone else OTHER than the original poster.

 

[oldman]

Dumbass he isn't hitting fuel cut b/c he has a boost leak it's because his turbo is creaping to 19psi. if he had a boost leak he'd fuel cut at like 10 psi. go play with ## tinker toys till you get a clue.

Not only this is uncalled for, you're incorrect. Hitting fuel cut at 19psi is a clear indication something isn't right, especially with the stock fuel system, that something is usually boost leaks. Daren_p has been right on in this thread, I don't think he's the one who needs to get a clue. In any case, whether you're right or wrong, please be repectful of other members in your future posts.

 

[daren_p]

Dumbass he isn't hitting fuel cut b/c he has a boost leak it's because his turbo is creaping to 19psi. if he had a boost leak he'd fuel cut at like 10 psi. go play with ## tinker toys till you get a clue.

Thanks for the informative reply My post was in response to another poster. The origional poster didn't say that he crept to 19 psi & no I don't have a 1g so I don't know the specific point at which it hits fuel cut. A boost leak test is always a good idea when haveing issues such as these. Did I specifically said he was hitting fuel cut because of a boost leak, no. I guess everyone isn't a dsm god, such as yourself

Edited for spelling

 

[~laser_craver~]

I havent unhooked it and tested, but i can do that to i spose. But yes it still creeps, hesitates at 10 and goes to 18-20 by 5400 rpm, unless i dont give ful throttle then itll stay at a certain level of boost.

 

[daren_p]

I havent unhooked it and tested, but i can do that to i spose. But yes it still creeps, hesitates at 10 and goes to 18-20 by 5400 rpm, unless i dont give ful throttle then itll stay at a certain level of boost.

Yes, run it with the actuator disconnected & tell us what it does. This way we can narrow down the actual cause of the creep.

 

[~laser_craver~]

I have to get a new stinkin alternator first.... GRRRRR

 

[gsxtacy]

I am just jumping in after reading everything. I am willing to say its the actuator itself.

The flapper "should" open a BUNCH, not just .375", if it isn't opening .44-.62" I would be pretty upset.

Remove the circlip and see how much movement your flapper has, retest the actuator unhooked and see if it moves same/more.

Creep issues are right there with the flapper/wastegate hole. Its also a issue of the flapper not opening enough because the restriction builds the creep at rpm/air flow increase.

Good luck, ohh and if possible try a stock actuator, I know the 14b actuators fit on 16gs. Another thing, No KINKS in any pressure line. To the BOV, WGA, MBC.

 

[oldman]

I am just jumping in after reading everything. I am willing to say its the actuator itself.

I would have to agree with this, unless you have got the biggest pinky in the world, you have an old and tired actuator.

ok i tested my wg actuator and at 10 psi itll open all the way but it only opens like 30* barely enough to jam my pinky finger between the flapper and the turbine housing...

Also, if your port job was good enough, you should not be able to build more than 2-3psi when the actuator arm is disconnected from the flapper. If you are able to build more than 5psi, you need to revisit the port job. If in fact you can only build less than that by red line, it's almost certain that the problem is the actuator not extending far enough.

 

[tstkl]

Not only this is uncalled for, you're incorrect. Hitting fuel cut at 19psi is a clear indication something isn't right, especially with the stock fuel system, that something is usually boost leaks. Daren_p has been right on in this thread, I don't think he's the one who needs to get a clue. In any case, whether you're right or wrong, please be repectful of other members in your future posts.

honestly, I think your at a much higher elevation or something, because I don't have any boost leaks and I have hit fuel cut at 18 psi, then I leaned it out, and hit it at like 21, then I bumped up the base fuel pressure and don't have any problems since I could lean it out even more (by compensating for larger injectors aka higher base fuel pressure, which btw, I do not recomend to anyone running california gas) and I don't have any airflow problems, but even with the maf on the upper intercooler pipe Ill see 1600+ hz really easily. Even after fixing all my leaks on my stock set up I still hit fuel cut at around 18psi. I think the cold weather and the fact that Im at like 500 feet above sea level makes it so I hit fuel cut much faster than you guys.

I understand that maybe you don't hit fuel cut at 20 something psi on your small 16g or whatever it was, but maybe you shouldn't be preaching that anyone hitting fuel cut in the high high teens/ low twenties on small turbos should not be hitting fuel cut.

then again, YOUR the wiseman, not me... maybe Im wrong. don't let this post take anything away from oldman's street creds, hes a really basic, down to earth guy when it comes to dsm's. (as in he follows things by the book and does it right)

 

[talondsp1]

I just went thru this same thing with my brother in laws eclipse. his t25 went bad, and we put on an brand new evo III 16g, and went for a ride, and it would creep past 20psi everytime.
we thought the flapper was hitting the o2 housing because it wasn't opening up that far when we applied pressure to the actuator, but when we took the actuator arm off of the flapper, it would open 90 degrees. so we opened the flapper all the way, and it still would go to 20psi at high rpm.

He has a cat, but full 3" exhaust. and a tubular o2 housing. we pulled the turbo off and ported the flapper hole to the same size as the flappper, all the way around. then we ported in the cone area where the exhaust enters the turbine housing. we made it nice and smooth so it could flow out the flapper hole without restriction. This worked great, and it now holds boost fine, and the new actuator only opens the flapper about 35 to 40 degrees.
I would really reccomend you port the flapper hole as others have stated in this thread. You should not have to replace the flapper with a bigger one, or a honda valve, since the small flapper is working fine now that the hole is bigger. hope this helps you. good luck!

 

[oldman]

honestly, I think your at a much higher elevation or something, because I don't have any boost leaks and I have hit fuel cut at 18 psi, then I leaned it out, and hit it at like 21, then I bumped up the base fuel pressure and don't have any problems since I could lean it out even more (by compensating for larger injectors aka higher base fuel pressure, which btw, I do not recomend to anyone running california gas) and I don't have any airflow problems, but even with the maf on the upper intercooler pipe Ill see 1600+ hz really easily. Even after fixing all my leaks on my stock set up I still hit fuel cut at around 18psi. I think the cold weather and the fact that Im at like 500 feet above sea level makes it so I hit fuel cut much faster than you guys.

Simply put, T25 will not flow enough air to hit fuel cut at 19psi, not when everything else is functioning properly. If memory serves, you were hitting fuel cut at 10psi last time when we were troubleshooting your car after your maft and fmic install. I think we had it narrowed down to either boost leaks or wrong maft readings, personally I think it was both but it took me a while to convince you to perform a leak test as you insisted that it couldn't have been boost leaks because you had a blow through setup. That said, I'm glad to hear that you have fixed more leaks and are up to 18psi now.

 

[tstkl]

Simply put, T25 will not flow enough air to hit fuel cut at 19psi, not when everything else is functioning properly. If memory serves, you were hitting fuel cut at 10psi last time when we were troubleshooting your car after your maft and fmic install. I think we had it narrowed down to either boost leaks or wrong maft readings, personally I think it was both but it took me a while to convince you to perform a leak test as you insisted that it couldn't have been boost leaks because you had a blow through setup. That said, I'm glad to hear that you have fixed more leaks and are up to 18psi now.

no I was hitting it at like 16 or something, but still....

my bad, thought we were talking 14b or greater, if your hitting fuel cut at 19 psi on a t-25, your magical, not because hitting fuel cut at that psi on that small of a turbo isn't possible, but because I thought getting a t25 to 19 psi was near impossible. that thing starts running out of air at like 3000 rpms, doesnt it?

Im up to 20 something psi. It just wont stop creeping. whatever, once I solve these ignition timing problems and find some way of increasing the octane rating I get on fuel... O DADDY!!! (long story short, my dads a chemist and is friends with this guy, Im going to have a long talk with him tomorrow about his magic juice: http://www.lotusespritworld.com/EOtherstuff/MadProfessor.html)

hopefully he will teach me his high octane formula so I can stop knocking all over the place and having to worry about going wot since Im pulling so much airflow now. It actually was my maft for the most part, Im currently set at 520cc injectors with -30% at wot on stock injectors with a vr-4 fuel pump and (explains a lot right here: ) a base fuel pressure setting of 46 psi over the stock 37 psi. At 20-22 psi I was just seeing too high of idc's and since I can't turn down the boost I had to bump up the fuel per aircount and lean it out so that I was actually running a good afr and my ecu wasn't stopping me because it thinks I don't have enough fuel, when I do. this has totally screwed over my ignition timing, as I have already pointed out to you guys.


edit: I did end up having a leak at the manifold flange though, so in the end, your down to earth, basic methods explained a lot of what was going wrong. Im just to stubborn to be wrong sometimes. I just have to learn that sometimes, every once in a while, theres a small chance, that I just might be wrong, maybe.