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

[oldman]

Sorry, it's a 95 Talon TSi AWD Auto Tranny. I will complete the profile after I post this. I have the Dejon MBC and I have the shortest possible hose route, it's hooked to the compressor housing on the turbo, and the wastegate. I'm running and holding about 11-12 PSI, and it's spiking to 15'ish after shifts. I have not done any porting on the turbo, because I plan on doing a 16G setup sometime in the near future.

A 3 psi spike is pretty much what everyone else is seeing and something you can live with, the Dejon MBC is a ball and spring and it's definitely routed correctly, not much else you can do or need to do.

BTW I think I know you from the other forum, welcome to tuners.

 

[nad1]

Yeah, I usually stick around on the other forum.

The thing that sucks is that I can't turn up the boost anymore, because then I'll be spiking too high. So I guess I have to run stock boost until I get the money for a 16G setup etc...

Thanks oldman, I appreciate your help.

 

[oldman]

The thing that sucks is that I can't turn up the boost anymore, because then I'll be spiking too high. So I guess I have to run stock boost until I get the money for a 16G setup etc...

Thanks oldman, I appreciate your help.

No problem, you can turn up your boost to about 15psi, most are running 15psi while spiking to 18psi, not an issue.

 

[RJD2]

Dont get too serious about porting behind the flapper, the wastegate arm wont even open it as far as you can open it with your finger with the arm off, people dont understand that sometimes. If you want to definitely get rid of the creep just buy an atmospheric O2 dump. Whats another $120 bucks when you have all those mods and so much time just in porting to try to solve it?

Also, with your exhaust, did you get rid of your car also? If you did that wont help at all. But, get a O2 dump and be done with it.

Yeah I remember my friend telling me about the arm not being long enough to open all the way when I first got the 16g. As for the car yeah I got rid of the cat when I got my downpipe and exhaust done but I was running the T-25 back then. Any suggestions on which o2 dump to get??

 

[oldman]

Any suggestions on which o2 dump to get??

I have already told you O2 dump will do little for your creep, either re-visit the port job or go external.

 

[SnowBird]

Yeah I remember my friend telling me about the arm not being long enough to open all the way when I first got the 16g. As for the car yeah I got rid of the cat when I got my downpipe and exhaust done but I was running the T-25 back then. Any suggestions on which o2 dump to get??

I was pretty sure the dump cured creep, but I guess we are talking about spike here now. I wouldnt pay more than $150 for any O2 dump.

But listen to what oldman says, the dump could cure and it couldnt, I usually here of people creeping, but instead of porting they go lazy and get a dump. I see where oldman is coming from being that everything is this issue was already ported.

 

[RJD2]

Oldman, I have had the turbo off twice and ported the hell out of the inlet each time. I cant go any further with out going thru the other side of it next the the wastegate hole.

 

[oldman]

Oldman, I have had the turbo off twice and ported the hell out of the inlet each time. I cant go any further with out going thru the other side of it next the the wastegate hole.

How bad are you creeping? As for the port job, it's where you port, not how much you port. Did you follow the EVO3 porting article?

 

[GST98BIG16G]

i have been trying everything with my big16g , nothing helped. The one and only answer for you is to get an external WG, that saved me !! I thank god i did that , i have full 7cm ported 2g manfold and external HKS standart wastegate. Spring is 14.7 , it stops at 14.7 with No boost creep at all!! If you want to make your life esaier trust me , go with external wg. You can get TIAL cheaper , but please dont buy knock offs on ebay , it will ruin your life (from personal experience) . If you have any more questions ask me , i will be glad to answer. DSM!

 

[RJD2]

How bad are you creeping? As for the port job, it's where you port, not how much you port. Did you follow the EVO3 porting article?

For example say I'm in second at around 3500 rpms and I roll into it, my boost goes to 15 psi and holds till about 4500-5000 rpm then it creeps up to 20 and over sometimes fairly quickly.

 

[oldman]

For example say I'm in second at around 3500 rpms and I roll into it, my boost goes to 15 psi and holds till about 4500-5000 rpm then it creeps up to 20 and over sometimes fairly quickly.

That's pretty bad still. If you followed this tech article and your inlet look pretty much like the picture shown, I would say your only other option would be a manifold mounted external wastegate.

 

[RJD2]

Yeah I followed that tech article when I ported it but oh well I guess I'm just gonna go with an external wastegate. Thanks for your help everyone

 

[oldman]

Yeah I followed that tech article when I ported it but oh well I guess I'm just gonna go with an external wastegate. Thanks for your help everyone

Another thing you can do is to have enough supporting mod to run 20+ psi.

 

[rcrullamas]

i would like to say that this thread really help me alot. i had boost creep well over 25psi in 3rd gear. after reading how to fix the problem and porting work i no longer have boost creep. i like having a 3 inch DP no cat and 3 inch exhaust. Now i can actually use my MBC

 

[Spades]

hmm, i followed those tips & articles and they worked out for me on my 1st attempt at porting, i have an evo turbo also and my boost holds solid with my HOMEMADE mbc

RJD2 - when you port at the inlet passage of the wastegate, did you round off the corner? that usually helps when you want the air to turn. Also, maybe your wastegate actuator is not working, pressurize it and see if it moves

 

[hellraz0r1337]

i have the knock off ebay 16g turbo (auction was for the real one but for 300 bucks i dont care) and im having boost creep issues to andi dont have a tool to port with alot of people told me that my boost creep could be solved with getting rid of my 2g o2 housing also but i changed that and nothing happened......


now sincei have a pos turbo i dont want to take it off again port it and spend the shop time for getting it ported since i dont know the first thing about porting so id have to spend like 50-100 bucks to get the turbo taken off and ported.

 

[toojung2die]

I dont have a tool to port with ....

You can buy an electric die grinder with carbide porting burr for less than $50.
http://www.yourtoolshed.dyndns.org/index.php?act=viewProd&productId=369
http://www.american-carbide.com/Burs/ESB.aspx

i dont know the first thing about porting

So read the tech article on porting your turbo like oldman suggested. No one is born knowing how to port. It's not hard and once you get started it's addicting. You'll be looking for things to port once you get hooked. http://www.dsmtuners.com/forums/showthread.php?t=186525

HATE THIS CRAP....

Then don't mod your car. If you don't enjoy the process of problem solving and busting a knuckle or two then don't do it. But I would suggest you push forward because the satisfaction that comes from doing it yourself makes savoring the results worth it.

 

[hellraz0r1337]

bah yea nothing like when i put my turbo on and couldnt use my fingers for like 2 days


but i have a industrial dremel its nasty will that work plus that carbine bit i mean i need to have my flapper welded into place right the 34mm one i have to cut the old one off and tack the other in place i cant do that i guess i can have it done,


and the bits thank you for the link and your help, i guess ill just have to rip my turbo off again and leave the car sit there for another week or so as i do more work. I have a stock 2g o2 housing if i port out my turbo and keep the stock o2 housing will i be ok? cause i have a full 3" exhaust from o2 housing back and i hear that sometimes stock o2 housings cause creep.

 

[toojung2die]

but i have a industrial dremel its nasty will that work

It can be done but it'll take forever with a dremel. I wouldn't want you to give up halfway through and have wasted your time. Having the right tool is 90% of the job.

I have a stock 2g o2 housing if i port out my turbo and keep the stock o2 housing will i be ok? cause i have a full 3" exhaust from o2 housing back and i hear that sometimes stock o2 housings cause creep.

Yes they do cause creep, especially with the 16G. You will want to port the O2 housing as well as the turbo wastegate path. After I finished porting and polishing my Big28 I was on a roll and continued on porting my exhaust manifold, O2 housing and even ported the turbo inlet section of my aluminum eBay intake. Put on some goggles and gloves, hook up the headphones and go for it.

 

[Zakrecony]

Hey guys i have a little problem with boost creeping on me, well heres the story.

I bought the car 95 Awd Talon its got few mods but here it is

6 bolt motorr
honed to .20
new 1g rods mounted on 2g pistons.
balance shafts eliminated, block and head were resurfaced
ported and polished head, 3 angle valve job was performed

new stainles steel 1mm oversized valves
new valve guides and seals,
new 3g non tick lifters and crower springs.
full fuel modes and dsm link

The turbo i am running is a SBR G50 it had an internal gate but i took that out and got an 38 MM Tail external and an new o2 housing with external dump. so i put the turbo on and start up the car no problem but when i went to test drive it i saw boost hitting like 15 psi so i changed the spring in the wastegate to a 6 psi one and went for test the car is still overboosting its hitting like 12-13 psi and i am using wastegate presure.. You guys think i am taking too mutch air in ### of the head work and the 2g exhaust mani cant handle it or maybe some other ideas

 

[JusMX141]

What boost level do you plan on running in the end? Seems like 12-13 is awful low for a G50.

 

[Mr Peepers]

Boost creep is from the wastegate being unable to bypass enough exhaust gas around the turbine. It is completely exhaust related. Changing the spring and/or running wastegate pressure will not affect the real cause of creep.

On that note, how do you have the external gate set up?

 

[JusMX141]

If you think you're getting boost creep with an external gate dumped to atmosphere, you should keep looking.

Is the wastegate hooked up properly? You're aware that the pressure line hooks to the bottom of the Tial gate (nearest the manifold mount) not the top, right?

 

[Zakrecony]

well i am planing to get around 22 psi max and yeah i have the waistgage connected to the lowwer nipple not the one on top and its working off the 02 housing with external dump

 

[No_Skillz]

Why not just run 22 psi?