Help put exhaust on now Over Boostin!!!!!

[macdaddyvu]

Hey Fellow DSMERS

I have a 95 gst with the evo 16g,adjustable FPR, front mount,walbro 255 fuel pump,intake,
boost controller,NO Safc Or Afc,but i just put on My 3Inch Exhaust turbo back,downpipe is 2.5 then flares to 3in,no cat then 3inch the rest of the way back,i had my boost controller set at 20psi,but until i put the exhaust on i cant make it stay under 20 it goes past 20,
it was working fine until i put it on can some one help me!!!

 

[qiklitltsi]

It is creeping because of the unristiced exhust flow, the evo3 16g is known for it. You can solve the problem by porting the turbo to cut down on the sharp turn to the gate that opens the let exhust gas out.

 

[BootlegGreg]

Big exhaust will do that. I know some 3" exhausts come with multiple silencers to help slow

the exhaust flow down a bit to help the wastegate keep up. An external gate or a smaller

exhaust are about your only options. Do you have a cat that would help too.

 

[fwdmaster]

Port your wastegate area so the flapper opens all the way, or go external wastegate

 

[Boost92awd]

Also look into a ported exhaust manifold and o2 housing to help with the boost spiking that your most likely getting also.

 

[macdaddyvu]

k thnaks guys,i just dont understand everything worked fine before the new exhaust,how about if i downsize the exhaust will that help?

 

[cavillac]

k thnaks guys,i just dont understand everything worked fine before the new exhaust,how about if i downsize the exhaust will that help?

They just told you, if you take restriction of smaller piping out, exhuast flows alot faster right.... well it is flowing so fast your wastegate cant keep up.

So why would you consider downsizing your exhaust after you just put one on? WTF
The more intellegent thing to consider would be to get an external wastegate or do some mild porting

 

[macdaddyvu]

what would be a good sized wastegate? what would be easier port or wastgate?

 

[Mr Peepers]

Get a logger, something to tune with, and injectors. I can almost guarantee you're maxing out the stock 450's at 20 psi and getting a good amount of knock too.

Take of the turbo and port the turbine housing for boost creep. Search "boost creep" or "boost creep porting" etc to find tons of info on the subject. By the way, this does not mean just porting behind the flapper to get it to open all the way, the wastegate actuator won't even open it half way in the first place.

 

[DougR]

$$$ or Time, which do you have?

We have some awsome vendors that will work with you. look in the vendors section and start calling ppl...


Just always remeber , "you get what you pay for"

 

[joe]

Get a logger, something to tune with, and injectors. I can almost guarantee you're maxing out the stock 450's at 20 psi and getting a good amount of knock too.

Take of the turbo and port the turbine housing for boost creep. Search "boost creep" or "boost creep porting" etc to find tons of info on the subject. By the way, this does not mean just porting behind the flapper to get it to open all the way, the wastegate actuator won't even open it half way in the first place.

Well everything he said ^^^ plus there must be something wrong with your set up if your ecu is even allowing you to run 20 psi without hitting fuel cut you need to turn your boost down and port your turbo.....Or you can just replace your engine soon.WTF

 

[1992awdlaser]

Back when my car was stock besides a boost controller I had the boost set at 15psi. I put my 3" Buschur turboback on and my Buschur o2 dump and the boost went to 24psi. The exhaust flows so well that it goes right by the wastegate passage and into the turbine wheel which creates more boost(boost creep). It does this because in order for the exhaust gases to get out via the wastegate it has to make a 90 degree turn while in the turbine housing. The exhaust gas looks for the place of least restriction to go which is through the turbine wheel and out of the exhaust.

To fix this you need to port the wastegate passage first of all so the exhaust gas doesn't have to make a 90 degree turn to get out. Now disconnect the wastegate actuator from the wastegate flapper. Then port where the wastegate flapper closes. You will see a ring from where the flapper sits. Port some of the material away while using the ring as a guide as to not go to far. If you go past the ring then your car is going to take longer to spool. Now open the wastegate flapper just like it would open when under boost. You will see that the flapper arm hits the turbine housing which limits how far it will open. Cut away some of that material so the flapper can open 90 degrees. This WILL fix your problem.

You can also port the exhaust manifold and turbine inlet which will also help control boost slightly because it should make the turbo take slightly longer to spool because of the increased space that has to be filled before the exhaust gas can get to the turbine wheel. This will also make your turbo capable of more power.

 

[el guapo]

you could turn your boost controller down ....wait no what am i saying thats just stupid.

 

[1992awdlaser]

you could turn your boost controller down ....wait no what am i saying thats just stupid.

The lowest mine would go was 18psi. That was with no boost controller and the vacuum lined hooked up directly to the wastegate actuator. Of course I didn't do any of the porting that I mentioned.

This is a way to try to fix the problem. But it is not the correct way to fix the problem.

 

[macdaddyvu]

Well everything he said ^^^ plus there must be something wrong with your set up if your ecu is even allowing you to run 20 psi without hitting fuel cut you need to turn your boost down and port your turbo.....Or you can just replace your engine soon.WTF

i dont hit fuel fut b/c i have a 255 fuel pump,and a adjustable Fuel Pressure Reg.
i set the FPR @20 and then i adjusted my boost controller at 20psi works fine no CEL,
No Knocking Everything Works Fine,

But thanks for the input guys,ill be letting you all know how it goes.

 

[1992awdlaser]

Your fuel pressure should be at 43psi with the vacuum line disconnected from the regulator. Fuel cut is based off airflow not fuel supply.

 

[Mr Peepers]

Back when my car was stock besides a boost controller I had the boost set at 15psi. I put my 3" Buschur turboback on and my Buschur o2 dump and the boost went to 24psi. The exhaust flows so well that it goes right by the wastegate passage and into the turbine wheel which creates more boost(boost creep). It does this because in order for the exhaust gases to get out via the wastegate it has to make a 90 degree turn while in the turbine housing. The exhaust gas looks for the place of least restriction to go which is through the turbine wheel and out of the exhaust.

To fix this you need to port the wastegate passage first of all so the exhaust gas doesn't have to make a 90 degree turn to get out. Now disconnect the wastegate actuator from the wastegate flapper. Then port where the wastegate flapper closes. You will see a ring from where the flapper sits. Port some of the material away while using the ring as a guide as to not go to far. If you go past the ring then your car is going to take longer to spool. Now open the wastegate flapper just like it would open when under boost. You will see that the flapper arm hits the turbine housing which limits how far it will open. Cut away some of that material so the flapper can open 90 degrees. This WILL fix your problem.

You can also port the exhaust manifold and turbine inlet which will also help control boost slightly because it should make the turbo take slightly longer to spool because of the increased space that has to be filled before the exhaust gas can get to the turbine wheel. This will also make your turbo capable of more power.

The flapper will NOT open 90* unless the WGA arm is disconnected from the flapper. It may be true with some turbos, but not an MHI E3 16g, the WGA only allows it to open ~1/3 of its total travel. It will not always cure boost creep, it depends on what boost they are trying to run and how everything else in the system flows. Also, if you do enlarge the WG hole to better match the flapper, close the flapper to check your progress many many times; it's easy to go too far. You want the overlap to be about as thick as a nickel.

Porting the turbine housing into a cone shape doesn't help with boost creep because of the extra volume, but because it causes a "lip" at the bottom of the WG passage that catches some of the exhaust gases. Seen here: http://www.dsmtuners.com/forums/art...oler/186525-how-cure-boost-creep-porting.html

you could turn your boost controller down ....wait no what am i saying thats just stupid.

It doesn't matter what psi you set your boost controller too, it will still creep to the same amount. Although he shouldn't be trying to run 20 psi without any tuning in the first place, he will still see 20+ psi by redline with a line going directly to the WGA. Boost creep is an exhaust related issue.

i dont hit fuel fut b/c i have a 255 fuel pump,and a adjustable Fuel Pressure Reg.
i set the FPR @20 and then i adjusted my boost controller at 20psi works fine no CEL,
No Knocking Everything Works Fine,

Your fuel pressure should be at 43psi with the vacuum line disconnected from the regulator. Fuel cut is based off airflow not fuel supply.

1992awdlaser is absolutely right.

How do you know you aren't knocking? You just stated you don't have anything to tune with, not even a logger. Listen to some of the advice from these forums. We are only trying to help you and your engine.

 

[erald01]

You dont need to do any porting or anything, or even change the wastegate. Its simple you have free flowing exhaust with no restriction, so that means you making more boost because the turbo is spoolong freely. The solution is to turn your boost down and if that is not working try and unplug the boost controller so it goes back to stock boost which for a 16g i think is 10 or 11 psi i think, then go fromt there.

 

[1992awdlaser]

You dont need to do any porting or anything, or even change the wastegate. Its simple you have free flowing exhaust with no restriction, so that means you making more boost because the turbo is spoolong freely. The solution is to turn your boost down and if that is not working try and unplug the boost controller so it goes back to stock boost which for a 16g i think is 10 or 11 psi i think, then go fromt there.

Doing that won't always lower the boost enough. Did you read my post about doing that? And it is not fixing boost creep it just makes it tolerable.

 

[MrBoxx]

Disconnecting the MBC isn't going to stop creep, period.

Everything MrPeepers and 1992awdlaser have said to this point is totally correct. Peepers is an expert when it comes to the WGA and flapper areas of the TD05H housings. See his MWGA tech article for proof of his ingenuity.

And as 1992awdlaser mentioned, fuel cut has nothing to do with your fuel pump or your AFPR or your injectors. If you overrun the MAF/MAS, you'll hit fuel cut, plain and simple, unless you have something that prevents that from happening (FCD, DSMLink, etc.) And he's correct in saying that the AP should be set to at 43.5 psi with the vacuum hose disconnected. 20 is FAR too low. Get a logger and learn to use it ASAP.

 

[macdaddyvu]

The flapper will NOT open 90* unless the WGA arm is disconnected from the flapper. It may be true with some turbos, but not an MHI E3 16g, the WGA only allows it to open ~1/3 of its total travel. It will not always cure boost creep, it depends on what boost they are trying to run and how everything else in the system flows. Also, if you do enlarge the WG hole to better match the flapper, close the flapper to check your progress many many times; it's easy to go too far. You want the overlap to be about as thick as a nickel.

Porting the turbine housing into a cone shape doesn't help with boost creep because of the extra volume, but because it causes a "lip" at the bottom of the WG passage that catches some of the exhaust gases. Seen here: http://www.dsmtuners.com/forums/art...oler/186525-how-cure-boost-creep-porting.html



It doesn't matter what psi you set your boost controller too, it will still creep to the same amount. Although he shouldn't be trying to run 20 psi without any tuning in the first place, he will still see 20+ psi by redline with a line going directly to the WGA. Boost creep is an exhaust related issue.





1992awdlaser is absolutely right.

How do you know you aren't knocking? You just stated you don't have anything to tune with, not even a logger. Listen to some of the advice from these forums. We are only trying to help you and your engine.

i am taking as much advice as i can it has been really help ful,what i did i went and had a 3inch magnaflow cat put on,and i just orderd the turboxs boost controller,b/c the one i have on is the generic on the one that says"boost controller"on thie side i think it was 20$,then if that doesnt work then i will take the turbo off and do the port,as for the AJFPR i havent diconnected the vacuum and seen what it was at its at 20 with it connected,i just adjusted it when i put the fuel pump and turbo in,when i floor it i think it goes up to 40 something,i just set it where i wasnt hitting fuel cut anymore.

 

[MrBoxx]

Set your AFPR to 43.5 psi with the vacuum hose disconnected. If you have fuel cut after that, then you have other issues to track down.

 

[1992awdlaser]

i am taking as much advice as i can it has been really help ful,what i did i went and had a 3inch magnaflow cat put on,and i just orderd the turboxs boost controller,b/c the one i have on is the generic on the one that says"boost controller"on thie side i think it was 20$,then if that doesnt work then i will take the turbo off and do the port,as for the AJFPR i havent diconnected the vacuum and seen what it was at its at 20 with it connected,i just adjusted it when i put the fuel pump and turbo in,when i floor it i think it goes up to 40 something,i just set it where i wasnt hitting fuel cut anymore.

The cat might work but I doubt it. The boost controller deffinatley isn't going to fix it though. Set the fuel pressure to 43.5psi with the line disconnected. Your getting fuel cut because you are flowing over a certain amount of air. Once the maf reads over a certain limit and tells the ecu the ecu will in turn cut fuel to prevent damage to the engine. The manufacturer did this as a safeguard so they wouldn't be replacing engines left and right under warranty when the car was new.

 

[macdaddyvu]

ok the magnaflow 3in cat DOESNT work,now waitin for a good boost controller ,and a dffr 02 housing, the reason i tried the cat is because my friend has almost the same setup but hes running open down pipe then he put a cat on and it fixed it.

 

[MrBoxx]

You're definitely going to need to port your turbo, then. Look up how to do this on www.vfaq.com