Just installed downpipe. Now my car is acting really messed up.

[rob1621]

Ok i just installed my megan dp. (cat eliminating) so i go down the road and give it 70% gas and its all good till i hit around 5k rpm then the car like stops all power like someone just pushed the clutch in. I dont know its really hard to explain. Its like the cars going going going then stops. I dont know if it goes after that because both times it happend i just put it in nuetral. I really need help with this because i have no idea what it could be i mena all i did was install a pipe.

 

[Bud92gsx]

Looses all power like hits a brick wall when you know it should be pulling hard?

 

[viperbenz1]

my car was doing the same thing when i installed my turbo back exhaust , i was hitting fuel cut, how much boost are you runing after you installed the downpipe?

 

[rob1621]

Boost is unknown, im installing my boost gauge on wed. when i get my boost controller.

I dont exactly know what 'fuel cut' is. But if its what i think it is then yeah fuel cut.

Like imgaine building boost in 2nd, your foots on the gas, and right around 4-5krpm someone pushes your clutch in and releases really fast. Your goin, you stop for like half a sec. and then it kicks back in and jerks the f**k out of you.


As for fuel cut, why would i be hitting it? i got intake, turboback exhaust, and a 14b that i think is half ass working. and i havent turned the boost up at all.

 

[allrice4g63]

BOOOOOOST CREEP!!!!!! you need to take the exhaust housing off that 14b and port it to hell as well as the 02 housing. whatever your boost was before after installing the bigger downpipe its more now because its creeping. i know this ### it happend to me on two cars. its pretty simple take the manifold off loosen the vband clamp pull the exhaust housing off and get a dremel or whatever and go to town porting it out.

 

[allrice4g63]

or just try looping ## vaccum line from jpipe nipple to wastegate and run 8 psi then it will creep to like 10-12 psi and u should be ok. but right now ## ###### running 12psi off the stock setup and its creeping to say 16psi and the stock fuel system cant handly anymore than 14psi 15-16 with a rewire.

 

[Bud92gsx]

BOOOOOOST CREEP!!!!!! .

Quote unquote..You exhaust is flowing to much..The turbo continues to spool, and create more boost..When boost goes to far on stock ecu/tune, you hit what's called "fuel cut".

It feels like hitting a brick wall...

 

[rob1621]

i see. but doesnt the 14b flow 10-11psi stock? and is safe to 15psi? dont you usually creep only a few psi? how much do i have to hit before fuel cut on a 14b?


And when i get my boost controller, cant i just set my boost to 8-9psi so it creeps up to where ever?

 

[No_Skillz]

i see. but doesnt the 14b flow 10-11psi stock? and is safe to 15psi? dont you usually creep only a few psi? how much do i have to hit before fuel cut on a 14b?


And when i get my boost controller, cant i just set my boost to 8-9psi so it creeps up to where ever?

Don't half-ass compensate. It'll be more of a headache down the road. You should have gotten a boost gauge as your FIRST mod. Upgrading a turbo without any idea what it's doing is a great way to grenade your motor.

Do things the right way. Do a boost leak test. You should be able to pressurize up to 20 psi and it should slowly leak to 0 in about 30 seconds. Then route the vac line from the wastegate directly to the compressor cover to run the minimum boost possible. Then, if you really love your car, you won't boost until you've gotten a boost gauge.

 

[rob1621]

Don't half-ass compensate. It'll be more of a headache down the road. You should have gotten a boost gauge as your FIRST mod. Upgrading a turbo without any idea what it's doing is a great way to grenade your motor.

Do things the right way. Do a boost leak test. You should be able to pressurize up to 20 psi and it should slowly leak to 0 in about 30 seconds. Then route the vac line from the wastegate directly to the compressor cover to run the minimum boost possible. Then, if you really love your car, you won't boost until you've gotten a boost gauge.

mmmk. i have a boost gauge. It will be in on Wednesday, waiting on the boost controller.

 

[No_Skillz]

Why do you need a boost controller to install a boost gauge?

 

[rob1621]

because id rather do it all at once.

 

[95redturboawd]

Yeah my 14b was spiking to 20psi before I put in the boost controller. They might stop at 11-12 psi on a stock exhaust, but not aftermarket.

 

[rob1621]

So what psi did you set it to after you put on the mbc?


If i get n evoIII o2 housing, will it stop the boost creep?

Oh and boost gauge is goin in tomorrow, i should have my boost controller by then?

 

[No_Skillz]

If you are still getting boost creep, give it a good port job. Spend some extra attention on the wastegat flapper. Shape it so gasses escape easier.

For more info:

http://www.dsmtuners.com/forums/turbo-system-tech/183108-turbo-exhaust-creep-20-psi-question.html

 

[rob1621]

Does anyone know if the evo3 o2 housing matches up to a megan racing downpipe?

 

[reno23]

Does anyone know if the evo3 o2 housing matches up to a megan racing downpipe?

I think it should, i've asked the same question in the past and found different sources indicating that it does bolt up. Now its a different story on how perfect of a fit it will turn out to be in regards to everything else around that general area.

 

[whe3ls]

i dont believe it will. the holes may have to be slotted

 

[rob1621]

that sucks.


-but can anyone answer my question about if if set it to a low psi will it be fine then?

 

[Bud92gsx]

or just try looping ## vaccum line from jpipe nipple to wastegate and run 8 psi then it will creep to like 10-12 psi and u should be ok. .

Try this..It will only make 10-12 psi, but you shouldn't have a problem hitting fuel cut..

Or like everyone else said, Install the MBC and turn it all the way down to wastgate pressure, and It might not creep to say 16 psi..

You really need your boost guage installed, and you mbc.. So wensday when that stuff comes in the mail I want it installed asap..Then I want you to make sure the boost is turned down..And Go for a ride, see what happens. Watch the guage and figure out what it's actually creeping to before setting you boost controller to say 12 psi or so..


You should be fine to answer your last question..

 

[rob1621]

Nice. Thanks dude. The boost controller is coming today actually ...but i work from 11:00am to 11:00pm today and then have to change my sisters oil, so i dont think ill be able to get it in there today. Ill try tomorrow and run the turbo at 8psi and see what it does.

side question- if i run it at 8psi, and it creeps to say 14-15psi will the car be feelin like its at this power?

 

[EclipticalGS]

dude, if it creeps to 15psi youll still get the power of 15psi because its actually there. You pretty much are gonna be running 15psi but you have to set you mbc for 8psi because you have so much creep. Setting boost low to depend on creep to get you where you want is never good. I had friends that did this and I always laughed at them for how un-dependable their systems were. Get in that 02 housing and port it, then go into your wastegate Flapper and port it smoothly towards its exiting hole. the first thing you should ahve done was a oil press gauge and first of all a boost gauge. Then comes a wideband for tuning. If you had these gauges to begin with youd known how lean yo were running in overboost. Omg scary when you hit fuel cut and look at your wideband. Get those gauges!!!

oh and BTW never run your wastegate vacuum line from your manifold, this also causes overboost because by the time your turbo is pushing 15psi, your manifold sees 13-14 and that wastegate will stay open until it sees 15 which is a second after that turbo gets to 15psi. so youll hit roughly 1-2 psi above, well in my case. of my first tsi awd

 

[rob1621]

I see. Ok so if i were to get 2.5" o2 housing, and have my boost just regularly set to 15psi, would it still creep? what about if i rewire the fuel pump? (how bad does fuel economy suffer?)


Im lookin at this ebay one....

DSM PORTED INTERNAL O2 DUMP HOUSING Talon Eclipse 1g 2g:eBay Motors (item 350236641253 end time Aug-12-09 22:05:24 PDT)

 

[dsmfa9nutter]

I had no creep with a 2.5" SS o2 housing into a 2.5-to-3" megan downpipe with a 14b set at 16lbs. Fuel cut happened at anything above 17lbs for me. Make sure the wastegate pressure is plumbed after your intercooler and goes:

Boost reference port (I used a brass screw in from the hardware store)->mbc->wastegate actuator.

Do not T into existing lines, there really needs to be a good clean signal. Most of the people I've seen with boost creep have their wastegate t-d into a bov/boost gauge line and then they wonder why they have problems. You want the shortest vacuum lines you can run, I've got 8" from my port to my mbc and then 10" going down to my actuator. Just leave enough slack for engine movement if you mount your mbc to the frame and not the engine.

 

[rob1621]

well i have a ebc...