no exhaust only downpipe?

[talon913]

ok im running a 1g laser.. only with the down pipe cut b4 the cat.it pulls alot harder but feels like its fuel cutting around 5-6k b4 you get to redline and falls flat on its face and im at stock boost with no upgrades but hard pipe instead of rubber..so could it be backpressure.which most people tell me that your turbo counts for the back pressure needed.and what problems will i run into if i keep runnin it with no exhaust just str8 downpipe sorry about my typing kinda in a rush.......need help

 

[4Gmoney63]

without backpressure your 14b is not able to keep the amount of boost its building in check. This is called boost creep. You need to get a aftermarket boost gauge to see what you are hitting. This is very dangerous for your engine. Fuel cut is very scary when you hit it so you know. As for falling flat on its face its most likely from being at higher boost levels than your fuel system can handle, thus the computer retards timing trying to protect your engine from damage.

 

[talon913]

oh ok i didnt know that cause a couple of my buddies run there turbo cars on jus a downpipe and the run jus fine mine run jus fine until it tries to hit full boost then i thnk it its fuel cutting cause its sounds like the motor shuts off then starts back up only in high rpms .but why would i get fuel cut at 12psi which is stock boost??? i was thinkin bout puttin my other exhaust back on it but cutting it after the cat would this help any..and i jus put my ngks back in cause it started doin it worse when my bov hose came off and it started runnin rich plus i had those denso twin titanium that were fould out.i went back to my olld ones nd it solved it a lil bit but its still pretty bad.

 

[Dserge]

Sounds like balls I bet too.

 

[talon913]

nope actually sounds good well the down spool does anyway.but i wonder how it would sound cut right after the cat?

 

[4Gmoney63]

Do you have a aftermarket boost gauge to verify boost, I don't see one in your profile.

 

[pboglio]

Your fuel cutting cause the ECU is detecting high airflow that is forcing a large injector duty cycle. You can buy bigger injectors, run an AFC and lean the injectors back down thus fooling the ECU. Or you can lean out the motor using the MAF adjustment screw and yanking the bypass honeycomb and see what happens.

 

[talon913]

yea i should be getting a srt4 one today for very cheap hopefully...but whats the stock boost supposed to read??cause im consistently hitting 12-13 and thats on the stock gauge which i hear is wrong mor than half of the time

 

[turboglenn]

you definitely need a boost gauge and preferably some sort of tuning device/ability to start running with a DP only. Not to mention some sort of boost control as with lower back pressure you'll be pushing more boost almost 100% of the time. If you don't have AT LEAST a logger of some sort or wideband, put the DP back on and wait until you've got some tuning tools, extra fuel upgrades and some knowledge of logging and tuning to guide you.

 

[4Gmoney63]

The stock boost gauge is worthless. Its only a calculation of what the computer thinks boost is, it has nothing to do with whats really going on.

 

[talon913]

realy how do i adjust the screw and i was already thinkin bout taking the honey comb out.just to see what it would do but its not runnin realy rich no more well i think .

 

[e85_4g63]

do a boost leak test....

 

[talon913]

wow thanks guys yea ima go ahead and put my other exhaust back on but its already cut after the cat will this matter??and im get a bigger fuel pump sometime soon what else should i get to support fuel..im tryin to drop 13s soon or atleast a low 14 first it felt like it would now how hard it pulls but no use if it cuts out b4 redline

 

[cheap90gsx]

You should try searching or following the 1G upgrade path in the tech section. Just so you know without a aftermarket boost gauge you will never know how much boost you are creeping up to.

 

[aspekt9]

I had the exact same problem, I'm running an open downpipe and the car would boost to 12PSI on my 14b and then hit fuel cut. Turns out I was running PIG rich. Leaned up my trims with my MAF-T car held 12PSI like a champ.

 

[Dserge]

I had the exact same problem, I'm running an open downpipe and the car would boost to 12PSI on my 14b and then hit fuel cut. Turns out I was running PIG rich. Leaned up my trims with my MAF-T car help 12PSI like a champ.

Fuel cut at 12 PSI? Dang.. I would feel robbed. Haha.

 

[95fwdtsi18psi]

maybe 2g's are different but I had no problems what so ever on my stock open downpipe. I ran that for 2 months until I got my megan installed.

 

[dsmfa9nutter]

without backpressure your 14b is not able to keep the amount of boost its building in check.

From actual experience, over 2000 miles with a 2.5" o2 housing into a 3" open dump, that is not true. There is absolutely no such thing as backpressure being good for a turbo car.

Op, your fuel cut is probably from a boost leak or your wastegate isn't opening when it should and you're running too much boost. Get a boost gauge ASAP and make sure your vacuum line is running to your wastegate actuator.

 

[meliketoball]

You don't need any back pressure from a turbocharged car.

Give your car a tune up and check for vacuum leaks.

 

[black_clipse]

yea i should be getting a srt4 one today for very cheap hopefully...but whats the stock boost supposed to read??cause im consistently hitting 12-13 and thats on the stock gauge which i hear is wrong mor than half of the time

stay away from those stock srt-4 boot gauges... they're trash. I went thru 3 of them when I had my srt in less than a yr and a half... there's a reason y all the srt guys change em out quick... if you're looking for a cheap gauge, go w/ a prosport one

 

[talon913]

thanks guys comes out that i was runnin a bad fuel cut cause of the spark plugs i changed then out for my old ngks that had less than 50ml on them and now it runs perfect again..and for some reason it runs way better without the blowoff valve recurc. b4 with my exhaust on it used to cut off on me comin to a stop now it runs great even between shifting..and yea ima invest in getin a good ebay boost gauge and a 3in down pipe...for now its kool..to bad i cant drive it no more for a while just messed my clutch up rappin a vette messin with me at the light i scared the shit out of him he tried to race 2wice .to bad i own a dsm nd now i gotta tear it apart again after fixin something else...

 

[allthrottle]

I wouldn't recommend removing the lower honeycomb. I currently have mine out. My idle is slightly rough now, and I'm chasing down a lean/knock issue that could be related to it. Leave it in and get a safc or comparable device if you want to lean it out a little.

Without the bov recirculated, you should be running extremely rich between shifts and the engine should stumble and try to die after you let off the gas. If it isn't, you may have issues somewhere else, maybe boost leak related.

 

[talon913]

yea thats ### i was thinkin but i think its a lil more airflow \from runnin no exhaust and only down pipe thats helping out the bov..### when i had my exhaust on it would stumble run low idle and all of that i jus put hard pipe on and now i gotta figure out how to get the recurc tube back on but its been runnin the same to me..but it is running somewhat rich though but you cant tell during shift.its when your jus cruising around when you notice its runnin rich cause the idle starts to hop a lil bit.

 

[95fwdtsi18psi]

without backpressure your 14b is not able to keep the amount of boost its building in check. This is called boost creep. You need to get a aftermarket boost gauge to see what you are hitting. This is very dangerous for your engine. Fuel cut is very scary when you hit it so you know. As for falling flat on its face its most likely from being at higher boost levels than your fuel system can handle, thus the computer retards timing trying to protect your engine from damage.

Back pressure = pre-mature death of your turbo. Why don't you just shove a potato in your muffler to help the turbo maintain proper boost levels....

 

[jrohner]

I don't know why you guys are ripping a new one to the guy with post #2. He's right, and he NEVER said back pressure is good, it's that the free-flowing exhaust is causing more airflow.