Car bogs and blows fire out it's *** when boost hits high.

[Luderacer14]

I did a quick search, and it did'int help. Anyways, sometimes, when I hit boost, it bogs and backfires like a mofo. And I lose alot of power. I'm running straight downpipe. Am I not getting enough back pressure??? And yes, it shuts off after wot.

[fiznat]

post your setup.

[Jookmasta]

could be blowing out spark. my first move would be to check the plugs

[Luderacer14]

Ok,OBX front mount, hks bov, garret t28 turbo, vortex 12-1 fmu, 3 inch full cat thats not hooked on. turbonets manual boostcontroller. ngk v power spark plugs. Sparkplugs, ok i'll check them out. I heard I had to run colder plugs. I tried looking for them at autozone, but those guys have noooo clue. Me too, lol. Don't I have to close the gap on the sparkplug if it's blowing out though??

[klattr1]

too rich?

[DammitBobby]

What is your timing set at?

[Luderacer14]

It's stock, I hav'int messed with it yet.

[240SicknessX]

It's stock, I hav'int messed with it yet.

genral idea or rule of thumb is .5 degress of timing per lb of boost.

ex: retard 3 degrees for running 6psi.

its not worth your engine to try to get more power from keeping your timing advanced or trying to advance it, retard and add boost if your setup will allow safely.

[240SicknessX]

I did a quick search, and it did'int help. Anyways, sometimes, when I hit boost, it bogs and backfires like a mofo. And I lose alot of power. I'm running straight downpipe. Am I not getting enough back pressure??? And yes, it shuts off after wot.

backpressure shouldnt be too much of a problem becuase the turbo is there, someone correct me if im wrong.....

have you had the car tuned at all to check your afr's?

shuts off after wot?...... do you have a atmospherically vented bov?, or dose it just shut off after wot and not 3\4 throttle.

you could be too rich, how many psi are you running, and that 12:1 fmu is on the 270 injectors?

[Luderacer14]

Yea it shuts off after WOT. It's a atmospheric bov. I'm running it on 270cc injectors. 7 pounds boost. I swear it looks like it goes to 15 pounds. It has'int been tuned yet. I'm thinking about dynoing it this weekend.

[240SicknessX]

i meant to say it shuts off after i let off the gas when it is boosted. It's a atmospheric bov. I'm running it on 270cc injectors. 7 pounds boost. I swear it looks like it goes to 15 pounds. It has'int been tuned yet. I'm thinking about dynoing it this weekend.

ok well im guessing you dont have a safc, or emanage to allow for proper fuel tuning inbetween shifts with the atmospherically vented bov.

becuase the bov vents back into the air, the air that is being drawn in is being metered by the mafs, but when you let off the gas no air is going into the engine, but still traveling past the mafs, this will indefinitly promote rich conditions inbetween shifts. with the ecu dumping fuel according to the amount required metered by the mafs, its probably rich enough to stall the motor when you let off the throttle in boost. The excess fuel that is being injected into the engine while you have the throttle closed is being expelled into the exhaust and creating the backfires that you describe.

if you recirculate the bov, i belive after the mafs but before the turbo, it should solve your probems................ < someone check me on that one, im not sure (wait until you get someone to back me up before you try recirculating the bov)

[Luderacer14]

The backfire thingy makes sense, I think i'm just gonna get a safc now on ebay. Dang, I hate using my creaditcard.

[virus77]

you should recirculate the BOV.

[sil80drifter]

SAFC II can account for atmosperic BOVs, they have this function for it, forget what it's called.

sil80

[wild_maxx]

if you do get the safc, it does have a decel setting it that will allow you to take out the correct amount of fuel as the rpm's drop. meaning the car wont stall out. correct me if i am wrong please.

[C-Kwik]

When exactly is it occurring? If it's occurring during or immediately after a shift, then it might be the BOV. But if it's just while you are still accelerating, then you are likely blowing out the spark as Jookmasta already brought up. You'll either need to close the plug gap some and/or upgrade the ignition.

[DammitBobby]

He is using a FMU and does not need a SAFC. Timing doesn`t need to be messed with unless you plan on going over 8psi. I am running a FMU and stock timing with 10psi. I would make sure that you do not have any leaks in the ic piping. Sometimes you can see it if you use carb cleaner and spray around the hoses. If it leaks you will see bubbles. Yes BOV open atmosphere will sometimes cause the engine to stall if you stop hard.

[DRIFTEADOR]

Yea it shuts off after WOT. It's a atmospheric bov. I'm running it on 270cc injectors. 7 pounds boost. I swear it looks like it goes to 15 pounds. It has'int been tuned yet. I'm thinking about dynoing it this weekend.

did anyone else catch this? dynoing isnt a bad idea to at least give you a baseline and hopefully an a/f curve, but you wont be able to tune if you have nothing to tune.

[PapaSmurf2k3]

He is using a FMU and does not need a SAFC. Timing doesn`t need to be messed with unless you plan on going over 8psi. I am running a FMU and stock timing with 10psi. I would make sure that you do not have any leaks in the ic piping. Sometimes you can see it if you use carb cleaner and spray around the hoses. If it leaks you will see bubbles. Yes BOV open atmosphere will sometimes cause the engine to stall if you stop hard.

You will not see bubbles, the intake is in vaccuum (or however you spell it) most likely the revs will pick up or something. Your probably thinking of the bubble trick with tires, if you suspect a leak, you spray it with a soapy solution thing and the escaping air creates bubbles

[WDRacing]

The only way to trouble shoot this is to quit screwing around.

Does the car boost to 15psi, if so, your running out of fuel pump with any FMU being installed causing a severe lean condition. Using a SAFC is dumb with stock injectors...nuff said about that.

The 12/1 FMU is to rich for the KA24DE, they will be much better suited for low boost and a 10/1 or even 8/1.

You need a better fuel pump if your using a FMU. The stock one will not pump enough volume.

Timing does not need to be retarded until you go over 8 psi of boost, again, what boost are you actually running?

Without definitive answers, we can't help. We're all just guessing in the dark here.

WD

[Structure240sx]

also when u say it stalls after wot, is it stalling whne putting it in neutral at high rpms? many car have this problem jsut keep it in gear and let it coast down

[DammitBobby]

You will not see bubbles, the intake is in vaccuum (or however you spell it) most likely the revs will pick up or something. Your probably thinking of the bubble trick with tires, if you suspect a leak, you spray it with a soapy solution thing and the escaping air creates bubbles

Yep I know because I actually did it to find a small leak!!!

[240SicknessX]

you should recirculate the BOV.

if he recircluates the BOV, should he recirulate it after the mafs but before the turbo. right?

[virus77]

Yup

[nissanfanatic]

Run an 8:1 FMU. I run a T04B .60ar S-trim compressor at 6psi with this and run a 12.2-5:1 AFR via PLX Wideband. Its safe.

The part numbers for the NGK plugs are

BKR6E-11 for one heat range colderBKR7E-11 for two heat ranges colder

Recirc for sure.

Gap to like .030"-.035". Its best to run the largest gap you can without having the spark blow out.

Another main thing you may want to consider is upgrading your coil. The stock coil isn't worth the labor that was put into making it. I would pick up a MSD blaster SS coil.

[Luderacer14]

Holy cow, It was bogging up to 15 psi , the boost controller i got was'int working or something. I called turbonetics and they said the boost controller only works on an external wastegate. I removed it and now it's running good at 7 psi. God, it would go to 12-15 psi and bog. thank god I did'int blow my engine!!! I'm gonna get rid of my fmu and put my 370cc when I receive my safc. Thanks alot for the help!!!!!!!!!!!
Modified by Luderacer14 at 5:14 PM 3/24/2005

[WDRacing]

A boost controller is a boost controller...doesn't matter who makes it or what wastegate your using it on.

Put down the crack pipe and step away.

[240SicknessX]

A boost controller is a boost controller...doesn't matter who makes it or what wastegate your using it on.

Put down the crack pipe and step away.

ROFL

yea, boost controller is boost controller, they restrict the about of positive pressure that travels to the wastegate allowing the wastegate to open later\less creating more boost.

[2d-ink]

Just out of Curiousity does a SAFC and VAFC have these Anti Stall System that you can run a Open Atmosphere BOV with out your car stalling? I'm asking more towards a VAFC because I have one sorry if I kind of push this out of topic

[sil80drifter]

you should ask that question in your original VAFC thread. or do google search, and compare "vafc vs. safc"

sil80