Huge Shot Gun Bang On Boost!

[humz]

ok someone please help this problem is giving me the major shits!

the car is r33, with wolf4, pump, reg, Innovative To4e, with mid 300rwhp.

the problem is as soon as its about to come on boost there is these massive shotgun bangs, WTF is it???? its driving me crazy! it obvisiously doesnt come on boost properly when it does this. but off boost it drives fine.

ok its been tuned but couldnt do a proper power run coz of this problem so i dont think its the tuning that causes it. however the tuner reckon somethings going on with your timing on boost... go change crank sensor and come back, done that but same shit!

its soo frustrating some one know wats going on??? this is obviously no good for my engine ye???

is there any diff between series1 and series2 crank angle sensors????

any help much appreciated, thanx

[604cefiro]

Holycrap you know what, I was JUST ABOUT TO POST THIS about my car!

I have an RB25DET w/ GT30R in my R32 skyline. Running 1bar wastegate spring. I make about 400whp.

This has happened to me as well since last Sunday.

Normal driving, it's ok.

Once I hit high boost and the wastegate starts dumping, I get a popping / banging sound.

I am thinking that it is misfiring, possibily bad sparkplugs.

You should also put a wideband on it and see how the AFR is.

I'll be playing around with it today, i'll see what I find out.

[R31Nismoid]

Plugs in good condition?

Coils working?

side note 604 - 14psi/gt30/rb25 300rwkw = impossible

[604cefiro]

I'll be pulling the plugs today and check the coils as well.

I remember you questioning my setup and power in a previous thread: http://www.skylinesaustralia.com/forums/in...23697&st=20

Yes, 400WHP is possible with a GT30R on a RB25... dyno sheet speaks for itself. Just cause you've never seen it / heard of that much power at 1bar, doesn't mean it's not possible

Yea, power is at the topend...

Plugs in good condition?

Coils working?

side note 604 - 14psi/gt30/rb25 300rwkw = impossible

Edited July 26, 2006 by 604cefiro

[r33_racer]

I find that hard to believe mate....our rb30det with a gt35/40 on 18psi is only making 240rwkw.... If your making that magical 300rwkws on 1 bar your turbo truly is magical.

I have a gt30r on my own r33 and im running 1 bar atm...sure as hell aint 400rwhp!

Not 100% sure but i think there maybe a difference in the sensors, maybe the plug? I know there was a difference in the rb20's.

Obviously read ya plugs, cause it seems like its over fueling when coming onto boost and the whole mixture isnt getting burnt and is igniting as it passes out the exhaust. Or it is ya timing and its retarding something fierce when ya start boosting. Strange one. I dont understand how the timing would do something like that once its set during tuning, it cant change by itself well not that dramatically especially with a/m ecu.

[humz]

ok thanx some good info, but in regards to

plugs: mine are new as, so it rules that out! but i hear to gap them at .8 is better on relatively hi hp cars??? yes/ no?

af sensor: using wolf so no a/f sensor. so thats ruled out!

come on other peeps someone else must be havin same problem, im sick of spending my coin on dick chops who cant find teh problem!

to me it doesnt sound like its mis firing, its just massive gun shot/ detonation noises that are repeated if u keep your foot down on boost. could be the overfueling but wouldnt all this have been sorted out in the dyno i had?? how do i check if its this, back to the dyno i guess!

thanx fellas

[R31Nismoid]

I'll be pulling the plugs today and check the coils as well.

I remember you questioning my setup and power in a previous thread: http://www.skylinesaustralia.com/forums/in...23697&st=20

Yes, 400WHP is possible with a GT30R on a RB25... dyno sheet speaks for itself. Just cause you've never seen it / heard of that much power at 1bar, doesn't mean it's not possible

Yea, power is at the topend...

Thats cause its not possible

I know, i had a GT30 on an RB25 (surpsise)

Plus thats graph and its power delivery looks more like something i'd expect from a 800-900hp turbo

Its quite easy to make a car seem like its got a LOT more power than it has

Humour us, go take it to the drags and see what you get... my get is a high 12.

[Al]

What state do you live in?

ok thanx some good info, but in regards to

plugs: mine are new as, so it rules that out! but i hear to gap them at .8 is better on relatively hi hp cars??? yes/ no?

af sensor: using wolf so no a/f sensor. so thats ruled out!

come on other peeps someone else must be havin same problem, im sick of spending my coin on dick chops who cant find teh problem!

to me it doesnt sound like its mis firing, its just massive gun shot/ detonation noises that are repeated if u keep your foot down on boost. could be the overfueling but wouldnt all this have been sorted out in the dyno i had?? how do i check if its this, back to the dyno i guess!

thanx fellas

[humz]

perth W/A...

[Hypn0tiK]

Hey man, Im in WA

Does the car shudder when entering boost?

What does the bang sound like, record it or something

[Hypn0tiK]

Hey man, Im in WA

Does the car shudder when entering boost?

What does the bang sound like, record it or something

http://www.automotiveforums.com/vbulletin/t93061.html

Just found that - maybe you have ALS? or maybe something is retarding you timing when you enter boost? causing a huge missfire and loss of boost?

i'd say some setting on ECU maybe? even tho he said it was fine?

[R31HOOCH]

I'm havin the exact prob with my RB20DET also... When taking off and driving slowly with boost pressure in vacuum its fine... As soon as you go to boost it up it just looses power and starts broad minded persontereing then if you keep your foot into it it'll let off a huge backfire and a nice flame...

I've got new platinum plugs, replaced 2 coil packs, o/hauled alternator, replaced O2 sensor, cleaned AFM and checked fuel pressure, pump and regulator... Its really starting to do my head in... I WANT BOOST!!!!

[humz]

i thoght i was the lucky one to only have this problem hahah, makes me feel better now that im not the only one!

hmmm... "turbo ALS(Anti-Lag System), it first starts off by running rich then retards the ignition timing by 40 degrees. with the delayed ignition timing this results in some of air fuel mixture being vented into the exhaust manifold unburned. when the mixture hits the hot exhaust manifold it ignites on contact and this is what keeps the turbo spooling even when the driver lifts off the throttle. with the air fuel mixture igniting outside cylinder is what causes the loud bangs. some of the mixture will continue buring through the exhaust system resulting in flames shooting out the muffler. i will note that a misfiring system will wreck havok and greatly reduce the life of an engine. its also illeagal to use on the streets since theyre so loud, especially in CA with strict emmisions."

somehow i dont think wolf4 has antilag so i dont think that is my/our probem,

IS ANYONE ELSE USING WOLF4 IN PARTICULAR or AFTERMARKET ECUs WITH SAME PROBLEM?????

i think i may have to put std ecu back in to exclude the ecu, will keep posted!

[humz]

Hey man, Im in WA

Does the car shudder when entering boost?

What does the bang sound like, record it or something

"shudder" as in jerk back and forth??? yes it does that on boost, it feels like a learner taking off at the lights.

the bang sounds excatly like a shotgun to me, if you ease off when it bangs it will only do it once, however if u keep your foot down it will go BANG... BANG... BANG... while jerking/ shuddering at the sametime until you ease off!

soooo annoying and im thinking mega unhealthy for engine.

[R31HOOCH]

Mine is running standard ECU and is doing it... Only since a real wet day a few weeks when i went through a huge puddle...

[R33S2]

Does this happen when the motor is warm?

[Al]

If you live in Perth, contact Ant95GTR and ask if he could give you a copy of his map. Sounds like the tunner has not programmed the wolf properly or has accidentaly turned a feature on that he shouldn't have. The wolf is capable of running "anti-lag", but this is unlikely to be your problem.

Have you tried plugging the factory ecu and airflow sensor back in? If you have std injectors there shouldn't be too much of an issue, just as a short test.

It just sounds like a bad tune :

[paulr33]

cooler pipes or the silicon joiners somehow?

[ossie_21]

Exact same thing happened to mine with what seems the common set up in this thread, on a standard rb25, gt30r turbo with external gate running with a wolf ecu. The same thing happened to me a couple of times, but I found only before the engine warmed up. Before you think it, I don't thrash my car when it's cold, but it only did it not long after start up. If it didnt make a huge bang & shudder, it would just pop from the exhaust. This hadn't happened for a while before my engine let go, so this wasn't related to it. From a bit of research & the symptoms of them, chances are it's the standard coilpacks causing this to happen.

But this NEVER happened after I had been driving it a while, only in the first 5-10 under mild acceleration.

[Endless604]

i am having the exact same problem...

only under WOT and at high rpm, it starts popping like im bouncing off a rev limiter, very rapidly, it almost sounds like popcorn popping. my sparkplugs are new/gapped...this is pissing me off