[Lane]

Originally Posted by 5soko335i

Boostnation:
the 335i is a pretty solid car in gerneral stock, if your scared lean back on the tunes and PSI, take the filter out and that downpipe out aswell. i guess you do have a boost gauge to monitor things. you seem to have a pretty heavy modded car, if you are concerned go to a light tuned n54.


another question while this is on the topic, i was reading on another forum that sstt and JB's dont have boost spikes or the car would limp if there was any?why does the v2 have boost spike?

Does stock boost control use TPS-input? That might explain the difference. If not, then other tunes spike somewhat as well, but those with less boost have lighter spikes.
I would just adjust UTs rather than remove supporting mods.

[5soko]

Originally Posted by Lane

Does stock boost control use TPS-input? That might explain the difference. If not, then other tunes spike somewhat as well, but those with less boost have lighter spikes.
I would just adjust UTs rather than remove supporting mods.

your guess is as good as mine. im just trying to grasp and understand, from what i did read, there are some boost spikes even stock? but when they become to a certain extent, the car goes into limp mode? something using the closed loop system and stock taper system i was reading aswell, cant find the exact quote at the moment. i know the SSTT uses all the OEM safety features and uses the cars OEM high altitude mode to make power, which might be why the computer tapers the boost off and wont alot excssive boost spikes, not sure how the jb products do it or why the PROcede is different, but looks like u can set how the PROcede tapers boost off.

[V1.47fan]

Originally Posted by shiv@vishnu

I really appreciate the time you took to write this. However, some of the info that you have provided (especially in point 3) is [unintentionally i'm sure] misleading. I'll elaborate later tonight. Gotta run some errands right now...

Cheers,
shiv

I agree.

[V1.47fan]

I have a question,if you keep boost at no more than 13psi,will less back pressure from a less restrictive exhaust setup make the turbos work harder?I have an E90 335i,I was thinking about a less restrictive catback exhaust.
Also Is the E92's exhaust system less restrictive than the E90's?

[e.n335]

Originally Posted by V1.47fan

I have a question,if you keep boost at no more than 13psi,will less back pressure from a less restrictive exhaust setup make the turbos work harder?I have an E90 335i,I was thinking about a less restrictive catback exhaust.
Also Is the E92's exhaust system less restrictive than the E90's?

A less restrictive exhaust will not make to work the turbos harder, the opposite will be the case. The e90 and e92 exhausts seem to be equal restrictive, the e90 has a resonator which the e92 doesn't have, but the resonator does not seem to be restrictive at all ( you can look through it ).

[Craigito]

If the packing peanut theory is right....what can you say...most expensive peanut in history

What surprises me is RIGHT after you throw a new mod on the car you would "stab" it? I know on stuff i've done on other cars, I take it pretty easy and slowly get more aggressive. Like breaking in a new engine. I don't know if "stab" means WOT or not, but why wouldn't you take it slow at first?

If it was a foreign object, you we'e toast the minute you installed it so I know it's kind of a moot point. Sorry to the OP...what a headache.

[bmwzimmer]

I witnessed a catless downpipe install and there were defintely peanuts inside the pipes. The tech had to use a air hose to get them out. Worse case scenario for downpipes, a couple peanuts in there would just melt onto your secondary cats and possibly over your o2 sensors. Those peanuts are very static and need to be CAREFULLY removed and pipes need to be clean...

[O-cha]

Originally Posted by trueblue

Simplified Turbo control 101:
MAP sensor reading -> ECU -> Injector Duty
^ |-> Waste Gate --|
|------------------------------------------------------|

This is turbo control in the simplest form. The MAP sensor provide the manifold pressure readings to the ECU, the ecu find the appropriate injector(s) output from the fuel/ignition map for that particular pressure and moves the wastegate to maintain the given pressure.

All this is done under a few fixed conditions.
1. The flow restrictions is constant (stock cats etc.)
2. The intake restriction is constant (stock airbox, IC etc.)
3. Maximum turbo control delay <= Max inj output delay

When you add a box to fool the ecu and intake and exhaust, you have pretty much altered all 3 basic premiss.

1. The exhaust restriction is now removed. On a NA car this would provide more hp at high rpm range because of lowered back pressure, the engine would actually accelerate faster. But on a turbo charged car the exhaust is the source for controlling the turbo it self, and changing the flow characteristic means that the wastegate open/close function curve is now wrong. Free flow exhaust on ANY turbo charged car will cause boost spikes and creeps. Both boost controller and wastegate itself are usually replaced in order to counter act this change. Left unchecked, the turbo WILL fail prematurely.
2. Not as detrimental as free flowing exhaust the changes in the intake will also change the turbo spooling characteristics. It's simple, the turbo is designed to spin at certain rpms giving the pressure encountered at both the turbine and compressor wheel, you lower the pressure on either side guess what?
3. "Tuner Boxes" no matter how good is a signal interceptor. By adding an additional electronic device that has to change the intercepted signal WILL add delay to the signal. Someone will probably jump up and down at this point and scream "but it's only milliseconds", let me save you the trouble by just saying the turbo spins over 4000 revs per second, a boost spike happens faster than you can blink. This delay in it self is just a small part of the picture, the whole idea is to "fool" the ecu into thinking everything is still functioning within the designed parameter so in essence everything in the control loop mentioned before has been altered. The ecu no longer sees the real manifold pressure, the output to the wastegate has been altered, the injector duty has been altered. Mathematically it is just changing the in/out signal by altering the intercept (basic trig, Y=mX+b, m=slope, b=intercept). The BIG problem occurs when you consider that making changes to the flow characteristics (as described in 1,2) will cause spike and creep from the STOCK boost level (spinning at STOCK rpm), what do you think the spike and creep will hit when you are boosting at TWICE the stock boost level. This is the reason why ALL high hp tuner cars must use standalone ecu (in most cases are even faster than the stock ecu), NOT piggybacks.

All things mechanical has a MTBF, any moving component (especially something that moves as fast a turbo) will be subject to stress. By making it move faster you WILL increase the stress and reduce the MTBF, this is a giving. People's lack of understanding when it comes to providing the proper support mod for ANY given power mod will send many more of these great cars to the junk yard in the years to come.

What you have said applies to some car, hell not even the majority. But it does not apply to this one for sure.

[Bubbles]

Originally Posted by O-cha

What you have said applies to some car, hell not even the majority. But it does not apply to this one for sure.

I'm O-cha and I approve this message.

[O-cha]

I think he used to drive a Subaru, In fact I'll put money on it.

[T Bone]

I look forward to Shiv's response..... It would be a great feat to diagnose a turbo failure to a foam peanut...by phone

[O-cha]

Originally Posted by e.n335

If I would buy a Z4M I would add a supercharger or turbos and in such a case, the N54 is the better engine.

How many N54 engines do you know that put a daily 470 to the wheels in durations of years 100% reliably?(not an exaggeration)

[e.n335]

Originally Posted by O-cha

How many N54 engines do you know that put a daily 470 to the wheels in durations of years 100% reliably?(not an exaggeration)

Well, add "for me." to what you quoted. Then you are right and it's ok again .

[hotrod182]

Originally Posted by T Bone

I look forward to Shiv's response..... It would be a great feat to diagnose a turbo failure to a foam peanut...by phone

Whether or not Shiv is right or wrong, who knows. But either way, there is a lot of useful information here for the whole N54 community. Bottom line is to be aware of the complex scenarios that can occur out seemingly simple situations. You never know if the turbos may have already been compromised through high boost spikes/etc, and then they were finally pushed over the edge. Regardless of it being the tune, or the intake "peanuts" , bottom line is it probably wasn't a factory defect that caused it, and therefore there wasn't warranty coverage afforded. I really feel bad that the poor guy had to be one of the ones with a costly failure.

[Bubbles]

Originally Posted by T Bone

I look forward to Shiv's response..... It would be a great feat to diagnose a turbo failure to a foam peanut...by phone

T Bone want proof, here's your proof.

[OpenFlash]

Originally Posted by who's ur daddy?

Wow just wow if the cause were a packing peanut...

lol.. it wouldn't have been a first. However, the owner of the car just called me to tell me that he remembers the ends of the pipe were taped off so no peanuts could get in there. So i'm back to the notion that something got in there during installation. Easy to do unless you are careful (put rags in the intake pipe as soon as you get the airbox off, clean the inside of the tube of machining grit, etc,.) I've been known to cut some corners myself so I've just been pretty lucky.

shiv

[OpenFlash]

Originally Posted by T Bone

I look forward to Shiv's response..... It would be a great feat to diagnose a turbo failure to a foam peanut...by phone

Peanut or something else... something got in there when the intake was installed. The fact that he didn't even get far down the street until the rear turbo suddently failed catastrophically (the first time got on boost after the install) adds quite a bit of credence to this theory.

Shiv

[cn555ic]

holy shit...Thank god thats the first thing I did when I installed my intake and DV's was to make sure it was clear of packaging peanuts and debris from the intake pipes!!! I think I would have shitted on myself if this happened to me...Damn that sucks balls

[T Bone]

Originally Posted by shiv@vishnu

Peanut or something else... something got in there when the intake was installed. The fact that he didn't even get far down the street until the rear turbo suddently failed catastrophically (the first time got on boost after the install) adds quite a bit of credence to this theory.

Shiv

I guess my intake and stock ECU is OK after running it for a week then??

That would suck if it was the foam peanut caused the failure..... It doesn't even cost one cent. Probably 1/50 of a cent.

I have always wondered how reliable those drag cars are with the exposed impeller blades....

[scalbert]

Originally Posted by trueblue

(basic trig, Y=mX+b, m=slope, b=intercept).

Correction, the linear equation is basic Algebra.

[theDude]

Originally Posted by e.n335

A less restrictive exhaust will not make to work the turbos harder, the opposite will be the case. The e90 and e92 exhausts seem to be equal restrictive, the e90 has a resonator which the e92 doesn't have, but the resonator does not seem to be restrictive at all ( you can look through it ).

Right, but doesn't a less restrictive situation increase the possibility of boost spikes? and a boost spike does make the turbo 'work harder'...err faster.

Just want to make sure I understand what I've been reading

[Robertbog]

Originally Posted by BALLAJL15

thanx for your guys concern... well first off I just joined the post after seeing a hug picture of my car at the dealer... And to all the ppl saying its a driver error... think again... I never ran high than 100 octane and my user torque settings were never over 92... so hers what happened... I was running perfect the the v2 and the dps... I put on the intake and it started up fine.. no turbo wine no noting... drove down the street stabed it and a HUGE wine came out... didnt know it was the turbos and just put the factory air box back on and it still had the massive wine... took it to a mechanic in Simi Valley and he said both turbos were deff gone then it was towed to the dealer... after taking off the cats and procede of course but I did leave my magnaflow muffler on thinking a muffler shouldnt void the warranty... and I was very wrong... wasnt even cat back just a muffler... they claim backpressure was reduced and thats what caused the turbo falure and now I have a 14g bill....

Im gonna stick with the driver error thing. You didnt have a boost gauge, and I really dont see a packing peanut being your issue. I honestly believe the issue is you were holding 22+psi and not realizing it, I wouldnt of without a gauge... Intake + DP's can definitely = 22psi, not having a boost gauge wasnt smart.