downpipes+no tune= blown cylinder head and fried spark plugs?

[BPe90M3]

just spoke to some who said I was "crazy" for running downpipes in my car. he said downpipes led to a blown cylinder head and fried spark plugs. I'm not an engineer, nor am I an expert in automotives, but I have owned 2 other turbo cars in my life and have never heard anything like this. how can increase exhaust flow blow a cylinder head or spark plugs? just curious.

[BIGW0RM]

Originally Posted by BPe90M3

just spoke to some who said I was "crazy" for running downpipes in my car. he said downpipes led to a blown cylinder head and fried spark plugs. I'm not an engineer, nor am I an expert in automotives, but I have owned 2 other turbo cars in my life and have never heard anything like this. how can increase exhaust flow blow a cylinder head or spark plugs? just curious.

From my Subaru STI days, you NEVER added a DP without a tune. Nor did you EVER run a OTS tune (Cobbs OTS accessport tunes were ok though). If you added a DP, you HAD to get a tune or you would eventually get KAAAABOOOM!


I frankly find it CRAZY that we M3/M4 owners run OTS tunes and dont have custom tunes for DP's. But everyone keeps telling me our cars computers are much more advanced than your typical car so its ok.

I personally would not run a DP without a protune. But thats just me.

I do however think the NA OTS tune for the E9X M3 is ok though.

[TeKiZeRo]

Originally Posted by ILSMKU

From my Subaru STI days, you NEVER added a DP without a tune. Nor did you EVER run a OTS tune (Cobbs OTS accessport tunes were ok though). If you added a DP, you HAD to get a tune or you would eventually get KAAAABOOOM!


I frankly find it CRAZY that we M3/M4 owners run OTS tunes and dont have custom tunes for DP's. But everyone keeps telling me our cars computers are much more advanced than your typical car so its ok.

I personally would not run a DP without a protune. But thats just me.

I do however think the NA OTS tune for the E9X M3 is ok though.

That would make sense for the STi/Evo, because the stock ECU doesn't read AFR so it can't compensate for the engine becoming leaner with downpipes. This is why you have to tune it to add more fuel, to make it more rich. The M3/M4 is different and the ECU will compensate and change the AFR so its within safe limits.

[Mike@N54Tuning.com]

Originally Posted by TeKiZeRo

That would make sense for the STi/Evo, because the stock ECU doesn't read AFR so it can't compensate for the engine becoming leaner with downpipes. This is why you have to tune it to add more fuel, to make it more rich. The M3/M4 is different and the ECU will compensate and change the AFR so its within safe limits.

+1

People have been running downpipes on stock BMW turbo cars since 2007 without any such issues. Most have tunes but I have had a lot of customers with just downpipes and no tunes over the years. Never any issues, other then the CEL from the missing cats.

Mike

[VCP]

That should not be.

[BPe90M3]

besides what ilsmku said, I am in agreement with you all. however, I used to own an Evo with cat less test pipe and although I had a tune for most of its life, I never had any issues when it was untuned. on the other hand, if you add an intake,leaning out the fuel will pose a serious threat. just my 2 cents. thanks for all the responses.

[TeKiZeRo]

Originally Posted by BPe90M3

besides what ilsmku said, I am in agreement with you all. however, I used to own an Evo with cat less test pipe and although I had a tune for most of its life, I never had any issues when it was untuned. on the other hand, if you add an intake,leaning out the fuel will pose a serious threat. just my 2 cents. thanks for all the responses.

The Evo runs pretty rich from factory though, so its fine to add some parts to it. The STi runs leaner from factory and I guess its for emissions purposes -- which is why you hear stories of them with blown motors with an intake or exhaust.

[BIGW0RM]

IMO, I wouldnt want a CEL and I wouldnt want to leave any power on the table either so I would get the tune if it was me.

[Turbo_435i]

Do it, add DP and report back after 10 WOT pulls.

[TeKiZeRo]

Originally Posted by ILSMKU

IMO, I wouldnt want a CEL and I wouldnt want to leave any power on the table either so I would get the tune if it was me.

What tune are you talking about? A piggyback isn't really a tune that tailors to mods. There are some ECU flashes out, but no one has really posted any solid data on it yet.

[BIGW0RM]

Originally Posted by TeKiZeRo

What tune are you talking about? A piggyback isn't really a tune that tailors to mods. There are some ECU flashes out, but no one has really posted any solid data on it yet.

To be honest I have no clue what's out or isn't. I was simply sharing my STI experience and my own personal views on what I'd do. I'm still happily in a e92 m3.

[BPe90M3]

Originally Posted by TeKiZeRo

The Evo runs pretty rich from factory though, so its fine to add some parts to it. The STi runs leaner from factory and I guess its for emissions purposes -- which is why you hear stories of them with blown motors with an intake or exhaust.

this is true but adding a true CAI will dangerously lean it out. 9 of 10 times nothing would happen but it's still not ideal

[BPe90M3]

Originally Posted by schybrid

Do it, add DP and report back after 10 WOT pulls.

LOL. I've been running downpipe and no tune for 7 months with not a single issue so not sure what your point is

[Mike@N54Tuning.com]

Originally Posted by BPe90M3

LOL. I've been running downpipe and no tune for 7 months with not a single issue so not sure what your point is

+1

You and many others.

Mike

[Siciliano611]

Get these former STI/EVO guys off the forum, 99% of the time they spew ignorant nonsense

[BIGW0RM]

Originally Posted by Siciliano611

Get these former STI/EVO guys off the forum, 99% of the time they spew ignorant nonsense

Simmer down. No one here spewed anything ignorant other than you.

Like I said in my original post. I was told it's ok. But I personally wouldn't do it because of the CEL and power left on the table.

You're comment makes you sound like the typical BMW elitist douche. Grow up. We're having a civil conversation about our experiences which may or may not give the OP a piece of mind.

What did you offer? ...exactly.

[mike@x-ph.com]

On a BMW you will not have any problems running DP without a tune.
It is just a waste of money.

[pikkagtr]

Originally Posted by Siciliano611

Get these former STI/EVO guys off the forum, 99% of the time they spew ignorant nonsense

I think when you generalized that about former sti/evo owners,
You're the one spewing ignorant nonsense

[48Laws]

Originally Posted by schybrid

Do it, add DP and report back after 10 WOT pulls.

[48Laws]

Originally Posted by Siciliano611

Get these former STI/EVO guys off the forum, 99% of the time they spew ignorant nonsense

I've owned 2 STIs and I can assure both of those communities are some of the most knowledgable, helpful of all car enthusiasts. And I guarantee majority of them track on the regular. Stop being that way.

[tareemaa]

If sti don't monitor A/F and you began to run lean, yes you will detonate and blow your motor, I don't that's the case in these or even the n54s. Just got my dps installed last week, the car is very different with them on, in a very good way 😎

[BPe90M3]

Originally Posted by mike@x-ph.com

On a BMW you will not have any problems running DP without a tune.
It is just a waste of money.

thanks for the response, but how is it a waste? faster spool up, much better sound, and gains are there EVEN WITHOUT A TUNE. did are before and after race with are e92 and it's obvious that even without a tune the DPs added, at a minimum, 10-15 horse and more torque.