[smdandb2]

So here it is. I am not a scientist, so I may call things wrong.

I'm not drawing a bunch of lines. Just plotting points and connecting some dots.

What Nick said above is correct. Its all math, but some assumptions were made. The VE is a variable for sure, but BMW documents show a VE that can be as high as +100% on the N54 (I'm glad I know people). I worked mostly with a 90% VE though. I did one plot of 94% VE, and you can see how it just makes the situation worse if you are trying to justify running them that high.

I put all the calculations on the image, so you can check my work if you want.

One thing that is getting disputed is the stock IC efficiency. Guess what? BMW has a map for this in MSD80/81. They tested it, and mapped it. Looking at multiple points (such as what Nick did) you can generate some equations to figure it out thru various PRs. Maybe BMW was off, but the fact remains there is SOME pressure loss.

But, I just stuck with 2psi drop thru the WHOLE system. Feel free to check my math and do a 3psi drop, its hilarious!

It's math, not rocket science.

[NickG_TechniqueTuning]

Originally Posted by smdandb2

One thing that is getting disputed is the stock IC efficiency. Guess what? BMW has a map for this in MSD80/81. They tested it, and mapped it. Looking at multiple points (such as what Nick did) you can generate some equations to figure it out thru various PRs. Maybe BMW was off, but the fact remains there is SOME pressure loss.

But, I just stuck with 2psi drop thru the WHOLE system. Feel free to check my math and do a 3psi drop, its hilarious!

It's math, not rocket science.

One thing you have to remember is that the pressure drop from turbo to intake manifold will NEVER be a constant, but will ALWAYS rise exponentially as a function of airflow. This isn't my opinion, but plain old physics (ie, fact) that cannot be disputed or ignored. I've flowtested many intercoolers and pipes in the design of my BMW turbo kits, and know how to predict, or rather calculate, the pressure drop of a system on the car as a result of the flowbench data.

[NickG_TechniqueTuning]

Originally Posted by A418t81

Couple issues with above:

1. Your calculations make some assumptions that aren't true. The main one being that N54s run anything more than about 10-11 psi at 6500 rpm. Boost ramp down after 6k is precipitous regardless of what it was prior to 6k. Figure 17 psi at 6k, but even that is pushing it. Most 17 psi power runs tend to make peak power at around 5500 rpm, if on 100+ octane and basic supporting mods = ~410 whp, give or take 10 whp.

Many people have documented 13psi of boost above 6000rpm on these engines with piggybacks and non-stock software. Just a few posts before this one is a prime example. So my example of 13psi in the intake manifold is very much valid.

2. Most running that amount of boost are going to aftermarket intercoolers that are looking at 1-1.5 psi of pressure drop at MOST at those flow values (~42 lb/min). That's hardly the ~5 psi you are using. Frankly, I don't agree with the nearly 3 psi pressure drop across the IC at stock boost pressures that you are figuring either, and neither does the pressure testing data that has been carried out on the stock IC vs. upgraded ones as far as before and after comparisons.

The pressure drop from turbo to intake is not just dependent on the intercooler, but also the pipes connecting everything together. You have to think of it as a *system* of parts. And just cause you don't agree with my numbers, doesn't make them wrong. My numbers are based on BMW's design figures and physics, both implemented using simple math. If you have actual test data to refute it, then by all means post it. But saying *you think* something is wrong, but not being able to back up your statement with simple math or documented testing, won't get you too far

[Rob@RBTurbo]

In the chart I posted, of which I wanted the demand lines plotted over the 10T compressor map... it also shows what you speak of. That is a rising compressor outlet PR to make up for the increasing system losses.

[A418t81]

SMB, I agree with your plot, looks totally reasonable and around ~38 lb/min at ~112F with PR loss of the system (which I am well aware of.)

You guys can calculate and graph all day long, but the results speak for themselves. Up to around 15 psi of boost, the N54 gains between 12-15 whp. That is impressive. This means regardless of the math, that the entire system still has quite a bit of headroom before flow starts becoming a problem for the smallest "bottleneck" which appears likely to be the hotside. I used to do the same thing back when I was relatively new to this, and would not consider notions because the math wasn't spot on. That's how you go slow. The innovators get their noses out of the books and calculators and actually test things in real life.

Anyway, I leave you with this. Many of us owned chipped 1.8Ts at some point the past. Its been proven without a shadow of a doubt that chipped cars have great turbo reliability. Many of them going well over 100k miles on the stock turbo. Chipped cars run nearly 20 psi in the midrange, tapering to 12-ish up high (around 6k).

Here is the standard K03 mapped for the 1.8T with completely reasonable VE (90%) and 12 psi. These turbos make 40-50% more power at the wheels than the compressor map is even mapped out to....and they last. I have no doubt that the Mitsus will be similar and early data supports this, IMO.



OMG, what were the tuners thinking? There's no way that turbo can support that flow and last, etc, etc, etc. It has, and it does...and does it well. Enjoy.

[smdandb2]

And when you blow it up, the repair is how much?

Thats part of the dispute/discussion here. The price to pay on replacement parts and labor.

Its funny, because I was in the VAG arena for a while. Saw lots of blown stock turbos with chips. Sure, some turbos fare better than others. But there was a fairly large amount of people replacing the stock K03s. In fact, I've done 2 on a 1.8T Passat since the guy bought it 2 years ago.

You will always have factory freaks. It happens.

We have seen turbo failures here, hell I found a thread earlier talking about premature failure running high boost on the 335s. I didnt read much into it though.

What it comes down to is, run the boost as HIGH AS YOU WANT IT. Be ready for BMW to prime their rubber penis when something fails.

[smdandb2]

If you ever hear that... you're screwed. Noise like that is NOT normal, despite what may have been said by other people here. That is a failure, waiting to happen. One of my cars is down right now waiting for a turbo replacement... bet you cant guess the noise its making?

[Prince ///M]

Originally Posted by smdandb2

Well, compressor maps have NOTHING to do with the safe limits of the engine.

Compressor maps are all about the turbos.

If you want to go "semantic" turbos are part of the engine... and their failure can harm also parts of the block, exhaust intake and so on.

BTW the calculations are quite similar to the one I posted...and I agree on the fact that over 13psi at 6500rpm are too much.

I think that calculations over 6500rpm are nonsense under the assuption we can realistically make (and this is the reason why I'm not considering boost to redline). Please consider that at 6500rpm DME starts to close throttle valve, so volumetric efficiency is hugely reduced, no matter the pressure ratio.

P.S.
The sound in the video you posted if for sure abnormal... but for "level" not for "kind". The same noise is present (barely noticeable) on several stock cars at turbo spool on light throttle between 1500 and 2500 rpm.

P.P.S.
Here on the board turbo failures are very, VERY rare... (maybe two in three years) and not always related to excessive boost.

[Bubbles]

Originally Posted by Prince ///M

P.P.S.
Here on the board turbo failures are very, VERY rare... (maybe two in three years) and not always related to excessive boost.

Only 2! It's more than 2. I'm rocking a pair of replacement turbos.

[Prince ///M]

Originally Posted by Bubbles

Only 2! It's more than 2. I'm rocking a pair of replacement turbos.

So, also Dinan tuning is too much for the turbos?

[Bubbles]

Originally Posted by Prince ///M

So, also Dinan tuning is too much for the turbos?

Maybe--- throwing out the statement that only 2 turbos have failed isn't accurate.

[smdandb2]

Originally Posted by Prince ///M

If you want to go "semantic" turbos are part of the engine... and their failure can harm also parts of the block, exhaust intake and so on.

You specifically said the safe limits for the engine, not the turbos. Yes, a turbo failure COULD damage the engine, but at the same time it could simply turn into a smoke factory. The engines safe limits are unknown right now, and no stock compressor map is going to tell you where that is. A bad spark plug could damage the engine too, but there is no map for that. One day someone could make 800hp on a big single on the N54, we just don't know yet.

BTW the calculations are quite similar to the one I posted...and I agree on the fact that over 13psi at 6500rpm are too much.

I think that calculations over 6500rpm are nonsense under the assuption we can realistically make (and this is the reason why I'm not considering boost to redline). Please consider that at 6500rpm DME starts to close throttle valve, so volumetric efficiency is hugely reduced, no matter the pressure ratio.

Its all assumptions at this point. You assume one way, I assume the other. Even at 6500rpm, its off the charts at a 90% VE. And a 90% VE is probably on the low side for the N54.

P.S.
The sound in the video you posted if for sure abnormal... but for "level" not for "kind". The same noise is present (barely noticeable) on several stock cars at turbo spool on light throttle between 1500 and 2500 rpm.

Its bad, especially at that volume. There is no way that is acceptable.

P.P.S.
Here on the board turbo failures are very, VERY rare... (maybe two in three years) and not always related to excessive boost.

Seems as if someone else has already chimed in there.

And as someone else said in another thread I was reading... what good would it be for anyone who has had any catastrophic failure to go reporting it here? Makes no sense at all.

[Prince ///M]

Originally Posted by smdandb2

You specifically said the safe limits for the engine, not the turbos. Yes, a turbo failure COULD damage the engine, but at the same time it could simply turn into a smoke factory. The engines safe limits are unknown right now, and no stock compressor map is going to tell you where that is. A bad spark plug could damage the engine too, but there is no map for that. One day someone could make 800hp on a big single on the N54, we just don't know yet.



Its all assumptions at this point. You assume one way, I assume the other. Even at 6500rpm, its off the charts at a 90% VE. And a 90% VE is probably on the low side for the N54.



Its bad, especially at that volume. There is no way that is acceptable.



Seems as if someone else has already chimed in there.

And as someone else said in another thread I was reading... what good would it be for anyone who has had any catastrophic failure to go reporting it here? Makes no sense at all.

Maybe I have problems in writing correct english (I'm Italian).

Obviously I was meaning with the word "engine", "the part of the engine called TURBO" (semantic...).
I think that here almost everyone knows what a compressor map indicate.

For the rest of your post I can't see any reason for hiding a turbo failure... unsless Shiv is payng for that (and I do not think that is the case ).

I agree with you for the sound (I already said that).
But the problem is the "volume", not the kind of noise.

[NM_BMW]

Originally Posted by smdandb2

If you ever hear that... you're screwed. Noise like that is NOT normal, despite what may have been said by other people here. That is a failure, waiting to happen. One of my cars is down right now waiting for a turbo replacement... bet you cant guess the noise its making?

Sounds like a police siren. The audio isn't that great in the video, but I'm sure that is REALLY loud in person.

[HEY32G]

Could someone just tell me, a stupid bond trader, how much more horsepower I could safely get out of my engine without causing any damage? I know that's the unknown right now, but does some level headed person have a feeling what that number is? And please compare it to the stock 300 that it came with whether that's at the flywheel or at the wheels.

Btw, I've enjoyed reading the posts and some of you guys know your stuff. I'm the most unmechanical person in the world.

Thanks.

[A418t81]

Originally Posted by smdandb2

And when you blow it up, the repair is how much?

Thats part of the dispute/discussion here. The price to pay on replacement parts and labor.

Its funny, because I was in the VAG arena for a while. Saw lots of blown stock turbos with chips. Sure, some turbos fare better than others. But there was a fairly large amount of people replacing the stock K03s. In fact, I've done 2 on a 1.8T Passat since the guy bought it 2 years ago.

You will always have factory freaks. It happens.

We have seen turbo failures here, hell I found a thread earlier talking about premature failure running high boost on the 335s. I didnt read much into it though.

What it comes down to is, run the boost as HIGH AS YOU WANT IT. Be ready for BMW to prime their rubber penis when something fails.

I worked for APR, there were hardly any reports of blown turbos. I have also had 3 tuned 1.8Ts in the family, all with 50K+ miles of chipped "abuse." They were all fine. I have 3-4 friends with chipped 1.8Ts with mileage in the 70k+ range, they are all fine. There is not that much mention of turbos failing on vortex. There will be turbos to fail, but some will fail regardless of boost. Your guy replacing two in a year or two is doing something wrong, or maybe you are during installation. Are you replacing the feed line every time?

Regardless, APR has become a premier engineering house, and works directly with VAG/VW racing. They see fit to run those turbos that far off the map, and call them reliable. If there were a significant issue with this, it wouldn't have been done. In fact, there is not a SINGLE 1.8T tuner that lives anywhere close within the confines of the compressor map.

Finally, cost is a consideration, but with BMW stuffing the N54 in every car they make, and with aftermarket turbo solutions looming the horizon, I don't feel it will be that much of an outlay in the future to pick up some stock replacements. Hell, people already occasionally find them in perfect condition for $200 on ebay.

One other point I wanted to make, but forgot about, is that I feel the hotside is more of a bottleneck than the cold side. I think that as compressor flow nears peak mapped flow, the hotside is already a bit closer to nearing peak flow, and is negatively impacting the VE of the system. This obviously would dec the CFM the compressor would need to flow at higher PRs in relation to the math above as preturbine pressures (even post turbine pressures in cars with stock DPs) increase, especially in the 6k+ region.

[Remonster]

Originally Posted by GH32335i

Could someone just tell me, a stupid bond trader, how much more horsepower I could safely get out of my engine without causing any damage? I know that's the unknown right now, but does some level headed person have a feeling what that number is? And please compare it to the stock 300 that it came with whether that's at the flywheel or at the wheels.

Btw, I've enjoyed reading the posts and some of you guys know your stuff. I'm the most unmechanical person in the world.

Thanks.

First off the stock horsepower rating is supposed to be 300 at the crank at 5,800RPM, based on dyno tests of the 335i and figuring typical drivetrain losses this engine is actually under rated and probably makes 330 or more horsepower at the crank.

If you're worried about damage to the car, as any sane person would be, and assuming you have the money why not get the Dinan tune? It's covered by their own warranty so you won't live in fear of some catastrophic failure. Compared to the other tunes available, Dinan's is fairly conservative and seems well suited for reliability and longevity while the other tuners seem to be after 1/4 mile times and power to the wheels now. The reliability of the N54 at increased boost is still an unknown since it has only been on the market for two years, it'll be after a few more years after people have dealt with blown turbos, cracked heads, broken rods etc. that we will really know what a safe boost level is.

Tuning is a gamble, it always has been. If you absolutely can not risk damaging your car maybe you should leave it stock, but as long as you understand that it COULD break and possibly cost a lot of money to fix and are able to deal with that possibility then there is a lot of power to be found in this engine.

[sd390r]

Originally Posted by A418t81

I worked for APR, there were hardly any reports of blown turbos. I have also had 3 tuned 1.8Ts in the family, all with 50K+ miles of chipped "abuse." They were all fine. I have 3-4 friends with chipped 1.8Ts with mileage in the 70k+ range, they are all fine. There is not that much mention of turbos failing on vortex. There will be turbos to fail, but some will fail regardless of boost. Your guy replacing two in a year or two is doing something wrong, or maybe you are during installation. Are you replacing the feed line every time?

Regardless, APR has become a premier engineering house, and works directly with VAG/VW racing. They see fit to run those turbos that far off the map, and call them reliable. If there were a significant issue with this, it wouldn't have been done. In fact, there is not a SINGLE 1.8T tuner that lives anywhere close within the confines of the compressor map.

Finally, cost is a consideration, but with BMW stuffing the N54 in every car they make, and with aftermarket turbo solutions looming the horizon, I don't feel it will be that much of an outlay in the future to pick up some stock replacements. Hell, people already occasionally find them in perfect condition for $200 on ebay.

One other point I wanted to make, but forgot about, is that I feel the hotside is more of a bottleneck than the cold side. I think that as compressor flow nears peak mapped flow, the hotside is already a bit closer to nearing peak flow, and is negatively impacting the VE of the system. This obviously would dec the CFM the compressor would need to flow at higher PRs in relation to the math above as preturbine pressures (even post turbine pressures in cars with stock DPs) increase, especially in the 6k+ region.

[smdandb2]

Originally Posted by A418t81

I worked for APR, there were hardly any reports of blown turbos. I have also had 3 tuned 1.8Ts in the family, all with 50K+ miles of chipped "abuse." They were all fine. I have 3-4 friends with chipped 1.8Ts with mileage in the 70k+ range, they are all fine. There is not that much mention of turbos failing on vortex. There will be turbos to fail, but some will fail regardless of boost. Your guy replacing two in a year or two is doing something wrong, or maybe you are during installation. Are you replacing the feed line every time?

Regardless, APR has become a premier engineering house, and works directly with VAG/VW racing. They see fit to run those turbos that far off the map, and call them reliable. If there were a significant issue with this, it wouldn't have been done. In fact, there is not a SINGLE 1.8T tuner that lives anywhere close within the confines of the compressor map.

Finally, cost is a consideration, but with BMW stuffing the N54 in every car they make, and with aftermarket turbo solutions looming the horizon, I don't feel it will be that much of an outlay in the future to pick up some stock replacements. Hell, people already occasionally find them in perfect condition for $200 on ebay.

One other point I wanted to make, but forgot about, is that I feel the hotside is more of a bottleneck than the cold side. I think that as compressor flow nears peak mapped flow, the hotside is already a bit closer to nearing peak flow, and is negatively impacting the VE of the system. This obviously would dec the CFM the compressor would need to flow at higher PRs in relation to the math above as preturbine pressures (even post turbine pressures in cars with stock DPs) increase, especially in the 6k+ region.

And youre spot on, to a point.

You read on these forums, and its warranty this and warranty that.

You make it sound like no one gives a shit about the warranty. If thats the case, hell yeah crank the boost up. That has always been the underlying tone of my argument.

If you dont give a flying shit about your warranty, thats the way to go.

Here is a scenario to ponder...

Say Joe Schmoe has a 335i. He has been running with a box since his car was new. At 30k, his car starts to shown signs of turbo failure. So instead of risk going to BMW to have them replaced, he picks up some stock ones for $200 and has someone install them. A year later, something catastrophic goes wrong. He takes off the mods and goes to BMW. In their inspection, they can see signs the turbos have been tampered with (could be something as simple as wrenching marks on one bolt). Whole powertrain warranty is toast.

You shouldnt be running shit on the ragged edge and expect BMW to pick up the tab. And as long as this keeps happening, expect the anti tune measures in the software to increase along with the scrutiny of the techs when ANY service is being done.

[smdandb2]

Like I said, I did not want to go in to this because someone always thinks they know better.

So I'm done with this. The chart is there, people can figure the data out on their own.

[Zeph]

Originally Posted by smdandb2

Like I said, I did not want to go in to this because someone always thinks they know better.

So I'm done with this. The chart is there, people can figure the data out on their own.

I agree with you, if you run the turbo melter tune and ruin your turbos then you shouldn't try to cover it up and expect BMW to fix it for free. But I also know that the tunes/mods don't always cause the problems. If your HPFP goes out, that is a known bad part. You take off your mods and yes you should expect BMW to cover it. Sad part is that you have to take your mods off ONLY because BMW will do "wrong" and try to screw you over. So, unfortunately, it goes back to the game we all have to play. In a perfect world everyone would always do the right thing, but anyone whose been around the block a while knows that will only get you sh*t on daily.

[scottp999]

Originally Posted by Zeph

I agree with you, if you run the turbo melter tune and ruin your turbos then you shouldn't try to cover it up and expect BMW to fix it for free. But I also know that the tunes/mods don't always cause the problems. If your HPFP goes out, that is a known bad part. You take off your mods and yes you should expect BMW to cover it. Sad part is that you have to take your mods off ONLY because BMW will do "wrong" and try to screw you over. So, unfortunately, it goes back to the game we all have to play. In a perfect world everyone would always do the right thing, but anyone whose been around the block a while knows that will only get you sh*t on daily.

and the fuel pump is not that expensive and should not be real hard DIY. So you can weigh all the work of returning to stock vs. the around $300 cost and labor to do it yourself. Sorry