so apparently it is possible to get too much air

[justaddcoffee]

well, after repeated check engine lights for throttle position sensor failure, the dealer said they wanted to seriously look at the car because they couldn't keep the CE light cleared (even with a new TPS installed).

so here's their conclusion: with a cold air intake (eurosport), acs delete elbow, big bore throttle body (dinan), an m-50 manifold and either stock or conforti programming, you can actually flow so much air that the HFM will produce numbers above the expected paramaters for any given throttle position.

and blamo! you get a CE light.

now for me, i'm a bit of a perfectionist so CE lights bug the hell out of me. but the only options would seem to be a visit to nick g. or karl for a custom tune (because reinstalling the stock parts is not an option).

anyone else have a bright light bulb of an idea?

-scott.

[fsmtnbiker]

If that was the case, every turbo and blower car would be triggering a CEL at every blip of the throttle.

I have a hard time believing their diagnosis. How many miles on the car? Original oxygen sensors?

[paul e]

If that was the case, every turbo and blower car would be triggering a CEL at every blip of the throttle.



Not true! Ever wonder what the Dinan box labeled 'turbotronics-9' which sits between the HFM and the ECU is for? Ever heard of an 'HFM SCALER'? The max voltage the ecu can deal with coming off the HFM is 5v. Well, on many supercharged cars, 5 volts would be reached around 4000 rpms at wot. So, the purpose of the scaler, as you can probably guess from the context of this discussion, is to scale back the hfm signal, so that it doesnt go above 5v. Of course, the ecu must be rewritten to handle the revised voltages accordingly. One thing that switching to the Euro HFM does is so raise the amount of raw voltage acted upon before scaling is required, so that instead of hitting 5v near 4000 rpms, for example, it can perhaps reach 5300 rpms.. But, it still needs a scaler of some kind.

[justaddcoffee]

then i think i may have to look at that new turner kit with the bigger HFM, injectors and programming. i'll shoot them an email and see what air flow limts are. hmm, or maybe it's just time to go FI.:D

[fsmtnbiker]

Paul, I understand that they do other things to handle the airflow - But the statement that it was simply 'too much air' is not true - I would suspect another sensor fault or something like that to be the problem.

One question I'd have for Dinan (and others) is, why don't they just use an HFM that has the metering capacity to handle the airflow created by the supercharger/turbo? Instead of hindering the car with a too-low ceiling for airflow reading and then using a voltage modifier to band-aid the problem. One thing to keep in mind is that the HFM is still pegged at 5v at 4000 rpms, but the voltage modifier just sucks that voltage down - Effectively what this means is that the HFM is no longer in use and that the car is running off a pre-programmed table, regardless of air mass - the exact function of the HFM to measure. What this effectively leaves you with is a car that will run different AFRs at different temperatures and barometric pressures. Not exactly ideal.

[paul e]

Paul, I understand that they do other things to handle the airflow - But the statement that it was simply 'too much air' is not true - I would suspect another sensor fault or something like that to be the problem.

One question I'd have for Dinan (and others) is, why don't they just use an HFM that has the metering capacity to handle the airflow created by the supercharger/turbo? Instead of hindering the car with a too-low ceiling for airflow reading and then using a voltage modifier to band-aid the problem. One thing to keep in mind is that the HFM is still pegged at 5v at 4000 rpms, but the voltage modifier just sucks that voltage down - Effectively what this means is that the HFM is no longer in use and that the car is running off a pre-programmed table, regardless of air mass - the exact function of the HFM to measure. What this effectively leaves you with is a car that will run different AFRs at different temperatures and barometric pressures. Not exactly ideal.

Of course its not ideal.. but its not all that simple...
>>why don't they just use an HFM that has the metering capacity to handle the airflow created by the supercharger/turbo? <<

Thats the crux of the problem.. The problem isnt only the HFM; its the ECU as well. Its the 5v limit.. ECU wont read higher. Well, you might ask.. Why then dont the developers at Dinan, or elsewhere, change it in the ECU. Again, not that simple.. There are hard stops, limited data structures, and things that just cant be readily changed, without introducing all kinds of new problems.. Welcome to the frustrating world of BMW ECU programming, and why there are maybe 5 people in the country who can even do it at all! Hence, HFM signal scalers. There ARE some ECUs which you see used which Do produce a signal that can go to redline without surpassing 5v, so our ecu can use it.. theres a Porshe hfm which you see used which is one such remedy.

>>so here's their conclusion: with a cold air intake (eurosport), acs delete elbow, big bore throttle body (dinan), an m-50 manifold and either stock or conforti programming, you can actually flow so much air that the HFM will produce numbers above the expected paramaters for any given throttle position.
and blamo! you get a CE light<<

There IS a CEL code related to an HFM being out of load range, so they might have something there. However, that should be easy to determine, because if thats the case, the code will tell you that.

[Def]

Stock 3" HFM doesn't have much headroom, so you might in fact be maxing it out on occasion.

If it's a general code about fuel trim or something like that - you have a vacuum leak.


I'm more inclined to think vac leak.

[///M3///M5]

Are you running any kind of aftermarket SW?

[dinomite]

To find out for sure, reinstall your stock airbox, or somehow inhibit the air entering your filter by, say, duct taping a towel around it. Drive around for a few days and see if you stilll get a light; if so, then it's not "too much air."

[E36M3E]

well, after repeated check engine lights for throttle position sensor failure, the dealer said they wanted to seriously look at the car because they couldn't keep the CE light cleared (even with a new TPS installed).

so here's their conclusion: with a cold air intake (eurosport), acs delete elbow, big bore throttle body (dinan), an m-50 manifold and either stock or conforti programming, you can actually flow so much air that the HFM will produce numbers above the expected paramaters for any given throttle position.

and blamo! you get a CE light.

now for me, i'm a bit of a perfectionist so CE lights bug the hell out of me. but the only options would seem to be a visit to nick g. or karl for a custom tune (because reinstalling the stock parts is not an option).

anyone else have a bright light bulb of an idea?

-scott.

for any given throttle position??? that's the part that has got me stumped. you'd think that this wouldn't be a prob till WOT and the voltage limit of the meter had been reached?

I have heard that westcoast riots has had problems with their BBTB and the conforti software...I can't imagine why but I know a guy that works there and he claims that there may be issues with that combo - BBTB and conforti sw. but that's the riots TB not the dinan so I have no clue.

[saab guy]

From what I have gathered, using a blower or ram air does not help at all, it actually hurts you. The reaons is that "blowing air" into the intake actually causes turbulance which slows down the air being sucked in. You can't blow air in faster than the car naturally sucks in through the intake, apparently. Anyways, thats just what I have gathered from my forum, and this turbulance may only be true because I am turbo, but I am not sure. But either way, I'm pretty sure that a blower or a true cold air intake does not help you. Just my $0.02

[szumlins]

A blower does the same damn thing as your turbo more or less. Hop in a boosted car and take off the boost and tell me it hurts efficiency and performance.

You may have the info confused with an electric supercharger, which can't keep up the CFM at higher RPMs and actually starves the motor of air...

[saab guy]

A blower does the same damn thing as your turbo more or less. Hop in a boosted car and take off the boost and tell me it hurts efficiency and performance.

You may have the info confused with an electric supercharger, which can't keep up the CFM at higher RPMs and actually starves the motor of air...

I'm just saying that I have a boosted car, and wanted to add some tubing to bring more air to the filter and everyone i talked to told me not to because it would just add turbulance, thus hurting me performance wise...all im saying is that in my case it was not a good idea to try to artificially bring more air to the filter..thats all

[Bud Brown]

pull a homer simpson and stick some electrical tape over the CE.

[paul e]

From what I have gathered, using a blower or ram air does not help at all, it actually hurts you. The reaons is that "blowing air" into the intake actually causes turbulance which slows down the air being sucked in. You can't blow air in faster than the car naturally sucks in through the intake, apparently. Anyways, thats just what I have gathered from my forum, and this turbulance may only be true because I am turbo, but I am not sure. But either way, I'm pretty sure that a blower or a true cold air intake does not help you. Just my $0.02

Let me get this straight.. YOure saying that a supercharger causes less air to enter the manifold than normal induction? Is this what youre saying? Its hard for me to believe anybody could actually think this, so, please, let me know if IM misreading you.

[saab guy]

Let me get this straight.. YOure saying that a supercharger causes less air to enter the manifold than normal induction? Is this what youre saying? Its hard for me to believe anybody could actually think this, so, please, let me know if IM misreading you.

i dont know ANYTHING about superchargers, and i have an average knowledge on turbochargers....all im saying is that in MY case i was told that blowing extra air in any way to the intake would cause turbulane, which would not let the turbo spools as quickly...thats all lol dont look too much into what i said, i just wanted to let you know what my experience was about having too much air to the intake as the thread states in the title

[saab guy]

Let me get this straight.. YOure saying that a supercharger causes less air to enter the manifold than normal induction? Is this what youre saying? Its hard for me to believe anybody could actually think this, so, please, let me know if IM misreading you.

since you seem to know a lot about forced induction, any pointers? is it a good idea for me to use a ram air to get more ait to the intake?

[ParadigmGuy]

Let me get this straight.. YOure saying that a supercharger causes less air to enter the manifold than normal induction? Is this what youre saying? Its hard for me to believe anybody could actually think this, so, please, let me know if IM misreading you.
I think he's means some sort of a fan (blower), not a supercharger (blower). Either way, he clearly doesn't know what he's talking about.

[saab guy]

I think he's means some sort of a fan (blower), not a supercharger (blower). Either way, he clearly doesn't know what he's talking about.

how so? are you saying its good to have a blower? because I am referring to a turbod car...and no1 has yet to answer if it is bad to have a blower on a turbo....every single person i have talked to has said it is bad for the turbo

[ParadigmGuy]

since you seem to know a lot about forced induction, any pointers? is it a good idea for me to use a ram air to get more ait to the intake?
Yes, more air means more power as long as you can add more fuel to compensate for it.

[saab guy]

Yes, more air means more power as long as you can add more fuel to compensate for it.

ok, im just saying that only thing ive heard that it was bad because of the whole turbulation issue...thanks for correcting it

[paul e]

Ok... lets clarify some terms.. A 'Blower' is used to connote a Supercharger. The two have become interchangeable. Its not usually used to pertain to a Turbo, which to this day, is still a Turbo.

Now, with a Supercharger on our cars, the air enters the air filter, then the HFM, THEN it gets to the blower which speeds it up and fires it out undercompression to the intercooler, where the charge is cooled, and finally, it flows into the throttle body and the manifold. So, the air isnt 'blown' through the HFM; rather, its 'sucked' through it, if you will. Now, if there were this turbulence youre referring to, can you imagine what that would do to the HFM signal? It would render it totally useless. .. The ECU relies on a smooth voltage signal from the hfm, indicating MASS of air, ie, amount in weight, passing through the hfm, to know how much FUEL to order up via its voltage signal to the injectors. Turbulence in the HFM will destroy the operation of this system; it wont work. Everything is designed to Remove turbulence from the air flowing through the intake system. So, a properly designed supercharger, as well as a properly designed turbocharger, will do nothing to cause turbulence in the intake stream.

Now, as for ram air... ram air in our cars does NOTHING to increase power. However, thats not to say that its not beneficial to provide as much access to your filter via outside air, as is possible.

[fsmtnbiker]

Of course its not ideal.. but its not all that simple...

Thats the crux of the problem.. The problem isnt only the HFM; its the ECU as well. Its the 5v limit.. ECU wont read higher. Well, you might ask.. Why then dont the developers at Dinan, or elsewhere, change it in the ECU. Again, not that simple.. There are hard stops, limited data structures, and things that just cant be readily changed, without introducing all kinds of new problems.. Welcome to the frustrating world of BMW ECU programming, and why there are maybe 5 people in the country who can even do it at all! Hence, HFM signal scalers. There ARE some ECUs which you see used which Do produce a signal that can go to redline without surpassing 5v, so our ecu can use it.. theres a Porshe hfm which you see used which is one such remedy.

The 5v limit really isn't that big a problem - They make airflow meters that will read a lot more airflow than that while staying under 5v at peak - You just have to give the computer the new curve. You do lose a bit of low airflow resolution, but in my experience tuning with them it isn't even noticeable. For example, a stock 55mm meter on a SHO will meter up to 850 kg/hr @ 5v. The popular swap to an 80mm Lincoln Mark VIII bumps it up to 1168 kg/hr @ 5v. That's enough for a 6 psi blower car but not much more. The Lightning 80mm MAF is the next step up, at 1550 kg/hr @ 5v... Or enough airflow metering to support around 450 whp. If that isn't enough (a few guys are surpassing that level) there is the lightning 90mm with 1850 kg/hr metering... Considerably more than double the stock meter. This is all still using a stock ECU with a programmable chip (obd1).

I have a hard time believeing that BMW doesn't have an application with a higher capacity HFM somewhere... You mentioned the Porsche TT which would certainly be a good place to start, unless the car uses two HFMs in which case you're back to square one.

[paul e]

The 5v limit really isn't that big a problem - They make airflow meters that will read a lot more airflow than that while staying under 5v at peak - You just have to give the computer the new curve. You do lose a bit of low airflow resolution, but in my experience tuning with them it isn't even noticeable. For example, a stock 55mm meter on a SHO will meter up to 850 kg/hr @ 5v. The popular swap to an 80mm Lincoln Mark VIII bumps it up to 1168 kg/hr @ 5v. That's enough for a 6 psi blower car but not much more. The Lightning 80mm MAF is the next step up, at 1550 kg/hr @ 5v... Or enough airflow metering to support around 450 whp. If that isn't enough (a few guys are surpassing that level) there is the lightning 90mm with 1850 kg/hr metering... Considerably more than double the stock meter. This is all still using a stock ECU with a programmable chip (obd1).

>>I have a hard time believeing that BMW doesn't have an application with a higher capacity HFM somewhere<<

Its not just a higher capacity HFM which is needed; its an hfm which is scaled such that the entire airflow at wot for the given application to redline is 'conveyed' to the ecu under 5v.
I have a hard time believeing that BMW doesn't have an application with a higher capacity HFM somewhere... You mentioned the Porsche TT which would certainly be a good place to start, unless the car uses two HFMs in which case you're back to square one.

Believe it! The only way for you to know for sure is to have worked with one of the handful of tuners capable of rewriting the factory ECU. Now, IM not going to claim I have dissassembled our ecu instruction set, but ive learned enough from the man who rewrote my software to know that the 5v 'limit' is an ECU thing, and the reason companies like Dinan, RMS, and AA have all chosen to scale the signal down rather than rewrite the ecu to be able to read >5v is that it cant practically be done. YOu get into trouble as soon as you start making assumptions about OBDII M3s based on Fords, or any other cars.. BMW is a breed unto themselves, and OBDII can not be inferred from OBDI.

>>I have a hard time believeing that BMW doesn't have an application with a higher capacity HFM somewhere<<

Its not just a higher capacity hfm; its an hfm which can measure the given application's entire wot 7k airflow, and 'convey' it to the ecu in 5v or less.

[fsmtnbiker]

I understand the 5v limit - that is a limit that just about every car equipped with a Mass Airflow system has - But you can measure a whole lot of airflow with a 0-5v signal provided you can input the new HFM response curve into the computer. Since people can do it with the Euro HFM, I doubt there is any real roadblock to rewriting it to use just about any HFM out there. As I mentioned, there are many higher-metering capability HFMs out there. Its just a matter of finding one that is plug and play and that the response curve is known (which is typically the hardest part).

[mobil1]

I think he's means some sort of a fan (blower), not a supercharger (blower). Either way, he clearly doesn't know what he's talking about.


+1

[ParadigmGuy]

Ok... lets clarify some terms.. A 'Blower' is used to connote a Supercharger. The two have become interchangeable. Its not usually used to pertain to a Turbo, which to this day, is still a Turbo.

Now, with a Supercharger on our cars, the air enters the air filter, then the HFM, THEN it gets to the blower which speeds it up and fires it out undercompression to the intercooler, where the charge is cooled, and finally, it flows into the throttle body and the manifold. So, the air isnt 'blown' through the HFM; rather, its 'sucked' through it, if you will. Now, if there were this turbulence youre referring to, can you imagine what that would do to the HFM signal? It would render it totally useless. .. The ECU relies on a smooth voltage signal from the hfm, indicating MASS of air, ie, amount in weight, passing through the hfm, to know how much FUEL to order up via its voltage signal to the injectors. Turbulence in the HFM will destroy the operation of this system; it wont work. Everything is designed to Remove turbulence from the air flowing through the intake system. So, a properly designed supercharger, as well as a properly designed turbocharger, will do nothing to cause turbulence in the intake stream.

Now, as for ram air... ram air in our cars does NOTHING to increase power. However, thats not to say that its not beneficial to provide as much access to your filter via outside air, as is possible.
He meant blower, not supercharger. As in something that would BLOW air into the air filter.

[paul e]

I understand the 5v limit - that is a limit that just about every car equipped with a Mass Airflow system has - But you can measure a whole lot of airflow with a 0-5v signal provided you can input the new HFM response curve into the computer. Since people can do it with the Euro HFM, I doubt there is any real roadblock to rewriting it to use just about any HFM out there. As I mentioned, there are many higher-metering capability HFMs out there. Its just a matter of finding one that is plug and play and that the response curve is known (which is typically the hardest part).

Agreed. However, realize that with 11 psi vortech blowers, like alot of us are using, even the 3.5" Euro hfm is inadequate for measuring at wot the amount of airflow up to redline, before hitting 5v.. Its good to somewhere between 5500 and 6000 rpms, so, it too must be scaled.. Just not as much ;)

[justaddcoffee]

well, to clarify the NA issues as explained to me by the dealer is that whatever position the throttle is in, the ECU expects to see an air intake value within a certain high-low range. since i have modified everything from the intake to the manifold (except the HFM), the amount of air coming into the engine is above the upper limit of the range. under these conditions, the ECU identifies the throttle position sensor as faulty (thinking that throttle must actually be open more than what the sensor is registering).

what i basically need is custom programming that either doesn't care what the TPS says or has a different ranges for different throttle positions.

*sigh*

[E36M3E]

I still don't believe it...let us know how you remedy the prob. the reason...I know guys running cams along with everything else that you mentioned and thay don't have probs with their CELs.

[k22alinnaz]

well, to clarify the NA issues as explained to me by the dealer is that whatever position the throttle is in, the ECU expects to see an air intake value within a certain high-low range. since i have modified everything from the intake to the manifold (except the HFM), the amount of air coming into the engine is above the upper limit of the range. under these conditions, the ECU identifies the throttle position sensor as faulty (thinking that throttle must actually be open more than what the sensor is registering).
what i basically need is custom programming that either doesn't care what the TPS says or has a different ranges for different throttle positions.
*sigh*
That is defnitely how they work and a possibilty although with your setup I'm not sure if something else on the throttle position sensor or absolute manifold pressure sensor is at fault (which essentially measure air pressure in and out for the ECU functions and thus AFR).

[Brent951]

I have the same problem with me CE light throwing a TPS error but replacing the TPS didn't fix the problem. Mine will only happen at idle after about 30secs if I don't touch the throttle. Mine was doing it with the stock intake and the Conforti intake and the 3.5 HFM.

thanks, Brent

[paul e]

That is defnitely how they work and a possibilty although with your setup I'm not sure if something else on the throttle position sensor or absolute manifold pressure sensor is at fault (which essentially measure air pressure in and out for the ECU functions and thus AFR).

Thats interesting, since we dont use an Manifold Absolute Pressure (MAP) sensor, like alot of Japanese cars use; we use an MAF (Mass Air Flow) sensor which measures the weight (Mass) of the air flowing passed the sensor, recorded in voltage to the ecu.

[k22alinnaz]

Thats interesting, since we dont use an Manifold Absolute Pressure (MAP) sensor, like alot of Japanese cars use; we use an MAF (Mass Air Flow) sensor which measures the weight (Mass) of the air flowing passed the sensor, recorded in voltage to the ecu.
+1
Yes they do..I got it mixed up, then thinking I was right. Guess not.

The MAF sensor on the airbox, you are right, does do exactly what you have stated... and is the best way to measure the volume and density of air an engine takes in (engine load). Thats why you can measure outputs measured by a scanner or dvom that can measure frequency etc.

Right you clicked my forgotten misplaced little-bits-I-know into place.

Shows I really don't remember much.

[k22alinnaz]

Thats interesting, since we dont use an Manifold Absolute Pressure (MAP) sensor, like alot of Japanese cars use; we use an MAF (Mass Air Flow) sensor which measures the weight (Mass) of the air flowing passed the sensor, recorded in voltage to the ecu.
+1
Yes they do..I got it mixed up, then thinking I was right. Guess not.

The MAF sensor on the airbox, you are right, does do exactly what you have stated... and is the best way to measure the volume and density of air an engine takes in (engine load). Thats why you can measure outputs measured by a scanner or dvom that can measure frequency etc.

Right you clicked my forgotten misplaced little-bits-I-know into place.

Shows I really don't remember much. Thanks

[liilpa09]

well, to clarify the NA issues as explained to me by the dealer is that whatever position the throttle is in, the ECU expects to see an air intake value within a certain high-low range. since i have modified everything from the intake to the manifold (except the HFM), the amount of air coming into the engine is above the upper limit of the range. under these conditions, the ECU identifies the throttle position sensor as faulty (thinking that throttle must actually be open more than what the sensor is registering).

what i basically need is custom programming that either doesn't care what the TPS says or has a different ranges for different throttle positions.

*sigh*
I don't understand then how I'm not throwing a CEL. My car has dinan intake, 3.5" HFM w/ the green gizmo, MPact throttle body boot, dinan big bore throttle body, and extrude honed schrick manifold. I'm runing dinan stg. V software and no problems yet?