Rules

#41

I will use a fuel pressure regulator on my car I know. It was pinging a little here and there after I put on the straight pipe exhaust first time out at VIR. I was also drawing air from directly behind the hotside of the radiator too, i’m sure that hurt me some.

Increasing the base fuel pressure increases the available duty cycle on each injector so they can flow more fuel at any given pulse width. At some point I will install a electronic one that I can adjust in increments. With a wideband O2 I will be able to tweek it. This is common for base adjustments on turbo cars. Sorta has same effect as chipping the car to a degree without actually changing software. After I get my stuff together I plan to offer it as a kit, but all the parts are allready out on the market. I’m not sure but a 325 may run rich enough to not need it. Disconnecting the 02 Sensor probably throws the car totally back into open loop mode. You basically run a rich default map. The computer has no backup signal though to correct the mixture. This is a bit of a dangerous for those tweeking the tune for a few extra horsepower. It’s probably best to just tune the engine to run properly with the 02 working, driveability should be better too.

Stock FPR’s are adjustable, and way cheap. Just precisely restrict the outlet and it will build more pressure. Keep a spare in the toolbox as this will shorten it’s life. Run a fuel pressure gauge so you know when it starts to go south for the winter. Even if adjustable FPR’s are banned there are 10 other ways to adjust the fuel flow. BMW tunes all thier engines really well from the factory, you aren’t going to gain more than a few ponies by playing with it on a single cam engine.

#42

My 2 cents…

Let’s not mess with the exhaust. As long as it’s open past the down pipes, it gives everyone an area to play, while not having any real great effect (+/- 5hp).

I also think the mirror should be open. That has no real effect on budget or performance and is really a matter of what works best for any given driver.

Stick to your guns :angry: No Rule changes… even if I’d like to see a few.

If it closes a loop hole? Change it. Otherwise… leave it alone.

#43

LSD, OEM only.
Exhaust, whatever you decide, just before the first race please.
Don’t play with the engine. That was the main reason I decided to race in this series, oem engines. Since I’m not an ingeneer, and don’t want to learn.

#44

Patton,

Changing the exhaust seems to represent some difference hp/torque, however, it seems that unless we resort to a standard exhaust system - tube diameter, specified muffler (glasspacks, etc.), location of bends, etc., that there will be some differences between cars. Unfortunately, this could be an expensive proposition. Most of us go to a local muffler shop and have them fabricate something to mount to the stock downtube setup (i.e., cut off before the cat). There will be obvious variations - bends, etc. - that may result in hp/torque differences between car.s

I believe the current language is reasonable and fair. It appears as if you spend $$ or $$$ there will be little difference in performance gained if you eliminate the cat - and stay close to the stock pipe diameter, which seems to work quite well.

Ed

#45

Ed, I agree, after the testing of exhaust last March and the minimal results,I think that Carter and Mike got it right the first time and that the current exhaust language is sufficient.

Yo Rob, you’re going to make a great inspector as the Bimmerworld staff knows all of the tricks. Thanks to you, Sean and Eric for helping me learn about fuel pressure. But one question: Are "wideband O2 sensors" legal? Will the search for f/p and wide band sensors become the next big $$$ drain to find a mystical advantage?

I think I’ll spend my money on seat time.

We’ve drawn attention to the f/p topic and I’ll resign myself to let the rules makers discuss this item.

I think the non-race season is too long. Let’s go racing.

Regards, Robert Patton

#46

The way “narrow� band o2 (what we have in our cars) sensor and wideband O2 sensor work is different – you can’t just unplug narrow band and substitute it with wideband sensor. You would need some additional electronics to “drive� the wideband O2, and in most cases output of narrow band sensor is between 0-1 V and output of wide band is 0-5V, so our ECU wouldn’t know how to properly interpret the signal. It is possible to connect another “signal converter� elect box in-between wide O2 and ECU so that signal can be interpreted properly. That said, I don’t think that such configuration, where ECU gets signal form wideband O2 sensor, is legal in SpecE30 – that’s my opinion but Carter can tell us for sure.
We can use wideband O2 sensor as a part of tuning, monitoring or data acquisition system – as long as there isn’t feedback loop to ECU, or other controls, i.e it’s just a stand alone sensor. To do that you would have to cut another hole in the exhaust (at proper location) and weld another bong. BTW, I think it’s good diagnostic tool for our purposes….

PS. another vote for leaving exhaust system rules as is
P.S.2 - when I use "you" in this post I don’t mean R. Patton, but rater general "you"…
Regards,
Igor

#47

I have extensive experience with wideband O2 as I tune Hondas on the side and use a wideband with my software.

AEM makes a wideband O2 sensor with gauge and a signal converter to convert it back into a narrow band signal that OE ECM’s can read.

My personal interpretion of the rules would allow someone to use a wideband O2. If I did it I would send the signal back to the original location so if you wanted to plug in a narrowband O2 and I would have to do is unplug the wire from the AEM unit.

The question is does this become a big money drain for 2 hp. To those who care it may be a temptation. But as we all know and has been said at least twice in the thread alone that fuel without spark alteration means NOTHING. Sure adding fuel at a specific point on the RPM range may gain HP, however since you have to up it across the entire band and not just in one spot it could also drop power at another point. I’ve spent many hours on dynos and know that when tuning a car with just a fuel pressure regulator it is damn near impossible to gain on the entire band and typically if you gain up top you lose mid or down low.

The real truth is a person will not gain much from wideband tuning since you can not tune the factory ECM. That is where real power is made. Since you can not gain anything nominal I say if a person wants to blow money using a wideband for 1 hp that they won’t help them, then let them.

Why does the actions of one person, whose effects are all for nought, have to change rules that do not matter in the grand scheme of things?

My personal opinion is; since it is documented that a person will only gain a few (2 hp max) from fuel pressure just leave the rule as is.

As for the Exhaust, please remember that your rules will have a different effect on those who are planning to use the 318is. While I plan to use a 2.35 in inside diameter (2.5in outside) for my exhaust, It’d be nice if the wording for the rules allow for a small pipe if the person wants. So to say that exhaust piping can be no larger than 2.75in outside diameter. I have no problem with running a muffler as I planned on it anyway (2.5" elderbrock race series).

Thanks!

#48

Man, I’m learning more than I wanted about fuel pressure and O2 sensors. Enough to know that I’ll spend my money on seat time as that will provide the biggest bang for the dollars spent. Thanks Igor and Daniel for the further insight on the f/p topic.

Carter, Mike, others(?) that look at the rules, good luck. This thread has provided some excellant information without the bickering and backstabbing that is seen elsewhere on the web. A thanks to everyone for their civility and willingness to help.

Regards, Robert Patton

#49

This would probably be protestable as it piggybacks the ECU signal. I think an ELF unit or similar that can affect ignition timing would qualify too. You are modifing a signal to the ECU directly affecting the engine tuning, you might as well use chips and save yourself the money.

If you look on our site we have a unit called the LM1. You use it by welding in another exhaust bung. It simply reads the signal like a gauge and can log the A/F during a session with RPM reference. You’d use that reading to adjust your FPR manually. There are lots of units just like it out there.

I’d deem any piggyback or alteration of an ECU signal illegal as the rules are written. You could also use EGT measurements to tune the engine. That takes a decent amount of testing though. Adjusting fuel as the rules are written now can be done free of charge with the existing FPR, and aftermarket units are cheaper than a chip. Seems ideal if a lightly modified engine needed a little more fuel. Fuel pressure adjustments via the regulator are the only legal means we have.

#50

double post
:blush:

#51

my interpretation of what would be legal is: if you have a wideband O2 sensor for monitoring, and it outputs a simulated narrowband signal (of the unprocessed* wideband signal) that you feed that to the stock ECU.

*That is, no mods of the O2 signal based on other sensors/processing.

cheers,
bruce

Igor wrote:

[quote]The way “narrow� band o2 (what we have in our cars) sensor and wideband O2 sensor work is different – you can’t just unplug narrow band and substitute it with wideband sensor. You would need some additional electronics to “drive� the wideband O2, and in most cases output of narrow band sensor is between 0-1 V and output of wide band is 0-5V, so our ECU wouldn’t know how to properly interpret the signal. It is possible to connect another “signal converter� elect box in-between wide O2 and ECU so that signal can be interpreted properly. That said, I don’t think that such configuration, where ECU gets signal form wideband O2 sensor, is legal in SpecE30 – that’s my opinion but Carter can tell us for sure.
We can use wideband O2 sensor as a part of tuning, monitoring or data acquisition system – as long as there isn’t feedback loop to ECU, or other controls, i.e it’s just a stand alone sensor. To do that you would have to cut another hole in the exhaust (at proper location) and weld another bong. BTW, I think it’s good diagnostic tool for our purposes….

PS. another vote for leaving exhaust system rules as is
P.S.2 - when I use "you" in this post I don’t mean R. Patton, but rater general "you"…
Regards,
Igor[/quote]

#52

badboypolar wrote:

one reason to remove it from the rules is so that novices don’t assume that it will provide a benefit and waste money on it. It wasn’t really "documented" prior to this thread (so thanks!)
cheers,
bruce

#53

Patton wrote:

Acutally you are correct. It is documented that fuel pressure robs horsepower. I personally don’t think that a FPR should be "banned" as people who travel to different tracks at different altitudes may want it to keep it running at a certain spec. And honestly they aren’t really that expensive.

My opinion is that some things like this that don’t really matter, and should be left up to the person if they want to use one or not.

Again I forget that the point of Spec is that all cars remain equal with little difference. I have to remember that.

Thanks.

#54

A few comments…

Today/tonight, Mike and I are hammering-out the final specs on the exhaust and the other small items.

9.3.13.14. Water temperature, oil temperature, fuel pressure, oil pressure, exhaust temperature, engine RPM speed (tachometer), and mixture gauges are permitted, but shall be securely mounted and may perform no secondary function.

My car clearly made a few more hp and produced a better torque curve with the O2 sensor unplugged but the rules don’t say I can unplug it (or change it, or replace it with something else, etc.) so it has to stay as it came from the factory; plugged-in and working.

And remember, Spec E30 is not designed to award "creative engineering." The cars are simple and will stay that way.

If someone wants to show-off his engineering talents, he needs to find somewhere else to race. We can discuss anything (and I like to learn about the cars’ workings) but every driver should read the rules very closely before making any change to the car.

The rules will be finalized in the next day or so but again, built cars will not need any modifications for some time. And those that will be required will not be expensive, and more importantly, will help our series in the long run.

Carter

#55

Hi Carter,
just to clarify,
presumably (there’s that word that gets you in trouble …), the sensors associated with those gauges are also OK. A wideband O2 is the sensor for the mixture gauge. You can either replace the stock O2 sensor and feed the simulated narrowband signal to the ECU, or add a totally separate wideband sensor and leave the stock one. Are both of these courses of action OK?

cheers,
bruce

#56

leggwork wrote:

[quote]Hi Carter,
just to clarify,
presumably (there’s that word that gets you in trouble …), the sensors associated with those gauges are also OK. A wideband O2 is the sensor for the mixture gauge. You can either replace the stock O2 sensor and feed the simulated narrowband signal to the ECU, or add a totally separate wideband sensor and leave the stock one. Are both of these courses of action OK?

cheers,
bruce[/quote]
No, you are changing the stock configuration.
Stock is stock, not "manipulated" stock.
The car didn’t come with another separate sensor or a wideband sensor or a simulated signal. Like Carter said, if doesn’t say to change it, don’t change, modify, or alter it.
I’m not engineer, and don’t want to be, that’s the main reason I joined this racing series, simple rules, and cheap.

#57

BETO wrote:

[quote]leggwork wrote:

[quote]Hi Carter,
just to clarify,
presumably (there’s that word that gets you in trouble …), the sensors associated with those gauges are also OK. A wideband O2 is the sensor for the mixture gauge. You can either replace the stock O2 sensor and feed the simulated narrowband signal to the ECU, or add a totally separate wideband sensor and leave the stock one. Are both of these courses of action OK?

cheers,
bruce[/quote]
No, you are changing the stock configuration.
Stock is stock, not "manipulated" stock.
The car didn’t come with another separate sensor or a wideband sensor or a simulated signal. Like Carter said, if doesn’t say to change it, don’t change, modify, or alter it.
I’m not engineer, and don’t want to be, that’s the main reason I joined this racing series, simple rules, and cheap.[/quote]

Let me preface this by saying I do not intend to use a WBO2 sensor in a SE30, anytime, ever.

However, I think using a WBO2 sensor to drive a gauge is perfectly legal based on the fact that mixture gauges are allowed (see Carter’s post above). You can leave the stock system along with the NB giving a signal to the ECU, and still have another WBO2 sensor. They are not mutually exclusive. However, using the NB output of a WBO2 controller could be considered illegal.

#58

the wideband O2 is legal since a mixture gauge is legal to monitor the health of an engine. Just trying to get a clarification on how it can be implemented.
cheers,
bruce

BETO wrote:

[quote]leggwork wrote:

[quote]Hi Carter,
just to clarify,
presumably (there’s that word that gets you in trouble …), the sensors associated with those gauges are also OK. A wideband O2 is the sensor for the mixture gauge. You can either replace the stock O2 sensor and feed the simulated narrowband signal to the ECU, or add a totally separate wideband sensor and leave the stock one. Are both of these courses of action OK?

cheers,
bruce[/quote]
No, you are changing the stock configuration.
Stock is stock, not "manipulated" stock.
The car didn’t come with another separate sensor or a wideband sensor or a simulated signal. Like Carter said, if doesn’t say to change it, don’t change, modify, or alter it.
I’m not engineer, and don’t want to be, that’s the main reason I joined this racing series, simple rules, and cheap.[/quote]

#59

I believe that the "may perform no secondary function" statement in 9.3.13.14 means that you can add a wide-band sensor and gage but that sensor’s data can’t be used in place of the OE O2 sensor’s input to the DME.

#60

Carter, you might as well allow disconnecting the O2 sensor. All you need to do is disconnect the battery right before race time and your ECU will not pay attention to the O2 sensor for that session since it is in "learning" mode.