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I have a question regarding the ECU rules for next year.
"Other existing sensors, excluding the stock air metering device, may be
substituted for equivalent units."
Specifically, does this mean I can replace my O2 sensor with a wideband and use that at the track for tuning purposes (air/fuel targeting) or if not, is the addition of a wideband legal?
What say the rules gurus?
With the new rule? Yes.Quote:
...does this mean I can replace my O2 sensor with a wideband...[/b]
It is currently legal to install a wideband under the "additional gauges" (you're installing an AFR gauge) but it is not currently legal to replace the stock narrow-band O2 sensor as an input to the current ECU.Quote:
...if not, is the addition of a wideband legal?[/b]
I would disagree with Greg. A wideband is equivalent to a narrow band...they do the same thing the same way. It would be legal to substitute one without using the extra wideband sensitivity, therefore it should be legal to substitute for use with the open ECU rule. Flame suit on...flame away..Chuck
Looks like Greg's comment on the wideband is relative to the current rule today, not the new rule. You can already install a wideband for a gauge.
The new rule says that you can use a wideband solely for the ecu w/o need for a gauge. At least that is how I read it.
Minor edits to my original post to clarify...
Just a note this is a proposed rule change:
The ITAC debated and made a recommendation to the CRB, who in turn debated it and has passed it along to the BoD for their approval. They meet in August to go over all the proposed changes, and vote on them.
IF the BoD decides that the ECu rule change is a good one for IT, they will approve it..... if not, it will be turned down, and the rule will remain as is.
Now, I do know there is some support on the BoD for the change, but i do not know if it is more than 1 person, or all of them or any thing in between.
So, if you like the proposed rule, by all means seek out your BoD person and let them know. If you do not, do the same. This is NOT a no brainer, and there is some squaking about what idiots the ITAC and CRB are for even thinking of this. There has been considerable support as well. I can see the BoD reacting in either direction, but if they have real input, and well reasoned input, (if you're going to make sweeping generalizations, providing actual facts to back them up is always important) they will have a much better "feel" for the situation, and will be better informed.
It's your club, exercise your voice.
jake - clean out your inbox! :P
Two openings available, or you can email me via my sigs email...
So to :dead_horse: further...
Current rules state:
So those cars that have Crankfire ignition systems, i.e. computer controlled, will now be able to control timing? And those that have a distributor that controls timing mechanically are stuck? Or can you control the timing through the open ecu and the "Internal component modification" and just use the distributor for distribution of the spark?Quote:
Any ignition system which utilizes the original distributor for spark timing and distribution is permitted. Internal distributor components and distributor cap may be substituted. Crankfire ignition systems are prohibited unless fitted as original equipment.[/b]
If the distributor guys are stuck this will make the field split even further.
Trying to get an understanding to help build a car up for next year. IF the ruling passes.
Thanks,
Derek
Many cars with hall effect distributors can use that signal to feed an ecu and control timing as well, so the split would not be defined by distributor or not. It would be old mechanical distributor or not. Of course those can be recurved to create custom timing advance maps.
Like the other potentail gains from such a system, I would be interested in seeing data of any gains/results from total timing control in race lap times that folks can share. I expect this would matter more for rwd cars that spend more time modulating the throttle. When I am racing I am at the full load/advance state all the time, or I just screwed something up, so I run fixed timing. It would run a bit better in the paddock with programable timing though. :P
Yeah, like shwah says - not really a big deal, and it's already doable anyway; furthermore, the way I read the current distributor rule, the only limitation is that the trigger has to be inside the distributor; you can still, for example, ditch points for a Pertronix trigger and run that into, say, a Megajolt, if you're real ambitious. Of course, again as shwah noted - pretty much full-out all the time while racing, so fixed advance works pretty good.
New guts can be installed into old mechanical distributor as per above stated rule. Even if a kit isn't available for your model, retrofit isn't to tough and signal can be fed into separate controller (msd or whatever) to control advance curve, rev limit or what have you.Quote:
Many cars with hall effect distributors can use that signal to feed an ecu and control timing as well, so the split would not be defined by distributor or not. It would be old mechanical distributor or not. [/b]
No split.... no haves and have nots....
Andrew Rowe
Yes this is what I was getting at. For example an old Honda with a vacuum/ mechanical advanced vs. a newer Honda where the distributor just distributes the spark and the timing is done via the ECU.Quote:
Many cars with hall effect distributors can use that signal to feed an ecu and control timing as well, so the split would not be defined by distributor or not. It would be old mechanical distributor or not. Of course those can be recurved to create custom timing advance maps.
[/b]
Does not matter if you are a WOT all of the time. You will still not be able to optimize the advance as the vehicle will be going through the RPM band, and through different loads (2nd vs 4th etc.). Also you can take advantage of running more timing when the engine is cool (begining of a race) vs. hot, vs. intake air temp etc. With fixed timing you would not be able to realize these gains. To me these gains will be greater than just controlling fuel alone.Quote:
Like the other potentail gains from such a system, I would be interested in seeing data of any gains/results from total timing control in race lap times that folks can share. I expect this would matter more for rwd cars that spend more time modulating the throttle. When I am racing I am at the full load/advance state all the time, or I just screwed something up, so I run fixed timing. It would run a bit better in the paddock with programable timing though. :P
[/b]
This is why I am more interested in what Andrew pointed out, and if this is legit.
Those theories are sound. The magnatude of change is not clear though. I would like to see some real results from someone achieved by fully mapping timing in racing operating envelopes. Full load is full load, gearing changes the accelleration rate of the car, but the force applied from the crank is the same... Of course that accelleration rate change may alter some dynamics in the combustion chamber (although we are still talking about individual compression/ignition cycles separated by valve train events so maybe not...), so maybe that is where full mapping gains come from.
I am not discounting the idea, just a bit skeptical of the actual result it can provide in my application.
Anything goes for ignition as long as you use the original distributor for the timing signal. Also, anything goes on the inside of the distributor as long as you don't modify the housing. Rip out the advance mechanicals and install a direct drive to whatever timing sensor you choose. Send that to your ignition computer (heck use Motec if you want) and add sensors to anything else in the entire car. The only trick is it can only be used for the ignition system. Traction control, while easily possible, isn't legal per GCR 9.3.2 however.Quote:
Yes this is what I was getting at. For example an old Honda with a vacuum/ mechanical advanced vs. a newer Honda where the distributor just distributes the spark and the timing is done via the ECU.
Does not matter if you are a WOT all of the time. You will still not be able to optimize the advance as the vehicle will be going through the RPM band, and through different loads (2nd vs 4th etc.). Also you can take advantage of running more timing when the engine is cool (begining of a race) vs. hot, vs. intake air temp etc. With fixed timing you would not be able to realize these gains. To me these gains will be greater than just controlling fuel alone.
This is why I am more interested in what Andrew pointed out, and if this is legit.
[/b]
Quote:
Anything goes for ignition as long as you use the original distributor for the timing signal. Also, anything goes on the inside of the distributor as long as you don't modify the housing. Rip out the advance mechanicals and install a direct drive to whatever timing sensor you choose. Send that to your ignition computer (heck use Motec if you want) and add sensors to anything else in the entire car. The only trick is it can only be used for the ignition system. Traction control, while easily possible, isn't legal per GCR 9.3.2 however.
[/b]
That is one way to read the rules but as I read them the distributor must be used for timing, aka it is triggering the ignition, not a timing signal.
I just don't want to have gone through all the trouble to pull the mechanical advance system, spending the time on the dyno, only to go to the first race of the season to have the car disqualified due to the systems being integrated into a single ecu. Just looking for some guidance...
Shwah: Just go dig around the net and look for tuning software and or tables. If you look at the base timing tables they are usually based on rpm vs. load and even at full load they will not be static. If I find a good example I will post one. Now, what the gains will be will be up to what you start with. Some systems may be close to being optimum for what you run now. It also may not be worth the effort to squeeze that last little bitout vs. doing a handling/ traction improvement.
I know that the tables are not static when you have the ability to create one. I guess your last sentance sums up what I suspect. Very little effect at racing speeds/loads.
When you look at a timing table you will find that in general bewteen idle and 2500 rpm timing changes mostly with rpm, and that from 3500 to 6500 timing changes mostly with load (kPa). This is why I wonder about the significance of this for our application. EDIT - looked at some more tables and there are some with more changes and less changes w/rpm and kPa on either end of the graph, obviously each application is a bit different.
The cool thing is that someone running a programable system could easily drop in a fixed timing map next time they are at the dyno, record some data, and let us know what differences they measured between the variable map. That would be neat information to see.
Your logic makes sense and is certainly safe, but I would say that my proposed method does utilize the distributor for timing as required in the rules. Just for the sake of argument (I don't remotely believe this is true) an ultra strict read your way might make the rev-limit modules common on upgrade ignition systems illegal since they don't follow the distributor once the rev-limit is exceeded.Quote:
That is one way to read the rules but as I read them the distributor must be used for timing, aka it is triggering the ignition, not a timing signal.
I just don't want to have gone through all the trouble to pull the mechanical advance system, spending the time on the dyno, only to go to the first race of the season to have the car disqualified due to the systems being integrated into a single ecu. Just looking for some guidance...
[/b]
That said, every car I've run in nearly a decade has used EFI...
Grafton
Hey, what aout this.
We don't have many people wanting to build purpose built race cars, so why not setting up a class where people can bring a car to the track and run races. We'll divide them up as best we can but everyone will have a good time and drive there car to the best of there combined limits. And on Monday you can drive it to work and pick up the groceries on the way home.
Let's call it
Grand Touring....
No Production....
No Imptoved Touring...
No...
Everybody wants to go faster, competition drives us, and it's hardest to improve the human element.
I ramble on.....
Holy Crap..........it seems like the variable cam timing cars get yet another advantage.
Actually no they don't. If it is controlled by the ecu today, then they can already tune it however they want.
Nothing more than they can do now, right?