ECU mods

[OTLimit]

Originally posted by Bill Miller:
Andy,

I'd like to hear the explanation of that one.

Bill,
I don't think much of an explanation is required. What we have seen and heard at the track over the last 11 years pretty much supports this theory.



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Lesley Albin
Over The Limit Racing
Blazen Golden Retrievers

[Eric R287]

After doing some reading I've found that my ECU can make calculations based on the MAP sensor(along with the other, standard sensors) OR it can be set to make calculations based on the Throttle Position Sensor(along with the other, standard sensors). Supposedly, this isn't the easiest way to tune it, but if it works I'm sure I'll adjust.

Sorry for hi-jacking this post, but at least this info can be useful to someone else...

[ITSRX7]

Originally posted by Bill Miller:
Andy,

I'd like to hear the explanation of that one.

Bill,

I've posted my thoughts on this multiple times before on this board but would be more than happy to take it offline so as not to bore the group. Drop me an e:mail.

AB

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Andy Bettencourt
06 ITS RX-7
FlatOut Motorsports
New England Region #188967

[Bill Miller]

Andy (and Leslie),

I don't see how something that someone has done, that has yet to turn a wheel w/ it, supports that theory. I could just as easily say that people getting DQ'd out of the ARRC supports the theory that the folks at the front are there, because they're cheating.

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MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608

[Jake]

Eric - you're actually more on topic than some others.

Interesting info. What kind of mods/gains do you get with your megasquirt setup?

[Eric R287]

I have yet to put it on a dyno, but if I see a gain of at least 5hp I'll be happy. I'm going to get some good dyno time in at my friends shop when the weather gets better. I'll have to put the original ECU(L-Jet) back in place and do a before and after.

[Knestis]

The key here is that, if a system can be tweaked, it can be optimized for the narrower operating parameters of the race track.

It bears remember that it is not ever going to be the case that an aftermarket engine management system simply bolts on more power. In fact, it is as likely to slow a car down as it is to speed it up, unless the entrant commits to the dyno time necessary to get it right.

K

[Eric R287]

Originally posted by Knestis:
It bears remember that it is not ever going to be the case that an aftermarket engine management system simply bolts on more power. In fact, it is as likely to slow a car down as it is to speed it up, unless the entrant commits to the dyno time necessary to get it right.

The dyno time would certainly take away any doubt that it's set up right. Especially with a wide-band o2. My process for tuning it was not very exacting, but I feel strongly that I have it set pretty darn close judging from how the car's driving. It's definitely running a tad richer than stock.

The program I use to tune it makes it very easy to figure out and gives so much info if you want it. The info can be logged and processed with a seperate program later on, as well. This seperate program will then make suggestions for smoothing out the fuel map.

Hopefully I can keep this system in the car using either speed-density(MAP) or alpha-N(TPS--no vacuum line). I'm going to have to meet up with some of the local racers and see what advice they can give me--something I should do no matter what.

http://home.earthlink.net/~jcgebhart/mswhys.html

[Geo]

Originally posted by Eric R287:
It's definitely running a tad richer than stock.

If it's richer than stock, in all likelihood it's slower than stock. Stock maps tend to be on the rich side rather than the lean side. It's a common misconception that adding fuel will add power.

The reason most stock maps are on the rich side is it's safer for the OEM. The engine will run cooler, with less chance of detonation. Leaning the engine out is usually what will add power unless the engine has a lot of parts that have changed VE significantly to already have the car running too far on the lean side.


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George Roffe
Houston, TX
84 944 ITS car under construction
92 ITS Sentra SE-R occasionally borrowed
http://www.nissport.com

[ITSRX7]

Originally posted by Bill Miller:
Andy (and Leslie),

I don't see how something that someone has done, that has yet to turn a wheel w/ it, supports that theory. I could just as easily say that people getting DQ'd out of the ARRC supports the theory that the folks at the front are there, because they're cheating.

<font face="Verdana, Arial" size="2">I don't know why, but I have a feeling no one is really going to care about my ecu unless my driving skills + car = unfair advantage. I have a ways to go before that happens...</font>

Bill,

It's the mindset that 'as long as I am not at the front, illegal parts or modifications don't matter' that supports my theory. Like I said before, if you want to e-mail me, I would be happy to take it offline - or just start another thread.

AB

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Andy Bettencourt
06 ITS RX-7
FlatOut Motorsports
New England Region
www.flatout-motorsports.com

[Eric R287]

Any anticipation that the ECU rules will become more lax in the future?

Has anyone been able to accomplish this ECU modification successfully?

[oanglade]

You need to pick a car who's ECU box is big.




There are cars with MOTEC systems stuffed inside the stock box.

[Eric Parham]

Okay, ECU = Engine Control Unit, which may control both fuel and ignition. But, many older cars had separate computers for fuel (e.g., EFI controller) and ignition (e.g., ICU or knock controller or electronic rev limiter). Thus, when attempting to upgrade an older system with separate computers, what does the rule permit as far as using a single computer in place of two? Recall that we were allowed to add ICUs even before the new ECU rule, as long as they used the stock spark distribution method (e.g., distributor if there was one). Any reason why the added ICU can't reside inside the stock EFI controller housing along with the fuel control (that is, besides fitment/size issues)?

Very pertinent rules:
17.1.4.D.1.e -- ignition
17.1.4.D.1.a.6 -- ECU
17.1.4.D.1.s -- ECU

Other possibly related rules:
17.1.4.D.9.c -- gauges (sensors?)
17.1.4.D.9.j -- radios (wiring alternative?)
17.1.4.D.1.b -- fuel pumps/lines (injectors?)
17.1.4.D.1.a -- jets (injectors?)
17.1.4.D.1.c -- MAF penalty


[This message has been edited by Eric Parham (edited March 17, 2004).]

[Eric Parham]

Originally posted by Knestis:
Clever... What rule are you using to allow the additional vac line? I've never thought about this approach.
K

How about "Adjustable fuel pressure regulators are permitted" (17.1.4.D.1.a.6, last sentence). Adjustable fuel pressure regulators almost always require a vacuum connection to the intake manifold, AFAIK.

[oanglade]

Eric,
If your question is "Can I put everything into one box, instead of two?", In my opinion, if you can fit everything you need into one of the stock computer housings and use the unmodified stock harness that plugs to that computer housing to do everything you need, then you can do that and leave the other box empty.

I don't think that you can use one rule like "adjustable fuel pressure regulators are permitted" to break another rule like "Only the stock (OEM) unmodified ECU connection to the wiring harness may be used. The allowance to modify the ECU in no way permits the addition of wiring, sensors, or piggybacked computers outside of the OEM ECU harness. The stock (unmodified) wiring harness must be used."

On the first paragraph of Section "D" it says: "No permitted component/modification shall additionally perform a prohibited function".

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Ony Anglade
ITA Miata
Sugar Hill, GA

[Bildon]

Wow..good thread. This is an issue that is too complex for the SCCA right now, IMHO.

For a while now I've been struggling with the definitions of components outlined elsewhere in this thread and the open interpretations which can be made.

If there are any IT Ad Hoc or CB folks listening in, I'd appreciate knowing if A) there is any talk of refining the ECU related ruiles or if they/you woul liek any feedback from the memebership to help with this.

- Bill

[zracer22]

Now that I've wasted my time reading this thread, I'll waste a couple more minutes writing a reply.

This whole ECU thing has been a cluster f#*% from day one. The ECU rules were changed because everyone(figuratively, not literally) was cheating and they didn't want to police the issue. Now, a rule change that was added to allow aftermarket chips in stock ecu's is being distorted.

I have a chip in my BMW's ecu, and all it does is raise the rev limiter. There are no real HP gains to be had. Why someone would spend the $$$ stuffing a motec into a stock ecu box for IT racing makes no sense. "If" the engine is legal, minimal gains can be made by altering the ecu. Unless you can alter cam timing, altering ignition timing has very limited benifits. No matter what you do with the ECU, you can't change the amount of air going into the engine. Air = HP.

Do you want to see a huge performance gain? Then spend more time in the driver's seat learning to carry more speed thru and off the corners. Tune the suspension, not the ECU. I'll take a great driver in a 150 HP car over an average driver in a 160 HP car any day!



[This message has been edited by zracer22 (edited March 17, 2004).]

[zracer22]

Originally posted by Bildon:
If there are any IT Ad Hoc or CB folks listening in, I'd appreciate knowing if A) there is any talk of refining the ECU related ruiles or if they/you woul liek any feedback from the memebership to help with this.
- Bill

I agree! Either open the rules to allow any engine management system or clarify what mods are allowed. If the intent was to allow aftermarket chips, then rewrite the rule to say that.

[Eric R287]

"As long as it fits in the OEM casing" I can safely fit a MAP sensor according to the rules. I can't use that sensor because I can't run a vacuum line to it? What good is having the ability to fit whatever is humanly possible into that box if you can't connect to it?

The rules talk a lot about unmodified wiring and connections, but nothing specific is mentioned about a stray vacuum line. Vacuum line ain't wirin'. How wrong am I?

I wish this were easier to figure out. I wish this didn't require figuring out.

[oanglade]

Can you run it inside the box without modifying the box?

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Ony Anglade
ITA Miata
Sugar Hill, GA