ECU mods

Eric Parham

Eric Parham

New member
If I start with a car that has an mass air flow sensor (MAF) signalling the stock ECU, but the modded ECU only accepts a manifold absolute pressure (MAP) input (all of the less expensive ones work this way), 1) am I allowed to add a MAP sensor to the intake manifold (assuming I can get the signal to the modded ECU through the stock ECU electrical connector), and 2) can I remove or disable the unused stock MAF sensor?
 
Originally posted by Eric Parham:
If I start with a car that has an mass air flow sensor (MAF) signalling the stock ECU, but the modded ECU only accepts a manifold absolute pressure (MAP) input (all of the less expensive ones work this way), 1) am I allowed to add a MAP sensor to the intake manifold (assuming I can get the signal to the modded ECU through the stock ECU electrical connector), and 2) can I remove or disable the unused stock MAF sensor?
Click to expand...

No in both cases.


------------------
George Roffe
Houston, TX
84 944 ITS car under construction
92 ITS Sentra SE-R occasionally borrowed
http://www.nissport.com
 
The rule is simple - you can mod it as long as those mods are done within the stock box. Any mods or aditional sensors outside of the box are clear no-no's.
 
Originally posted by Jake:
The rule is simple - you can mod it as long as those mods are done within the stock box. Any mods or aditional sensors outside of the box are clear no-no's.
Click to expand...

I believe this includes adding additional wires to the box... In other words, I'm pretty sure it must utilize the stock, unaltered wiring harness/connector.



------------------
Darin E. Jordan
SCCA #273080, OR/NW Regions
Renton, WA
ITS '97 240SX
DJ_AV1.jpg
 
Clever... What rule are you using to allow the additional vac line? I've never thought about this approach.

K
 
Plus, disabling the MAF might fit under the "altering the value" of the sensor. In this case you are just altering it to zero.

Britt

------------------
Soon to be SSC Mazda MP3

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

Thanks, but unfortunately I don't even know for sure if this is going to fly when the car is tech inspected. I wonder if anyone has been able to replace their ECU with aftermarket equipment while completely satisfying the rules.
 
Oh, and for anyone who's interested I used a megasquirt EFI controller. Why? It was cheap and a fun project that kept me busy for months on end. I love projects and I learned a TON about EFI systems. At this point I've tuned it and only assume it's making extra HP, but being able to monitor exactly what's going on with my car is what makes it worth it. http://www.bgsoflex.com/megasquirt.html

BTW Kirk, I've been talking to you on honda-tech/RR as Eric.
wink.gif
 
Originally posted by Eric R287:
Thanks, but unfortunately I don't even know for sure if this is going to fly when the car is tech inspected. I wonder if anyone has been able to replace their ECU with aftermarket equipment while completely satisfying the rules.
Click to expand...

Tech inspectors are not going to look at your car for anything other than safety issues unless someone protests you.

Your car will be illegal.

17.1.4.D.1.a.6:

"Fuel injected cars may alter or replace the engine management computer, or ECU, provided that all modifications are done within the original OEM ECU housing. Only the stock (unmodified) OEM 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 housing. The stock (unmodified) wiring harness must be used. Adjustable fuel pressure regulators are permitted."

Unless you were able to fit the stock MAP sensor in the ECU, I don't see how you can get around the fact you are not allowed to add sensors. Also, I don't see how you can get a vacuum line into the ECU housing w/o modifying it.

I wish tech inspections looked for cheating.


------------------
George Roffe
Houston, TX
84 944 ITS car under construction
92 ITS Sentra SE-R occasionally borrowed
http://www.nissport.com
 
I still have all the original ECU parts so if I ever start doing any actual competition I can revert back to it. 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...
 
Once again supporting my theory that the illegal cars are in the mid-pack trying to keep up with the ultra-prepped, well driven cars. No offense intended, just an observation.

AB

------------------
Andy Bettencourt
06 ITS RX-7
FlatOut Motorsports
New England Region #188967
 
Very interesting, I hadn't thought of putting the MAP sensor inside the box either. I know of several computer boxes (VW) that do have a vacuum connection to the intake (I think for ignition advance rather than fuel metering), so they already have a MAP-type sensor in the box
smile.gif
I guess we could use that as the main sensor and just let the computer do whatever it wants with the extra MAF input. Now, do we have to use the stock injectors?
 
Originally posted by ITSRX7:
Once again supporting my theory that the illegal cars are in the mid-pack trying to keep up with the ultra-prepped, well driven cars. No offense intended, just an observation.

AB
Click to expand...

Andy,

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

------------------
MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608
 
I am not doing any competition of any kind at this point. I'm still learning about racing and learning/working with my car; especially since it has been Winter. I probably won't do any competition this Summer, even.

When I started building that ECU I realized I could more or less make it conform to the rules. So far I just have to deal with a vacuum hose that shouldn't be there. I've overcome a lot, though.

Even if I cannot possibly find a way to make it work I will just have to switch back to the stock set up. I mostly built that ECU for the fun of it. It only cost about $200 to do and as far as I can tell performs like a $2000 set up.

Pics of my ECU... I got this far! I passed the emissions test without a cat...
http://b18c5.org/race/ecu/
http://b18c5.org/race/ecu/10.jpg
http://b18c5.org/race/ecu/passed.jpg
 
You must log in or register to reply here.
Back
Top