MAF sensor rule question

[Paul]

Rules state:

14.10 ENGINE

Engine and transmission must remain unmodified, including emissions
equipment, except as noted below:

C. The air intake system up to, but not including, the engine inlet
may be modified or replaced. The engine inlet is the throttle
body, carburetor, compressor inlet, or intake manifold, whichever
comes first. The existing structure of the car may not be
modified for the passage of ducting from the air cleaner to the
engine inlet. Holes may be drilled for mounting. Emissions or
engine management components in the air intake system, such
as a PCV valve, or mass airflow sensor, may not be removed,
modified, or replaced, and must retain their original function
along the flow path.

I think means the sensor and not the sensor housing.

[hancheyb]

Re: MAF sensor rule question

That would be "modifying" it, IMO. You guys are splitting hairs on this one. I just spent too many hours and money going BACK to a stock HFM. You bet I'm going to be support strict observation of the rule. SCCA will say by "sensor" they mean the whole thing, not just the wire.

[John in Houston]

Re: MAF sensor rule question

While I agree that you should enforce the rules, I would hope that you (Brian) would also be campaigning to get rid of this stupid rule.

[hancheyb]

Re: MAF sensor rule question

While I agree that you should enforce the rules, I would hope that you (Brian) would also be campaigning to get rid of this stupid rule.

I figured it was way too late for that. They got one letter when it was proposed.

[McCall]

Re: MAF sensor rule question

While I agree that you should enforce the rules, I would hope that you (Brian) would also be campaigning to get rid of this stupid rule.

Agreed. Us NA guys need all the help we can get.

The STi and RX8 both have the MAF integrated into the airbox but the sensor itself unbolts from that housing. So when you do a "cold-air" system, you basically replace housing of the MAF but not the sensor itself. I believe in the case of the BMW, the whole thing, including the sensor, is replaced with an aftermarket unit. So in the case of the RX8 and STi, I can see where it could be legal. It's a grey issue.

Now, I know Hollis made a post about this and the SEB's intent. Does anyone have it?

[hancheyb]

Re: MAF sensor rule question

When an RX8 or a STI does a cold air, is the housing that the MAF sensor is in, bigger? If so, I would think the SCCA would have a problem with that.

[McCall]

Re: MAF sensor rule question

When an RX8 or a STI does a cold air, is the housing that the MAF sensor is in, bigger? If so, I would think the SCCA would have a problem with that.

I have to verify on the RX8, but with the subbie I know it's the same I.D. The subbie guys were saying something about it messes with the ECM if you change it.

[Paul]

Re: MAF sensor rule question

When an RX8 or a STI does a cold air, is the housing that the MAF sensor is in, bigger? If so, I would think the SCCA would have a problem with that.

No, it is the same ID as factory. Otherwise you run into all kinds of tuning problems.

[hancheyb]

Re: MAF sensor rule question

No, it is the same ID as factory. Otherwise you run into all kinds of tuning problems.

Only if you don't change the computer programming to account for the new diameter.

[Fair!]

Re: MAF sensor rule question

A Mass Air Flow Sensor is more than just the "hot wire" electronic portion - it also includes the calibrated sensor housing. If you change the housing, you are modifying the MAF. We got a VERY clear ruling on this from Andy Hollis.

It doesn't matter if your aftermarket MAF housing "is the same diameter as stock", it's an aftermarket MAF housing. Therefore ALL of the Subies with these aftermarket housings are illegal. Sorry, Charlie.

edit: Feel free to leave these in place! Just making it easier.

It sucks, we fought this ruling "clarification", but it's just the way things are for now. note: changing the BMW MAF can include the housing + sensor or just the housing. The sensor electronics can be removed from anything.

[Paul]

Re: MAF sensor rule question

A Mass Air Flow Sensor is more than just the "hot wire" electronic portion - it also includes the calibrated sensor housing. If you change the housing, you are modifying the MAF. We got a VERY clear ruling on this from Andy Hollis.

It doesn't matter if your aftermarket MAF housing "is the same diameter as stock", it's an aftermarket MAF housing. Therefore ALL of the Subies with these aftermarket housings are illegal. Sorry, Charlie.

edit: Feel free to leave these in place! Just making it easier.

It sucks, we fought this ruling "clarification", but it's just the way things are for now. note: changing the BMW MAF can include the housing + sensor or just the housing. The sensor electronics can be removed from anything.

Thanks Dr. Terry for that ruling "clarification". Unfortunetly it is incorrect information according to Doug Gill. The ruling refers to the sensor, not the housing.

From Henry Lin:

"I did some digging and exchanged a couple of emails with Doug Gill. The
consensus we came to is if the MAF sensor is available as a separate part#
from the "housing", the "housing" is not considered a part of the MAF
sensor.

I verified with the dealerships that the MAF sensor is a separate part for
the STi, the EVO, and RX-8. The SRT-4 uses a MAP sensor so it's not
applicable.

Now on the E36 M3, the MAF sensor is not a separate part. It's listed with
the "housing" as an assembly with one part number. I called BMW of Dallas
and Classic and verified this. Here's a parts diagram I found online,
http://www.realoem.com/bmw/showparts.do?model=BF93&mospid=47486&btnr=13_0381
&hg=13&fg=15.

Now, that's not to say the E36 guys can't use an aftermarket intake. I did
a quick search and all of the intakes I found ends at the stock MAF
assembly.

I asked Doug to pass all of this along to the STAC/SEB for an official
clarification.

If someone protests you this weekend at the Pro, use the above as an example
for your agreement. And if you have a fax number, give Chris F. a call and
ask him to fax you the Air Cleaner & Element parts diagram."


ps: Any protests will be met with vigor. And I am keeping the $50 bucks too (to be spent on booze and food for all of us)!

pps: email is just like the internet, if you read it there it must be true.

[hancheyb]

Re: MAF sensor rule question

I don't think that is really the intent of the rule. Proving the sensor is a separate item means nothing to me. The intent is that if you get a BIGGER opening, newer opening, smoother opening regardless of diameter, you're getting a performance advantage.

I hate this stupid rule anyway. I had to backout things on my car and I'm still not done with it. It has cost me more to do the takeback than just keeping it. Silly. I might protest just to prove how stupid this rule is! Win or lose the protest, I want the rule fixed.

[McCall]

Re: MAF sensor rule question

Ok, I just spend about 30-45 minutes on the SCCA forums trying to find the rule clarification on the MAF. Can some one post the actually rule change as well as Andy's or the SEB's wording?

[Paul]

Re: MAF sensor rule question

I don't think that is really the intent of the rule. Proving the sensor is a separate item means nothing to me. The intent is that if you get a BIGGER opening, newer opening, smoother opening regardless of diameter, you're getting a performance advantage.

I hate this stupid rule anyway. I had to backout things on my car and I'm still not done with it. It has cost me more to do the takeback than just keeping it. Silly. I might protest just to prove how stupid this rule is! Win or lose the protest, I want the rule fixed.

I agree with this. You should protest so that the STAC and SEB or whoever has to make a commitment regarding this. I also think that if you protest this you should protest the ECU for the very same reason.

[hancheyb]

Re: MAF sensor rule question

I agree with this. You should protest so that the STAC and SEB or whoever has to make a commitment regarding this. I also think that if you protest this you should protest the ECU for the very same reason.

What ECU issue? Piggybacks or the fact you can adjust boost?