It's May 1st...How's your SIR???

[Banzai240]

... is that it's possible that the dyno sheets that the ITAC/CRB did get, were not indicitive of the max potential of the car.
[/b]

DING-DING-DING-DING... We have a winner!

That's what we've been saying all along... The dyno sheets that we DO have, clearly show that the typical, well-preparred E36 makes 195+whp... That puts them in the 240hp range at the flywheel... Based on the prep description of these cars, along with additional dyno information that has not been seen, but has been talked about (so-and-so saw the dyno sheet of XXX and it read this...), the true potential of the car is expected to be at least 5 or 10hp more than the "official" sheets we've seen...

Simple math using the process takes over from there...

By the way... I hope you guys realize just HOW UNIQUE it is to have Stan here posting such insightful posts... You now have dialog directly with a CRB member, as well as the ITAC, and are getting more first-hand information than ever before...

I'd say that's a good thing...

[gpbmw]

Just ordered and received my SIR from Raetech. Installed it using a modified Bimmerwold airbox. Car didn't run considering the air intake went from approximately 3" to 29mm. BMW is now in storage and probably for sale and will run my RX7 for the rest of the year.

[BMW RACER]

E36.
Where in relation to the air mass sensor did you mount the SIR? I attached mine to the stock rubber elbow that came off the throttle body, then mounted the Air Mass Sensor in front of that and then attached an ITG air filter to the front of the Air Mass Sensor. It's a tight squeeze but it fits.

[dj10]

E36.
Where in relation to the air mass sensor did you mount the SIR? I attached mine to the stock rubber elbow that came off the throttle body, then mounted the Air Mass Sensor in front of that and then attached an ITG air filter to the front of the Air Mass Sensor. It's a tight squeeze but it fits. [/b]

We mounted it the same as you John. Sorry for not responding to your pm, running crazy here.
Dan

[lateapex911]

Just ordered and received my SIR from Raetech. Installed it using a modified Bimmerwold airbox. Car didn't run considering the air intake went from approximately 3" to 29mm. BMW is now in storage and probably for sale and will run my RX7 for the rest of the year.
[/b]

"Didn't run"?????

Huh?

What does that mean?

and, look around a bit before you jump of the ledge. While the SIR isn't everything it's cracked up to be, it is NOT an item that kills your car! Joh Norris has hed predictable results, and I KNOW that it can be installed and make power..I have done it.

If your car "Didn't run", you have other issues.

[gpbmw]

All:

Thanks for the response in heping me to resolve the SIR issue. I'm new to the board. Here's some additional information:

I'm using a BimmerWorld airbox since BimmerWorlds built my car. The problem I have is due to the limited space. What I did was mount the SIR in the airbox and in front of the MAS. It appears this created the rough idle and caused the engine to run rich.

Thanks to your (John Norris et al) posts I can now visualize the application in a completed stage. My question to the board then becomes....Am I back to using an OE airbox since the aluminum BW box leave me space challenged...?


Gerald Potts
www.myriadracing.com
Atlanta, GA.

[lateapex911]

You were getting a turbulence related issue that affected your AFM. ( I am NO expert, but I suspect the turbulence creates areas of highhr speed, and varying pressure zones, which cool the wire at a rate not related to the actual airflow, causing the poor running, due to the ECU compensating)

Our immediate solution was to mount the SIR Downstream of the SIR. Remember, the short end of the SIR goes forward, the tapered section goes downstream.

So, the order that will work is: Open air> Filter>AFM> SIR> Intake boot> Intake> engine.

Now, the other possibility is to leave the AFM in place, and then build a longer intake tract, perhaps bending it to fit and increase the length, with a filter within, getting the SIR at the head of the tract and as far away from the AFM as possible. I understand that will work, perhaps even better, but haven't had first hand experience.

Finally, don't panic. The car WILL run, and run well. Maybe not *quite* as well as before though...which is the intent.

Now, how would you like to run your car, without ANY restriction, at around 2760 lbs?? On 8" rims??
If you like that idea, don't sell it!!!!!! Write a letter to the CRB asking them to approve the just submitted ITR Proposal. (Details on this site elsewhere)

[gpbmw]

Thanks for your help. I'm gettting close. I expect to have it running tomorrow. I'm actually getting ready for a ProIt at Road Atlanta in two weeks. I've run out of room to retain the BW airbox so my question then becomes...what type of airbox/air filter can I best utilize in place of the BW unit...?







Gerald Potts
Myriad Racing LLC
Atlanta, GA.

[lateapex911]

Can't give you specifics, but I have heard that cone filters are successful...

[dj10]

Thanks for your help. I'm gettting close. I expect to have it running tomorrow. I'm actually getting ready for a ProIt at Road Atlanta in two weeks. I've run out of room to retain the BW airbox so my question then becomes...what type of airbox/air filter can I best utilize in place of the BW unit...?
Gerald Potts
Myriad Racing LLC
Atlanta, GA. [/b]

If you pm me, I'll tell you what I use. I refuse to adverstise in public for anyone who doesn't help my effort.
dj

[Ron Earp]

Based on what Stan wrote it appears to me that some BMW owners/builders contributed to the SIR issue. If top cars (Whittel, BimmerWorld, the builder that did BimmerWorlds motors that advertised here, NE guy I can't remember, and lots others whom I don't know) had ponied up 100% full builds, full disclosure, then maybe the ITAC could have been decisive and the SIR debate avoided. Who knows, maybe they did pony up, but that isn't the impression I got from Stan and the ITAC.

I feel for the BMW folks who have to put the SIR on their cars without a lot of time for development, but by the same token with better teamwork that could have been avoided. Maybe the BMW owners couldn't realize that yes, they were going to get something added to the car, and they had some control over "what" they got depending on how they reacted. Water under the bridge and a "bad" time for IT IMHO.

I sincerely hope that BMW 325 racers will support ITR and race in that class. Unrestricted, at a lighter weight than they race now (and VERY obtainable looking at year old arguments about weight), they will fit the class well and be competitive. Plus, the 328 and 330 cars will be there too.

Ron

[kthomas]

It is not financially safe to run in IT anymore, so I suspect most of your E36 owners will not only not go to ITR, but will leave IT or SCCA altogether.

[JeffYoung]

K, is that because of the cost of having to deal with varying rules? If so, that I understand. First the FP restrictor and then the SIR.

Maybe if the SCCA shows BMW drivers a stable ruleset for a few years, they will come back.

I agree though, this is driving the E36 out, which is bad. I have yet to see an E36 BMW run in an SIR event, and only saw one (Carlos Garcia) before May 1. SARRC/MARRS was sad -- no York, no Giovannis, no Whittel, no Lytle, no Jordan, no Kleinpeter -- could name about 4-5 E36s that usually run that did not.

[kthomas]

"K, is that because of the cost of having to deal with varying rules? "

Yes. We have just set a precedent for competition adjustments. At least in a Pro series the response to adjustments can be race to race, and SCCA tech is there at every race and knows the level of prep and driver capability etc. Here, based on heresay and God knows what else, SCCA can render a car uncompetitive for a year or two before they "collect enough data" to know what they did.

For people that don't play to win- no affect. For winners, the price just went way up.

[JeffYoung]

What is your opinion (which I respect highly) on weight, the SIR and the E36? Specifically:

1. Do you believe the car was correctly classed at 2850? I don't think so but interested to hear others thoughts on this.

2. If not, was the SIR the answer? I certainly don't think so.

3. How about reclassed at 3150?

If you don't feel comfortable weighing in, I understand.

Jeff

[DoubleXL240Z]

As someone who was building an E36, its for sale now, stock!! I don't know if I'm to build a 2850 lb./SIR car or maybe just maybe a 2750 lb. ITR car, with bigger wheels? or what? and then will it happen in '07 or '08. Develope a car for this year that will be changed for next year, or turn it into a 12 month project to see if it will change next year and I'll be ready.

[lateapex911]

IF ITR is to happen, it has been proposed as a 2007 class, and the Proposal has been submitted in time for that to happen. At least on our end. No predicting how long the CRB and the BoD will take with it, nor what it might morph into is it does come to pass.

[kthomas]

What is your opinion (which I respect highly) on weight, the SIR and the E36? Specifically:

1. Do you believe the car was correctly classed at 2850? I don't think so but interested to hear others thoughts on this.

2. If not, was the SIR the answer? I certainly don't think so.

3. How about reclassed at 3150?

If you don't feel comfortable weighing in, I understand.

Jeff
[/b]

I didn't think it was correctly classed at 2850 when we were racing a 240Z. But since the class intent didn't guarantee competitiveness, we accepted that with the wide range of available cars there could, from time to time, arrive a car that would be tough to compete against. So after it became a struggle to compete against the E36 (even though we hadn't yet been beat by one) we decided to build one. So you might say the original classification of the E36 cost us a 240Z. Never really thought about the possibility of having the rules changed. Was always under the opinion that there were far too many variables (prep, driver skill) in IT for SCCA to ever make comp adjustments. That was the class we chose to run in, good or bad. Was it fair that our 240Z was rendered "uncompetitive" by the intro of the E36? You would say no, unless you remember that the class wasn't set up to be fair.

I personally don't think any adjustment should have been made, especially several years after the car is originally classed. Folks in our situation had time to change cars on their own terms, and newcomers to the class saw what was winning or not and chose to enter accordingly.

Let's say post SIR all the E36's quit winning. Then I dust of the 240Z and dominate with it again (2 ARRC's in a row before it was retired). What's to keep SCCA and the whiners from slapping a restrictor on it? Bad precedent we've set.

It would be easier to swallow if a new car was to enter the class and relegate our E36 to second. It always takes a few years for a new car to develop and show up in numbers, and gives owners of existing cars time to have options. Much harder to swallow a rule change, which overnight (relatively speaking) changes the landscape in a class where no competition adjustments has been the norm.

That's just my opinion on this whole mess. I could be wrong.

[JeffYoung]

That is the most thought out logical post on the BMW and the SIR that I've seen.

Let me just raise one point:

The 240z is, I would say, "classed correctly," meaning that its power/weight "fits" the ITAC formula. The 325is is not. Is it not acceptable to fix this issue? I understand the no guarantee of competitiveness, etc. but if it is a flat out error that renders one car an overdog, should that not be "correctable" or are we stuck with these kinds of mistakes because people (and were fully justified in doing so) relied on them?

I think that competition adjustments are bad, and I don't think there would be a risk of the ITAC slapping a restrictor on the Z car because it does fit the ITAC formula.

What really mucked this up (in my limited view) was the CRB's good intentions. They didn't want to put the weight on the car that it should have had at the start, which would have been a correction of a mistake and much easier to justify in the realm of "IT-thought." Instead, they went with the SIR, which smacks of a comeptition adjustment which is not very "IT."

I completely understand the frustration with the CRB over this, especially those guys just building 325s. They don't know what class they will be in, and whether they will be restricted or not.

One last question (again, don't answer if you don't want to): could the 325 be competitive in ITS at 3150? Would the harder on tires/brakes disadvantage it already has be exacerbated to the point that the fast RX7s would be able to beat it regularly?

[kthomas]

That is the most thought out logical post on the BMW and the SIR that I've seen.

Let me just raise one point:

The 240z is, I would say, "classed correctly," meaning that its power/weight "fits" the ITAC formula. The 325is is not. Is it not acceptable to fix this issue? I understand the no guarantee of competitiveness, etc. but if it is a flat out error that renders one car an overdog, should that not be "correctable" or are we stuck with these kinds of mistakes because people (and were fully justified in doing so) relied on them?

[edited]

One last question (again, don't answer if you don't want to): could the 325 be competitive in ITS at 3150? Would the harder on tires/brakes disadvantage it already has be exacerbated to the point that the fast RX7s would be able to beat it regularly?
[/b]

Maybe I missed it, but until very recently I didn't think "The Formula" was known by anyone other than the Comp Board. Had it been published, and the spec page for the E36 mistakenly printed with the wrong weight, and the correction made immediately, I would agree that it shoud be corrected. But a lot of folks traded/sold/built E36's long after they were inducted.

I'm sure at some tracks the E36 could race at 3150. At Road Atlanta we're already pacing the tires. And being the single biggest expense after you build the car it's not the thing I would want to punish. I really don't mind the SIR concept, but it needed real world testing by the right people. It's about lap time, not horsepower. Looking at peak power to weight, a Z beats an E36. I don't think dyno testing was the way to test it.

I'm not afraid of a fair fight, but when a crew chief and driver who have won 4 ARRC's in ITS in 2 different cars think the E36 is dead based on their tests, we (the Club) might have a problem.