April SIR ruling

[dj10]

Sorry if this has already been addressed. I'm trying to do 3 things at once at work and this is one I shouldn't be doing at the moment.

This engine has one day break-in. I suspect it's still a bit tight. Also, the AF ratios don't look great. However, sometimes the dyno widebands aren't the most accurate (as opposed to a Horriba), so the ratios may or may not be accurate. Mostly I suspect it's still a bit tight.
[/b]

Well I know Chuck, and his engines are clearanced to make HP immediately.

All these personal attacks and accusations have to stop, guys this isn't JR HIGH SCHOOL! I'm disappointed that the results haven't been posted as promised, I'm alittle bummed that the CRB hasn't made it manditory for the placement of the SIR so now it's a gussing game. The CRB has made a decision. Try it if you don't like the results, we have other options.

[lateapex911]

Here ya go. This dyno is a 29mm SIR on a freshly built (1 race w/ BMWCCA) Stickley motor, custom tune non-Motec. This is, excepting the 3 or 4 ponies Motec may provide, a max motor. I don't have the baseline or I would happily post it as well.

An ITAC member was in attendance and witnessed that the install and dyno are legit. The car would not reve past 3k rpm w/ the SIR in front of the HFM.

And yes, I was fully aware of this dyno when I posted weeks ago. The owner of this car now states that he will not race with SCCA in any class.


[/b]

What's interesting about that run is what it really revealed. Not much. Scientific procedures require tossing out that data point as the A/F ratio was off the mark...by a lot. lok at the graph and note the lean condition. I understand that the baseline for that car also had similar issues with the A/F ratio. In short, that car wasn't a good indicator. Custom programmed chip or not, it wasn't putting down proper power levels in baseline trim.

Observations show that the car does adjust for such things, and the jagged line might be an indication of just that.

It's too bad that those results were pretty much voided by the tuning issues going in. I know we all appreciate the owners time and trouble. And perhaps he learned something too.

A note on the SIR. I had expected to see a commentary regarding the best placement, but it appears that it's not there. From observations, I would advise that the SIR be placed AFTER the AFM. The AFM seems to like a clean and linear stream of air, which is best found right after the filter and before the SIR.

So, it should be installed in this order:
Outside air>air filter>AFM>SIR>TB>manifold> pistons, etc. All air, of course, must pass through the SIR.

Also, I have been informed that inquiries to the supplying companies indicate that only Raetech had sold any SIRs, and will exchange the 27mm insert for a 29mm insert, at no cost.

[Andy Bettencourt]

The sheets are up on Bimmerforus.com. 180whp is the baseline.

I hesitate to put words in the CRB's mouth before they post a summary but the questions regarding the power output are valid. 2 issues I am aware of:

1. The SIR needs to be placed AFTER the HFM. The velocity of the air seemingly freeked the thing out to the point the cars did not run well - AT ALL. Placing them behind the HFM brought back the driveability.

2. SIR's do have an effect on all states of tune as shown by this and other pieces of data. This was a factor the CRB had to weigh in their decision.

To the proponents of weight, the same can be said for that as well. If you are running an underdeveloped car, a weight set based on a cars potential (like all the weights for all the cars are) will hurt as well.

Here is the baseline run DoubleD.



AB

[Singletrack1]

1. The SIR needs to be placed AFTER the HFM. The velocity of the air seemingly freeked the thing out to the point the cars did not run well - AT ALL. Placing them behind the HFM brought back the driveability.

[/b]

That is in direct contradiction to what David Finch told me when I told him about my dyno results. He stated it has to be in FRONT of the HFM to make the full 180HP. When I told him about my car and the other car not running past 3k with it in front of the HFM, he stated we need to do more development.

Why can't the CRB tell us how they got the car to run 180HP with the SIR in front of the HFM and give us the results of this final test where they tested SIR's up to 33mm?

2. SIR's do have an effect on all states of tune as shown by this and other pieces of data. This was a factor the CRB had to weigh in their decision.

[/b]

This is in direct contradiction to what the ITAC and CRB told us the effect of the SIR would be. I can quote your post and others that state that the SIR only caps HP and it should not have affected my 180HP baseline.

Yes, my car was lean and it has since been corrected.

So, the story changes - it went from "unless you have a full build making 200+HP, you won't be affected" to "YOU MUST DO A FULL BUILD INCLUDING MOTEC TO GET THE TAGETED 180HP".

It doesn't matter to me in the end as I will be moving on to NASA and BMWCCA. You guys can accuse me of taking my ball and going home and so be it. But, I can say I got kicked in the nuts and decided it was better to go home, than continue to get kicked in the nuts. I have no interest in fighting for position with drivers that I should be dominating.

Yes, I did get the track record by .1 second, but I thought track records didn't matter?

I am tired of all this and had made racing no fun at all. This is a great reminder of why I quit national SOLO II competition.

Bill Kim

[stevel]

Yes, I did get the track record by .1 second, but I thought track records didn't matter?
[/b]

I'm sure they matter to someone. But it's a great example of how a sub par effort (not saying your whole effort is sub par but with 180whp it's certainly not all it could be) in a car that weighs 300lbs less than it should can still break track records. If that doesn't tell you that you didn't have an advantage then there's no convincing you.

s

[Singletrack1]

I'm sure they matter to someone. But it's a great example of how a sub par effort (not saying your whole effort is sub par but with 180whp it's certainly not all it could be) in a car that weighs 300lbs less than it should can still break track records. If that doesn't tell you that you didn't have an advantage then there's no convincing you.

s
[/b]

But you are assuming the person who set the previous record had a full out effort in a 100% driver.

It also assumes driver is not a large factor.

If I add 300# and still get the track record against a 100% effort by a RX-7 or 240Z, then you can say that the BMW had an advantage. That is not the case and I can assure you that the previous holder's car isn't a 100% or a 100% driver.

I don't see how using your logic can get to your conclusion that my car has an advantage.

You are accepting a conclusion without the supporting facts.

[Andy Bettencourt]

That is in direct contradiction to what David Finch told me when I told him about my dyno results. He stated it has to be in FRONT of the HFM to make the full 180HP. When I told him about my car and the other car not running past 3k with it behind the HFM, he stated we need to do more development.[/b]

Then so be it. Maybe we need to define 'in front of'. The SIR's do not work directly in front of the HFM. That is the air filter side. They have made the power after the HFM but before the throttle body.

Why can't the CRB tell us how they got the car to run 180HP with the SIR in front of the HFM and give us the results of this final test where they tested SIR's up to 33mm?[/b]

To correct you, they tested up to a 35mm - which lost all of 3-5hp. Again - there should be a summary coming out. NO test yeilded 180whp with the SIR in front of the HFM as defined by the above comments. After the HFM but well before the TB.

This is in direct contradiction to what the ITAC and CRB told us the effect of the SIR would be. I can quote your post and others that state that the SIR only caps HP and it should not have affected my 180HP baseline.[/b]

That has been stated earlier in this thread. There were items that were not 'as sold' to the CRB by Finch. The resultant effect on all cars was a data point the CRB had to weigh when deciding the outcome.

So, the story changes - it went from "unless you have a full build making 200+HP, you won't be affected" to "YOU MUST DO A FULL BUILD INCLUDING MOTEC TO GET THE TAGETED 180HP".[/b]

Unfortunately, yes. But I will say that if you want to be at the peak of the power to weight ratio of the class, you have to do that anyway. If you do the 100% build, you are in the same position as everyone else...same target pw/weight at 2850.

It doesn't matter to me in the end as I will be moving on to NASA and BMWCCA. You guys can accuse me of taking my ball and going home and so be it. But, I can say I got kicked in the nuts and decided it was better to go home, than continue to get kicked in the nuts. I have no interest in fighting for position with drivers that I should be dominating.[/b]

I understand.

Yes, I did get the track record by .1 second, but I thought track records didn't matter? [/b]

Especially when you are 25whp down from where you COULD be.

What formula do you want published - the 'process' for weight has been hashed over a hundred times, the SIR stuff is for engineers - the END RESULT IS the point.

[Singletrack1]

What formula do you want published - the 'process' for weight has been hashed over a hundred times, the SIR stuff is for engineers - the END RESULT IS the point.
[/b]

If you can publish the "process" in simple terms such as "weight * X /Y + Z = HP", that would be helpful. And some explaination of where X, Y, Z came from.

I think a simple summary would be helpful as it helps to see where new cars may go in terms of weight.

Thanks,

Bill

[Andy Bettencourt]

If you can publish the "process" in simple terms such as "weight * X /Y + Z = HP", that would be helpful. And some explaination of where X, Y, Z came from.

I think a simple summary would be helpful as it helps to see where new cars may go in terms of weight.

Thanks,

Bill [/b]

Bill,

You will find it in detail in the rediculous thread on Bimmerforums. Post 101.

You miss that? You are one of the guys that took the most swings at me personally on that site. Thanks for paying attention.

And just because AB thinks I am a smart ass I want to thank Steve E. for once again validating why we should not use race or track results....... Steve's underdog RX7 hung a lap this weekend within a couple tenths of the track record at VIR. For those who dont know, VIR is a very HP oriented track and the record is held by that villainous Chet guy in a UNRESTRICTED e36. Not sure if you classify Steve's car as a 100% build either.... but several RX7's were hovering in the 2:14's and even a Z found itself down in that range. But I am sure the BMW was sandbagging a few years ago. It's the process, I know......... [/b]

Care to mention that Chet's car did that in the heat of the summer when all the other cars were running 4 seconds slower? Think the air-temp had anything to do with power this weekend? I can spin the data as fast as you can.



Why can't you accept that it IS about the numbers?

[dj10]

That is in direct contradiction to what David Finch told me when I told him about my dyno results. He stated it has to be in FRONT of the HFM to make the full 180HP. When I told him about my car and the other car not running past 3k with it behind the HFM, he stated we need to do more development.

This is in direct contradiction to what the ITAC and CRB told us the effect of the SIR would be. I can quote your post and others that state that the SIR only caps HP and it should not have affected my 180HP baseline.

Yes, my car was lean and it has since been corrected.
Bill Kim
[/b]

Bill, I will not dispute Dave. He know's way more than I'll ever know. Maybe Jake can help us out here, he was at some of the tests? The way it was explained to me, that the AFM needed uninterupted air to be effective, that is why the SIR was placed after the AFM and between the TB. I would imagine the C & G Performance will be talking to Dave Finch when they order my SIR. I would like to hear from anyone with actual knowledge of these SIR's and their placement. I had also heard some time ago that unfortunately like the FPR it would effect all level of preped cars, but so would have the weight too.
Bill did you Dyno your car after you richened it up? If so what were the results?

[Singletrack1]

Bill, I will not dispute Dave. He know's way more than I'll ever know. Maybe Jake can help us out here, he was at some of the tests? The way it was explained to me, that the AFM needed uninterupted air to be effective, that is why the SIR was placed after the AFM and between the TB. I would imagine the C & G Performance will be talking to Dave Finch when they order my SIR. I would like to hear from anyone with actual knowledge of these SIR's and their placement. I had also heard some time ago that unfortunately like the FPR it would effect all level of preped cars, but so would have the weight too.
Bill did you Dyno your car after you richened it up? If so what were the results?
[/b]

I edited my original post to make it more clear.

1. My car and the other did not run at all past 3K RPM with the SIR in front of the HFM
2. The dyno runs on my car was done with the SIR after the HFM and in front of the throttle body.
3. When I pointed out this to David Finch, he stated the SIR need to be in FRONT of the HFM and that was the last dyno they did at 180HP with the 29mm SIR. When I pointed out my low dyno results, he attributed it to the placement of the SIR after the HFM, not that I needed to start with a motor with more HP.
4. He also claimed the ITAC/CRB did not listen to him and that he did not recommend the 27mm size.

I will have the dyno results with the richer fuel map soon. I am waiting to finish some other parts to test at the same time and that is why I haven't retested it yet.

My 27mm Raetech SIR is for sale in the classified section - Raetech said they will replace it with a 29mm for free.


Bill

[dj10]

I edited my original post to make it more clear.

1. My car and the other did not run at all past 3K RPM with the SIR in front of the HFM
2. The dyno runs on my car was done with the SIR after the HFM and in front of the throttle body.
3. When I pointed out this to David Finch, he stated the SIR need to be in FRONT of the HFM and that was the last dyno they did at 180HP with the 29mm SIR. When I pointed out my low dyno results, he attributed it to the placement of the SIR after the HFM, not that I needed to start with a motor with more HP.
4. He also claimed the ITAC/CRB did not listen to him and that he did not recommend the 27mm size.

I will have the dyno results with the richer fuel map soon. I am waiting to finish some other parts to test at the same time and that is why I haven't retested it yet.

My 27mm Raetech SIR is for sale in the classified section - Raetech said they will replace it with a 29mm for free.

Bill [/b]

I guess he didn't tell you exactely where to put it, like how close to the AFM or HFM or how close to the air filter it needs to be?
Thanks

[Knestis]

Back when I was a junior high school teacher, I had a kid announce in front of the class that I was discriminating against him because he was black. I gave him a pass to see the principal, so he could file the official greivance with the district, warranted by that kind of treatment. He didn't do it, came back to class, and worked harder.

The moral as it applies here?

If you honestly believe that any ITAC or Board member is letting a vested interest influence his/her/their club business decisions, you have an obligation to either (a) make an official complaint to SCCA, or ( shut the hell up.

K

[lateapex911]

Back when I was a junior high school teacher, I had a kid announce in front of the class that I was discriminating against him because he was black. I gave him a pass to see the principal, so he could file the official greivance with the district, warranted by that kind of treatment. He didn't do it, came back to class, and worked harder.

The moral as it applies here?

If you honestly believe that any ITAC or Board member is letting a vested interest influence his/her/their club business decisions, you have an obligation to either (a) make an official complaint to SCCA, or ( shut the hell up.

K
[/b]

Thankyou Kirk. I'd like to add that you should sign your complaint/charge, and be very specific in the charge with as much backing documentation as possible.

I do wish that the internet didn't bring out a side of people that (I hope) I wouldn't see in person. If I am ever approached by anyone in the immature way that I have see some demonstrate here, I hope that I will just turn on my heels and walk away. Therefore, I won't respond to any of the less than reasonble comments and claims here.

In terms of the placement of the SIR that I observed at the tests I was present for, I can say this:
When the SIR was placed directly in front of the HFM (?) AFM (?) the car ran poorly and was clearly affected by the pressure variations the SIR presented, even low in the rev range. So we moved the meter to a location, as I explained many posts up, upstream of the SIR.

The wire reached easily, we didn't see the same issues, and the A/F ratio was right in the range it should be, and matched the baseline runs.

Now, is it possible to mount the SIR further upsteam of the meter and acheive good results? I don't know. I understand that Dave Finch (from what has been repeated here) states that that is the way he tested, but I am unaware of any tests he conducted.

[dj10]

Therefore, I won't respond to any of the less than reasonble comments and claims here.

In terms of the placement of the SIR that I observed at the tests I was present for, I can say this:
When the SIR was placed directly in front of the HFM (?) AFM (?) the car ran poorly and was clearly affected by the pressure variations the SIR presented, even low in the rev range. So we moved the meter to a location, as I explained many posts up, upstream of the SIR.

The wire reached easily, we didn't see the same issues, and the A/F ratio was right in the range it should be, and matched the baseline runs.

Now, is it possible to mount the SIR further upsteam of the meter and acheive good results? I don't know. I understand that Dave Finch (from what has been repeated here) states that that is the way he tested, but I am unaware of any tests he conducted.
[/b]

Jake, we'll be talking to Dave shortly. If we find out any new info I'll post it. I'll also be testing my car on track and dyno so I'll have info from the tests. I have a new engine and I'll break it in before I get on the dyno.
I would like to know Jake if you tried the SIR in differnet positions upstream of the AFM? I would think the best place if any would be just after the air filter if it would work at all. But I've been know to be wrong before.

[Knestis]

...and not surprisingly, people are still PO'd.

I'd of gone with lead, instead. e36 entrants would still be upset but there would be fewer side issues, red herrings, confusion, and distractions to deal with; and the math would be simpler to defend.

K

[Singletrack1]

...and not surprisingly, people are still PO'd.

I'd of gone with lead, instead. e36 entrants would still be upset but there would be fewer side issues, red herrings, confusion, and distractions to deal with; and the math would be simpler to defend.

K
[/b]

If they would only publish the Math.

I'm interested in the actual formula, not the end result. If the formula is fair and legit, why not publish it?

Bill

[seckerich]

...and not surprisingly, people are still PO'd.

I'd of gone with lead, instead. e36 entrants would still be upset but there would be fewer side issues, red herrings, confusion, and distractions to deal with; and the math would be simpler to defend.

K
[/b]

AMEN brother and much easier to fix if it went too far. We all want even racing--not kill a class.

[JeffYoung]

Bill, it's been published here many times. It basically shoots for a 14:1 to power to weight ratio using the stock hp figure plus an adjustment for expected improvements in IT trim. Then, intangibles are used as adders/deducts from the weight (IRS v. live rear, discs v. drums, aero, etc.).

As Jake, George, Andy and others have presented it, it seems to make sense to me although it is probably not as "mathematical" as those on the short end (or perceived short end) of it would like.

One other point, and maybe I shouldn't make this one, but I think the ITAC majority (including your scapegoat) was firmly behind using weight as the fix, not the SIR. So, for me at least, a lot of the whining directed at the "scapegoat" is pretty damn offensive.

I promised myself I wouldn't post on this issue again, but here I am. Let me say this: I think SIRs suck, I think they have no place in IT, I think you guys (BMW guys) got screwed on the timing of this, I think that extraordinary efforts were made to test the SIR but things still didn't come out in a completely logical way and most of all I think that you guys were made to feel like a target by the whole process.

That said, any objective (as objective as the process can be) look at your cars (the E36) considering stock hp, known dyno plots for built motors, brakes, and suspension shows that 2850 at 205 whp is too light.

Can one of you guys justify the 2850 weight without reference to this years ARRC or the RX7 that pulled you by 4 car lengths over a 1/4 at Lefty Righty International Raceway at 3:32 p.m. on May 4, 2005? Stick to stock hp, IT gains, dyno plots and power to weight ratios.

Jeff

[Fastfred92]

And just because AB thinks I am a smart ass I want to thank Steve E. for once again validating why we should not use race or track results....... Steve's underdog RX7 hung a lap this weekend within a couple tenths of the track record at VIR. For those who dont know, VIR is a very HP oriented track and the record is held by that villainous Chet guy in a UNRESTRICTED e36. Not sure if you classify Steve's car as a 100% build either.... but several RX7's were hovering in the 2:14's and even a Z found itself down in that range. But I am sure the BMW was sandbagging a few years ago. It's the process, I know.........