April SIR ruling

[e36its]

The ruling is in: 29mm SIR effective 05/01/2006.
April Fastrack

I'm a little disappointed test results were never published, to be honest.

tom

[edit: I wrote 2007 when I meant 2006... and the rules say 2005!]

[Andy Bettencourt]

I don't know if that was the place for them to be posted but I will push to make sure there is a write up posted somewhere.

AB

[stevel]

The ruling is in: 29mm SIR effective 05/01/2007.
[/b]

Where did you see that? All I saw was this -- >

"Improved Touring
ITS
1. Effective 5/1/05: BMW 325i/is (2 & 4 door) (92-95), p. 18, change the specs to read as follows: Notes: Trunk mounted fuel cell with no
larger capacity than stock. 29mm SIR required and must comply with GTCS section 17.1.2.F.4.i.10."

And this was at the top of that section
"All changes are effective 4/1/06 unless otherwise noted."

steve

[Andy Bettencourt]

Cripes. The flippin FT has a typo. All those tech bullitens are effective 4-1-06 unless otherwise noted. The date on the E36 item should have been 5-1-06, not 05.

AB

[dj10]

I don't know if that was the place for them to be posted but I will push to make sure there is a write up posted somewhere.

AB [/b]

AB,
Can you ask or find out why no results were posted as promised? Did they ever rule on the weight placement issue?
Thanks
dj

[stevel]

Did they ever rule on the weight placement issue?
[/b]

Read the FT.

[seckerich]

AB,
Can you ask or find out why no results were posted as promised? Did they ever rule on the weight placement issue?
Thanks
dj
[/b]

Check the April fastrac thread DJ, it was addressed.

[buldogge]

Hey Andy... Could you or George please comment on the 161hp dyno posted over on Bimmerforums that George was witness to.

Please tell me you have some other information regarding the need for placement ahead of the HFM (as Mr. David Finch points out to be the "issue") and its possible implementation garnered from the various dyno tests you witnessed/were party to.

TIA

I don't know if that was the place for them to be posted but I will push to make sure there is a write up posted somewhere.

AB
[/b]

[DoubleD]

The ruling is in: 29mm SIR effective 05/01/2007.
April Fastrack

I'm a little disappointed test results were never published, to be honest.

tom
[/b]

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.

[Andy Bettencourt]

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.

[/b]

The baseline was 180whp. It was the weakest of all motors used by the CRB as data to make this decision (although he did set a track record in Texas recently!).

19whp taken off the top with 5 ft/lbs lost.

AB

[e36its]

Where did you see that? All I saw was this -- >
"Improved Touring
ITS
1. Effective 5/1/05: BMW 325i/is"[/b]

Mea culpa, fingers got ahead of me and wrote 2007 (despite the 2005 typo in the FT... guess I moved a year in the wrong direction adjusting for the typo!).

tom

[DoubleD]

The baseline was 180whp. It was the weakest of all motors used by the CRB as data to make this decision (although he did set a track record in Texas recently!).

19whp taken off the top with 5 ft/lbs lost.

AB
[/b]

We were told, by you, that the SIR would cap power, not cut it accross the entire usable RPM range. So much that, eh?

At least Finch is only charging a 25% restocking fee on the 27mm SIR.

Well, on the bright side, the RX7 just got more valuable and, being as it is the car to have, folks building/tuning them will now have a financial opportunity.

[rx3sp]

The baseline was 180whp. It was the weakest of all motors used by the CRB as data to make this decision

AB
[/b]

Um... according to previous posts by the backmarkers, the SIR should penalize all motors down to a certain level, and the original horsepower level is inconsequential.

So then why do you mention it here ?

P.S. please stop misusing the word "decision". The process used here by the ITAC and CRB definitely does not meet this definition:

DECISION: a position or opinion or judgment reached after consideration; "a decision unfavorable to the opposition"; "his conclusion took the evidence into account"; "satisfied with the panel's determination"

RX3SP

[e36its]

The baseline was 180whp. It was the weakest of all motors used by the CRB as data to make this decision (although he did set a track record in Texas recently!).
19whp taken off the top with 5 ft/lbs lost.[/b]

Somewhat confused... I thought since the SIR doesn't affect airflow below a certain HP level a low(er) HP motor would be less affected. If the calculated output for the 29mm is 180 RWHP, wouldn't we expect a motor making 180 RWHP to be virtually unaffected and one making 205 RWHP to be losing 25 RWHP?

tom

[dj10]

The baseline was 180whp. It was the weakest of all motors used by the CRB as data to make this decision (although he did set a track record in Texas recently!).

19whp taken off the top with 5 ft/lbs lost.

AB [/b]

AB, for a fact this BMW you know had a baseline of 180 rwhp without the SIR correct? If this is the case, #1. I don't believe this is a Stickley motor, I know for a fact that his baseline engines are much higher than 180 rwhp with FPR restrictors and without SIR's.

[rx3sp]

Well, on the bright side, the RX7 just got more valuable and, being as it is the car to have, folks building/tuning them will now have a financial opportunity.
[/b]

Actually, you are only partially correct. The 944 is the car to have, if you want to win a race mano a mano.

However, in the new way of doing things in IT, there are no races without handicappinng winners until the RX7 wins.

so, you are right, in the new world world of Sissy C. A. Improved Touring,

[DoubleD]

AB, for a fact this BMW you know had a baseline of 180 rwhp without the SIR correct? If this is the case, #1. I don't believe this is a Stickley motor, I know for a fact that his baseline engines are much higher than 180 rwhp with FPR restrictors and without SIR's.
[/b]

It was over 180. I'll see if I can get the baseline. Also, and more importantly, comparing hp numbers from diffeerent dyno's is a tricky business. I've seen variation of 5% in stock E46 M3 motors from dyno to dyno. Heck, I've seen a dyno plot that showed a 100% stock E46 M3 making, if you assume a conservative drivetrain loss, 360chp. Obviously it was not....the dyno was just reading a bit high.

[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

[gpeluso]

It was over 180. I'll see if I can get the baseline. Also, and more importantly, comparing hp numbers from diffeerent dyno's is a tricky business. I've seen variation of 5% in stock E46 M3 motors from dyno to dyno. Heck, I've seen a dyno plot that showed a 100% stock E46 M3 making, if you assume a conservative drivetrain loss, 360chp. Obviously it was not....the dyno was just reading a bit high.
[/b]

Obviously the SIR does not perform they way we were TOLD by ITAC. 161whp, what can you do with that? Is this the final word from the SCCA? Can someone from the SCCA step in and stop the madness from the ITAC and the CRB? This decision will hurt all car counts in ITS. The fight has been fought and the BMW guys lost......hopefully the SCCA regions realize this will hurt their bottom line. Some regions may suffer more than others. Does anyone care? Long live the MAZDA. Where can I get one of those?

Greg