BMW SIR Discussions

[zracre]

I am starting this thread for discussion on the SIR results. Post comments here so we can have IT.com forums back! It seems like many conversations end up on the SIR. We can look at the results from the Info thread and talk abt it here!

The lap times did not seem to drop terribly...what were the competition's lap times?...or what does a non BMW run there for comparables?

[BMW RACER]

Last year we ran this configuration at Buttonwillow http://www.buttonwillowraceway.com/ Click on track maps and look for #27 clock wise. It's about 1.6 miles, not much in straight aways, moderate speed corners. I looked up the official results from 2005, I won both races with a quickest lap on Saturday of 1:16.072 using Hoosiers. On Sunday I won with a quick lap of 1:17.410 on Toyos. This year I ran Hoosiers both days and won with a quick lap of 1:17.485 on Saturday and 1:17.404 on Sunday.
Unfortuntely the timing wasn't working right on Saturday so all of my competition didn't get lap times. The next quickest car was a Mazda. His quickest lap on Sunday was 1:17.697.

At the first glance it all looks pretty good. The BMW is a little over a second a lap closer and didn't run away in the race. I'm waiting to see how the next race turns out. It's at California Speedway, that's the other extreem, lots of straight aways.

Am I the only person who raced this weekend with a SIR?

[zracre]

There was one at Daytona but I didnt see him at all...im not sure who he was or level of mods...It will be interesting to see how it does on a hp track

[DoubleXL240Z]

I spoke with the BMW guy at Daytona last Sunday. New car, totally stock sedan, no tricks, basic suspension, simple simple cage, was running 2:29s on sat. Burned up the engine on lap7 or 8 during the enduro. The car looked nice, the guy was real cool, told what he had done etc. He Was not running the SIR, figured he would be so far out of it, there would be no need. Seems like at Daytona that set up (SIR), would get waxed!! especially the way Flynn and company where running.

[benspeed]

Well, I raced with a very quick E36 driver at Pocono this weekend. He's always run up front at this track and with the SIR he wasn't even remotely close to his old times. It really blew the weekend for him and his crew. They tried a variety of things to try and get more speed. Changed the diff and who knows what else. Still didn't help much.

He isn't running a race motor but the car is very well prepped and only needs the full blown engine. But with the choke hold on the motor they don't know if it's worth building that engine and still might run in the middle of the pack.

I recognize the intention here is to even up the playing field and push the E36 to the level of development that most of the front running ITS cars are investing, but it was a real bummer to see a fellow competitor that far off the pace.

I think he's a perfect example of an E36 racer who is taking a bad hit for the guys who have spent $40-50K on their cars. Those guys crush the field and the guy who doesn't have that kind of $$ gets really pushed to the back with the SIR.

On the other hand some guys have race built motors in their cars - not $40K but some big $$. A junkyard motor shouldn't keep up with a built motor in a Z, Teg or a RX7.

I think the old Plate and some weight is a more managable way to achieve parity. By the time word gets around about the SIR results, it won't matter. All the E36 guys will be gone (most are this year in the NE).

I also learned the SIR cost $400 - that's an expensive part by any standards.

The ITAC will certainly be looking at this case and I'm sure monitoring the results around the country for the next several months. They will make every effort to determine how to fairly manage the performance of this particular car, but this will take time and the bimmer guys ain't gonna be happy.

I'm interested to see the results in the SARRC/MARRS series with the E36 since those two regions seem to have the most highly developed E36 cars in the country. Those results could prove that the race committe was correct implementing the SIR, but that just makes the E36 a financially poor decision to race. Pick another car and run fast for much less $$.

[JeffYoung]

Doubtful (to me anyway) that anyone is going to build a maxxed out SIR E36. NONE -- zero, zip, nada -- at SARRC/MARRS at VIR this weekend, and we used to get 5-8 of them.

Looks like the SIR has them all runt-offed.

[JamesB]

Well two of them where there, under ITE.

[dj10]

Well, I raced with a very quick E36 driver at Pocono this weekend. He's always run up front at this track and with the SIR he wasn't even remotely close to his old times. It really blew the weekend for him and his crew. They tried a variety of things to try and get more speed. Changed the diff and who knows what else. Still didn't help much.

He isn't running a race motor but the car is very well prepped and only needs the full blown engine. But with the choke hold on the motor they don't know if it's worth building that engine and still might run in the middle of the pack.

I recognize the intention here is to even up the playing field and push the E36 to the level of development that most of the front running ITS cars are investing, but it was a real bummer to see a fellow competitor that far off the pace.

I think he's a perfect example of an E36 racer who is taking a bad hit for the guys who have spent $40-50K on their cars. Those guys crush the field and the guy who doesn't have that kind of $$ gets really pushed to the back with the SIR.

On the other hand some guys have race built motors in their cars - not $40K but some big $$. A junkyard motor shouldn't keep up with a built motor in a Z, Teg or a RX7.

I think the old Plate and some weight is a more managable way to achieve parity. By the time word gets around about the SIR results, it won't matter. All the E36 guys will be gone (most are this year in the NE).

I also learned the SIR cost $400 - that's an expensive part by any standards.

The ITAC will certainly be looking at this case and I'm sure monitoring the results around the country for the next several months. They will make every effort to determine how to fairly manage the performance of this particular car, but this will take time and the bimmer guys ain't gonna be happy.

I'm interested to see the results in the SARRC/MARRS series with the E36 since those two regions seem to have the most highly developed E36 cars in the country. Those results could prove that the race committe was correct implementing the SIR, but that just makes the E36 a financially poor decision to race. Pick another car and run fast for much less $$.
[/b]

[JeffYoung]

Dan, did you have car issues? Was looking forward to meeting you.

On another thread below, a CRB member indicated that one reason they went with the SIR instead of weight was that no top E36 builder would submit a dyno sheet. As a result, they (the CR apparently (my guess here) believed that they could not properly set the power/weight ratio as they didn't know what the top examples were making. Instead, they went with the SIR to "guarantee" a known level of power.

Take from that what you will.

[dj10]

Dan, did you have car issues? Was looking forward to meeting you.

On another thread below, a CRB member indicated that one reason they went with the SIR instead of weight was that no top E36 builder would submit a dyno sheet. As a result, they (the CR apparently (my guess here) believed that they could not properly set the power/weight ratio as they didn't know what the top examples were making. Instead, they went with the SIR to "guarantee" a known level of power.

Take from that what you will. [/b]

You could be right on this, it seems like you have more 1st hand knowledge than me. But it makes sense that if you can get another 30 hp out of a engine for 8K (as a example) and your going to lose 15 to 20 hp after you paid the 8k. Well you do the math. I'm still planning to test my SIR when the right race comes around.

Only issues was the weather Jeff. I wasn't going to drive 400 miles if the weather wasn't in my favor. I made the right choice for me & you because the way my luck's been going (ask Marshall Lytle), I would have got there and there would have been a blizzard or a flood. I am more upset about not having a chance to meet you southern boys. I'm sure we would of had some fun.

[erlrich]

Doubtful (to me anyway) that anyone is going to build a maxxed out SIR E36. NONE -- zero, zip, nada -- at SARRC/MARRS at VIR this weekend, and we used to get 5-8 of them.

Looks like the SIR has them all runt-offed. [/b]

Jeff -

Looking at the qual sheets, we did actually have one bimmer in the group, although I don't remember seeing him either. Harold Corbin finished 6th OA Saturday and 9th OA Sunday. His fast laps were about 3 seconds behind Steve's on Saturday and 4 seconds behind Sunday.

Btw, what happened with the TR8 this weekend? I was really disappointed to come around NASCAR bend and see you way off the pace Sat.; and then again on the pace lap Sun. I hope it was nothing serious.

Dan - you did miss out. It was great to meet some of our southern friends from the IT boards, and the weather held up nicely all weekend, at least for our group (don't know if group 7 got finished before the downpour Sunday?). I made certain we would have dry racing all weekend - I promptly went out and bought a new set of rains first thing Saturday

Hope to see you at Summit.

[JeffYoung]

Earl, thanks again for buying the rains and keeping us dry.

Seriously, good to meet you. Your car looks great.

Harold Corbin has a very fast E30 325 --- not an E36.

The 8 actually ran great, the driver/mechanic is an idiot. Set and reset my personal best at 2:21.5 in the race Sat. Didn't manage the brakes like I should and lost them at the end of the front stretch. Car was fine, I just took it easy to finish since I was well behind the rest of the ITS field.

On Sunday, my mechanic (that's me) failed. I had the right front caliper on and off three times trying to figure out why i was tearing that rotor to shreds -- finally figured out the caliper is warped. Went home Sat. night and rebuilt my spare, and put it on...leaked like a sieve. Pulled it off and found a "new" seal had failed. Rebuilt again. Put it on and...forgot to tighten the caliper bolts. Nailed the brakes on teh backtraight on the pace lap and got a huge vibration, knew immediately what I had done. Had to pull in. I'm an idiot.

Off ot CMP -- hope to see you at SARRC/MARRS next year.

[DavidM]

Well, I raced with a very quick E36 driver at Pocono this weekend. He's always run up front at this track and with the SIR he wasn't even remotely close to his old times. It really blew the weekend for him and his crew. They tried a variety of things to try and get more speed. Changed the diff and who knows what else. Still didn't help much.

He isn't running a race motor but the car is very well prepped and only needs the full blown engine. But with the choke hold on the motor they don't know if it's worth building that engine and still might run in the middle of the pack.
[/b]

Hmm. I thought the whole idea of the SIR was that it would "choke" HP at a certain level. If you weren't above the choke point then you wouldn't see any change. I.e. If the choke point is 200 HP then you shouldn't see any change unless you're above 200. Am I understanding this correctly? It sure doesn't sound like that's what happening if this guy's motor isn't built and he's losing performance. I thought the idea was to slow down the super fast cars, but not affect the mid pack guys.

It does bring up an interesting dollar/performance trade-off. Why spend that $10k to get a fully built motor if you can't use all the HP. You might be able to get the same performance with a $5k motor. The $10k motor may have better area under the curve so to speak, but is it worth an extra $5k. I can see how it sucks for those guys who already have the $10k motor.

I hope all the BMW guys don't bail, but it's gonna be a rough adjustment period.

David

[JeffYoung]

They've bailed, at least around here.

[dj10]

Dan - you did miss out. It was great to meet some of our southern friends from the IT boards, and the weather held up nicely all weekend, at least for our group (don't know if group 7 got finished before the downpour Sunday?). I made certain we would have dry racing all weekend - I promptly went out and bought a new set of rains first thing Saturday

Hope to see you at Summit. [/b]

Sounds like all was dry and I did miss a good weekend. I'm telling you the truth, if I would have showed up it would have poured all weekend! So you can thank me for not showing up.

[Bill Miller]

Hmm. I thought the whole idea of the SIR was that it would "choke" HP at a certain level. If you weren't above the choke point then you wouldn't see any change. I.e. If the choke point is 200 HP then you shouldn't see any change unless you're above 200. Am I understanding this correctly? [/b]

Yep, and Raetech has some nice swampland in Florida for you too! :P

[mlytle]

Sounds like all was dry and I did miss a good weekend. I'm telling you the truth, if I would have showed up it would have poured all weekend! So you can thank me for not showing up.
[/b]

thanks dj!! i helped too...had brand new set of hoosier rains sitting in the trailer.

still, would have been nice to run with you in a session or two. you in sir trim and me in "non" sir trim (otherwise pretty equally upper level prepared cars).

marshall
one of the two "ite" e36's at vir.