Revised ITR list in Fast Track

[JeffYoung]

To the BMW guys -- thanks for the help and info. Much appreciated.

[dj10]

To keep thing simple just list the BMW's we need more data on. This would be less confusing and lets get to work.

[Andy Bettencourt]

DJ,

Check this out. I am not sure we want to micro-micro manage these weights (like 'slightly bigger brakes' on this X) but recommendations are accepted where you think we are off...

BMW 325i/is (92-95) 2765
BMW E36 328i/328is (96-99) 2850
BMW E46 325i/ci coupe (01-02) 2765
BMW E46 328ci (00) 2900
BMW E46 328i (99-00) 2900
BMW 330i (01-02) 3290
BMW 635 (83-84) 2925
BMW M3 (88-91) 2700
BMW Z3 2.8 (97-00) Coupe or roadster 2800
BMW Z3 3.0 (01-02) Coupe or roadster 3240

Boy it's gonna be hard to police these things...

For description:

E30 rear is -50 from E36 rear. E46 is + 50 from E36 rear. E46 325's may look light but make slightly less power than E36 versions.

Keep the commentary coming! Time is running out for a final list.

[Knestis]

The voices in my head continue to be anxious about some of how this is shaking out on the ground. For the zillionth time, please, please, PLEASE don't let on-track performance - or perceptions of potential on-track performance - creep into the process.

If the rationale at this point for a 50# hit is "that windshield angle is going to give it an advantage," then the door is wide open for "Hey - it's not faster, we got the windshield adder wrong, let's make it 50# lighter."

The point was made earlier (or elsewhere, nearby) that the fact that weights are set in 25# increments is evidence that we think the system is accurate to +/- 25#. FWIW, I agree with that interpretation - but NOT that the system IS that tight.

The list of "adders" and "subtractors" has gotten longer in the last 18 months, seems like, and they are getting added and subtracted a lot in the ITR planning. These start to feel like little, baby competition adjustments (bleah) based on the conversation and rationale being applied.

Please don't let them grow up and reproduce.

K

[Andy Bettencourt]

Don't worry Kirk. That is not what is happening. ITR is rare in that we get to start from scratch. We get to not only get to run everything through the process, but we get to do what we think is right for the cars in question. These considerations might be a little minute when you look at the other classes, but we have never had the luxury we have here.

It really isn't that different from what we do now, we just have the ability to get things a little closer to 'right' before they get locked down.

[dj10]

DJ,

E46 325's may look light but make slightly less power than E36 versions.

Keep the commentary coming! Time is running out for a final list. [/b]

Hmmmmmm I have a E46 325 as well as my E36. From where I'm at they make the same only the E46 is stiffer and has double vanos. My call would be for 2800#. I'd like maybe Marshall to comment either to me or here on the site. I'd listen to James too.

[Z3_GoCar]

Hmmmmmm I have a E46 325 as well as my E36. From where I'm at they make the same only the E46 is stiffer and has double vanos. My call would be for 2800#. I'd like maybe Marshall to comment either to me or here on the site. I'd listen to James too.
[/b]

Hey Dan,

Thanks for the vote of confidence.

All I want is for my car to be properly classed. Not an overdog, and not so far behind that I have no hope of keeping up.

The M-52TU and M-54 have dual adjustable cams where both the intake and exhaust are computer adjustable, and a dual plenum intake manifold. These motors are both tuned for less hp and more torque, so given a Motec type system a larger than usuall hp gain my be possible, with a little creative programming.

Also as a side note, the 3.0 liter motors have electric throttles. There's no direct throttle linkage, just a spring and rheostat, wires into and out of the computer and an electric actuator. I believe that this isn't acceptable to the GCR's in that the throttle must have a positive return spring and defective wiring may result in a fully open throttle. World Challenge gets around this by spec'ing the replacement of the throttle assembly with the assembly from the 2.5 liter. Do I hear the first spec line exception?

[JoshS]

Also as a side note, the 3.0 liter motors have electric throttles. There's no direct throttle linkage, just a spring and rheostat, wires into and out of the computer and an electric actuator. I believe that this isn't acceptable to the GCR's in that the throttle must have a positive return spring and defective wiring may result in a fully open throttle. World Challenge gets around this by spec'ing the replacement of the throttle assembly with the assembly from the 2.5 liter. Do I hear the first spec line exception? [/b]

Lots of cars currently running in Showroom Stock and Touring have electronic throttles, without any special exceptions on their spec lines.

This year in Seattle, the little plastic throttle stop in my Subaru STi broke, allowing the electronic throttle pedal to travel about 1/8" more than it normally can. This caused the computer to get confused about the pedal, and the car basically went into limp mode, fixing the throttle at 6% open. At 6%, I couldn't get up the hill on the back side of the track, and had to just pull over and wait for a tow.

I'd rather have a mechanical throttle, but I guess my point is, the GCR doesn't seem to disallow these cars, or at least, we're all somehow getting logbooks despite the requirement you cite.

[dj10]

The M-52TU and M-54 have dual adjustable cams where both the intake and exhaust are computer adjustable, and a dual plenum intake manifold. These motors are both tuned for less hp and more torque, so given a Motec type system a larger than usuall hp gain my be possible, with a little creative programming.

Also as a side note, the 3.0 liter motors have electric throttles. There's no direct throttle linkage, just a spring and rheostat, wires into and out of the computer and an electric actuator. I believe that this isn't acceptable to the GCR's in that the throttle must have a positive return spring and defective wiring may result in a fully open throttle. World Challenge gets around this by spec'ing the replacement of the throttle assembly with the assembly from the 2.5 liter. Do I hear the first spec line exception? [/b]

Thanks James great post and certaintly somethings the ITAC should consider. What is the difference between a 323/ 328 throttle body & the 2.5 throttle body? I know the manifold is identical for the 323 & 328 (smaller than the 2.5).

[Z3_GoCar]

Hey Dan,

Thought I should revisit this thread, and saw your question.

I'll look into the part numbers for the TB's on the 23(really a 2.5 liter) and the 28. My suspicion is that they're the same.

The reason I was revisiting this thread is that my car had the ecm dyno-tuned today. We did like about 10 runs before I made the final choice on the program. We did the tunning on a dynapac, and without giving the exact numbers, lets just say I'm somewhere around stock flywheel hp numbers, now at the wheel. Also my torque peak is at 4800rpm, and it's a definitly a peak. What'll make my car fast won't be the power alone, it scaled to sub-2300lbs empty. Also remember I've got several IT non-compliant parts and assemblies, like no AFM, S-52 cams, and a stand-alone without even the stock motor harness. Now granted my standalone was current in the late 90's, it's practically historic today.

I need to give props to Kevin MacDonald for sending me to Richard Clewett at Clewett Engineering, to Richard for changing out the ecm chip so that my TECII was programable on the fly, and then doing a great job of optimizing the programming, and finally to Mike Haddad at Haddad Motorsports for his expertise on running the dyno. I also got an annual tech from Chris Welch at Bullet Motorsports Speedlab for my race in two weeks. Chris got me all lined up on what the car and I will need. All in all today was too much fun. Tomorrow I'm out for a test day at Buttonwillow.

[944s2racer]

Hi,

This is my first post here. I have a 944S2 which sometime back I saw listed among the cars considered for ITR. Where do I go to see the latest on the ITR development? Also, is there any information on allowed preparation for ITR? My car is prepared as a PCA F car which allows coilover and aftermarket a-arms among others. I know these modeifications were not allowed in GCR for early 944s running in ITS.

Thank you

[JoshS]

This is my first post here. I have a 944S2 which sometime back I saw listed among the cars considered for ITR. Where do I go to see the latest on the ITR development? Also, is there any information on allowed preparation for ITR? My car is prepared as a PCA F car which allows coilover and aftermarket a-arms among others. I know these modeifications were not allowed in GCR for early 944s running in ITS.
[/b]

ITR is still in the proposal stage, although we expect to see that it has been approved when the next Fastrack comes out on the 20th of September.

The proposal has the same preparation rules for ITR as for ITS, except for larger wheels than ITS.

[lateapex911]

Hey- I was on the ITR ad hoc group that kind of spawned the idea and presented it to the ITAC. And I'm on the ITAC. Right now we are about 4 days away from the official announcement in Fastrack, but I feel VERY strongly that ITR is a go for next year. The recent Fastracks have posted the list of cars and weights. I THINK the 944s2 is in the sub 2800 range.

Interestingly, I also have a 944S2, and I bought it last spring when I decided to gamble on ITR becoming a reality.

The ITR rules will be exactly the same as the prep rules for the rest of IT. The exceptions will be wheel width (8.5 max width, I think) and of course vehicle weight is set to ensure close competition.

Unfortunatley, marque clubs deal with very specific situations, and their solutions tend to backfire in multi marque racing, so the rules package between PCA and IT has some differences. That said, we hope that ITR proves to be a great chance to get some great cars on the track more often than is possible in PCA racing, as the SCCA sanctions more events...

Take a read through the book, and see what you think.

[dj10]

Hey- I was on the ITR ad hoc group that kind of spawned the idea and presented it to the ITAC. And I'm on the ITAC. Right now we are about 4 days away from the official announcement in Fastrack, but I feel VERY strongly that ITR is a go for next year. The recent Fastracks have posted the list of cars and weights. I THINK the 944s2 is in the sub 2800 range.

Interestingly, I also have a 944S2, and I bought it last spring when I decided to gamble on ITR becoming a reality.

The ITR rules will be exactly the same as the prep rules for the rest of IT. The exceptions will be wheel width (8.5 max width, I think) and of course vehicle weight is set to ensure close competition.

Unfortunatley, marque clubs deal with very specific situations, and their solutions tend to backfire in multi marque racing, so the rules package between PCA and IT has some differences. That said, we hope that ITR proves to be a great chance to get some great cars on the track more often than is possible in PCA racing, as the SCCA sanctions more events...

Take a read through the book, and see what you think. [/b]

Jake, I'm a little worried about less and less track time with more and more groups coming out. You have any thoughts on this?

[Andy Bettencourt]

Jake, I'm a little worried about less and less track time with more and more groups coming out. You have any thoughts on this?

[/b]

My thought is that you will only get less track time if these groups fill up. If they fill up, it's a good thing for SCCA. ITR can certainly run with ITS until it warrents it's own space.

[mlytle]

My thought is that you will only get less track time if these groups fill up. If they fill up, it's a good thing for SCCA. ITR can certainly run with ITS until it warrents it's own space.
[/b]

for wdcr, all the run groups are already pretty full. i won't really be about less track time, it will be about how to jam yet another class into an already full race weekend sked. should be an interesting comp committee meeting this winter when we try to sort this our for the marrs events.

[dj10]

My thought is that you will only get less track time if these groups fill up. If they fill up, it's a good thing for SCCA. ITR can certainly run with ITS until it warrents it's own space.

[/b]

Not only if they fill up but like on Sat. a VW rolled on the 1st lap of qualifying and we ended up with 2 or 3 laps for the whole qualifying session. Group 6 had a 6 lap race! Just something to keep in mind. More isn't always necessary better. Why not put the historical events with the vintage?

[lateapex911]

Dan, you fell victim to two things:

The glens conservative rules and the issues with a long track,
and

The regions desire to ensure the event made money.

Historic run groups are a regions way of making the entry count higher, and it protects them from losses.

But when things go haywire, and you're at the glen, and the region has sold lots of entries, there is little room for schedule adjustment. So somebody loses.

The Glen also, (Hard to believe with all of 3 cows within a mile of the place) has noise curfews, so there is a definate end to the available time. And add the fact that the Glen would rather rent to:

The Porsche club
or the BMW club,
or any driver ed club,
....or host a NASCAR event,

and it becomes apparent why it can be a real crapshoot for us SCCA types as to whether we actually get full races in when we're there, more than at any other track.

[Jiveslug]

Ok, my turn to chime in here. I think ITR looks pretty good so far, but I do see one vehicle that has been thrown in the mix that probably should not. That car would be the MKIII Toyota Supra. Granted, it is a 3.0 inline 6 with 200hp stock, but that engine is pretty maxed out. I have done a lot of research on these cars as a potential ITS racer, and I have discovered that getting one to make 230hp at the flywheel is tough. The guys out there who are doing that are the ones who are swapping out cams and the like. In addition, the mass of the car makes the sub 3000lb. spec weight hard to hit. These things weigh 3500lbs from the factory. Granted, they have a LOT of luxury junk to remove, but you would have to be able to pull 700-800 lbs off the thing in order to get it close, once you add in the driver and safety gear. I know that the thing has a good suspension set-up and aeros, but I really think that it is not going to be able to make up for the power deficiency. I would say leave it in ITS and even bring the weight down to 3250 in that class.

Just my thoughts...

[Bill Miller]

How come that car didn't get dual classification when all the other ex-ITS cars did???