Teach me about ITR 325's

Ron Earp said:
Oh my goodness!!! :o

You mean the designers of The Ultimate Driving Machine have made an engineering error that leads to their creation having a perceived flaw for track use?

No way, I don't believe it. All the BMW Club track days start out with "Your BMW was born and bred for the track, it'll be fine to use just as is...."

Heaven forbid we get uneven pad wear and a really squishy pedal.....Jeez, I wish that was all I had to worry about on my IT dinosaur.
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Easy Ron, I don't want to see you stroke out on us.:)
 
Doc Bro said:
And air as a bushing is justifiable in your mind....give me a break. Is air then justifiable as a washer bottle or wiring harness in your mind?

R
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Can you cite someone/some car who actually does this and claims it's legal? I think it's bantered about but in reality it's internet folklore.
 
Andy Bettencourt said:
Can you cite someone/some car who actually does this and claims it's legal? I think it's bantered about but in reality it's internet folklore.
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No AB. I know no one. But I remember the discussions about it ad nauseum, as I know you do.

My comments were only directed at the fact that the GCR offers no clarity on the questions I posed. Next thing you know I'm a rules creeper. As I stated mine are stock rubber, period. Reminds me of the RX7 1st gen rear wing guy.....easy to see why he made the mistake....even easier to see why he got beat up here. I guess I learned my lesson....I'll spend more time with my family and less time on IT.com. I'll let the "pro's" chase windmills.

R
 
*I* don't feel like the GCR has to offer clarity to the questions you posed Rob, because *I* don't feel you have posed reasonable questions.

The bushings on your racecar are not free. Suspensions bushings may be replaced. Has nothing to do with brakes. By your logic, engine mounts would be free because they are bushings. Just not true.

The section of the ITCS in which an allowance is given IS applicable.
 
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While we're kicking this can down the road, I would like to mention one of my pet peeves. There is a word that is used a lot in this forum that sometimes only adds to the confusion hereabouts... the word is "free", as in "...bushings are free", "pads are free", etc, etc.

The word "free" does not exist in the ITCS, and to my knowledge, never has. Since the word "free" means many things to many people, and since it is not in the ITCS, I would suggest we quit using it.
 
JoshS said:
Here you go Mike:

http://www.turnermotorsport.com/html/detail.asp?PRODUCT_ID=CBMW1

The issue is that all of these cars have single-piston sliding calipers, and the caliper slides on metal pin, but with a rubber bushing. The brake can feel really squishy and cause uneven pad wear due to the flexibility in the rubber, especially as the pads get low and the piston is extended.

These metal replacements are very common for track cars and BMWCCA club racing.
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there are ways to avoid squishy pedal and angled pad wear as they get low without using illegal metal bushings.....
 
JoshS said:
I've never seen any acknowledgement by BMW for the diff mount/trunk floor problem, just like I've never seen anything for the E36 problem.

Therefore, such a dealer-installed repair would not be legal in IT, even if a verbal agreement with a BMWNA employee allowed BMWNA to pay for the repair.
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Just because the GCR mandates that the manufactures provide XYZ (in this case it's a document stating dealer repair methods) to a racer doesn't mean that the manufacturer will. In this case of drastice chassis repairs, there is probably legal liability reasons for the absense of such a document along with proprietary reasons. Just because the document doesn't exist doesn't means it strictly illegal either.
 
Wow...never knew THIS was where the rules and regs soap opera went!

For the record, Air bushings. It is said that RX-7s (early cars like mine), when lowered will bind the rear axle and destroy U joints. That's because the stock upper trailing arm pulls the axle forward at teh top at that point in it's travel. The rules allow the addition of traction bars, and with a properly designed traction bar, one can do what you wouldn't normally think of: use really soft bushings as opposed to the typical hard replacements, in the upper trailing arms. This allows the axle to rise and fall without twisting forward, and removes the binding.

Now, I haven't crawled under anyone's RX-7 in a long long time, but rumour has it that not only are the bushings just not replaced at all, but the upper trailing arms are just left off certain cars. Honestly, it wouldn't surprise me, but, at the front, my bet is all RX-7s are legal. Mine runs hard foam in the upper trailing arm bushing locations. (I can't imagine the racket air would create if used as a bushing!)

Air bushings? Silly boys!
 
A bushing made of closed-cell foam would in fact be a composite of an elastic material and air. Not a problem under the current regime. Removing the [whatever] altogether would be OK if the rule allowed replacement or "removal." Remember some rules (e.g., the sway bar allowance) didn't actually allow that, although in this example the language was changed.

We should all - myself included - read Gary's really good point a few more times.

K
 
Andy Bettencourt said:
The RX-7 had many different (both high and low production versions) that make up the ITS RX-7. The big brakes came on many versions, the rear wing on even more and the non PS cars were actually the lower end units. The 5th gear was indeed from the GTUs of which plenty were made in 1989 but just 100 in 1990.
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It has been pointed out to me offline that I may have inferred that ITS RX-7 drivers were creating a model that didn't exist by cherry-picking the best stuff from different models. What I was trying to do for Rob was to show him that the items he listed for the most part, were not low production stuff and indeed available on all RX-7's.

The model that is being created is the 89-90 GTUs. The desirable part from this model is the 5th gear ratio (.76 instead of .71). And even at that number, it is worse than most everything in ITS.
 
Andy Bettencourt said:
It has been pointed out to me offline that I may have inferred that ITS RX-7 drivers were creating a model that didn't exist by cherry-picking the best stuff from different models. What I was trying to do for Rob was to show him that the items he listed for the most part, were not low production stuff and indeed available on all RX-7's.

The model that is being created is the 89-90 GTUs. The desirable part from this model is the 5th gear ratio (.76 instead of .71). And even at that number, it is worse than most everything in ITS.
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My opinion is when you can change so many pieces and create a parts room model that exceeds the model that was classified then there should be a re-evaluation. I think that some of these RX-7 models should be on an individual spec line just like the 92 325i should be on a different spec line from the 93-95 325i
 
Rob, on the BMW, is that due to OBDI v. OBDII? Or is it some other fundamental differences between the two different groups of model years?

I'm just curious, didn't realize there were differences in the E36 run.

Thanks.

Jeff
 
robits325is said:
My opinion is when you can change so many pieces and create a parts room model that exceeds the model that was classified then there should be a re-evaluation.
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But you are infering by saying 'parts room model' that what is on track never existed when in fact, peple are creating the 1989-1990 GTUs. Here are some facts for you:

It has no more HP than ANY other 89-91 RX-7
It has the SAME brakes as the GXL
It has the same rear wing as the GTU and GXL

The differences were a 4.30 viscous (vs 4.10 open) and the slightly upgraded 5th gear of that the only thing applicable to IT racing is the transmission...and oh yes, it did have an aluminum hood that it shared with the convertible.

And it wasn't limited production like the MT 325. Only about 1100 were made but that was due to lack of demand, not a limited production run. It was a fully documented model in the brochures.
 
JeffYoung said:
Rob, on the BMW, is that due to OBDI v. OBDII? Or is it some other fundamental differences between the two different groups of model years?

I'm just curious, didn't realize there were differences in the E36 run.

Thanks.

Jeff
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The 92 had different engine internals; springs, pistons, non-vanos, and different cams as well as a different ECU and harness (eliminated by the ECU rule now)
 
robits325is said:
My opinion is when you can change so many pieces and create a parts room model that exceeds the model that was classified then there should be a re-evaluation. I think that some of these RX-7 models should be on an individual spec line just like the 92 325i should be on a different spec line from the 93-95 325i
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All that would do is split out the 86-88 Rx7s which would have to be at a lower weight due to the lower horsepower.
 
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