ITR WHEEL SIZES

[BMW RACER]

Maybe I was only reading what I wanted. But I know ITR can run up to 8.5" wide wheels, but I also thought we could run up to 17" max diameter. Looking through the 2007 ITCS I noticed the E36 325 is still stuck with 15"/16" diameter. That really restricts wheel choice (Tirerack has none)

[JoshS]

My read: just because there is a wheel diameter on the spec line doesn't mean that the car has to use that diameter. The rules are fairly clear: "Cars classified in ITR may utilize any wheel diameter up to 17” or retain their stock diameter wheels if larger."

So go get those $200 17x8.5 Kosei K1 from Tire Rack. It's a no-brainer. Every ITR BMW will probably be on these wheels.

[JeffYoung]

Josh is right -- the intent when we drafted that was to listed the stock sizes on the ITCS and have the rule allow bigger wheels IF the stock ones were smaller. Go for the big ones John.....

[dj10]

Maybe I was only reading what I wanted. But I know ITR can run up to 8.5" wide wheels, but I also thought we could run up to 17" max diameter. Looking through the 2007 ITCS I noticed the E36 325 is still stuck with 15"/16" diameter. That really restricts wheel choice (Tirerack has none) [/b]



John, that's the way I read it also. I know it's a mistake, so don't lose any sleep over it and get the 17's if you want.

[JeffYoung]

Dan, just to clarify, not a mistake (although there are others on there that we need to correct see 968v. 944 S2 gear ratios). The ITCS lists the STOCK wheel sizes which you can run. The RULES then specify that you can run 17X8.5 if that is bigger than stock.

[ed325its]

The rule does not limit ITR cars to a maximum of 17" -- "Cars classified in ITR may utilize any wheel diameter up to 17” or retain their stock diameter wheels if larger."

[JeffYoung]

That is correct as well, and another reason why the stock sizes are listed. If they are bigger than 17X8.5, you can run them.

[dj10]

If they are bigger than 17X8.5, you can run them. [/b]



??? I don't think you can run anything bigger than 17 x 8.5

[JeffYoung]

"Cars classified in ITR may utilize any wheel diameter up to 17” or retain their stock diameter wheels if larger."

[GKR_17]

there are others on there that we need to correct see 968v. 944 S2 gear ratios[/b]

Make sure to notice the BMW 328 also. It has E36 years, but E46 specs.

As for the wheel question, what about the width? I would assume it was intended to allow larger than 8.5" width if stock, but that allowance is only stated for diameter. So if a car came with 18x9's it could run 18x8.5's but not the actual stock wheel.

Grafton

[JeffYoung]

Good points both, although (I can't remember precisely) I think the intent was no more than 8.5 wide with the thought being (someone checked this I think) that there aren't any/many 18X9 wheels stock on these cars.

Grafton/Dan, would one of you guys help me with filling in the last gaps on the BMWs on the ITR ITCS chart? I'm way behind on getting those to Andy/ITAC and having some trouble with the Bimmers.

Thanks guys.

[Andy Bettencourt]

So to clarify:

Cars may run their stock diameter and up to 8.5" in width

Cars may run any diameter ABOVE stock - up to 17" - and up to 8.5" width

Cars may run their stock diameter over 17" if so equipped - but no more than 8.5" width ever.

[Z3_GoCar]

Make sure to notice the BMW 328 also. It has E36 years, but E46 specs.

As for the wheel question, what about the width? I would assume it was intended to allow larger than 8.5" width if stock, but that allowance is only stated for diameter. So if a car came with 18x9's it could run 18x8.5's but not the actual stock wheel.

Grafton
[/b]

The reason for this is that it covers all 328's both the e-36 and e-46 variety, as with the Z3 2.8l everything with a 2.8l motor is lumped togeather in one spec line. So I guess I can install a double Vanos motor in my single Vanos car and be legal, although the gains seen from a single Vanos car would be different than the double the potential is counted as the same and the weight is applied accordingly. Stock there's a 3hp difference as given by BMW (marketing??) Is that 3hp difference really there? Does this mean I can also swap stock ecm's across two different motors? How about motor harnesses? Sure there'll be some wires disconnected.

As for the rims there's the 330i performance package on 18" rims, seems like since they're a optional stock size you'd get to keep 18" rims.

James

[Ron Earp]

We probably need to re-write the rule to simply state that 17" diameter 8.5" width wheels can be used on all ITR cars and are the maximum wheel dimensions allowed for the class. That will make the wheel issue clear and folks can choose accordingly.

Maybe James could help out with the BMW gaps. We've not had much luck recruiting for assistance on the fleshing out of ITR - lots of folks excited about it but the "work" part has been light.

Ron

[Andy Bettencourt]

Except smaller than stock is not allowed in IT.

[dj10]

We probably need to re-write the rule to simply state that 17" diameter 8.5" width wheels can be used on all ITR cars and are the maximum wheel dimensions allowed for the class. That will make the wheel issue clear and folks can choose accordingly.

Maybe James could help out with the BMW gaps. We've not had much luck recruiting for assistance on the fleshing out of ITR - lots of folks excited about it but the "work" part has been light.

Ron [/b]



Ron, I agree with you, keep the rule writing simple and to the point, and again use common sense.

Ron, I disagree with you about people helping. If Jeff asks for info, I and I know other have tried to help him. How much we did help is another question. :D

I can't believe that the rules allow 18" Wheels!!!??? I thought the whole idea was to limit the cars to a 17 x 8.5" wheel!! Period end of discussion.

dj

[JeffYoung]

I have had help from the BMW guys and it is much appreciated. Thanks guys.

Dan, the thinking was that if the car had 18X7.5 stock, they should be allowed to run them. I think the ITR ad hoc committee was pretty much agreed/unanimous on this and it probably won't change from our end. If you guys want to change it, send in a letter (not trying to sound rude, just saying what probably "is").

Again, Josh, Dan, others, thanks for the help on the Bimmers. Those and the Porsches, plus some oddbals are where the caps remain. Hope to have this complete soon.

Jeff

[Ron Earp]

I suppose I didn't pay a lot of attention to it in the since that I thought the idea was to have a 17x8.5 limit so that all cars have potentially the same wheel. Allowing cars with "wheel packages" from the dealer in some cases will be hard to prove or validate, especially as the years go by.

And James, thanks for any help you've sent Jeff along the way. I know we still have some more to go on the BMWs, but more so on some of the less known cars on the list.

Ron

[BMW RACER]

It was anticipation of impending turkey consumption that was clouding my reading ability!

YOU GUYS ROCK!

Thanks for the response.

I new I read 17" somewhere, should the ITCS get cleaned up to remove confusion?

[Knestis]

... Allowing cars with "wheel packages" from the dealer in some cases will be hard to prove or validate, especially as the years go by. ...[/b]
Luckily, that only has to be when cars are listed or updated, which is yet another good reason that the approved stock diameter be listed in the ITCS spec lines.

K

[dj10]

Grafton/Dan, would one of you guys help me with filling in the last gaps on the BMWs on the ITR ITCS chart? I'm way behind on getting those to Andy/ITAC and having some trouble with the Bimmers.

Thanks guys. [/b]



Jeff, I have the BMW Tech manuals on my computer. I'll try and fill in the blanks for you.

[JoshS]

I already sent everything to him except for the E30 M3. But feel free to check my work. I found that the brake rotor sizes were wrong for pretty much everything, not to mention the 6-speed listing for the Z3.

[dj10]

I already sent everything to him except for the E30 M3. But feel free to check my work. I found that the brake rotor sizes were wrong for pretty much everything, not to mention the 6-speed listing for the Z3.
[/b]

Cool, thanks

[JeffYoung]

Thanks guys.

Need help with the 635 as well. Not sure anyone will build one, but would be cool if they did. Don't have much on it (see GCR). DAn, you have a manual for that car?

Thanks again.

[dj10]

Thanks guys.

Need help with the 635 as well. Not sure anyone will build one, but would be cool if they did. Don't have much on it (see GCR). DAn, you have a manual for that car?

Thanks again. [/b]



I should as soon as I get a chance to get to my computer I'll check and I'll let you know one way or the other.

[Ron Earp]

ITAC, R committee, I really think this is a bad idea to let this BMW 18" wheel thing sit as is. I do not know definitively if any other cars in R have 18" wheels as an option. In fact, I'm not sure the BMWs have the option either - that is as a real option when the car is built, not as a dealer installed item. I'm sure the BMWs had it as a dealer installed item as BMW has plently of bling running around in the showroom and parts counter here in NC.

Either way, it'll be hard to document this as fact and I think what will happen is that the BMWs are going to have something different than the other cars in ITR, i.e. 18" wheels and we're going to see something similar to the E36s fiasco that we saw in ITS (hate to bring that up again). Seems the logical thing to do is cap it at 17"x8.5" and avoid the issue all together.

Ron

[Knestis]

If any cars were/are/will be available with 18" wheels as DELIVERED from the factory - no dealer-installed stuff - on an ITR-eligible car as delivered, then I think we have an obligation to allow them. That standard should also define the diameter listed in the ITCS.

K

[Bill Miller]

I agree w/ Kirk. If the car came w/ 18" (or larger) wheels AS STOCK, they should be allowed (but nothing wider than 8.5", regardless of stock width). The cars are new enough, that it shouldn't be that hard to find out stock sizes. And I think it needs to be listed on the spec line.

[lateapex911]

Allowign the stock diameter is consistant with current philosophy, and I suppoert it.

As it is, there are occasional issues with larger than "Stock" requests, and the ITAC has handled those, so I see no reason it can't handle a few more.

Stock=factory equipped = OK
Dealer equipped, even if it's a factory part, = Not OK, unless it was available on the car when it came on the boat from the factory,

[dj10]

Allowign the stock diameter is consistant with current philosophy, and I suppoert it.

As it is, there are occasional issues with larger than "Stock" requests, and the ITAC has handled those, so I see no reason it can't handle a few more.

Stock=factory equipped = OK
Dealer equipped, even if it's a factory part, = Not OK, unless it was available on the car when it came on the boat from the factory, [/b]



As long as your not going to allow the width to be more than 8.5", I can handle this too.

[Ron Earp]

If any cars were/are/will be available with 18" wheels as DELIVERED from the factory - no dealer-installed stuff - on an ITR-eligible car as delivered, then I think we have an obligation to allow them. That standard should also define the diameter listed in the ITCS.

K
[/b]

Ok, I can see that, but the cars that can have those will be speced in the line for that car, correct?

Ron

[Knestis]

Just as all the rest are, I would sure hope so. Someone shows up with wheels bigger (or smaller!) than allowed by their spec line in, say ITA, it doesn't matter what kind of case they can make at the track.

K

[Z3_GoCar]

.... I do not know definitively if any other cars in R have 18" wheels as an option. In fact, I'm not sure the BMWs have the option either - that is as a real option when the car is built, not as a dealer installed item. I'm sure the BMWs had it as a dealer installed item as BMW has plently of bling running around in the showroom and parts counter here in NC.

Either way, it'll be hard to document this as fact and I think what will happen is that the BMWs are going to have something different than the other cars in ITR, i.e. 18" wheels and we're going to see something similar to the E36s fiasco that we saw in ITS (hate to bring that up again). Seems the logical thing to do is cap it at 17"x8.5" and avoid the issue all together.

Ron
[/b]

Ron a Simple google seach turned up this Car&Driver article:

Car & Driver Test of 330i PP (http://www.caranddriver.com/roadtests/6978/bmw-330i-with-performance-package-page2.html)

I'd know of the perfromance package because I saw a few for sale while we were looking for my wife's 330, as well as auto-crossing aginst one with my street Z3. Unless someone wants to pony up the big bucks for BBS rims I doubt any good light weight 18" rims exist. My friend with the 330 PP would swap out for 17" Kosi's with Kumho's.

James

[JeffYoung]

Also, does wheel diameter really matter that much from a performanced perspective? Width is what we car about; wheel diamter is mostly just cheap gearing right?

[lateapex911]

Also, does wheel diameter really matter that much from a performanced perspective? Width is what we car about; wheel diamter is mostly just cheap gearing right?
[/b]

Right....

Tests have shown that all other things equal, going to the largfer size wheels can actually hurt performance.

As a matter of fact, SUVs that get the "upgrade" from say 18" rims to the big 20" rims, (with low profile tires) end up handling worse, riding worse, and the really bad part, they take longer to stop from 70MPH...lots longer.

Also, I've read a number of times now that auto writers prefer the smaller rims on certain cars over big rim option packages, for a variety of reasons, some of which are performance based.

And yes, no matter what, ITR max width is 8.5", max diameter is 17" or whatever came stock if that's greater than 17".

[GKR_17]

Ron a Simple google seach turned up this Car&Driver article:

Car & Driver Test of 330i PP (http://www.caranddriver.com/roadtests/6978/bmw-330i-with-performance-package-page2.html)

I'd know of the perfromance package because I saw a few for sale while we were looking for my wife's 330, as well as auto-crossing aginst one with my street Z3. Unless someone wants to pony up the big bucks for BBS rims I doubt any good light weight 18" rims exist. My friend with the 330 PP would swap out for 17" Kosi's with Kumho's.

James
[/b]

I assume from the article, that package was available on the 2004 models. Even more interesting than the wheels are the "hotter cams" and six speed transmission. Since they were optional equipment they will be legal unless noted otherwise if that year model is included in the spec line later on, along with the already mentioned 18s.

Grafton

[greendot]

Allowing the stock diameter is consistant with current philosophy, and I support it.
[/b]



If any cars were/are/will be available with 18" wheels as DELIVERED from the factory - no dealer-installed stuff - on an ITR-eligible car as delivered, then I think we have an obligation to allow them. That standard should also define the diameter listed in the ITCS.

K
[/b]


Just to keep the record straight, it may be current philosophy or percieved obligation as pertains to ITR, but it has not always been the philosophy that IT used. Case in point, when I first started running a second gen RX7 in ITS I had a conversation with (I think it was) Bob Burns about the 89-90 GTUs model came from the factory with 16" wheels and weren't they legal although they were not listed on the spec line. He said no and the reasoning was that "everybody with an RX7 would need, or think they would need, to buy 16" wheels."

Lo and behold, the GCR the following year had a specific mention in the spec line saying no 16" wheels.
Now I have to say, that's the quickest service I every got from "Central Office", especially since I didn't "write a letter" :lol:

[lateapex911]

Thats a very good point, yet the ITCS list is litterally littered with cars that list stock diameter as "15 or 16 inches". In the RX-7s case, it was decided to make the GTU guys buy smaller, rather than allow the non GTU guys to opt to a larger dimeter....hmmm.

[greendot]

OK, just to be perfectly clear for those that are not too familiar witht he RX7's various models, there was in 1989 and 1990 a limited production model called the GTUs which is different than the many other years models called GTU. That is the only non-turbo model that came with 16" wheels, but one of the other features was a closer ratio 5th gear which is a very common upgrade in all 2nd gen cars.
I'm not wanting to :dead_horse: , just adding some insight, which I have very little of. :wacko:

[Bill Miller]

OK, just to be perfectly clear for those that are not too familiar witht he RX7's various models, there was in 1989 and 1990 a limited production model called the GTUs which is different than the many other years models called GTU. That is the only non-turbo model that came with 16" wheels, but one of the other features was a closer ratio 5th gear which is a very common upgrade in all 2nd gen cars.
I'm not wanting to :dead_horse: , just adding some insight, which I have very little of. :wacko:
[/b]


I'm not a Mazda guy by any stretch of the imagination, but wasn't the GTUs also a bit lighter? I seem to recall that it was more of a 'Club Sport' type model (less extra BS, more track-ready). I thought I heard once that none of the GTUs cars came w/ power windows or AC.

[greendot]

Close to true. I've had two and they both had air, but Club Sport would be a good description. They came with the brakes, suspension and wheels (hence the 16") that the Turbo cars had. Otherwise a good shopping of otherwise off the shelf stuff available on other models, such as no sunroof, aluminum hood, aluminum spare wheel. Only the 5th gear ratio and the 4.3 axle ratio were unique. They were focused on some showroom stock race category back in the day. The "Turbo" brakes and suspension were also available on other non-turbo uplevel models.