Confirmation on rim width for AP and FM classes Options

[grantsfo]

In my reading of the PCA rules in zone 7 914 AP and FM classes allow 6.0" rim width. Is this correct? I'm thinking I'll complete a few more AP class AX and then jump into FM class when I upgrade my engine. I wanted to go with 7" wheels but it appears I can only go to 6" in FM class. Is that how you other FM class people see the rules?

[Trekkor]

Grant, you can run any size rim and tire combo you like. DOT tires only.

The rules state:
" Street tires: Any street tire/wheel combination may be used. Tires must be DOT approved.
Race tires: Race tires may be used, but may not be mounted on wheels wider than seven inches or one inch wider than stock, whichever is greater. This leaves open the possibility of cars being competitive on very large street tires. "

Soooo....As long as Andy was on 7" rims he can stay in FM. Otherwise he goes into "X" with Steve Nieslony. (IMG:http://www.914world.com/bbs2/html/emoticons/unsure.gif)

Leaves a lot of room for choices, doesn't it?

KT

[Demick]

Ap you are definitely limited to 6" wheels. If you make motor changes, then you skip by Bx and into Fm. Like Trekkor says, in Fm, wheel width is unlimited on DOT tires, but limited to 7" on race tires.

Demick

[Porsche Rescue]

It is my understanding that PCA rules say anything more than 1" wider than factory bumps you up. That would make 6.5 ok.

[Mueller]

QUOTE (Porsche Rescue @ May 24 2005, 06:25 PM)

It is my understanding that PCA rules say anything more than 1" wider than factory bumps you up. That would make 6.5 ok.

in our region it's .5".....so a factory /6 could run 6.5" but not a /4 if I read it correctly....

[grantsfo]

Ok so looks like I could go with 7" and play in FM with an underpowered car. Better than winning AP where I have no one to run against. I'm sure I could do a few tweaks to my 1.8 like cams, higher compression etc that would put me in the game while I work on getting a nice 2056 built.

Trekkor, where did you find that rule that says one inch larger or 7" which ever is greatest

Anyone have a nice light set of 15 x6.5" or 7" wheels they want to sell before I have a set of custom wheels made?

[Demick]

QUOTE (grantsfo @ May 24 2005, 06:53 PM)

I'm sure I could do a few tweaks to my 1.8 like cams, higher compression etc that would put me in the game while I work on getting a nice 2056 built.

Cams and compression are not tweaks. They requre a complete teardown. So you might as well just build the 2056.

Demick

[Randal]

Trekkor's quote is correct for FM. 7" rim is the limit, but you can race tires, including the cantilevered ones..

[Mueller]

QUOTE

" Street tires: Any street tire/wheel combination may be used. Tires must be DOT approved. Race tires: Race tires may be used, but may not be mounted on wheels wider than seven inches or one inch wider than stock, whichever is greater. This leaves open the possibility of cars being competitive on very large street tires. "

so...how wide does the street/DOT tire/wheel combo have to be in order to be equal to a "race" tire on a 7" wide rim????

285's on a 10" rim or what???

is it even a fair question??

[grantsfo]

QUOTE (Demick @ May 24 2005, 05:59 PM)

QUOTE (grantsfo @ May 24 2005, 06:53 PM) I'm sure I could do a few tweaks to my 1.8 like cams, higher compression etc that would put me in the game while I work on getting a nice 2056 built. Cams and compression are not tweaks. They requre a complete teardown. So you might as well just build the 2056. Demick

Yeah but that means finding a 2.0 with good heads etc. I was thinking of having heads on my 1.8 shaved a bit to rasie compression. That isnt buying a 2.0 cracking the case buying, new sleeves, pistons, etc, etc. I may just stick with my wimpy stock 1.8 the rest of the year knowing I'll never catch the fastest of you in FM.

[Randal]

You could run Hoosier DOT tires in P275/50ZR15 and with 9-10.5 inch rims you'd have a footprint of 10.1." Autox compounds aren't available in 15", but they are in 16" where an 8-10" rim width would net a footprint of 10.3; and they are available in autox compound. Expensive but available.

BTW that is about an inch bigger than the 9.5" race tires we run on 7" rims.

[grantsfo]

QUOTE (Randal @ May 24 2005, 06:23 PM)

You could run Hoosier DOT tires in P275/50ZR15 and with 9-10.5 inch rims you'd have a footprint of 10.1." Autox compounds aren't available in 15", but they are in 16" where an 8-10" rim width would net a footprint of 10.3; and they are available in autox compound. Expensive but available. BTW that is about an inch bigger than the 9.5" race tires we run on 7" rims.

Thanks Randal, I'll probably wait on going real wide until I have a motor that can turn those big wheels and tires. I think a real lightweight set of 15x7 with DOT hoosiers with AX compound will be a huge step for me. I'm not terribly greedy for grip right now. I can get my car moving pretty quick with my Yokohama's and 5.5" wheels. Slicks and wider wheels will give me a little more stability and better grip. I wish I had the cash to just upgrade to a 2056cc engine but my new business is sucking my modication budget dry currently.

[Randal]

Before I went on to race tires I asked a lot of question of the then GGR management about the tires rules.

As it turned out no one could answer the questions; in the end it finally went to Hank Watts, who I think was a major contributor on the original rules, who did answer my questions.

It was clear that running a 7" rim with a racing tire was acceptable.

Whether or not you could actually run on "unlimited rims" and/or a 275 Hoosier "DOT” tires in AutoX compounds, was not clarified.

I know what the rule says, but I'd sure want to get confirmation before spending a ton of money on 275 tires and 10" wheels.

[Porsche Rescue]

Mike, I suspect there are few people who would know enough to challenge, but I think 6.5 would be max for a factory six as well. Widest factory wheel was the 5.5x14 Fuchs and 5.5x15 Mahle "gas burners". Standard steel was 5.5x15. Probably get an argument, but I believe that if any 6x15 Fuchs were installed it would have been by the dealer (which might be OK, not sure).

[nebreitling]

Demick's got it right. last time i checked, i thought the rules were pretty clear.

grant, definitely just spend the money on suspension and tire and wheel right now. 6.5 or 7" shouldn't make much of a difference. when you're ready for an engine, you'll just need to drop it in an otherwise prepped chassis.

when it comes engine time, remember though: any non-stock cam -- regardless of displacement -- puts you in Fm.

[nebreitling]

QUOTE (grantsfo @ May 24 2005, 06:11 PM)

Yeah but that means finding a 2.0 with good heads etc. I was thinking of having heads on my 1.8 shaved a bit to rasie compression.

not worth it grant. you're going to tear down an original 1.8, lower the deck, re-ring and hone, all for another 10 (max) hp? that'll cost you $500 in machine work, and you've still got a worn bottom end and heads.

i'd stick with what you've got for now, build the hot 2056 in the off season, and aim for being competitive in 2006.

[Demick]

QUOTE (Porsche Rescue @ May 24 2005, 08:12 PM)

Mike, I suspect there are few people who would know enough to challenge, but I think 6.5 would be max for a factory six as well. Widest factory wheel was the 5.5x14 Fuchs and 5.5x15 Mahle "gas burners". Standard steel was 5.5x15. Probably get an argument, but I believe that if any 6x15 Fuchs were installed it would have been by the dealer (which might be OK, not sure).

The GGR PCA rules classify the 914-6 separately from the 914-4. 914-6's are allowed 6" wheels in stock class, and 7" wheels in the improved and productions classes.

[greglepore]

I use 15x7 cookies and Hoosier cantilievers. Have run the car on big DOT Hoosiers (275's on 9's) and the canti's stick better, even in R35. Plus, they have a much lower rolling diameter, effectively lowering all of your gears and giving you greater squirt out of the turns.

On top of that, you can get them slightly used from John Berget for around 300-350 a set.