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Posted by: Joseph Mills Feb 7 2003, 05:19 PM

I know a lot of you at this site either race or autocross and may be able to give me some insight into my predicament.

I'm replacing some very old Yoko 008SII rubber on my 914. They are mounted on 7" & 8" 16 inch Fuchs. The front tires are 225/50s and the rear are 245/45.

Using Tire Racks cross section specs of the tire width, the Hoosiers are basically the same size as the Yokos in the rear, but the 225/50s for the front appear to be about 1/2" wider.

My only option would be going to 16" 215/40s which provides a narrower cross section width, but is nearly 2 inches smaller in diameter (a difference that I would think undesirable).

I know that fender clearance varies from one 914 to another, but I am curious if anyone else is running 225/50 Hoosiers up front on a narrow bodied 914?

Help!! AX season is almost here! Many thanks.

Joseph

Posted by: Mueller Feb 7 2003, 05:30 PM

I was running 225/50/16's on 8" wide Phonedials (offset 23mm) on the front of my stock bodied 914 for a while......The fit was fine..the only spot the tires rubbed was at the front of the fender well at the very bottom, a little "tweaking" of the metal solved that.

Posted by: Demick Feb 7 2003, 05:31 PM

Smaller diameter is *generally* considered an advantage for autocross (not a disadvantage as you mention).

Posted by: Joseph Mills Feb 7 2003, 05:55 PM

I can surely understand the advantage to the lower unsprung weight of the smaller tires, plus the advantage to the car being 1" lower, but I was referring to the 2" difference I would have from the diameter of the front tires to the rear tires. Seems like that might upset the car's handling, but maybe not. Any experience in this area?

Mueller, were those Hoosiers you were running?

Thanks.

Joseph

Posted by: Dave_Darling Feb 7 2003, 06:11 PM

Mueller, you didn't have Hoosiers on there, did you??

The figure I've heard quoted often is, "205-width Hoosiers are really 225s."

Conventional wisdom is that 205 is all you can fit under stock fenders, unless you're really lucky, or have modified the fenders somehow.

I know a number of 914 racers that run 205-width Hoosiers all the way around. They seem to like them. ( <- understatement )

--DD

Posted by: Joseph Mills Feb 7 2003, 06:22 PM

Why is it everytime I perceive a simple upgrade to my 914, I'm suddenly cast in a whirling chasm of options that go way beyond my original intent of modifications? I'm getting dizzy (actually I'm getting a new dizzy)....

Okay. So should I dump my genuine 16 7 & 8" Fuchs for some 15 6 & 7"s??? I've got some nice looking Italian Fuch replicas for the street. It does provide more clearance and a smaller footprint from which to choose.

But can you ever have too much rubber? My first priority is optimized autocross handling.

Anyone interested in some 16" Fuchs and 48IDA Webers?

Posted by: Mueller Feb 7 2003, 06:26 PM

No I didn't, I believe the tires had been Dunlap SP40's or something like that.....

As DD mentioned, many 914's run the 205/50/15 Hoosiers which are closer to 225's than 205's.....so I would think that the 225 Hoosiers are even wider than the norm for a 225 sized tire....

Check the Rennlist Racing Forum and ask if anyone has a used 225/50/16 Hoosier to try out

Or stick one of those 245/45's on the 7" rims up front to test the fit....that way the most you'll be out is a few bucks for the mounting and dis-mounting of the tires...no spin balancing needed since you'll be taking them right off after testing....

Posted by: URY914 Feb 7 2003, 06:26 PM

Tell us what you're running for for wheels?

Posted by: chunger Feb 7 2003, 08:45 PM

215/40 R16's give you the same final diameter as running 205/50 R15's that a lot of people seem to use. . . would not lower the car the full 2 inches. . . only half of that. . . height measures the radius not diameter of the tire. Set of 16x7 fuchs I just bought have 214/40 16's on them. . . They were fine on a V8 street car.

-'Chung

Posted by: Racer Chris Feb 7 2003, 09:32 PM

IMO, the 205/50-15 Hoosiers are perfect for a narrow bodied 914. Go with 7" rims all around for convenience, but the offset will be critical for clearance in the rear. BTW, they fit fine on 914 Fuchs 5.5 x 15 as well.

Posted by: J P Stein Feb 8 2003, 11:48 AM

Joe2:

It would seem to me that you must have some flares on your car in order to run your present tire/wheel combo, is this correct?

Do you want to "optimize autocross handling" or just put on stickey rubber? There is a difference and (coupled with the "narrow bodied car") that may be causing your headaches.

The simple answer is *I* don't know anyone running 225 X 16 Hoosiers in front.

How's about a pic of your car. It's worth a thousand wurds.

Posted by: campbellcj Feb 8 2003, 03:50 PM

On my ravenna car, the 205/50 Hoosiers on 15x6 pano's were a very tight fit in the rear (stock fenders, not even rolled). They worked great but I can't imagine anything bigger without significant tweaking on the car. I may try the 215/40's with 16x7's on my current car, which has already been tweeked for clearance.

Posted by: Joseph Mills Feb 8 2003, 05:52 PM

I'm sorry - I didn't make myself clear. The front fender well is stock, however the rear fender well has steel 911 fender wells installed by the PO. Sounds kinda nutty, and purists would not care for it. But I think it looks pretty cool and makes it unique. What do you guys think? I will try to post a pic of it and I'm working on a small site page with more images and a list of modifications that I'll get done soon.

Mueller, that is an excellent idea on swapping the Yoko 245/50 to the 7" rim! According to the The Tire Rack, a one inch narrower rim will reduce that section width by almost 4 tenths of an inch - which would make it just a 3 tenths of an inch wider than a Hoosier 225/50. Gets confusing! So if it fits then a 225/50 would certainly fit. I'm going to try it.

I guess a question I have for all of you now is this: Say the 225/50 does fit (may have to roll the fender?), what would you do? Keep the 16 inch wheels, or sell them and acquire some 15 inch rims and go to smaller tires?

The only downside to the setup I have now is that in slow speed turns, the steering wheel effort is very high. Am I overlooking any other possible negative factors?

Thanks so much for your help. I wish I could contribute more than just questions - maybe someday I will.

Joseph

Posted by: Joseph Mills Feb 8 2003, 06:08 PM

Evidently I did something wrong in trying to post my photo. We just finished this site page so click on the URL below to view some photos as well as a list of modifications by the PO.

I just purchased this car late last summer. All I have done to the car so far is install fiberglass bumpers, shifting bushings and replace the exterior rear view mirror. I need to lose the 48IDAs and am considering a mallory dizzy.

The rear fender clearance is tight. When I drive it on the street with the AX wheels on when I hit a dip a rear tire will momentarily chirp. Even with the old rubber this car sticks and handles great - I just want it to be better!

Here's the URL: http://www.josephmills.com/porsche914/index.html

Thanks

Joseph

Posted by: SirAndy Feb 8 2003, 06:30 PM

the picture file still had the macintosh header to it.
on pc's you can't open it that way unless you have photoshop.
also, for all us PC users, if the file does not have the proper extension,
we can't open it unless we rename it. just add a .jpg to the file before
posting, that will save us some headaches.

Andy

Posted by: campbellcj Feb 8 2003, 07:45 PM

Here is the pic -

Posted by: J P Stein Feb 8 2003, 08:58 PM

Chris, have I ever accused you of puterwonkomania? If not, I shoulda'.....a freakin' whiz. No wonder Boeing pays you the big bucks.

OK, tires. I am presently fitting 225 X 50 X 15s (soon to be 225 X 45), on 7 inch wheels, at the front of my car. In a word, NOT..but a caveat.

Sure, they snuggle up in there, even with the suspension compressed. You just can't turn...a small problem.
The main problem is heigth.....ride height and tire height.

Your car seems (from the pics) to be pretty high up there.
This not the hot AX set-up.

At a ride height of 4.75 in (measured to the front doughnuts), all is well. At 3 inches(on the bump stops) no way. I'm flaring++ the front fenders to clear. One side is done.

These tires are about an inch shorter than the 16s would be. I could raise the ride height an inch, but that ain't good cause it dials in positive camber.....somewhere around .65 per for inch of ride height. I ain't hunkering the car down just so it looks cool.

IMO, you'll go faster with smaller Rspec tires with 2 deg negative camber at both ends and the car down lower.

Posted by: Zeke Feb 8 2003, 09:02 PM

I like the SC flares!

Posted by: J P Stein Feb 8 2003, 10:16 PM

Here's a "before" pic

Posted by: J P Stein Feb 8 2003, 10:17 PM

And here's one after...I can't figure out how to get 2 on one post. Humm.....the contrast in this pic sux, eh?

Posted by: campbellcj Feb 8 2003, 11:30 PM

JP - I'd fix the contrast in your pic for ya, but I might have to send you a bill

I've been trying to figure out this car, which coincidentally mine will be a virtual clone of (except not a factory six). This is Topper Chasse's 914-6 which I believe is running 16x7's with 8" or maybe even 9" slicks. (Perhaps they're 15's, I forget). It obviously had some tweaking done but it's pretty subtle, yet I recall that it appeared to have serious rubber underneath when I looked at it briefly in person.

Anyways, it definitely shows that one can stuff a decent amount of tire, and turn a decent lap time, in a narrow-bodied car. He really hustles this puppy around Willow.

Should I even mention that I think he's even older than JP

Posted by: J P Stein Feb 9 2003, 12:18 AM

It apperars as if he may have pushed out the rear fenders using the old porta-power trick. Hard to tell from that angle, but I think I see the fender pooched out behind the rear wheel. If that is the case, it's a nicely done job.

Posted by: J P Stein Feb 9 2003, 11:02 PM

Here's a better view of that flare.