Got more info on those centerlines and what tire to get???

Deep6

Registered User
Ok folks, It's getting pretty bad, I originally intended for those "pep boyz futura" tires to only last a year but with a 620 tread wear rating, I managed to squeeze 3yrs out of em'.

But they are going to give up the ghost really soon and since I have to plunk down significant cash to begin with, I might as well consider upping the rims on the car as well. But you see I live in a strange world and I don't want to add any additional unsprung weight to the car. But how will I do this if I want a bigger wider contact pactch????

Well, I just recently saw that centerline has released a new rotary forged aluminum rims that are *significantly* lighter than cast aluminum alloys by most major manufacturers. Example: their 17" rim that I'm looking at weighs a mere 13.5lbs. Compare that to 20+LBS for a cast 17" rim.

Here is the lowdown on the rims though, since they are mainly made for the rice crowd, these rims come in a 42mm offset and they are a 17x7" rim. The guy by the name of emmett from "ultra performance" in Arizona, told me that he could have the 4 rims shipped to my door for $1056. That computes to $264 per rim (shipping included) is that a good price?

But more importantly, I'm concerned with changing the offset to a 42mm up from 39mm. What positive and negative effects will I see by doing this?

Also, is getting a 17"x7" rim worth it? I was looking to fit a WIDER contact patch on my car for better grip, but with a rim thats 1" thinner than our stock 16x8", what's the widest contact patch that I could fit to these rims, maintaining stock circumference of course?

Last but not the least, I'm looking for a good set of skins. My requirements are different however, I need a good Z rated tire that is also "all-season". I know that I inherently sacrifice some ultimate dry handling by going this route, but I also want a tire that can "do it all". I've been considering the BF Goodrich G-Force KDWS. Tire rack seems to have good deals on this tire in the 17" size for around $130+ per tire. Unlike the heady $205 I was quoted by good ole' emmett....

Anyway, I know this is long winded but I'm looking to be pissing away around $1500+ pretty soon going this route, I wanna get my $$$$ worth. Any and all suggestions welcome.
 
Uhh our stock wheels are 16x7 bubba

Post a picture of these thoug. The 42mm thing shouldn't make much difference. The boyd coddingtons I have stick out a bit more and I think they are a 43mm offset.

Edit: What makes you think you need a z rated tire anyways? You must be travveling pretty fricken fast constantly to need a z tire. I just buy the cheapest/widest tire I can with the best dry traction rating and I am happy. Not like I am going to be doing 140+ for more then 30 minutes anyways
 
Skins for your wheels?

Are you planning on running 40's or 45's. Just p/u some 18 x 9 Cobra R Replicas and had 245 40 18 Kuhmo's mounted. Looked totally lame. Too much space between the wheel well and the tires. My car's even lowered. Ended up going with Nitto 255 45 18's. I wanted Centerline too but couldn't find anything for our cars.
 
A world of difference

Drive a Z up against even an H rated tire and you'll know right away. A stiffer sidewall is the first benefit, handling is much improved. Traction is also generally better with a ZR tire although this can differ by brand. Heat retention properties and a number of other factors are different by tire rating, it's not all about sustained speed. I could roast my h-rated tires for 100 feet or more without power braking to get it started and can maybe get 15 feet out of my ZR's.

One thing Joe, our stock wheels are 16X7.

A basic idea for wheel pricing is $130-200 is pretty typical for a conventional 17X7 - 17X8, the forged process tends to push towards the top of that or well past into even the $300 range per wheel. You can easily do a wheel and tire package in 17X7 for under $1000 if 17's are what you're after. If weight is your concern, forged is the way to go.


Adam Mullen
The SC Kid
 
Thanks for the feedback...

Sorry about the brain fart. I could have sworn someone told me that we had 16x8 rims stock. All the merrier then, at least I wouldn't be "down grading" on width.

And it sounds like going to a 42mm offset isn't going to seriously negativly affect the cars ride and handling?????

Adam, I figured that spending this kind of money per rim is worth it since I want to accomplish two goals 1. Bigger wider tire 2. Lighter weight.

If that means I've got to pay 64$ more per rim, I figure that a stark raving deal to shave some unsprung weight.

For the reasons adam mentioned, I am interested in getting a Z ratred tire. Adam is right, I have those pep boyz tires and those are 225/60r-16 tires. They are "S" rated however. Even though I have never taken my car past 100mph, I could immediately tell that our cars "Don't like" an "S" rated tire. Too much sidewall flex for the stiffness specified by the stock suspension. In firm ride I could actually feel the tread squirming over uneven pavement.

Ride was much smoother though....

So anyone have suggestions on what brand tire that I'd have good "all season" results with? And what would be the widest tire I could fit to a 17x7 inch rim.....
 
I can't speak for snow

I have never driven my SC in snow but from my experience the finest tire I have found is the Fulda Extremo. www.fuldatires.com can help you find a dealer. They are a european sport tire and not widely available here, but ask around at some of the porsche enthusiast sites and what not. They are the number one tire on the autobahn. I believe most run 245/45/17 on the 17X7's.


Adam Mullen
The SC Kid
 
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First of all, you are not going to get good "all-season results" with a big performance tire on the car, I don't care if it's an all-season tire or not. All-season tires are really Three-season tires for your geographical location. IMHO you should consider keeping your stock wheels to put a set of FOUR good winter performance tires on, you'll get through a lot better that way. And you'll save your nice shiny new rims from the ravages of winter. Here where I'm located (not far from you, Toronto area), I've done just that for the past 3 winters, and have done fine, even with the car lowered.

Now back to the main question ... 3 mm difference in rim offset is not going to be felt on a street car, however, for appearance, you may notice it, as the rims and tires will be tucked under the car a bit more. For a 17x7 rim, I would recommend either 235-50-17 or maybe 245-50-17 if you're trying to keep it close to stock tire diameter. A 245-45-17 would go on the 7 if you want something a bit shorter, but that's a squeeze for a 245-45, they should be on at least a 7-1/2" wheel. 235-45-17 would go, but now you're talking about a tire that is about 1-1/4" smaller diameter than stock, now you're getting into the big wheelwell gaps. Remember our cars have HUGE fender openings, that's why I went with 255-45-18 on my new rims this year, they are actually about 1/4" taller than stock. With the car down on Eibachs, the fender gap is the same almost all the way around the tire, a nice look.

hope this helps
cheers
Ed Nicholson
SCCoO
 
Ed, it is a nice look post a pic

If you've got one I think you should post a picture Ed.



Adam Mullen
The SC Kid
 
OK, if you insist ... :D


removed so I can post elsewhere ...

cheers
Ed N.
 
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Ed...

I don't think that I'd have the Loot for 18"s even though I think they'd really look good on the SC, I just couldn't swing the extra money. Plus I remember reading somewhere that in a comparision test of 17" and 18" rims (same overall rolling diameter) the handling was the same. The 18" wheels that centerline makes are 14.5lbs, so I'd be gaining an additional 4lbs of unsprung weight, but let's not forget the increased weight of 18" tires too. Any weight savings from the rims will be eaten up by the bigger tires. For me it's really more about performance and economy rather than "looks". Don't get me wrong, I love to make my car look good, but I would rather spend money on a modification that added performance to my car rather than something that made it look pretty.

If I ran a 245-50ZR-17 tire, that would only be a 10% reduction in aspect ratio from the stock tires, but it would 20mm more tread width. So I guess that I would still get a "rubber doughnut" look huh?

My car isn't lowered yet, but right now since I'm doing a little thing at a time, I guess I won't be able to do much until I can get lowering springs.

I wonder if those FULDA tires sell for a good price....
 
Thanks for the website adam,

Unfourtunatly I don't "spreichen ze deutch" and I couldn't figure out my a$$ from my elbow there. :)

I'll try running around and doing more searches. I usually trust the general populace here. I know the question has been asked a millions times (who makes the best tire) but I won't ask it. Rather I'd ask everyone else who has a "all season" tire on their car what they are running and how they like it.

Ed, our winters aren't THAT bad. You've got it much worse up there with all that "lake effect" snow. The heaviest snow storm we got this year was like 11" overnight. for you canadians thats like having flurries. :)

For the two times a year that we have a snow storm like that, I just don't drive on those days. But it's nice to know that I would have some tires that could handle a couple inches of snow should I get caught in a storm. I don't wanna be swapping tires back and forth. Plus I wax my wheels with liquid glass. All but one look great (the other one had an allergy and it's clear coat is sort of yellowing, don't know why).
 
The 245-50-17 size would be almost identical to stock diameter, so they would look fine. The ones I think look kinda strange are stock ride height SCs with tires that are an inch or more shorter than stock. I agree with your comments about 18s ... up until the end of last summer I had 255-45-17 Bridgestone S-02 Potenzas on ROH wheels ... I'm sure the 18s aren't really any better, just a bit more wet grip, but that's mainly because they are fresh, full-tread tires now. There are a few reasons I went to 18" this year ... I got a smokin' deal on the tires last fall ($200 CAN each for GY Eagle F1 GS-D2, one of their best tires, these would normally wholesale for $350 to $375 per up here), I was upgrading to the Cobra 13" brakes, and I knew that my old ROH ZR6 wheels would not clear without either some back of the wheel spoke or caliper grinding, neither of which I was crazy about doing (and I knew that I would have no trouble selling them to another club member in the Toronto area ... they now grace Bill McNeil's car) ... and, I wanted something unique on my car, esp. for my first trip to Carlisle. The Fittipaldi rims I finally found after searching a whole whack of websites have only been on the market since late last fall, and they don't come in 5 on 4-1/4" T-Bird bolt pattern, so I was guessing pretty strongly that nobody else at Carlisle would have a set on their SC ... I was right ;) ... the ROH 17s and 26" tall tires looked good on the car, but even with it lowered, the fender gap was still a bit much for my critical eye.

OK, I'll stop rambling now ...

cheers
Ed N.
 
Here is some more information that I have culled in the search for better rims....

Our stock tire size is 225-60zr16. To figure out overall diameter is sidewall+rim diameter+sidewall.

This would mean, 60% of 225=135mm or about (to convert multiply 135mm x .03937= 5.3inches.)

SO 5.3+16+5.3=26.6in

Now the rolling circumference is overall diameter x 3.14(pi)

So 26.6 x 3.14= 83.52inches. What he have to avoid going to a "bigger" tire is losing rolling circumference.

Discount tire direct recommends (as per their website) tire sizes of 235-50ZR17 and 245-50ZR17

Those would have rolling diams of
(117.5 (4.26")+17+117.5 (4.26"))=25.52

(122.5 (4.82")+17+122.5 (4.82"))=26.64

25.52x3.14(pi)=80.13" Rolling Circumference.

26.6x3.14(pi)=83.5" Rolling Circumference.

As you can see from the "math", goiing with the seemingly bigger 235ZR 50-17 over the 225-60Zr-16 your losing some inches in Rolling circumference.

The 245zr-50zr17 however is "Dead" on. And according to Discount tire direct.com, should Fit on a 17"x7" rim.

So it looks like that would be the Size tire I'd go for, unless there is a even bigger size equivilent in 18" which I have yet to research.

Now even though I like those centerline rims, I have also been looking at the Enkei RS5 17" which is advertized as "Lite weight" and the ATS DTM 2000 17" both are 17x7" rims and both are advertized as "lite weight". If choosing between those two I'd prefer the enkei's since they are a simple 5 spoke desgin as opposed to the "bicycle" spoke ATS DTM.

Problem is that wheel weights are not listed on their website, they are just advertized as light weight rims. At least centerline has published the weight of their wheels......

Any other "lite weight" options out there that I haven't overturned?

What do you guys think? Anyway to find out? Other than calling them of course...

BTW ed, those ROH snypers do look very cool, but so do your double spoke fittipaldi rims. Do you also think that the above mentiond rims would clear the 13" brake rotors when I decide to upgrade to them?

I'm still leaning to the BFGoodrich G-force KDWS. From what I have read, most guys have appreciated their balance of cost, dry and wet traction. However, they don't rate the snow traction as high. But still higher than say a pure summer Z rated tire.

Another option I've been looking at is the sumitomo HTR+ it's rated pretty good for it's price....

I'd still like to look into those falkens, fuldas and perhaps Hakkipalida's. ...
 
Just want to point out a small error in your math first ... the 235-50-17 should be about 26.25" tall ... the 117.5 mm X 0.3937 comes out to 4.62, not 4.26 ... an easy mistake to make when you're looking at that many numbers and sizes. So 235-50-17 would be not bad, but you're right, 245-50-17 is just about perfect. If you want to go 18", 245-45-18 is very close at 26.68" as well. If I had a choice, that's probably what I would have put on my car rather than the 255, but as I said, the price could not be beat on the 255 Goodyears. Ideally, I'd like to have 245-45-18 front, and 275-40-18 rear (26.66"), but with my current rim offset, I don't think they would go under the back, would need a bit more positive offset on the rear rims.

For the rims you've mentioned, I'm not sure which would have enough clearance for 13" brakes. As you've figured out, most of those are made for smaller cars, anything 17x7 in 5 on 108 mm with that much positive offset is pretty much targeted for a Volvo or Taurus, or maybe a Lincoln LS or Jag S-Type (they take 235-50-17 as OE on a 7-1/2" rim). If I may make an observation, I think you're barking up the wrong tree as it were with this quest for a lightweight wheel. I understand the theory for this, however, IMHO on a near 4000 lb. street car, saving 5 or 7 pounds per rim is not going to make up for what you lose by squeezing a tire on to it's minimum rim width. More is to be gained for cornering by putting a good tire on a wheel that is at the big end of the recommended width range. The 245-50 will fit on a 6-1/2" to 9-1/2" wide wheel, for max. cornering power it's going to work much better on an 8-1/2 or 9" wheel because the sidewalls are going to be much more stable by not being "folded in" to start off with in a static position. So my suggestion is to pick a style of wheel that you like in at least 17 x 8, preferably wider, with the correct offset for the car (my 8-1/2" at +35 offset are just about perfect), with clearance for a brake upgrade in the future, and don't worry too much about a few extra pounds per corner. Have you picked up one of those big lower rear control arms by chance ? There's a big chunk'o'pounds right there. As I said, maybe on a 3000 lb. or lighter car I'd be concerned with wheel weight, but on an SC for the street, not as much of an issue. On a side note, for my old 87 5.0 Mustang Solo I / regional race / summer street car I had a few sets of old 16x8 CSA Diplomat 5-spoke wheels (about 22 or 23 lbs. each I think), and one precious set of 16x9 Simmons 3-piece wheels ... on the track we could feel the difference in the lightness of the steering with the Simmons bolted on, just beautiful, much more nimble, they were probably 4 or 5 pounds lighter per wheel. But driving around on the street, beacuse I wasn't at the limit of adhesion of the tires (usually drove around on shaved R-compound tires :p ), the difference in steering could barely be noticed. BTW this was about 12 years ago when 17" rubber was still pretty exotic, and not much selection available in Mustang-sized R-compound stuff.

So there's an idea if you want light and wide ... check out some HRE, Fikse or Simmons multi-piece wheels, at about $500 each !@!@ :eek:

OK, I'll stop rambling again.
 
You bring up some interesting points ed.

I've got a plan though that I'd like to stick to. I think that my real problem is the fact that Manufacturers aren't quoting weights per rim like Centerline is doing. Bam in Road and Track, I saw the ad clearly stating the weights of the wheels. Considering the fact that I really didn't think about that before, I figured now would be a good time to start.

I know that shaving just a couple of pounds per corner may not seem like much, but surely even you recognize the benefits of losing some unsprung weight. I'm looking for a tire and rim package that can be driven comfortably on the street and track.

rather than pure drag racing, I'm thinking of doing some more handling events like Auto-x and road course laps. Etc.

In venues like that, I'm very sure that I would notice a difference.

I'm also starting to think that alot of SC'ers like to "over tire" their cars. This gives the suspension more to contend with when the road gets tough.

It looks like I'm on my own. But I will take your advice of considering a wider rim. What would you say could be the most comfortable width in front no rubbing in 17" size? I'd like to run the same size tire on all four corners, just to basically keep balanced handling.

Like I said, I've been looking at the BF Goodrich G-force KDWS tire. All the G-force tires come with steel bands in their sidewalls to significantly stiffen them up. If you still think that I'd have alot of tread roll with 7inch rims and a 255-45ZR-17 tire let me know.

Sorry about the math, I might consider the enkei Rs6 17x7" rim with a 38mm offset. That would be good right? Just as long as I can find out weights. Which I'll do on my own by calling up.

What was the diameter of those ROH snypers and width?

A 245-45-18 tire has a 26.68" overall diameter according to my calcs. Overall Circumference is 83.7. So that would be a good size. But the cost to me would be significantly higher and increase weight.

I'm not looking to spend $500 per rim. This car is street/strip so I need something that can stand up to the abuse that road wheels face. Is Enkei a good brand?
 
From what you've been talking about, I understand that better handling is your goal rather than worrying about how the car performs in a drag strip environment. I'm not going to post my whole racing background and resume here, but just let me say that it includes several years of Solo I and Solo II, and LOTS of laps at Shannonville, Mosport, Watkins Glen, Sebring, and Nelson Ledges, many of them done during 12 hour and 24 hour endurance races, and I did get a few trophies over the years for my efforts, so I do know of where I speak. I'm trying to make the point that on a big heavy car like the SC, even in a slalom / auto-X / open track situation, there is more to be gained by having the best tires you can afford on proper width wheels, rather than jamming a compromise tire on narrow lightweight wheels. On my 5.0 Mustang, after doing the Baer brake conversion and changing to 5-lug (before all the Cobra stuff came out), I bought a set of Ronal ACT 16 x 9-1/2" wheels for all 4 corners, to mount 245-50-16 on, and occasionally 255-50-16. The 9-1/2" rim was the max. width listed in the tire catalogue for what I was using, Bridgestone RE71 R-compound (back when they had a D.O.T. tire motorsport program, I was one of their sponsored drivers for Canada), and they worked great on the big wheels.

I agree with your thoughts on having the same size rim and tire at all 4 corners, makes sense for rotation purposes, and if anything a front heavy car like the SC should have bigger front wheels and tires for best handling, but that would look silly !! Even though I said that I would like to have a 245 front / 275 rear combo on my car, I don't think I would do that until I can go with a different set of springs that have more of a rear bias as far as spring rate goes to balance out the extra understeer that the bigger rear tires would give.

A 255-45-17 should be on an 8" rim minimum if you look at most tire manufacturers' specs, it may go on a 7-1/2, but a 7 would be too much of a squeeze. Even a 245 on a 7 is too tight IMHO. The ROH wheels I had on the car before were actually ZR6 wheels, not Snypers (think RWD Impala SS style). They were 17 x 8-1/2, I had 255-45-17 Bridgestone Potenza S-02 tires on those. They fit at all 4 corners no problem. Many guys have gone with 9" wheels all around, on the 93-up cars they are a pretty tight fit on the front because of the shape of the spindle. I would have bought 9s if the wheels I wanted were available in that size ( I specifically did NOT want Cobra R replicas, I like to have something a bit different ).

I cannot comment with personal experience on the Enkei wheels, other than to make the generalization again that a 17x7 wheel with that b.p. and offset is really aimed at being installed on a car that weighs 300 - 400 lbs. less than an SC. Keep in mind that sometimes an open-track event involves driving over a curbing or into a rut in the ground if you happen to make a mistake, and something that light and small on a heavy car might be more prone to bending. At Watkins Glen with my Mustang I experienced total loss of power brake assist at the start of a sprint race coming down the front straight for the first corner (try slowing down a 4-wheel disc car with no vacuum assist !!), and had to go over a sharp curbing and the grass, and back over another curb, to avoid pounding a couple of the unsuspecting racers in front of me turning into the corner. My heavy CSA wheels took this punishment without a problem, nice strong Aussie product (that's where ROH and Simmons are made as well). I don't think a lighter rim would have taken that abuse. That's an extreme situation, but the same type of thing could be encountered on the street if you happen to catch a nasty pothole or railroad tracks unawares.

OK, I keep getting more loquacious with every reply, I'm going to shut up now.

cheers
Ed N.
 
BTW, just let me add that I've had my SC out at Shannonville and Watkins Glen on 255-50-16 Hoosier R-compound tires jammed on 7" wheels, they were tight going on ... just imagine how a shorter sidewall 45 series tire would be on that same 7" wide rim.

Hope I'm not sounding too pissy with my last few responses. That's the biggest drawback of a message forum such as this, the tone and body language of a conversation doesn't come through, leaving too much open for interpretation.


cheers
Ed N.
 
Running it over here...

I've checked on the websites and they are recommending the 245/255 width tires in the 45 series. Maybe the website is screwed up.

I see what you are saying about extreme circumstances such as the one your mustang experienced. Rims with lower profile tires do see some abuse on the roadway. But I would think that most rims on the market must meet some sort of D.O.T standard. So if I bent a rim going over a pothole, there is pretty much a similar chance that I would have done that with a stock alloy.

Supposedly the Rotary forged wheels (the original ones I was talking about) are much stronger than a cast wheel. Therefore they are more "resistant" to bending and could probably take the abuse that an average street racer could dish out.

What if I was to ditch some additional lbs from the bird? Could then those lightweight rims fare better? The other thing I've noticed is that going with a wider rim in the same diameter jacks the price up almost as much as going up to 18"s. I guess I want my cake and to eat it too. I don't want to be spending oddles of money. That is why I want one set of tires to do it all. I know that I'm losing out on using a tire that is multi-season. But holding true to my philosophy, how much fun is a street/strip car, if you can only drive it on a sunny day and have to start to SH!T bricks when it rains or snows. THat doens't sound like much of a street car to me.

Fun for me is coming out for a day at the track "run whatca' brung". Click off some laps and then go home with the A/C on and radio blasting.

One other rim I've been tossing around is the Antera 309 I think is what it is. Its a nice 5spoke with sort of a "deep dish" design 17x8.5 and 35mm backspacing. They're pricey at $278 per. But if they are strong, and light.... Any thoughs on going less than stock backspacing?
 
If you get 8-1/2" wheels at +35 mm offset, that's about perfect ... my 18x8-1/2" Fittipaldis are at 35, they fit nicely front and rear. When you go wider on the rim than stock, the offset dimension is going to be smaller, because you need to position the wider rim properly to fit it under the car, and the same backspacing measurement on two different width rims will give you different offset measurements, since backspacing is measured from the very inside edge of the wheel, and offset is measured from the hub mouting flange.

BTW what sites are you looking at for the recommended wheel widths for the tire sizes ? I'd suggest going by the tire manufacturers' dimensions rather than the wheel vendors', if that's what you're going by. For example, taking a quick look on Bridgestone's site, for their 245-45-17, the suggested range for rim width is 7.5 to 9.0 inches, and they give the tire dimensions as mounted on an 8.0" rim (section width of a tire varies with rim width), and the 255-45-17 on 8.0 to 9.5 inch rim, measured dimensions on an 8.5 ... the measured dimensions are usually given on what they consider the best all-around rim width for that particular size tire to be on.


cheers
Ed N.
 
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