| Author | Message | ||
| Mule (Mule)
New member Username: Mule Post Number: 26 Registered: 6-2003 |
Chaz, I think that 18 inch wheel buys you some more space in the rear near the shock. Since the shock/spring angles down and outward towards the center of the wheel, each inch larger diameter moves the wheel edge higher where it is farther away. If someone had 19 or 20 inch wheels they would get more space, while a 15 inch wheel probably wouldn't work with a 245 tire. On the 17 inch wheel there isn't even an inch between the tire and the spring/shock. I have also learned each car is different, so I am glad to have the opportunity to put a set of larger tires and wheels on my car before buying. I haden't thought of 18 inch wheels. Do you have a picture of the 18's? | ||
| chaz richards (Chaa)
Junior Member Username: Chaa Post Number: 80 Registered: 5-2003 |
On my 329 i run 225/40/18s front. 255/35/18s rear. These are on split rims with no problems | ||
| Mule (Mule)
New member Username: Mule Post Number: 25 Registered: 6-2003 |
I stopped by Dave328GTB's house today to look at the wheel and tire setup he has. They are 17x8 with 225/45r17 front and 17x9 with 245/40R17 rear. He was kind enough to let me mount them on my car to see how they fit and look. The 245/40r17 rear is a tight fit near the shock/spring behind the tire. The 17 inch wheel moves the edge higher away from the spring, but it is still close. Dave 328GTB says a 255 would work, but I dont think it would work on a 16 inch wheel. I am going to get the same size tire and wheel combination. I am confident that nothing bigger would fit without moving the wheel out away from the spring. Thanks again to Dave 328GTB for actually letting me mount the tires on my car and see it first hand.   | ||
| DGS (Dgs)
Member Username: Dgs Post Number: 293 Registered: 5-2003 |
Changing the rake of the car (ride height front vs rear) shifts the weight distribution. While the 328 can stand a bit of shift forward, if you do this with wider rear tires, you'll want wider fronts, as well, or you'll have a lot more understeer, I think. But I can report from experience that lowering the front does mess up early ABS systems. After the rim broke in motion on my Celica, the body shop repaired the car with a lowered front. The increased rake looked "bad-a$$" to the ricer crowd, but it caused the ABS to intervene so early I was tempted to disable it. After installing the coil-overs and restoring the normal ride heights, the ABS returned to normal operation (for an '80s ABS). The Celica is AWD, so I don't know how much this relates to the 328, but all cars have four wheel brakes. After dealing the the '80s ABS in the Celica, I'm glad to not have ABS on my 328. But I've learned to shift suspension elements only to tweak handling. I give handling priority over "looks". | ||
| Dave328GTB (Hardtop)
Member Username: Hardtop Post Number: 666 Registered: 1-2002 |
Regarding ABS, I think it is especially bad to have one set of tires change OD significantly and not the others. If one set is rotating at a much quicker speed than the other set, then the ABS would interfere too soon or perhaps not at all. I'm certainly no expert on this, but I have read that changing more than a few % can lead to trouble. Newer vehicles can have lots of stuff reprogrammed but the '89 system is pretty primitive, although mine is definitely effective. DAve | ||
| Barney Guzzo (Trinacria)
Member Username: Trinacria Post Number: 420 Registered: 8-2002 |
Jeff, Sorry about the delayed response. Tires are Khumo Ecsta 712's. I like them so far but I am still experimenting. | ||
| Mule (Mule)
New member Username: Mule Post Number: 22 Registered: 6-2003 |
Dave328GTB, Bigger tires would be fine on my 89 328, since my ABS doesn't work that well as is. (Remember the ABS light issue?) I assume you mean that the ABS is programmed to work with a specific rolling diameter (stock), not that there are ABS hardware pieces that would hit bigger tires. When I put 35 inch tires on my truck, i was told that everything is based on the speedometer (shift points, ABS, odometer, etc) so reprogramming was neccessary if you went more than 5% over or under stock. I dont think the Ferraris (1989) are that well integrated, but I can see lessened performance from the ABS or even the ABS light illuminating if it senses something "out of the ordinary". Are tires that are 1 inch bigger "out of the ordinary"? I don't know. Again, the plot thickens.... | ||
| Dave328GTB (Hardtop)
Member Username: Hardtop Post Number: 661 Registered: 1-2002 |
For anyone with an 89 328, it is very important to keep the overall wheel/tire combo diameter very close to stock because of the anti-lock brakes. 245/45-16 or 245/40-17 are just right. Also, making the rear tire/wheels taller to achieve a "rake" will change the balance of the car at least slightly, though I don't think anyone would notice. It make the car handle on a level surfaces like it ordinarily would on a slight downgrade. Dave | ||
| jeff ryerson (Atheyg)
Member Username: Atheyg Post Number: 405 Registered: 8-2002 |
Looks good Barney,gets rid of some of the wheel gap What brand tires? | ||
| Barney Guzzo (Trinacria)
Member Username: Trinacria Post Number: 405 Registered: 8-2002 |
This is 308 and not a 328 | ||
| Barney Guzzo (Trinacria)
Member Username: Trinacria Post Number: 404 Registered: 8-2002 |
I am using 245/50/16 and 225/50/16. No problems.   | ||
| dave handa (Davehanda)
Intermediate Member Username: Davehanda Post Number: 1712 Registered: 5-2001 |
I had 245/45 on my old 308 and it looked terrific, unfortunately, I have no digital pics, only film and no scanner... It seems that the 245/50 works for some, and not for others, probably within the manufacturing tolerances of the cars...I wouldn't risk it, when we know for sure that the 245/45 is sure to work. Dave | ||
| jeff ryerson (Atheyg)
Member Username: Atheyg Post Number: 401 Registered: 8-2002 |
Good info, The 245/50 seems to fill the wheel well nicely but if it hits at all its not worth it The 308 may have a different offset for the wheel and suspension vs the 328 so I guess the only way to know for sure now is put 245/50 on | ||
| Mule (Mule)
New member Username: Mule Post Number: 21 Registered: 6-2003 |
Tillman, Thanks...great pictures, great car. I like the color, very understated and classy. I think it would make people take a second look to see what kind of car it was. Looks like that may be the route I go. By the way, I am using Goodyear Eagle HP Ultra Plus. That's what came with the car, so I only need to get two new tires, not four. | ||
| Tillman Strahan (Tillman)
Member Username: Tillman Post Number: 896 Registered: 11-2001 |
My 328 has 245/45 ZR16 tires on the rear. Photos can be found at www.ferrari328.com/gallery.html | ||
| Mule (Mule)
New member Username: Mule Post Number: 19 Registered: 6-2003 |
Not to continue beating this horse... The consensus seems to be that the 245/45 will fit and the 245/50 will not. To my inexperienced eyeball, I think, "If the two tires are the same width, and the 245/50 is only 1 inch taller, only 1/2 an inch will go in any one direction, and it looks like there is enough room". But, I trust the group opinion and experience on the 245/45. Especially, Philip saying he actually used the 245/50 and it hit. So, three questions: 1. Since a 245/45 is slighty shorter than the 225/50 stock size (2/10ths of an inch), can anyone eyeball the difference, and does the rear tire look shorter than the front? 2. Anyone have any good side profile pictures and pictures from the rear with 245/45 tires? 3. I have the same thoughts as Steve about a little more rake and taller tire in the rear, but there does not seem to be a tire that is a little wider, a little taller and will fit. Any other ideas or tires not yet discussed? | ||
| Mule (Mule)
New member Username: Mule Post Number: 15 Registered: 6-2003 |
Jeff, For my 89 328, I measured from the center of the wheel to the edge of the fender opening on the rear with 225/50 tires: To the top - 14.75 inches to the front - 14.75 inches to the rear - 14.50 inches From the top of the tire to the fender - 3.00 inches from the front of the tire to the fender - 2.50 inches from the rear of the tire to the fender - 2.50 inches The widest part of the tire is .60 inches in from the outside edge of the fender at the top and overlaps the inner fender edge by .30 inches. This is at rest and does not take into account compression and any sagging of the springs over the years. So under compression, the stock tire does not hit, but with an added 3/4 inch taller tire of 245/50 (or 3/8 in any one direction), it would certainly be closer. As is, the curve on the edge of the tire would strike the fender lip, but with a wider tire, the tread which is a larger diameter would be in line with the fender if they hit. I guess the real determination would be actual mounting and testing. Also, I dont know if the 89 and 88.5 convex wheels and the earlier concave wheels position the tire exactly the same in the wheel well. There was a 328 at FOD with 245/50 tires on the rear (concave wheels), and the dealer said he drove it and nothing hit. I looked at it, and there were no marks on the fenders. Picture of that car attached   | ||
| jeff ryerson (Atheyg)
Member Username: Atheyg Post Number: 376 Registered: 8-2002 |
Does anyone know if the dimensions are the same for 308 vs 328 tire clearances? | ||
| Philip Airey (Pma1010)
Member Username: Pma1010 Post Number: 369 Registered: 7-2002 |
I tried 245/50 at one time on the rear of my 308. Rubbed on the fender lip. 245/45s no problem. | ||
| Steve Magnusson (91tr)
Intermediate Member Username: 91tr Post Number: 2036 Registered: 1-2001 |
The 255/50s would probably improve the accuracy of your speedometer  . I think you'll like the look (a little more forward chassis rake looks great on the 308/328 coachwork IMO as does beefy rear rubber), but it's a big tire for an 8" wheel (what size wheels on your '89 328?) so you might check for tire size vs wheel width fitment recommendations with www.tirerack.com, etc.. Preferred 225/55s on the rear of my ex-308 for the same reason -- 225/50s looked smallish. | ||
| Mule (Mule)
New member Username: Mule Post Number: 14 Registered: 6-2003 |
I have had the same question myself. Plugging the numbers into a calculator (which is not tire size mounted): the 225/50 (stock) is 24.85 inches tall the 245/45 option is 24.68 (wider tire, slightly shorter) Would a 245/50 at 25.64 inches be too tall? Only 3/4 inch taller than stock. The 255/50 would be 26.03 inches, 1.15 over stock. It "seems" like it would fit by height, maybe not width, since only half of the increased height goes in any one direction. I would like to put the 245/50 on if it would work. Thoughts or experiece? | ||
| dave handa (Davehanda)
Intermediate Member Username: Davehanda Post Number: 1621 Registered: 5-2001 |
I just did some checking on www.tirerack.com. The 245/45/16 is the largest that will fit. 255/50 will definitely be too tall, and there is no such thing as a 255/40 or 255/45 or 265/40 or 265/45...so that pretty much answers the question. I used the 245/45 on my 308 and it worked fine; I know several others that are using it on 308's and 328's with no problem. | ||
| Phil Hughes (Ferrarifixer)
Junior Member Username: Ferrarifixer Post Number: 62 Registered: 7-2003 |
You need to keep your rolling circumference close to original, so you'd need a 255/40/16 not 50 profile. 245 is ample, the 328 chassis is not designed to grip like a barnacle so enjoy the nice neutral slides without straining your chassis beyond it's design limits. Grip can be gained in better ways than upping the tyre. | ||
| jeff ryerson (Atheyg)
Member Username: Atheyg Post Number: 375 Registered: 8-2002 |
Anyone know the max size without hitting? I am confident a 245/45/16 will fit but how about a 255/50/16 or? Thanks in Advance |