Bartman Posted July 18, 2007 Author Share Posted July 18, 2007 So to everyone that thinks the 9.5 rims won't fit without fender flares...you're right. I'm going to try and swap the 9.5's for 8.5's tomorrow so that I'll have the 8.5's all the way around. I loosened up the lower spring perch all the way and it's just not going to allow enough clearance for wheel travel. I guess some people just don't listen. Quote Link to comment Share on other sites More sharing options...
Clifton Posted July 18, 2007 Share Posted July 18, 2007 If I can get a 17x9 to work, I think you can get a 18x9.5 to work, just not with that spacer. You just need to pull it in. Quote Link to comment Share on other sites More sharing options...
Bartman Posted July 18, 2007 Author Share Posted July 18, 2007 If I can get a 17x9 to work, I think you can get a 18x9.5 to work, just not with that spacer. You just need to pull it in.Even with the 1" spacer I have now it's too close to the inner fender when the suspension is compressed. It can be made to fit because a6t8vw fit 9.5's on the back of his car, but I've been unsuccessful in my attempts to talk to him about his setuphttp://www.cardomain.com/ride/2314369 From what he's posted before he's using a 25 mm spacer on the rear of his setup. I don't want to deal with rubbing issues so I'm just going to make it easier on myself and stick with the 8.5's which will be easier to fit. I already talked with Stephen at SG Motoring and I'll be swapping the rims with the him this afternoon. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted July 18, 2007 Share Posted July 18, 2007 If a 23" diameter tire on an 8" wide rim with 5" of backspace hits the inner fender, then there must be quite a few cars out there hitting the inner fenderwell at full bump. I'm not trying to be argumentative, I'm just trying to understand all the issues and how they're being resolved. I know you've already figured out that your rims will be a problem, but I wanted to address this issue anyway because I think it's overlooked a lot. I don't think most people take the time to even check, and probably don't care if it rubs every once in a while. I was pretty shocked when I did the test myself, because it's something you just don't hear about. Mine didn't rub before I sectioned the struts, but afterwards it will definitely be an issue. With your larger wheel diameter I figured you'd be in roughly the same place. A lot of guys want to put the biggest wheel on their Z that they can and I think a LOT of them are having issues and are either oblivious to that fact or don't care. I know Clifton has issues with the tire rubbing the inner fenderwell, but I guess he figures it's not bad enough to worry about. I think maybe Jody said something about his 295's under 3" flares rubbing every once in a while. Based on what I've seen with my own car I think the max tire width with coilovers and non-sectioned struts and a non-flared 240Z is a 245. 280's may be different, I honestly don't know, but I do know that for the 245 to work without rubbing on a properly sized rim (9 inch) everything has to be just right. Quote Link to comment Share on other sites More sharing options...
veritech-z Posted July 18, 2007 Share Posted July 18, 2007 I've got a 255/40R17 mounted on a 17X8" wheel on my 280 and it doesn't rub (I know that tire is a bit wide for that wheel width...sure looks tough though) Quote Link to comment Share on other sites More sharing options...
Bartman Posted July 18, 2007 Author Share Posted July 18, 2007 That brings up another big ssue with differing opinions...what size tire based on rim size. I found a great local source with excellent pricing, so I'm looking at ordering up a set of Azenis RT-615 245/40R18's to install on my 18x8.5 rims. This is the Meas. Rim size listed on Falken's web site for this size Azenis tire http://www.falkentire.com/rt615_sizes.html There was a thread on the solo2 web site that discussed tire sizes for a given rim, and they talked about installing tires designed for wider rims on a narrower rim (like what veritech-z is doing). I thought that this practice would actually give you less traction that putting a narrower tire on the same rim. I posted to the thread asking about the actual perfromance differences between using a tire recommended for a given width as opposed to installing a tire designed for a wider rim...but I didn't get any answers. It appears I'm an autocross newbie and I shouldn't be questioning the old timers recommendations. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted July 18, 2007 Share Posted July 18, 2007 A lot of times in autox you'll have rules that determine the rim width and that is your limiting factor. That's why you'll see so many cantilevered slicks on the Prepared cars. Personally I think aside from cantilevered slicks, you should really stick with a tread width that is equal to the rim width (roughly). Now that I've just said that, I ran a 250 on a 8" wide rim for years, because that's what I could afford at the time. But I think the response from the tire is much better if the tire is not overly wide for the rim, and mine felt really floppy, especially when they were cold. As a case in point I referred to an old post from Tom Holt where he was talking about running 11" tires on his 16x10s, and he piped up to say that he had gone back to 10" tires because the transient response was better. Most of the DOT autox tires are really meant to maximize the tread width anyway, so putting a 245 Kuhmo or Hoosier on an 8" is even worse than putting a street 245 on an 8. My rule of thumb is 6" = 185, 7" = 205, 8" = 225 9" = 245 or 255, 10" = 275. Different tires are different sizes, so that's a general rule of thumb, but that's the way I would look at it first, and then modify based on the specific size of a given tire if necessary. Quote Link to comment Share on other sites More sharing options...
Evan Purple240zt Posted July 18, 2007 Share Posted July 18, 2007 Just a quick note for you guys, the 275/35/18s look a little wide on a 9.5" wide wheel on my 240sx. Pirelli P9000 SS tires. I had falken 265/35/18 and they were definitely stretched like the white car, but not as bad. I think falken tires run "skinny" so ask about actual tread width. Evan Quote Link to comment Share on other sites More sharing options...
Bartman Posted July 18, 2007 Author Share Posted July 18, 2007 I'm so confused now it's not even funny. I feel like I have a devil perched on one shoulder telling me to stick with the 9.5's and an angel on the other one telling me it would be much better to go with the 8.5's. From a purely aesthetic perspective the 9.5's look soooooo much better: They're both supposed to have the same +35 offset, but I don't know how that can be based on looking at them. On one hand I'll be pissed if I get the bigger rim and I have problems rubbing, but I'll also be pissed if I see someone else using the wider rims without any problems. My ST sway bars arrived yesterday, so my body roll will be minimized...so how much travel will I generally be using? The autocross course is flat, so body roll would be my main concern. Damned if I do...damned if I don't. Quote Link to comment Share on other sites More sharing options...
JustinOlson Posted July 18, 2007 Share Posted July 18, 2007 It looks like the 8.5" wheel has a deeper center section but shallower lip. Why not just do a quick measurement with a straight edge and ruler. Justin Quote Link to comment Share on other sites More sharing options...
texis30O Posted July 18, 2007 Share Posted July 18, 2007 I was figureing that on all four corners with rolled and pulled fenders within reason I would only be able to fit 245's all the way around on a 8" wheel. I am going to have everything measured by a local shop. They have a tool that bolts up to the hub and all measurements are taken from there....I am going to have coilovers and a big brake kit but I can not take any measurements untill I get everything Quote Link to comment Share on other sites More sharing options...
silversix Posted July 18, 2007 Share Posted July 18, 2007 I'd stick with the 9.5's. With your torque you should be encountering power oversteer with street radials already, so with the 9.5 section you could still run 255 (possibly 265) as opposed to 245 once your rolled and pulled. I'll be rolling and pulling my fenders to fit my 17x9.5 MJ9 manarays with 255 or 265 under them. Plus if you give up that lip...well this is SoCal..you know how we roll. Quote Link to comment Share on other sites More sharing options...
Clifton Posted July 18, 2007 Share Posted July 18, 2007 I know Clifton has issues with the tire rubbing the inner fenderwell, but I guess he figures it's not bad enough to worry about. I only have rub issues with MT DR's on big dips. With the V700's or 555R's it's ok. To get a regular 275 on a 9 to fit isn't hard but the offset has to be within 3mm of perfect. I think people are having problems because they are off 5-10mm one way or the other. Quote Link to comment Share on other sites More sharing options...
Bartman Posted July 18, 2007 Author Share Posted July 18, 2007 So I talked with Stephen again and I'm holding off on exchanging the rims. He'll give me up to a couple of weeks to decide which way I want to go. I'm thinking that I really want to make the 9.5s work one way or another. I'll try and make more measurements and figure out how to make it work. If the V8 can fit under the hood then big tires should be able to fit under the fenders. Justin, Now that you mention it, I see how the center section is much deeper on the 8.5 rims. I definitely prefer the look of the 9.5 rims on the back. Quote Link to comment Share on other sites More sharing options...
veritech-z Posted July 18, 2007 Share Posted July 18, 2007 Offset is the distance from the centerline of the wheel to the mounting flange of the wheel, so a wider wheel will be deeper with the same offset as a narrower wheel. My wheels are all +38 offset, but the front wheels are only 7" wide (whereas the rears are 8"). You can see the difference in the lip: Quote Link to comment Share on other sites More sharing options...
Bartman Posted July 22, 2007 Author Share Posted July 22, 2007 Well it looks like it's going to work after all. Here's pic's with the 275/35R18 Azenis tire installed and trial fit on the car. They're still pushed out a little too far, but I've got plenty of room on the inside. My adapters are a little over an inch wide, so I probably need to get them somewhere around 3/4" to 7/8" wide. I don't have any springs installed so that I can check clearance throughout the wheel travel, and I found out that I had an issue with the ZX caliper hitting the brake line! I'm making adjustments to ensure this will not be an issue in the future. Quote Link to comment Share on other sites More sharing options...
Clifton Posted July 23, 2007 Share Posted July 23, 2007 Are you running adapters or spacers? The wheels have a dual patern. Is the other patern 4x114.3? If so, you can get pretty long studs from napa that will fit so you can just run a regular spacer. Looks like you can move it in another 1/2". The spring collar with an 8" should be above the high spot on the tire so the clearance issue is just the strut tube, atleast for me it is. Quote Link to comment Share on other sites More sharing options...
silversix Posted July 23, 2007 Share Posted July 23, 2007 Looks mean! I knew it would work! Quote Link to comment Share on other sites More sharing options...
Bartman Posted July 23, 2007 Author Share Posted July 23, 2007 I'm currently running an adapter to 4x100, but the wheel is also drilled for the stock 4x114.3. So it looks like I could use a 5/8" to 3/4" thick spacer. I can't shim it with washers to check because the stock studs are too short. It would be easier to use an adapter, but I can't find them less than 1" thick. I'm just going to have to install longer studs and then confirm the width of spacer needed. Quote Link to comment Share on other sites More sharing options...
80LS1T Posted July 23, 2007 Share Posted July 23, 2007 You'll be glad you did all this extra work to get them to fit! Look'n good so far! Guy Quote Link to comment Share on other sites More sharing options...
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