grandprix104 Posted March 16, 2004 Report Posted March 16, 2004 Ok so right now i have 15x7 (i think its 7) wheels with 225/70/15 wheels my question is will a wheel that is 225/60/16 on a 16x6.5 be the same outside diamiter? Also how about the width do you think thier will be any rubbing? The backspace on the new wheels is 52mm, what is the backspace on the factory steel wheels i have now. Also how exactly do tire measurments figure as in XXX/XX/Wheel Size. Thanks guys Quote
bluegp Posted March 16, 2004 Report Posted March 16, 2004 Ok so right now i have 15x7 (i think its 7) wheels with 225/70/15 wheels my question is will a wheel that is 225/60/16 on a 16x6.5 be the same outside diamiter? Also how about the width do you think thier will be any rubbing? The backspace on the new wheels is 52mm, what is the backspace on the factory steel wheels i have now. Also how exactly do tire measurments figure as in XXX/XX/Wheel Size. Thanks guys Here's how you calculate the dimensions: http://www.tirerack.com/tires/tiretech/general/size.htm 225/70/15: 27.4" diameter --- 225/60/16: 26.63" diameter One thing to remember is that each tire is going to be a little different. You can put 2 different brand tires of the same size side by side and they will have different dimensions. I'm not sure about the stock 15" wheel's offset. I think the stock 16" wheels have somewhere around 38mm. A 52mm offset sounds a little too much to me; that sounds like the offset of the 2nd gen w-body. (I may be wrong, so don't take my word for it) The higher the + offset, the more the wheels will tuck into the body. The TireRack website has a nice diagram explaining offset: http://www.tirerack.com/wheels/tech/offset.htm Quote
GnatGoSplat Posted March 16, 2004 Report Posted March 16, 2004 225/60R16 should work fine. +52mm offset won't fit. It won't clear your front calipers. You would need at minimum, some hefty 1/2" spacers to make those wheels fit. That would require putting longer studs in your hubs, and since this will end up being lugcentric with none of the hub going through the center hole of the wheel, they'd better be some beefy strong studs! Quote
bluegp Posted March 16, 2004 Report Posted March 16, 2004 +52mm offset won't fit. It won't clear your front calipers. I see this posted quite often on different forums. The wheel's offset has nothing to do with the wheel hitting the caliper. The offset indicates the distance the outer rim's center line is offset from the wheel's mounting surface. The wheel center is the part that may contact the caliper and I have heard of this occuring with some wheels on our cars. Usually the cure is adding a spacer to push the wheel away from the caliper (consequently increasing offset). The reason a wheel would interfere with the caliper is because part of the cross section of it's center extends too far inward (into the path of the caliper). So, I wouldn't rule out a wheel just going by that. If it is an aftermarket wheel, maybe the maker has a template of the wheel's cross section available so caliper clearance can be checked. I'd also like to add that if you compare a 1st gen w-Body front rotor to a 2nd gen one, the wheel mounting surface of the 2nd gen rotor sticks out more. So the mounting surface on the 2nd gen is farther away from the rotor & caliper. Maybe that's why some of the wheels meant for the 2nd gen cars have caliper clearance problems on 1st gen cars. Quote
grandprix104 Posted March 16, 2004 Author Report Posted March 16, 2004 the wheels are off of a 2004 grand prix has anybody done this before? Also what is the general opinion of spacers? Ive heard good and bad about them. Quote
GnatGoSplat Posted March 16, 2004 Report Posted March 16, 2004 Actually, the offset determines how "tucked" the wheel is, and since +52mm is very much tucked in, it will hit the caliper. I know of NO +52mm wheel that has enough caliper clearance... and even if such a wheel had such unusually narrow and convex spokes that it DID have enough caliper clearance, a 215 or 225 tire would rub the inner frame rail at full lock. To +52mm offset, I say "Not a chance!" Quote
GnatGoSplat Posted March 16, 2004 Report Posted March 16, 2004 the wheels are off of a 2004 grand prix has anybody done this before? Also what is the general opinion of spacers? Ive heard good and bad about them. Always better not to run them, but if you insist on using these wheels, you really have no choice. Some people use spacers and have never had a problem. I would recommend checking lug torque regularly with spacers. Quote
grandprix104 Posted March 16, 2004 Author Report Posted March 16, 2004 it seems to me that you should be able to find a wheel spacer that has a lip that fits around the hub and on the other side has a raised lip for the wheel to mount on that would keep the wheel hubcentric and only put a little more pressure on the studs. I see pictures on the net of ones that look like that but I also see some of just flat metal discs and i do not like that idea at all. What would be involved in changing the mounting hubs/points over to the 2nd gen style 97-03? Quote
GnatGoSplat Posted March 16, 2004 Report Posted March 16, 2004 Yeah, I've heard of hubcentric spacers, but they'll cost you more than the wheels. You can't change the hubs to 97+ style, at least, not without transplanting a whole gen 2 suspension, and that's a major job because nothing bolts up. Quote
grandprix104 Posted March 17, 2004 Author Report Posted March 17, 2004 thats NOT the answer I wanted! Quote
Z34door Posted March 17, 2004 Report Posted March 17, 2004 ok this is how i got my 2003 Bonneville wheels to fit i took off the caliper brackets and took them to my bench grinder and took off 3/8" of and inch... then i put on a 1/4 inch spacer....... and with 235/55 17's they didn't rub.......or hit the caliper..... Quote
bluegp Posted March 17, 2004 Report Posted March 17, 2004 Look at this diagram: Each wheel's mounting surface is in line. The top wheel has more + offset. How would caliper clearance be different? I agree that a wheel with 52mm + offset may cause the tire to rub at full turn. There is a guy out there that put a 2000-up Monte Carlo wheel on the front of his '97 Monte Carlo with no caliper interference although I don't know if the 2nd gen W wheels have a 52mm offset (thought they were 42-45mm). Here's the link: http://www.cardomain.com/memberpage/333306/3 Maybe that particular wheel's backside has a little more clearance than some of the other 2nd gen W wheels. Bottom line is: you won't know if they fit until you bolt one on. it seems to me that you should be able to find a wheel spacer that has a lip that fits around the hub and on the other side has a raised lip for the wheel to mount on that would keep the wheel hubcentric I did a quick search and yes, they do exist. here's some: (near the bottom of page):http://www.ronalusa.com/shopping/index.html and here (click on wheel spacers):http://www.hrsprings.com/site/frameproducts.html IIRC, prices for similar ones are around $200/pair. Quote
GnatGoSplat Posted March 17, 2004 Report Posted March 17, 2004 Each wheel's mounting surface is in line. The top wheel has more + offset. How would caliper clearance be different? I agree that a wheel with 52mm + offset may cause the tire to rub at full turn. I know what you mean, but since we already have such a positive offset in the 30-40mm range, our offset is already much higher than the top picture in your illustration. For the offset to be in the 50's and have enough caliper clearance, the wheel would have to be very convex or the spokes really narrow. 50mm range is as positive offset as you can get. The hardest wheels to fit are the ones that are concave in a +40mm offset which I like the best looks-wise. The factory wheels with +40mm offset are convex. The only non-convex wheels are the crosslace and 94-96 Pontiac 5-star which have a +25mm offset so there's more room for more depth. As for those Monte wheels, I don't know their offset. Their offset could be different than a gen 2 GP. I noticed they're also quite convex. Quote
bluegp Posted March 17, 2004 Report Posted March 17, 2004 OK, I see what you are saying now. The higher the offset goes, the center gets pushed out and the spokes have to curve back to meet the outer rim. Our rotors being shallow (mounting pad not protruding much past the friction surface) doesn't help. Quote
bluegp Posted March 22, 2004 Report Posted March 22, 2004 grandprix104, I Don't know if these are the wheels that you were going to try, but this is interesting: http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=38662&item=2466815913 Seller says: "We absolutely guarantee these wheels to fit the following cars: Pontiac 1988-2004 Grand Prix" among others. Whats the guarantee, your money back? By the way, those wheels would look awesome on a 1st gen W GP. Quote
jamcneely Posted March 22, 2004 Report Posted March 22, 2004 I'm with bluegp, I thought those wheels had a +42mm offset not a 52mm. you also have to take into account that he is going up in diameter too, it would rub with a 52 and if he was staying a 15" but he is going to a 16" wheel and I don't think the offset is that much anyway. He should have enough clearance to keep from hitting the caliper. I think the wheels and tires will fit just fine. Oh, and where did you find those wheels grandprix104? What you don't want to buy mine Quote
grandprix104 Posted March 22, 2004 Author Report Posted March 22, 2004 the previously posted link is to one of the sets i was going to bid on but they are climbing out of my price range ( those ones already are). Since i wont be able to buy those ones Im up for anybody's that are for sale. Jamcneely email me (http://ryan@mydreamcomputer.com) some pics and I may consider although I cant remember the specifics on the wheels you wanted to sell. Im looking in the price rance of around $350, but more than wheels I NEED tires, so if i am unable to find both in that price range (i know it isnt likely) then I will just be buying tires. Quote
bluegp Posted March 22, 2004 Report Posted March 22, 2004 I'm with bluegp, I thought those wheels had a +42mm offset not a 52mm. I just looked at that listing. They do have a 52mm offset; there's a pic of the back of the wheel where it's stamped "OFF52". Previously, I didn't think they went that high. I also just saw some 2nd gen W torque stars on eBay with a description saying they had a 52mm offset. I could swear that I've seen many times that the 2nd gen wheels had either 42 or 45mm offset. Quote
jamcneely Posted March 24, 2004 Report Posted March 24, 2004 Wow, 52mm? Really? Thats surprising. I didn't think they had that type of offset either. I'll have to look on my stock wheels to see what offset they are. I didn't check it put my new wheels on because I just knew the wheels that I got would fit without a problem. Speaking of stock wheels. I got to thinking about it, and I think I'll want to hold onto my stock wheels. Sorry it will just make it alot easier for me if I ever want to sell the car in the future. Plus they will make great winter wheels. I will sell the tires though. I can sell them to you for $25 a piece. There are two of them that are a little over half worn, and two that are sitting at about half. I'll have to find someway of getting pics to you, and the specifics about the tires. I'm not even sure what brand they are, I'm pretty sure they are Bridgestones. I'll look later today and get back with you. Quote
z34_nut Posted March 25, 2004 Report Posted March 25, 2004 grandprix104, I Don't know if these are the wheels that you were going to try, but this is interesting: http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=38662&item=2466815913Seller says: "We absolutely guarantee these wheels to fit the following cars: Pontiac 1988-2004 Grand Prix" among others. Whats the guarantee, your money back? By the way, those wheels would look awesome on a 1st gen W GP. i will tell youi right now, that if it fits a 2000-2004 impala, i know for a fact it will NOT fit a 1990-94 lumina. Trust me i know from experience . i have 03' impala wheels on my car, and well, calipers need to be grinded down, and lug nuts needed to be extended. Quote
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