seb280z Posted August 20, 2014 Share Posted August 20, 2014 (edited) Hi. I have a 1977 280Z with the Reaction Research YZ widebody kit, and a complete AZC suspension, 5-lug conversion and custom brakes (330mm rotors all round 8-pot calipers front, 4-pot calipers rear) 6-point roll cage. My intention for this car is just to have a fun toy, Occasional track races and hopefully lots of trips to the Ice cream stand... I bought 2 sets of used rims, Ultralite Hikari 18*8,5 +35 offset. I mocked them up in the front and I have abour 1/2" clearence to the strut, but to get the rims out to the fender I would need to widen them 4" and that would put me at 12,5" wide rims in the front. I am still working on installing the rear setup so I have not checked how much they need to be widened, but I am assuming the same. My assumption is that the usual setup is staggered setup; wider tires in the back. Q: why? How would the car be with equal size tires front and rear with like a 295-335 wide tire? Can you even steer? The reason for two sets of rims is of course to run slick and street setup. (plus it was a package deal) Edited August 22, 2014 by seb280z Quote Link to comment Share on other sites More sharing options...
tube80z Posted August 21, 2014 Share Posted August 21, 2014 Square (all the same) or wider rear work fine. It's all in the setup if you're not matching the contact patch area to the weight distribution. Wider rear generally allows more throttle in a corner sooner and that gives a knock on effect down the next straight. It also depends a lot on the type of event you're doing. If the reaction stuff is a copy of the original IMSA items the rear was setup for 14 inch wide wheels. Cary Quote Link to comment Share on other sites More sharing options...
roger280zx Posted August 21, 2014 Share Posted August 21, 2014 Typically with a 280yz you see guys run 12 or 13 in the rear, and 10 or 11 in the front. Why is yours so much wider? Oh and I have some of those 15x14's from an imsa bodied car. Too bad they don't fit my zx, merrrr. Quote Link to comment Share on other sites More sharing options...
seb280z Posted August 21, 2014 Author Share Posted August 21, 2014 Typically with a 280yz you see guys run 12 or 13 in the rear, and 10 or 11 in the front. Why is yours so much wider? Oh and I have some of those 15x14's from an imsa bodied car. Too bad they don't fit my zx, merrrr. It typically says that a YZ kit is 3" wider than stock fenders. I don't know why my car seems to be that much wider, I have Z31 front hubs, they might have a different WMS offset compared to stock, but then again, clearance to the strut would be no different. I will measure the stock LCA's and compare with my AZC adjustable ones but that will probably just give me 1/4-1/2" adjustments. I'm just worried that on the street a 12" wide front will be undriveable with tracking issues. On the track it probably will be fine. I have not seen tires wider than 275 or so in the front before on streetable cars... Quote Link to comment Share on other sites More sharing options...
tube80z Posted August 21, 2014 Share Posted August 21, 2014 A friend with a performance oriented street Z had 305s on the front and 315s in the rear. It drove fine on the street. It had power steering and that's probably going to be a requirement unless you can leave with a high steering effort. Cary Quote Link to comment Share on other sites More sharing options...
G-E Posted August 22, 2014 Share Posted August 22, 2014 Unless you have a ton of downforce, the car just doesn't weigh enough to justify 275's up front, there is such a thing as too big... Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted August 22, 2014 Share Posted August 22, 2014 Tell that to the guys of formula 1. Quote Link to comment Share on other sites More sharing options...
1vicissitude Posted August 22, 2014 Share Posted August 22, 2014 (edited) Wait, a 18x8.5 -35 wheel is a half inch from the strut? People run x9" 0 offset wheels all the time, why is yours so close to the strut? That is ~42mm closer to the strut than yours. Somethings not right. It just doesnt add up. Are you sure your wheels are negative 35 offset? Do you know how to measure a wheels width and offset properly? A 18x8.5 -35 would need a big stretch and camber to fit stock fenders. However, they sit about the same as the ever popular Rota wheels in 17x9.5 -20. Upfront a 255 is just barelly poking out a zg flare with this size. If the YZ kit is truly only 3 or even 4 inches, I just dont see how your measurements are adding up. That said I have no experience with the kit, it looks huge though. Edited August 22, 2014 by 1vicissitude Quote Link to comment Share on other sites More sharing options...
seb280z Posted August 22, 2014 Author Share Posted August 22, 2014 (edited) Sorry, the offset is not negative (changed it in the first post). From this perspective you can't see the depth, but they are 4" tucked in there.. Edited August 22, 2014 by seb280z Quote Link to comment Share on other sites More sharing options...
Phantom Posted August 22, 2014 Share Posted August 22, 2014 My son has a 240 with subtle Z front fenders and YZ rear fenders. He has 17x8.5" wheels in the front wand 17x9.5" wheels in the rear. He currently is running 245's in the front and 275's in the rear but plans to move the 275's to the front and put either 305's or 315's in the rear, whichever size fits best. He has a stock suspension at this point with the Arizona Z Willwood 6 pistons in the front and 4 pistons in the rear of 12.2" rotors. Quote Link to comment Share on other sites More sharing options...
1vicissitude Posted August 23, 2014 Share Posted August 23, 2014 (edited) +35 okay. That makes a LOT more sense. You need negative offsets, or crazy wide wheels. Hop on the site willtheyfit.com It allows you to visualize how offset and width effect your fitment compared to your starting setup. You are going to have to go very wide, low offset, or a mix of both. Just remember, when width changes so does the measured offset. If you widened your 8.5" wheel, 12.7mm would extend in each directIon off wheel center, so the offset would then be +47.7mm. Or if you widened the outer lip only an inch, the offset would be reduced by 25.4mm, so it would then be +9.6mm. For example, the 17x9.5 -20 offset Rota I mentioned are 67mm further out to the fender than your setup now. With 275s that might not look too bad and wont break the bank. Edited August 23, 2014 by 1vicissitude Quote Link to comment Share on other sites More sharing options...
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