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18X11 Wheel fitment guide HI, this is a post to catalog what I did to fit 18X11 wheels on my 1992 RS Autocross car Here's 3 videos on the fitment I have a YouTube channel called (3rdGenGuy) and i make a mighty fine how-to video no talking over a potato camera, just clean well lit shots with ZERO waste. https://www.youtube.com/watch?v=bjaS...ature=youtu.be https://www.youtube.com/watch?v=Y6eA...ature=youtu.be https://www.youtube.com/watch?v=VlAh...ature=youtu.be i'll share some photos i didn't include with the videos. https://cimg8.ibsrv.net/gimg/www.thi...5f00b0b3fd.jpg WELD RACING S71 18X11 https://cimg9.ibsrv.net/gimg/www.thi...e16fe63f28.jpg The wheels on my 92 Autocross car with a unfinished 10in spoiler https://cimg3.ibsrv.net/gimg/www.thi...ad56c8dbc1.jpg 6.6in of back spacing on all 4 5/8in spacers in the front to get the back spacing needed and still be able to rotate tires |
Re: 18X11 Wheel fitment guide The first steps was to determine what back spacing would work with 18X11s and the tires i choose. I used a very expensive (Wheel-Right) fitment tool it can be rented for $50 if you can wait for one to show up the tires are a 200TW Yokahama A052 295/30R18 that measure 12-1/4in wide as with 200TW Autocross tires they often times under rate the width these 295s are wider than 315 TOYO 888R and are about the same width of the BFG Rival 315s https://cimg2.ibsrv.net/gimg/www.thi...bb25348641.jpg 6.0in of back spacing simulated for the front. Note that my BBU Wilwood brake kit pushes out track width my 0.300in on each side https://cimg3.ibsrv.net/gimg/www.thi...b8a5b3dacf.jpg rear set to 6.5in of back spacing, rear end is Stock track width https://cimg5.ibsrv.net/gimg/www.thi...b94bb8f275.jpg |
Re: 18X11 Wheel fitment guide the front needed to be cut a bit to fit the 91-92 factory ground effect body kit my car runs +6.0 degrees of caster, so that reduces clearances a bit. the front end rear inner rocker panel had to be cut up to fit these tires the front GFX kit had to be trimmed a little. Front fenders are ROLLED and wheel liners removed https://cimg7.ibsrv.net/gimg/www.thi...62166377fb.jpg 91-92 GFX kit https://cimg8.ibsrv.net/gimg/www.thi...b5462d2d5d.jpg trimming the plastic back https://cimg9.ibsrv.net/gimg/www.thi...f6a449d1a0.jpg metal cut and bent back, pretty easy, although I kinda rushed it a bit. https://cimg6.ibsrv.net/gimg/www.thi...f2afbabde3.png front fenders were rolled |
Re: 18X11 Wheel fitment guide Steering stops were lengthened a little (1/4in) to keep the tires from rubbing at full lock. I made my stops modular by drilling out the rivets and replacing them with bolts. you will loose about 5 degrees of steering angle. 5/8in spacers were used on the front to get the wheels (6.6in BS) to 6in back spacing in the front that way all 4 wheels can be rotated, VERY important for an autocross car with a SOLID Axle like 3rd gens. Bump steer kit was used to correct HORRIBLE bump steer from the 1/2in extended ball-joints 0.002in of bump steer, nearly PERFECT! i'll be making a solid Stainless spacer to remove these ugly steel shims. https://cimg1.ibsrv.net/gimg/www.thi...5c3e60c75d.jpg added some nuts behind the steering stops as an easy fix. https://cimg3.ibsrv.net/gimg/www.thi...c3309b4e0a.jpg Bump Steer kit fits under the 18x11s with 0.955in of spacers. About 1/4in of room between the wheel lip and the bolt. Aerospace 12 point bolt https://cimg5.ibsrv.net/gimg/www.thi...b54cb5acc9.jpg 1/2in extended studs Via QA1 Ultimate ball-joints Bump steer kit is REQUIRED if you install extended studs. https://cimg8.ibsrv.net/gimg/www.thi...daabc19625.jpg Bump steer kit was used to get 0.002in of bump steer at TOTAL front suspension travel. nearly perfect. Race teams recommend no more than 0.010in at each inch of suspension travel. |
Re: 18X11 Wheel fitment guide Now on to the REAR Springs, sway bar and shocks were removed important to test fitment at ALL heights these 18x11s rub at full droop, so the bump stop area will be trimmed and ground down 1/4-3/8in hammering of the rear inner fender is necessary for tire clearance https://cimg5.ibsrv.net/gimg/www.thi...9eb30d37a6.jpg rear bump stops were trimmed in height so i could lower the car more. no tires rub when rub on the bump stops https://cimg7.ibsrv.net/gimg/www.thi...ef9c33652d.jpg bump stop and chassis ground down. https://cimg8.ibsrv.net/gimg/www.thi...b7994a7f43.jpg (aftermarket) rubber bump stop trimmed about 3/8in https://cimg9.ibsrv.net/gimg/www.thi...967acdd9ec.jpg painted over bare metal https://cimg1.ibsrv.net/gimg/www.thi...97dce75e97.jpg you will need to hammer this area to clear the tire. SUPER easy and fast |
Re: 18X11 Wheel fitment guide 3in ARP studs are used with 12mm x 1.5 acorn LUG nuts with plenty of threads to spare the lug nut spline socket has no 1/2in drive on it. so it was welded on a 21mm socket for ease of use caliper to wheel distance is 1.5in with my 5/8 spacer. 1in of you ordered the wheel with 6.1in of back space rear 18x11s clear my LCA center of the S71 wheels is fairly small with a large shell/lip. this gives them the appearance of a smaller wheel, good because anything over 18 starts to look dumb on 3rd gens https://cimg7.ibsrv.net/gimg/www.thi...cb429728a7.jpg I used little 12mm x 1.5 acorn nuts as the WELD wheels have small Tapered seats. https://cimg8.ibsrv.net/gimg/www.thi...a6ad287898.jpg The acorn nuts have a dumb socket https://cimg9.ibsrv.net/gimg/www.thi...b6d0a2aada.jpg A quick pass with a TIG welder makes a single socket. Spline socket+21MM SOCKET https://cimg0.ibsrv.net/gimg/www.thi...60e5e1864e.jpg 3.in Extended ARP studs have plenty of grip range left even with a 5/8 spacer https://cimg1.ibsrv.net/gimg/www.thi...f97ed549d1.jpg my 13in 6 piston Wilwood brakes with Billet aluminum hubs fit easily. https://cimg5.ibsrv.net/gimg/www.thi...ed101a41a5.jpg the WELDS71 wheels have a smaller center section and larhe shells, so they look closer to 16s than they do 18s. this help with aesthetics https://cimg7.ibsrv.net/gimg/www.thi...196206c95d.jpg clears my tubular LCA no issues |
Re: 18X11 Wheel fitment guide NOTE: WELD RACING S71s are LUG-CENTRIC! DO NOT have a shop balance them with a HUB-Centric balancer you need to get a shop to order a LUG based balancer attachment since the wheels are LUG-Centric the 5/8 or 15.9mm spacer doesn't worry me much but i'll be attempting to have a Billet aluminum spacer made with the same center Hub as the factory 3rd gen-2.78in Hub bore https://cimg5.ibsrv.net/gimg/www.thi...8bef2fdcd8.jpg 0.600in Thick spacer 5x4.75 bolt pattern 2.78in bore I.D. |
Re: 18X11 Wheel fitment guide Weld wheels are not hub centric, or do they just use are larger hub? |
Re: 18X11 Wheel fitment guide
Originally Posted by McLovin1181
(Post 6408395)
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Re: 18X11 Wheel fitment guide Weld racing wheels are LUG centric. WELD is very specific about this. The hub bore on the wheels is over 3in, but it's not the true center of the wheels. the shims on the steering stops was just a 1/4in nut I put behind the stop. so the nut goes between the A-Arm and the steering stop. |
Re: 18X11 Wheel fitment guide
Originally Posted by McLovin1181
(Post 6408443)
Weld racing wheels are LUG centric. WELD is very specific about this. The hub bore on the wheels is over 3in, but it's not the true center of the wheels. |
Re: 18X11 Wheel fitment guide
Originally Posted by McLovin1181
(Post 6408392)
HI, this is a post to catalog what I did to fit 18X11 wheels on my 1992 RS Autocross car. 6.6in of back spacing on all 4 5/8in spacers in the front to get the back spacing needed and still be able to rotate tires |
Re: 18X11 Wheel fitment guide
Originally Posted by MarineIROC
(Post 6408550)
What pad height did you select? Was pad height same front and rear? I'm running Wilwood's 4R Front Brake kit with DS suspension front and rear. Thank you for sharing. I don't think these 18x11 even had the medium or low pad height as an option. (High pad looks better to me anyways) I have the 6 pot superlite Wilwood caliper. It has 1.5in of room between the spokes 1in if you just used 6.0in of backspacing and no spacer like I did. There's a pic if the distance posted |
Re: 18X11 Wheel fitment guide I 3d printed a spacer that reduces the 5/8 thick spacer Inside Diameter to the 3rd gen 2.77in Hub diameter. that way the spacer is centered more accurately. The wheels are LUG Centric so there's no wobble to worry about even if the spacer wasn't perfectly centered. https://cimg2.ibsrv.net/gimg/www.thi...2bb55a0048.jpg 5/8in spacer 3d printed center to reduce the I.D to 3rd gen spec Of 2.77in |
Re: 18X11 Wheel fitment guide You are obviously much more advanced than I am at this, but I have a couple questions. I'm going to install the 1" summit extended ball joints to bring the front of the car down and bring the RC up. My reasoning for it was I thought it would have less effect on bump steer than if I dropped via springs. Since the position of the spindle doesn't change in relation to the center link/tie rods, I thought it wouldn't change bump steer from factory... Or is bump steer induced because the angle of the A-arm is changed, and since the tie rods have a different radius (or angle) that is what induces the bump steer as the a-arm goes through it's cycle? Essentially the tie rods are more or less horizontal and the a-arm will be angled down more due to the extended ball joint and that different in angle is the cause of the bump steer? I do not have a performance suspension built yet, but I am piecing things together as time goes on. I'm hoping to do some autocross next summer for fun. |
Re: 18X11 Wheel fitment guide Great thread Mclovin! Thank you. |
Re: 18X11 Wheel fitment guide I think it's a 1:1 ratio of how much the car is dropped with the extension of the ball joint. The strut/mount/spindle assembly aren't supporting the chassis, it's just the spring. With the ball joint you're just separating the spindle and a-arm that amount, the chassis drops by that amount in relation to the spindle... Sort of like a drop spindle I think the midline of the spring is something like 45% the distance of the a-arm pivot point to the ball joint center, so a 1" shorter spring is close to 2" of drop. I've been reading as many posts about set up from the knowledgeable guys on here over the years to get this thing to handle better. I set up a fwd race car that was immediately at the top of our class in a really competitive field, all based off of picking people's brains and reading, so I enjoy the info... Not that I will ever seriously put this car through it's paces. I'd need a different car to really get crazy with this stuff and not mind the rash from hard track use. But, I do want to make sure it handles as good as I can get it to, if for nothing else than being safe! As far as dust covers, I'll take your findings so I don't have to wait to get my set and take measurements. I think energy suspension has a spread sheet on their site to find the right ones once you have measured things out. |
Re: 18X11 Wheel fitment guide I think it's a 1:1 ratio of how much the car is dropped with the extension of the ball joint. The strut/mount/spindle assembly aren't supporting the chassis, it's just the spring. |
Re: 18X11 Wheel fitment guide
Originally Posted by McLovin1181
(Post 6408576)
I have the 6 pot superlite Wilwood caliper. It has 1.5in of room between the spokes. 1in if you just used 6.0in of backspacing and no spacer like I did. |
Re: 18X11 Wheel fitment guide I wouldn't go any further than a 1/2in extended Ball-Joints. A 1in extended stud would make bump steer impossible to fix A 1/2in stud required lowering my bump steer kit nearly 3/4in. Extended ball joint will lower the car equal amounts to the extension of the stud.SO +1/2 stud=1/2 lower. The a-arm stays in the same position, while the spindle/wheel are raised 1/2in there are energy suspension boots that fit QA1 extended Ball-Joints. As far as the brake lines, I'm using a BBU Wilwood kit, with simple stainless lines. No issues with the lines hitting. The wheel is a 18x11 WELD S71 6.6in BS.(71HB8110B66A)Ur better off finding a 3rd party that orders from WELD.Summit or Jegs want $1,000 a wheel now, when in early 2020 they were $705.I got them from an eBay seller for $805 a pop.And even then I think I overpaid. Full custom wheels are in the $1K range so I feel like there are better options. https://cimg9.ibsrv.net/gimg/www.thi...47fc570515.jpg Earl's SS lines -3am With ground control KONI RACE double Adjustable 8611-1259 Struts. Line bolts in the same spot as sock. https://cimg3.ibsrv.net/gimg/www.thi...171626594f.jpg QA1 Ultimate Ball-Joint with 0.5in extended stud. 0.200 and stock lenght are available and can be swapped in no issue. |
Re: 18X11 Wheel fitment guide Thanks for the info. I'll just go with the .5" ball joints then and take the rest of the drop with cutting down the spring... I'm going to be building my own weight jacks with something like a 800lb front 175lb rear but likely not this season. It's fairly cheap to build that set up at home, but the dampeners is where the money is and I'm already near my annual car mod budget with this spring's updates. I'll mess around figuring out the bump steer by pulling the springs out, checking toe at ride height and then again under compression. |
Re: 18X11 Wheel fitment guide I wouldn't go any further than a 1/2in extended Ball-Joints. A 1in extended stud would make bump steer impossible to fix The a-arm stays in the same position, while the spindle/wheel are raised 1/2in Please allow me to clarify my previous statements. ...MOST of the reading that I've been doing about extended ball joints is done in conjunction with LIFTING the suspension at the time of installing the extended ball joints. I conflated the two ideas. This would essentially be (with a .5" xbj) a half inch drop, then lifting the suspension back up by .5". Ride height stays the same. Bump steer stays wherever it was before the modifications, and the A arm would now be....lowered, which raises the front roll center. Many posts cite changing/lowering the A arm as the goal of the extended ball joint, not to lower the car. BUT....as you stated, it DOES lower the car. I'll delete my previous suggestions to the contrary in my previous posts. |
Re: 18X11 Wheel fitment guide Extended ball joints in the front of a third generation f-body does wondering for handling. not necessary unless you are 100% serious about racing however. benefits: 1. Raises front roll center and helps balance the car. 3rd gens front RC is too low, while the rear is too high. Making the RC angle favor the front. Raising the front and lowering the rear RC helps a lot for mechanical grip.(think of a more flat line drawn across the car front and rear vs a heavily angled line) 2. Keeps the A-Arm angles from getting Wonky and point upwards if you lower the car. A-Arms should be parallel at static ride height at a Maximum. Ideally still angled downwards like stock. My A-arms are angled 3 degrees downward with a fairly low ride height. |
Re: 18X11 Wheel fitment guide Extended ball joints in the front of a third generation f-body does wondering for handling. not necessary unless you are 100% serious about racing however. |
Re: 18X11 Wheel fitment guide
Originally Posted by Abubaca
(Post 6409370)
I've asked this question a few times, as I realize it's never a black and white answer. Different drivers, skill, cars, and of course what KIND of driving you're doing. Where do you feel the line is between needing the revised A arm geometry? Weekend street car? Dedicated track car? A few Autox/track days a year? ....just curios of your thoughts. ...I have the extended BJ's but haven't installed them. If you want to do any autocross, you're wasting your time with any suspension "mods" that don't help you. It's hard to be consistent and learn a car when it is unpredictable. The course we have here uses our local 3/8 mile oval that has decent banking, and we transfer off the bank down to the little track in the infield, and bump steer there would really be an issue as the transition is abrupt and already upsets the car. |
Re: 18X11 Wheel fitment guide My 92 is only used an an autocross car so anything I can install to shave off 0.1 seconds is worth it to me. A-Arm angles that go upwards have a wonky camber curve and will cancel out any benefits of lowering of the Center of Gravity. Also, lowering the car without modifying the RC; puts the front roll center theoretically underground. I personally like how the extended ball joints make the front end more responsive to inputs. Making it ideal for the fast direction changes of an Autocross course. https://cimg1.ibsrv.net/gimg/www.thi...8245a69128.jpg if I was racing on smooth road courses with gentle direction changes, I'd keep the stock lenght ball joint studs. |
Re: 18X11 Wheel fitment guide Thank guys....I appreciate the input |
Re: 18X11 Wheel fitment guide Just an FYI, it looks like my bump Stop Mod isn't going to hold up. they bent a bit already I'll make better ones to fix this. https://cimg8.ibsrv.net/gimg/www.thi...bb328fe6af.jpg https://cimg1.ibsrv.net/gimg/www.thi...10c2511141.jpg |
Re: 18X11 Wheel fitment guide Here's what I did for steering stops. added 1/4in of scrap Aluminum behind the stop, and added 3/16in to the area that contacts the spindle knuckle. then welded a triangle brace for good measure. Reduced steering angle by about 3 degrees. No rubbing and the new stop is WAY stronger https://cimg2.ibsrv.net/gimg/www.thi...3cb62e6186.jpg https://cimg3.ibsrv.net/gimg/www.thi...8b3579ba29.jpg https://cimg4.ibsrv.net/gimg/www.thi...78d6206352.jpg |
Re: 18X11 Wheel fitment guide
Originally Posted by McLovin1181
(Post 6408443)
The hub bore on the wheels is over 3in, but it's not the true center of the wheels. |
Re: 18X11 Wheel fitment guide WELD RACING makes it super clear that the S71s are LUG Centric. the center hub bore is NOT the perfect center of the wheel. I do not know how far off the hub bore is from the center, but enough to mess up a tire balance. As far as a number, the hub bore could be 0.010in off and that's enough to cause issues with a HUB centric balance. So when you get tires, make sure they balanced with a LUG centric tool.The shop may need to order one(Discount tire shipped the LUG centric adaptor from another location) https://cimg5.ibsrv.net/gimg/www.thi...39503c7833.jpg |
Re: 18X11 Wheel fitment guide I think @iansane s comment wsa more of a WTF than an actual question |
Re: 18X11 Wheel fitment guide
Originally Posted by scooter
(Post 6412767)
I think @iansane s comment wsa more of a WTF than an actual question Either way, big rubber is cool. I have a set of 19x10s on now and am trying to shoehorn some 19x11s I have but many other projects seem to take priority. Mclovin, I just realized you're in tacoma. The videos are cool. Thanks for the effort. I don't have sound at work but the visuals are succint. |
Re: 18X11 Wheel fitment guide
Originally Posted by iansane
(Post 6413281)
but it seems like it'd be much more difficult to jig up a wheel off of the lugs vs off of the hubbore. |
Re: 18X11 Wheel fitment guide
Originally Posted by scooter
(Post 6413285)
That was my thought too. It really makes ZERO sense to make them ONLY lugcentric vs both/hubcentric 3rd gens are LUG centric as well. The wheel Hub bores are a big bigger than the mounting spot on the car. Sure it makes it easier to mount tires, but lug centric wheels always center themselves when you apply torque to the lugs nuts. Not really sure what the big deal is about? |
Re: 18X11 Wheel fitment guide
Originally Posted by McLovin1181
(Post 6414057)
Most cars are still LUG centric even today. 3rd gens are LUG centric as well. The wheel Hub bores are a big bigger than the mounting spot on the car. https://www.liveabout.com/hub-centri...wheels-3234497 From the article There are some people who will say that driving on lug-centric wheels doesn't matter as long as the lug-nuts are the self-centering cone type, as they will adequately center the wheel. These people are wrong. |
Re: 18X11 Wheel fitment guide The whole reason your shop had to order a lug centric adapter is because almost all OEM wheels are hub centric and they balance with the hub cone. It's a big deal. |
Re: 18X11 Wheel fitment guide
Originally Posted by scooter
(Post 6414062)
The whole reason your shop had to order a lug centric adapter is because almost all OEM wheels are hub centric and they balance with the hub cone. It's a big deal. Not sure why this topic is so touchy lol. WELD racing was pretty specific about the wheels being LUG centric. Considering the wheels needed like 1/2oz counter Weight, they are damn near perfectly balanced |
Re: 18X11 Wheel fitment guide You can think what you want, but you're not correct. There is a reason OEMs make the wheels hub centric. Not sure why you keep thinking they are lug centric, not sure why you won't accept that |
Re: 18X11 Wheel fitment guide The original 3rd gen manuals sent out in the 80s and 90s stay the wheels are LUG centric. not that it really matters since obviously a HUB balance is fine for the factory 235/245 sizes. Anyways, I gotta prepare for the 1st race of 2021 with my LUG centric WELD wheels. Stay tuned for more Racing Mods on my channel such asInstalling PENSKE 8300 coiloversAnd a Carbon fiber panhard bar. https://cimg3.ibsrv.net/gimg/www.thi...09a1c5fd40.jpg |
Re: 18X11 Wheel fitment guide
Originally Posted by McLovin1181
(Post 6414057)
Most cars are still LUG centric even today. 3rd gens are LUG centric as well. The wheel Hub bores are a big bigger than the mounting spot on the car. Sure it makes it easier to mount tires, but lug centric wheels always center themselves when you apply torque to the lugs nuts. Not really sure what the big deal is about? As an aside, lug centric wheels won't ALWAYS center themselves. You can most definitely improperly torque down a set of wheels and them be out of balance. The old wheels on my e30 had a hub bore that was larger than my hub and I had to be pretty meticulous about slowly tightening/aligning the lugs to make sure there wasn't a vibration. I'd wager most tire jockeys aren't going to spend that many extra seconds on every wheel that comes through their bay. Either way, appreciate your videos and your foray into properly fitting big meats on thirdgens. |
Re: 18X11 Wheel fitment guide Good stuff, OP. Not a huge fan the BFH, but if it works, it works. We picked up a '92 Z28 for my wife last summer and are going to get her back into autocross with it this summer. Your post on LS1tech brought me over here looking for info on your car. |
Re: 18X11 Wheel fitment guide What’s your wheel clearance to the strut? Thanks. |
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