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Rotatable GT350 Square Wheel-Tire Setup

The reason I am concerning is that one of my friends (he had engineer background) suggested me skipping spacers if I push the car hard on track.

Wtywly,

Its all come down to your comfort level....There are quite a few of us use spacers on the track because the wheel/tire configurations we have chosen dictate us to use spacers and we are comfortable with it and have not run into any issues. When a spacer is properly engineered, fabricated and installed, there is no gaps between the spacers and the wheels or spacers to the hubs, then all the forces that holding the wheels on the car are transferred to the lug nuts and the studs. That is why you should torque your lugs before you go on track (*COLD not after you come in from the session when everything is HOT!).

To answer your own question. If you dont use a spacer, will the new wheels you purchase work with the car? Are you happy to use the OEM setup or buy other wheels? Based on my personal research, I have yet to find a wheel that can fit both front and back without the need of a spacer for the front.

One more critical point. You should replace the OEM studs from the hubs with longer studs so that you are mounting the wheels to the hub through the spacers instead of the spacers that have bolts on them which mount the spacers to the hubs and wheels to the spacers instead. That would not be an ideal configuration for spacers setup.

I hope this helps.
 
Wtywly,

Its all come down to your comfort level....There are quite a few of us use spacers on the track because the wheel/tire configurations we have chosen dictate us to use spacers and we are comfortable with it and have not run into any issues. When a spacer is properly engineered, fabricated and installed, there is no gaps between the spacers and the wheels or spacers to the hubs, then all the forces that holding the wheels on the car are transferred to the lug nuts and the studs. That is why you should torque your lugs before you go on track (*COLD not after you come in from the session when everything is HOT!).

To answer your own question. If you dont use a spacer, will the new wheels you purchase work with the car? Are you happy to use the OEM setup or buy other wheels? Based on my personal research, I have yet to find a wheel that can fit both front and back without the need of a spacer for the front.

One more critical point. You should replace the OEM studs from the hubs with longer studs so that you are mounting the wheels to the hub through the spacers instead of the spacers that have bolts on them which mount the spacers to the hubs and wheels to the spacers instead. That would not be an ideal configuration for spacers setup.

I hope this helps.
Thank you for your detailed explanation! I haven't use any spacer in the past on track because my past vehicles run square setup from the factory and it is easy to find a set of rotatable wheels that have a square setup. That is why I want to make sure there are not any issues when using spacers on track. If I do not use spacers for my intended square setup, then I can change my wheel order to different offset. But the issue would be I have to dismount the tires whenever I need a rotation. Based on my past experience, I have to rotate tires before every track days. So if I do the setup without the spacers, then it is really a hassle for me in term of tire rotation.
 
That was one of the reason why setup with the square setup. I also learned something else. If your tires are NOT directional like the Michelin Super Sports (OEM) or the Cup 2 tires, you can rotate left and right after each track day/event if you like. By having the square setup, you can now rotate front to back as well as left and right. That should give all four of your tires a bit more even wear on each corner.
 
If done properly, meaning with race quality wheel studs like the ARP’s I posted a link to, there will be no issues. If you don’t want a rotatable setup then purchase specific offset wheels. With no disrespect to your friend wheels spacers have been used for decades. Many, 100’s?, of TMO members have used spacers with no issues. The photo below is a Ford Mustang factory race car using spacers.

D5C775EF-0E6C-4AE9-8475-BDD5B1A69FBC.jpeg
 
Bolted connections with the use of studs and fitted spacers is used throughout industry. When properly clamped they become one. The spacers register on the hub flange and the wheel register on the spacer flange, the studs pass through the hub, spacer and wheel and when properly torqued become one unit. If this type of bolted connection was unreliable wheels and wheel hubs would be an integrated component. Crankshafts would be machined with integrated flywheels and vibration dampers, cylinder heads would be cast one piece with the engine block, sky scrapers would not use steel beams bolted to concrete. A proper fitting spacer and wheel stud is fairly reliable.
 
Bolted connections with the use of studs and fitted spacers is used throughout industry. When properly clamped they become one. The spacers register on the hub flange and the wheel register on the spacer flange, the studs pass through the hub, spacer and wheel and when properly torqued become one unit. If this type of bolted connection was unreliable wheels and wheel hubs would be an integrated component. Crankshafts would be machined with integrated flywheels and vibration dampers, cylinder heads would be cast one piece with the engine block, sky scrapers would not use steel beams bolted to concrete. A proper fitting spacer and wheel stud is fairly reliable.
Thank you for ur explanation. This gives me peace of mind tracking the car.
 
If done properly, meaning with race quality wheel studs like the ARP’s I posted a link to, there will be no issues. If you don’t want a rotatable setup then purchase specific offset wheels. With no disrespect to your friend wheels spacers have been used for decades. Many, 100’s?, of TMO members have used spacers with no issues. The photo below is a Ford Mustang factory race car using spacers.

View attachment 3925
Wow, I never knew that. I thought race teams do not use spacers. Poor knowledge...
 
I just put in two track days with my new square setup and the car felt better balanced than with the stock staggered setup. Very neutral front/rear balance and stable during high speed transitions. I did not make any changes to the suspension. Here's my setup and let me know if you have any questions:

@Need4SpeedMotors
@bpracer
@modernbeat
@CSL
@ChopSui
@JAJ
@scmscout

4-N4SW Project 6G 19x11 +50 rear wheels
4-Michelin Pilot Sport Cup 2's in 305/30/19
2-25mm front spacer
10-ARP 14mm x 1.5 front wheel studs with stock wheel studs in the rear, part number 100-7733
20-Dorman 611-257 open lug nuts (you'll need a thin walled socket)

Each wheel/tire is 52 lbs while the stock wheel/tire is 62 rear and 61.5 front. That's a 10 lbs saving per corner in the back and 8 up front with the spacers. Not as light as the CF R wheels but not as expensive either. ;)

Front wheel with spacer
F695EE77-16ED-4472-9488-78402F7210B4_zpsnwst3ukp.jpg

Rear wheel with Dorman lug nuts
1BE30134-33EB-4C09-B1F3-A02A2AAF847D_zpsskxddh77.jpg


Spacers
DCB94FB0-80F7-49C0-B14F-EF5FF13793E6_zps5wmjvt7d.jpg

Torture tested
B3992D2D-688F-4E44-8D70-E83CB5BC631E_zpslkmqc1qh.jpg

So I know this setup will work on a regukar GT with the wheels sticking out about 1\4 inch. I have seen that a 10.5 with a 23mm offset will clear the stock gt front end. I am wondering what a 23mm offset on the rear will do though. The wheels i am looking at are only avaliable in that offset.
 

Bill Pemberton

0ld Ford Automotive Racing Terror
6,401
5,277
Exp. Type
W2W Racing
Exp. Level
20+ Years
Blair, Nebraska
I would use those rims as your street set and just get a new set of Apex rims. I spent hours discussing this with LMR and got numerous answers, none of which later proved to be correct ( and I do like some of their products ) , so why not just get a correct set from Apex? Contact Cory and he will give you straight answers and they have actually done all the work to make sure you have a correct set-up. Keep in mind , the most important thing about their wheels is they have great distance between the caliper and the barrel, so little chance of clagg or rocks getting wedged in between. Sure you will spend more, but you would still have to get two rims at LMR, and I was told they would not work. You will need a one inch ( 25mm spacer up front), and just go to Apex's Forum Line and send a personal message to them -- request and answer from Cory. Best of luck.
 
I know I've seen the regular ones used on the GT cars in a 19x11 square setup. If I get a new car I'm likely going to run only street tires (RE71's?) so I'd like to have two sets that could go street or track and prefer they all be rotatable. Good to have extra set on a track weekend.
 
369
146
Exp. Type
HPDE
Exp. Level
5-10 Years
Waco, TX
I considered getting a rotatable setup from Cory and we decided that a true R spec setup would be best for me. Honestly just tired of switching and rotating tires at this moment. Just prefer to arrive and drive. I will say that Apex has the best quality i've seen in a long time. It's up there with SSR when i got GT3's. I went with SM-10's and they are awesome and really compliment a white GT350.
 

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