Widest Tires for the Coupe?

[Alan_C]

I am in the planning stages for a Coupe to be purchased late this year. Realistically, can you select tires wider than 275 front and 315 rear. The engine combo I am looking at will be in area of 500 to 550 crank HP. Has anyone fitted 335s to the rear? If they did, what was required to make them fit? Since there are many out there running 275 on the front of their MK4s, I would suspect 275s fit fine on the coupe. Have some gone wider at the front too and again, what was required to fit the larger tires. I plan to buy custom width and backspacing so that I can fit the largest tires both front and rear.
Thanks

[GoDadGo]

Al,

It would be super cool if you could run 295's on the front with 335's out back.
Good luck and I can't wait to see what you build.

Steve

[edwardb]

I have 275's and 315's on my Coupe on 18" wheels. The 275's fit comfortably with no issues, body rubbing, whatever. Don't know if wider would fit. Also have power steering if that matters. For the rears, 315's fit OK. I have 25mm (1 inch) spacers and in four seasons of driving, have seen a couple of very light witness marks on a frame member through the front of the wheel well. Nothing concerning. I know several have put 335's on their Coupe and that same frame member can be an issue. If I recall, Erik Treves either removed or modified his. Maybe he'll weigh in.

[burchfieldb]

I know Greg from Cobra Daytona Build has them and had to make mods. Check out his video on it here.

https://youtu.be/JdaFVt4xijg?si=AMIRyavx0sP_QeLg

[Rsnake]

Thanks Burchfieldb for the shout out.
Yes I did go with 335's in the rear and if I built one again I would go 315's. First is the fit, the backspacing for 335 needs to be perfect and I still needed to trim the diagonal bar and the lip on the fender. 2nd is tire availability as 335 30r18 does not have a lot available compared to a 315. 3rd is tire heat, these cars are light and I can never get the rear tires up to the optimum temp for auto cross and track days. Just my thoughts but the do look badass.

[Alan_C]

I know Greg from Cobra Daytona Build has them and had to make mods. Check out his video on it here.

https://youtu.be/JdaFVt4xijg?si=AMIRyavx0sP_QeLg

Thank so much for your post, exactly the information and end result I was looking for. I can weld, so the mod, especially during construction is easy. I will go with a 3/16" plate gusset to restore the strength lost trimming the tube.

[Alan_C]

The info on the use of the 335s in the back was really helpful. However, not much said about fitting tires wider than 275s up front. That said, I believe I am going to do a 10.5" wheel up front and a 12" in the back. The 12" is the sweet spot for the 335 according to Continental. The 10.5 inch wheels for the front can handle from 275s to 295s, but the 10 is a standard width. Should 10.5 be cost prohibitive, I will go that route. I am a fan of Continental tires and once I saw they had 18 inch fitments for 315 through 355s and 275, 285, and 295s that can be used up front, my tire source is determined. When the time comes I will get one of the wheel fitment tools. They are only $110 from Amazon, cheap insurance when selecting wide tires and custom wheels IMO. I am using Team III wheels on my Mustang build, so I will go back to them again. Hopefully Jim can make a 10.5x18 for the front in their Halibrand look alike wheel. Since they will be custom offsets, or backspacing if you will, asking them to have the wheel centers powder coated in matte white should not be a big deal. I will have to approach Georgy at GasN as well for matte white side pipes. I really like the look of the matte white as it is a bit different than most of the coupes built that I have seen pics of.

[Rsnake]

Alan,
For the front tires and know snowman runs 305 30r19 with no rubbing or issues and I have heard 315's will fit but have never seen it in person. 275's are easy and not an issue.
I am also running the team three wheels which have been modified for simulated knock offs and like the wheels.

[TBull]

One of our members with a gen 1 coupe did a lot of work on his car but I know he ran 315s on the front. His name is Mike Marshall. He does a lot of autocross. He was running 315s all the way around..

[Dave Tabor]

https://thefactoryfiveforum.com/show...ire-Repository

[GT_Rich]

I run 315s up front. There is zero issue. I have them on 10.5 wheels, which is skinnier than I prefer but the wheels were dirt cheap.

[Alan_C]

I run 315s up front. There is zero issue. I have them on 10.5 wheels, which is skinnier than I prefer but the wheels were dirt cheap.

Thanks so much for your reply, I was starting to wonder if no one had done it especially since Eric Treves is going with 275s up front and 335s in the back. I would have thought he would have pushed the envelope at the front too. I have 285s on 10 inch wide wheels on the back of a vintage Mustang that will eventually be upgraded to 295s. I can use those wheels and tires as a test setup. You know, trust but verify as tires can be exchanged but custom wheels, not so much. I am going to go with the 18 inch Halibrand replica from Team III wheels so that I can set width and back spacing for both front and rear. While 315s at the front sound awesome, I think I would prefer a 295 or 305 at the front. Do you have any pictures of the fitment you can share. A few pictures would answer many questions like how much do the 315s stick out past the front wheel lips. I plan to use Continental Sport 02s and they just from 295 to 315, so looks like I will go with 295s up front if I like the fitment.

[flight_83]

I'm going to be running 355 in the back and 325 in the front. Of course, that's after I widen the body though haha. once my 2 piece forged wheels are finished in a few weeks and mounted on the car I can finish scaling the design and start printing the body.

[Alan_C]

I want to thank everyone for their input and especially to the link to the repository. I have decided to go with 19 inch wheels for tire selection and availability. I will be running a 305/30-19 front and 325/30-19 rear running Continental ExtremeContact 02 tires. Should be more than enough tire for a high performance street car.