Anybody tried 285/30 RE71R or RT660 on an 11" wheel? The wheel is 0.5" wider that recommended. Is this a big no-no?


Thanks

 

RT660 run wide, it would fit pretty square I'd wager. I know a couple guys running the 255 RT660 on 10.5" and they have a tiny stretch, just a hair more than my 275 RC1 is on my 10.5" wheels.

My bigger concern would be fitting the 11" wheel. If you're not wide bodied in the rear you need a very high offset wheel to make that work and those options are few and far between.

 

Thanks for the info!. STU guys are begging to buy my cruddy NT03 10.5" ET30 so I thought maybe i'd go wider. I just found out today that the Enkei GTC01RR 18x11" ET30 is not available with 5x114.3 (only BMW bolt pattern) *sigh*. so I'm back to shopping around for streetable wheel options.
My car isn't lowered and just enough to scrape getting off the driveway, and I was ok with a bit of tire sticking out at the back (shaved fender lip)..

 

Unless your rear quarter is very pulled an 11" +30 is still too low. You need to be around +40 to stay relatively underneath the stock metal. Konig, Forgestar and Momo all have wheels that fit the criteria but it's still a super tight squeeze and I don't know how much or little inner clearance there is.

 

I understand. just with 285, similar to what i have now (and not too lowered), the tire should technically stay where it is. the additional width will not reach the fender or spring perch (6" 60mm spring).


anything wider I'm back to the drawing board (shorter springs, mismatched offset, flares)

Are Konig wheels good enough for race applications? If so good to know!

 

The additional wheel width will unroll the tire slightly, so I wouldn't count on even the tread width staying the same. I wouldn't count on ride height to avoid contact, unless you can confirm that your rear shocks don't have enough travel. Whenever I remove the rear spring on my Ohlins and cycle the suspension I'm amazed at how much up travel I have back there. The tire and wheel really tuck into the body and you have to be prepared for that

There are some higher offset 5x114.3 18x11 wheels out there. Mustang fitments are a good place to look: https://www.apexraceparts.com/shop-b...ang-wheel.html

 

Yup, i will check how it tucks. I ran a pinched 295 hoosier a few years back and it get sliced by the fender, a bit to the side of the tire, but only on a local venue when they put an autox corner on a 'berm' section of the track That hasn't happened since 285/30 is a shorter tire and i have +100lbs more rear spring now.
I was looking at apex. won't ET52 need so much spacer for the fronts? what's the max spacer for folks here, with arp studs?

 

Yes the center of the tread stays in place but you still bring the sidewall out a 1/4" and that will likely rub.

Yes, tons of high level TA guys run Konig wheels. They make an 18x11 +40 Hypergram. I wouldn't run mustang wheels, they use M14 studs vs our M12 studs and you'll get a smaller contact area on the nut taper because of it.

I've run up to a 20mm slip on spacer on my ARP studs. I wouldn't run more, that's barely max thread engagement on my short open end nuts.

 

my current right tire has very slight fender scrape, i carry about 150lbs in the trunk to and from events. it can be a problem when carrying the rcomp set of wheels
This Hypergram ET40 sounds like worth the try. Should I get ET15 for the fronts? I dont need to rotate my tires (my front brake pad dust eats paint)



10,5ET18 is my ET30 & 12mm spacer, ET15 is with 15mm spacer. I tried both but kept the12mm since it does not touch the frame at max camber setting
Thanks

 

It would entirely depend how far you've stretched your front fenders. If you know what your inner limit is then shoot to stay above that. Sorry I can't give a definite answer, you're on a pretty thin line in the front. I run the same NT03 but with a 20mm spacer up front. I'm probably going to step down to a 15mm since I get a bit of fender rub under high compression corners.

Also, just something to note since it hasn't been brought up (and for anyone else who may read this thread). There's no chance of an 11" +40 fitting around the stock trailing arms (if you're still on stock) in the rear. So you'll need to either find an old set of R/T arms or get some SSB ones from Dallas.

 

Yeah, I will need to see the FA510s I just ordered first, before I get any where. I have confirmed with a seller they can do ET40/15 if needed
What tire do you have on the NT03? Paint and plastic on my frame side is gone so I put white shoepolish. I'll see in tomorrow's TT if I need to switch to 15mm spacers or reduce camber. Still 30% left on my sideskirt edge, so there room lol. I dont see a need for moving the front fenders tho.

SSB trailing arms FTW. Thanks guys!

 

I run a 275/35 RC1. It's a tad taller than your 285/30 but obviously a little narrower too. Will likely be jumping to a 285/30 when I have my car back together.

 

This was my pinched 295/17s. no issues with the fenders at this ride height, autox only set up tho.

 

Out of curiosity, how much does all this wider wheel and changing of offset effect the scrub radius and feel of the steering? It does seem to be something that doesn’t come up in conversation often, it’s always just a case of what fits in the space.

 

Nobody really talks about scrub radius because it takes a ton of work to get positive and there's not much downside to a negative scrub radius; you pretty much just need to make sure you're not at zero scrub.. The larger advantage comes from the wider track width up front and narrower track width in the rear which helps the car gain front grip and rotate better.