BFG Rival availability

[Vorshlag-Fair]

Has the whole "offset strut" offered by Cortex/Griggs been discussed already? Why doesn't Vorshlag consider that route? I mean if CSamsh has to have spacers to fit 295s and you have to spend money on ARP studs just to use the spacer.... I know Vorshlag would have already considered this (assuming). What was the verdict? Apologies if this has already been discussed and i missed it.

This trick is popular on the modern GTO, because they have ZERO room for wide front tires, but there is no such thing as a "free lunch". There are always downsides to making a geometry change like using "offset struts" to gain inboard wheel room. SAI gets all kinds of f*cked up, among other things. And from what I've read on this very forum, the Cortex set-up has trouble fitting more than a 10.5" wheel up front anyway, so...? Correct me if I'm wrong.

Cmash's car has our Forgestar F14 wheels in 18x11" and he has run 315/35/18 Kumho V710s all the way around, under stock fenders (see picture above). The "problem" is when trying to fit 315/30/18 BFGs, which are fookin HUGE tires. There's only so much room in there.

We build our Forgestar 18x11" front to work with stock geometry + some added negative camber at the top mount (not at the spindle - which eats wheel room) to fit most 295-315mm tires without a spacer, but again - the BFG Rival in 295/35/18 is fookin HUGE and just needs about 2-3mm more room than other 295-315 tires. Cmash's car is shown above on the same wheels with the 295mm Rivals. They are about the same size as the 315/35/18 Kumhos...

While looking up the Kumho specs I noticed a new size: 345/35/18. Well hello there, beautiful...

They also have a new 305/30/18, but its a bit short for the S197 Mustang. When did they start introducing new V710 sizes? Last time I looked there were only about 9 sizes being offered, but now there's 27 sizes. The 315/35/18 is one of the FEW wide R-compounds sizes made in an overall height favorable to the S197 Mustang (which comes with 27" tall tires, stock). The typical 30 series 18" tires always end up looking very short on these big cars.

The hubs are a wear item...they get replaced anyway, so I don't really consider that too much of a problem.

And part of our front hub wear problem has been HEAT, or so we think. When the calipers are sitting at 490°F all the time, and we have visible grease streaks coming off the hubs afterwards, that probably explains a lot. Now that we've added more brake and hub cooling with our 4" ducting, we'll see. Cmash also has upgraded to 4" ducting, too.

...the Rivals have a huge rim protector, hence the reason for the spacers. I don't need them (spacers) when I run 315 A6's or V710's.

Ahh, I thought the spacers weren't needed on your 315s. Yea, the Rival has a huge rim protector section, that makes sense. Shannon runs a spacer with 295 Rivals on 18x10" Forgestars, too.

In other news....THEY'RE BACK!!! 285/35/19 is a new size...and looks like all the big 18's are "In Stock" as opposed to "Special Order"

Wow, that's a welcomed shock! I was told by BFG/Michelin engineers at the launch last year that they were NOT going to make 19" sizes. That's actually a good idea, as too many OEM wheels have gone to 19's (like the upcoming 2015 Mustang GT). And with the 295/35/18 listing backup, we can finally compare some stats...

295/35/18 BFG Rival specs:
Section width: 11.9"
Tread width: 11.1"
Recommended wheel width: 10-11.5"

That's right, folks...the BFG "295" tire is nearly TWELVE inches wide. Our 18x11" wheel width recommendation is almost in the middle of the range that BFG recommends, too.

 

[Arustik]

Ordering my setup shortly. I'll be running them on my Apex 18x10s. I'll try posting some pictures to show how they sit on the car.

 

[Boaisy]

So 18x10's may need spacers for the 295/35's, or no?

 

[SlowJim]

Think that would depend on offset. Maybe something like 35 and below - yes, otherwise no

 

[dontlifttoshift]

I found a used pair of 295s but still needed two more tires in time for USCA in Michigan. I had a set of 315s mounted to 11" wheels for another project so I did some comparing. I then had a new pair of 315s mounted to the rear of my Vorshlag/Forgestar wheels with the used 295s up front., The 295s are huge but when you "pinch" the 315 on the 11" the difference isn't that large.










Section width difference is about 3/8" at the most but the difference in tread width is huge. The shape of the shoulders is what would keep it from working in the front. I need it to be round to clear the clamp on bracket for the endlinks. Terry can offer more insight but I do not think the 315 on an 11" wheel would turn in as well as the 295 does.

For me, this should be perfect. My car is looser than I would like at higher speeds and my limited big boy track experience.....perfect for autocross, though. This should tighten me up a bunch.

 

[csamsh]

So 18x10's may need spacers for the 295/35's, or no?

Depends on the strut size/shape- one of the OKC autocrossers runs this setup spacer-less.

 

[Boaisy]

Think that would depend on offset. Maybe something like 35 and below - yes, otherwise no

Depends on the strut size/shape- one of the OKC autocrossers runs this setup spacer-less.

Let's say Bilstein kit with wheels that have an offset of 43. Should be good then?

 

[modernbeat]

The Bilsteins have more inboard tire room than many competition style struts. I'd try it without spacers first. I usually look for 4mm of clearance at a minimum.

 

[Whiskey11]

This trick is popular on the modern GTO, because they have ZERO room for wide front tires, but there is no such thing as a "free lunch". There are always downsides to making a geometry change like using "offset struts" to gain inboard wheel room. SAI gets all kinds of f*cked up, among other things. And from what I've read on this very forum, the Cortex set-up has trouble fitting more than a 10.5" wheel up front anyway, so...? Correct me if I'm wrong.

You missed the part about those 18x10.5's being ET47 Enkei PF01's and fitting SQUARE, UNDER fenders, WITHOUT spacers. I'm sure a creative group such as Vorshlag could figure out how to make an 18x11 fit using the same offsets instead of having nearly an inch of difference in the offsets. I'm also pretty confident that Filip has done the foot work with a suspension geometry analyzer to see what the compromises are. He has with everything else he has designed.

 

[modernbeat]

You missed the part about those 18x10.5's being ET47 Enkei PF01's and fitting SQUARE, UNDER fenders, WITHOUT spacers. I'm sure a creative group such as Vorshlag could figure out how to make an 18x11 fit using the same offsets instead of having nearly an inch of difference in the offsets. I'm also pretty confident that Filip has done the foot work with a suspension geometry analyzer to see what the compromises are. He has with everything else he has designed.

The 11" wheels already fit under the fenders and it's not strut position that limits the offset. It's the HUB position. And an offset strut body with longer ears doesn't change the hub position.

Unless you want to change the arm, strut and tie rod to move the front hub outboard, then the same 11" wheel won't fit both ends.

FWIW, someone was contemplating a shortened rear axle to allow them to run the same 11" wheel front and rear.

 

[csamsh]

I'd rather have the extra 1/2"...he said...

 

[NDSP]

You missed the part about those 18x10.5's being ET47 Enkei PF01's and fitting SQUARE, UNDER fenders, WITHOUT spacers. I'm sure a creative group such as Vorshlag could figure out how to make an 18x11 fit using the same offsets instead of having nearly an inch of difference in the offsets. I'm also pretty confident that Filip has done the foot work with a suspension geometry analyzer to see what the compromises are. He has with everything else he has designed.

Hmmmm, I've seen a few cars with the Enkei PF01s and to my eye, they don't fit up front. Sticks out and looks like shit. IMHO


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[Whiskey11]

The 11" wheels already fit under the fenders and it's not strut position that limits the offset. It's the HUB position. And an offset strut body with longer ears doesn't change the hub position.

Unless you want to change the arm, strut and tie rod to move the front hub outboard, then the same 11" wheel won't fit both ends.

FWIW, someone was contemplating a shortened rear axle to allow them to run the same 11" wheel front and rear.

How is the strut not a part of this equation? Inboard tire room has as much to do with the wheels relation to the strut body as it does the hub location. Offset is the measurement from the center of the wheel to the hub mounting face of the wheel. They go hand in hand. A 45 offset wheel is going to be closer to the strut body than a 35 offset wheel, by 10mm. By relocating the holes on the strut mounting ears so the strut sits more inboard, you gain some additional clearance inboard.

As for 11" wheels fitting front and rear, they do, with drastically different offsets, which is not the point of the offset struts. The ability to run a wide wheel that fits front and rear without spacers is and that is exactly what the Cortex offset strut body does. Could a clever company squeeze an extra half inch or more of wheel room with some clever fitment? Yeah they could. Filip wanted an off the shelf option, hence the ET47 Enkei PF01's in Black (only available in black and only through limited suppliers like him).

Hmmmm, I've seen a few cars with the Enkei PF01s and to my eye, they don't fit up front. Sticks out and looks like shit. IMHO


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The PF01's you've seen in silver that poke out "up front" actually fit very well up front, they fit poorly out back where they stick out. Because no thread is complete without the picture:

The issue here is the half inch poking out of the rear fender arches, not the tucked in front wheels with some negative camber. The front suspension will tuck the tire in when it compresses, the rear will only tuck it in in roll, not in 2 wheel bump where issues arise. The best person to ask about this though is Sam Strano since the 18x10.5 Enkei PF01 ET38 setup was originally found by him (IIRC) and ran at Nationals by him.

The key difference between those PF01's and the ones Cortex sells is the 9mm of Offset that is different between the ET38's that you've seen and the ET47's Cortex sells. This brings them further inboard in the rear and removes most of the poke you see. I spoke with Filip about running those ET47 wheels on a stock location front coilover setup and he said with the right spacers anything could be made to fit if the offset was high enough. FWIW, he didn't seem very thrilled about doing that though.

 

[Arustik]

Well my shipment is in (hello beauties):

Take a look at the difference in size between the Pirelli 305 Slicks and the BFG 295 Rivals:

Will be giving these a shot at the NE-SVT Autox on Sunday

 

[Vorshlag-Fair]

You missed the part about those 18x10.5's being ET47 Enkei PF01's and fitting SQUARE, UNDER fenders, WITHOUT spacers.

:worth:

With all due respect, I would have to see it to believe it.

One man's version of "it fits!" is different from another. #hellafail

 

[dontlifttoshift]

315 Rivals on the rear Vorshlag/Forgestar 18x11s are more better. Once my balls were big enough to hold it wide open on the speedway part of the course at MIS, I missed the larger diameter of the 295s. No rubbing other than the plastic inner fender liner with just a panhard bar.

 

[Whiskey11]

:worth:

With all due respect, I would have to see it to believe it.

One man's version of "it fits!" is different from another. #hellafail

From the Cortex Website:

I'm not sure why this is shocking to anyone. You've read Neema's posts using the offset struts and have seen what kind of wheels and offsets he's put on and tested with spacers. I think you folk at Vorshlag should be more than capable of figuring just how much extra wheel and tire and the relative offset necessary to run them, the offset strut provides based on his data.

 

[BMR Tech]

We are about to place an order for some new wheels and tires.

18"x10.5" Weld RT-S and some 295 BFG Rivals.

Yummy!

 

[modernbeat]

From the Cortex Website:

I'm not sure why this is shocking to anyone. You've read Neema's posts using the offset struts and have seen what kind of wheels and offsets he's put on and tested with spacers. I think you folk at Vorshlag should be more than capable of figuring just how much extra wheel and tire and the relative offset necessary to run them, the offset strut provides based on his data.

That 18x12 that fits up front with the long strut ears is all fine and dandy. The issue is that the same wheel does not fit in the rear. And that is clear in the photo you posted.

 

[Vorshlag-Fair]

From the Cortex Website:

Yep, even from this angle it is just as I thought - That rear wheel is POKING past the fender. HARD. Even Pokey agrees... she pokes.

How does this not jump out at everyone? Even though it is common, it still doesn't mean that it fits. We've seen this since 2008, back when the Enkei 18x10.5" was popular with autocrossers. It poked then, it still pokes now.

I don't put definitive statements out there often, but this one is still true all these years later: You cannot fit an 10.5" or wider wheel on both ends of an S197 without vastly different offsets or some major modifications to the rear axle or front suspension.

Now I'm all for stuffing the most wheel you can under your fenders, and our very first 18x12" rears back in early 2012 fit under stock sheet metal better than that wheel on the white car above. It took some tricks to make the 12" fit back there (swaybar, watts), but it didn't poke. The front was borderline on these 315/35/18s, but that was our first set of 18x11" fronts and we revised the offsets we order based on that first test set.

But hey, everyone has their opinions on what fits. Mine is just different than some folks.