15" Drag Wheel Solution in the works...

[BMR guy]

We already have a thread about this in the drag race section but I thought I would share it over here too since some never make it over to that part of the site.

A few months ago we began a project with Wilwood Engineering, Strange Engineering, and Weld Wheels to develop a kit for the Fifth gen that would allow the use of 15" drag wheels on the rear of the car. As some of you have already found out, this is not an easy process. The lower shock mount is too low, the brakes are way too big, and practically every suspension link is in the way of a small diameter, deep backspaced wheel. In fact, a standard 15" wheel won't even fit over the spindle, let alone the brakes or rest of the suspension.
Weld wheels developed a wheel with a large inner barrel and the correct backspace to clear the spindles. By machining the spindle and using a custom offset, two-piece Wilwood rotor we were able to get Wilwoods 4 piston radial mount Dynalite calipers to mount to the spindles and clear the Welds.
One of the biggest problems with using a 15" wheel is the lower shock mounting position. The shock mount is wide and below the centerline of the control arm, directly in the way of the inner wheel lip. To solve this problem, we created a 4130 chrome moly control arm with narrow, relocated shock mounts to clear the wheels. The new shock mount location does not effect the motion ratio as it is mounted higher on the control arm, not further inward or outward. This requires the use of a Strange (or compatible) double-adjustable coil-over shock and our custom 4130 upper coil-over mount. The Trailing Arms must also be swapped to our low-profile TCA033 adjustable arm in order to clear the barrel of the wheel.

We currently have a solid, functional design being tested on our shop car. Over the next month or so we will be tweaking spring rates, optimizing alignment adjustability, testing range of motion, etc. Once everything is finalized design-wise we can estimate selling cost and availability. We will try to keep these threads updated as often as possible and feel free to ask questions!

[BMR Sales]

Here are few more pictures for you guys to check out!

[mlee]

Hmmmm I know someone in need of this right now...

[BMR Sales]

Originally Posted by mlee

Hmmmm I know someone in need of this right now...

We are still doing some street and track testing with this kit but I think it will only be another couple weeks before I have these parts available for everyone.

[Dangeruss]

How much of this would be needed for a 16"? Can I just buy the LCAs? I'm not dumping my Pedders coilovers and I've already purchased a V6 brake setup.

[BMR guy]

Originally Posted by Dangeruss

How much of this would be needed for a 16"? Can I just buy the LCAs? I'm not dumping my Pedders coilovers and I've already purchased a V6 brake setup.

The LCA has a relocated and narrowed lower coil-over mount to clear the 15" deep backspace wheels so it would not be compatible with your current coil-overs unfortunately. From what I understand though, you can modify the OE control arm to clear the 16's.

[Denis]

that looks awesome!

[Dangeruss]

Originally Posted by BMR guy

The LCA has a relocated and narrowed lower coil-over mount to clear the 15" deep backspace wheels so it would not be compatible with your current coil-overs unfortunately. From what I understand though, you can modify the OE control arm to clear the 16's.

Thanks. I was really hoping for a drop in replacement instead of having to modify the stock LCAs. You guys know I love your stuff...I'm just afraid that a system this big is going to be limited to very die hard drag racers. The cost alone will leave many out, and anyone who's already invested in a suspension package.

If you had a drop in LCA replacement for 16s, then the only other piece needed would be a set of V6 brakes.

I guess modification is my only option at this point. :(

It's still a really cool setup...good luck.

[BMR guy]

Originally Posted by Dangeruss

Thanks. I was really hoping for a drop in replacement instead of having to modify the stock LCAs. You guys know I love your stuff...I'm just afraid that a system this big is going to be limited to very die hard drag racers. The cost alone will leave many out, and anyone who's already invested in a suspension package.

If you had a drop in LCA replacement for 16s, then the only other piece needed would be a set of V6 brakes.

I guess modification is my only option at this point. :(

It's still a really cool setup...good luck.

This kit really was intended for the die hard, hardcore drag racers. We specifically eliminated the parking brake to keep it as light as possible, it uses aluminum hat, non-vented rotors, a true double-adjustable coil-over, and we made the suspension parts as light as possible (4130). We are still considering all of the variables however and your idea makes sense. In the future, once we see what direction people migrate, we may come back to this and build a 16" wheel-specific lower control arm that is compatible with an OE or OE dimensioned rear shock.
The current setup, once released will be compatible with 16" wheels and V6 brakes, you would just eliminate the modified spindle and Wilwood components to save the majority of the cost. It won't however save you the coil-over expense if you have already purchased them...