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Discussion Starter #1
We just finished the final test fit for our GTO boxed subframe connectors and will begin production by the end of the week.
They are manufactured from 1.5" x 2" x .120" rectangular tubing and laser cut, 1/4" mounting and weld plates. The subframe connectors tie into 5 structural areas and provide 4 seperate weld points. The rear mount replaces the factory suspension cradle mount allowing full accessibility to the cradle after the subframe connectors have been installed. Available standard in black powdercoat, additional colors also available by special order. More information can be seen on our website at http://www.bmrfabrication.com/GTO.htm
 

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It doesn't look like there's a weld point in the rear mounting area. Doesn't this reduce rigidity/longevity? How noticeable is the addition of SFCs? I sure it's not as night-and-day as on the F-body. Still, I definitely plan on getting these.
 

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Discussion Starter #4
sGTO-6453 said:
Will this fix the dreaded wheel hop slapping sound I hate so much?
Unfortunately wheelhop in an IRS car is a little more difficult to eliminate than in a solid axle car. A combination of things seem to contribute to wheelhop in the GTO:

There are three large rubber bushings that the rear suspension cradle attaches to the body with. These relatively soft bushings help make the ride quiet and comfortable by isolating road noise but they also allow the suspension to deflect under excessive loading.

The GTO rear springs and shock dampening are somewhat soft also. We have played around with dampening using some modified QA1 adjustable shocks and with the right settings and some driver technique, eliminated most of the wheelhop. Once we put Drag Radials on the car, we have not had any wheelhop at all.

We are not pushing the subframe connectors as a "wheelhop cure" but they do help a little. Subframe connectors are more of a handling mod than anything and keep the car rigid, forcing the suspension to do it's job better. They are beneficial to anybody with a unibody car whether you race it or not and installing them prevents those dreaded creaks and rattles from showing up as the car ages.
 

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Discussion Starter #5
BlueGTO said:
It doesn't look like there's a weld point in the rear mounting area. Doesn't this reduce rigidity/longevity? How noticeable is the addition of SFCs? I sure it's not as night-and-day as on the F-body. Still, I definitely plan on getting these.
Unfortunately, the Holden engineers didn't leave any exposed frame for us to work with in the rear. The frame points are underneath the rear cradle and not accessible from any angle that is accessible to welding. This forced us to create a specialized rear mount that is both strong and removeable and probably the biggest challenge we have faced in designing subframe connectors. Fortunately, the rear cradle supports utilize 4 reinforced mounting points in the chassis so we incorporated these into the design and made a stronger support also. This support then attaches to our subframe connector through tube sleeves welded into the connector. This mount is on an offset leg to prevent torsional rotation in the subframe connector as the car tries to "twist". Needless to say, since the load is spread out over such a large reinforced area, this connection is as strong as a weldpoint would be. ;)
 

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Very cool of you guys to have this out on the market already. A set of these will be high on my list :D :drink:
 

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Very, very impressive work. Does BMR also do subframe connector installations? I want to get these for my car, but am hesitant to have just anyone do the install, particularly the welding. I'm willing to bring my car to you for the install, provided that you offer that service. Please let me know.
 
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