Full Tilt Boogie Racing locks down the S550 IRS subframe and diff
By Steve Turner
Photos courtesy of Full Tilt Boogie Racing
Of course we all know that the suspension in the latest Mustangs offers great advancements over its predecessors thanks to a double-ball-joint front and an independent rear. However, as good as it is, this setup has to make some performance compromises to deliver the ride quality and quiet operation that the average Mustang customer expects.
For anyone reading this there is more performance to be gained from upgraded hardware, and Full Tilt Boogie Racing is one company offering a plethora of S550 upgrades, including its new differential and IRS subframe bushings.
“We took a slightly different approach when we addressed the subframe bushings,” Bruce Cameron of Full Tilt Boogie Racing said. “After a close inspection of the OEM subframe bushings, we determined it was not worth our effort to try to work around these poorly designed bushings, so we started over from scratch. This is a much different approach than what some of the other manufacturers have done.”
The Full Tilt Boogie Racing subframe bushings come as a complete kit, including isolation washers to reduce NVH transfer into the cabin.
“There are so many things wrong with the OEM bushings we felt it was better to not make ‘a band-aid’ or to fix ‘with a compromise’ but to do a complete redesign and do the job right,” he added. This design will secure the subframe in the chassis infinitely more securely than our competitor’s parts. We have had tremendous success with our UHMW subframe bushings in the SN-95 chassis and decided once again to go with UHMW for the subframe bushings in this new chassis.”
To install this system mandates removing and replacing the independent rear suspension, and that straight-forward approach is detailed here…
“The only NVH we encountered was after the installation of our diff insert bushings. The diff insert bushings added 2 db from our findings and there was a bit of a high-speed whine at 70-plus mph,” Bruce said. “In addition there was also backlash noise from the ring and pinion gears. We were able to subdue the noise with some Dynamat applied to the subframe and we also foamed the hollows of the subframe with Great Stuff.”
As you can see below, the combination of the subframe and Delrin differential insert bushings makes enough of a difference to give up a bit of NVH…
Normally the subframe bushing kit (PN FT530) will retail for $249, but they are available for the introductory price of $199, while the differential bushing kit (PN FT 535) goes for $199.