We slid the new axles into the Ford Explorer 8.8” diff housing.
Then we bolted the outer axle in place.
The OEM ABS ring gear measures 106mm in diameter. The ABS ring gear on the DSS axles measured 96mm, increasing the sensor gap by 5mm. DSS has assured us that they have not had issues with this ABS ring gear in decades of sales.
We noticed the ABS sensor had this 4mm thick spacer on it. The spacer is shaped differently to fit and be retained in the suspension upright.
We had to grind down the ABS sensor bracket to the same shape as the spacer to be retained in the upright. This reduced the 5mm gap increase down to only a 1mm increase. If a 5mm gap increase worked in the past, this is probably not necessary, but it was easy to do so we tried it.
Now that the Ronin Speedworks subframe kit, Ford Explorer 8.8” differential, Eaton Detroit Truetrac LSD, and DriveShaft Shop “Direct-Fit” axles are installed, our FD RX-7 has a rear end that is capable of handling over 1,000whp. Removing the subframe and welding in the mounting brace seemed a little daunting and labor-intensive, but it was actually far easier than we expected and definitely worth the effort.
The Ford 8.8” diff swap is a no-brainer when you consider that after selling the original OEM diff and parts, this upgrade is similar in price to upgrading the stock diff with a noisy clutch-type aftermarket LSD and trying to brace the weak, stock cast iron diff housing. We had countless final drive ratios and limited slip differential options to choose from that ranged in price and performance. We are ecstatic to have the Eaton Detroit Truetrac LSD in our FD due to its amazing performance on track and silent operation on the street.
Now that we have a stout rear end capable of over 1,000whp, the next weak link in our drivetrain is the transmission, which tend to fail from hard use in the 350-450whp range. Needless to say, we are going to have to address that next.
Stay tuned!
4 comments
This is vastly superior to any other 8.8 conversion I have seen for this car. Now to convince Jeff to do this to Project V8 FD!
We are spoiled to have so many updates on this amazing project lately! Keep up the hard work.
Great write-up and an impressive kit.
Although, it seems the support bridge could be easily revisioned to be at least half an inch lower so it wouldn’t necessitate beating up your pristine RX-7-s body.
Damn, great progress. 🙂
still loving the fact that this went from rest-mod to restless-mod.
been following from the beginning.