Photos Courtesy of JPC Racing and Fastest Street Car
The lethargic days of the AOD transmission are long behind us as Ford revamped the automatic-equipped Mustang landscape in 2005 and it has never looked back. The drag racing and street/strip markets have gravitated to the 6R80 six-speed auto that debuted in the 2011 Mustang GT, and it has become the go-to gearbox when you want to run fast with a Ford Overdrive transmission.
Yes, we are praising the 6R80 as a remarkable transmission that continues to leave a positive mark in the history books of Mustang performance. The Mod Nationals even has a dedicated category built around the transmission, showing the excitement the market has for it. However, there comes a time when the transmission isn’t suited for the vehicle’s intended purpose and JPC Racing has a solution. The 6R80 Delete Kit comes complete with all of the parts and pieces to add a Powerglide or TH400 to a S197 or S550 Mustang.
JPC Racing has showcased its capabilities in the heads-up ranks of NMRA with national championships and countless records, essentially doing the homework on what works and doesn’t work, so the 6R80 Delete Kit is turn-key for customers.
Eric Holliday, JPC Racing Shop Manager and NMRA Crew Chief of the Year, shared several thoughts about swapping from a 6R80 to either a Powerglide or TH400. “The swap should be taken into consideration when you are getting more serious about racing, like when you go class racing—locally or nationally. Reaction time and reliability are huge factors in your success in any type of racing and a ‘Glide or TH400 provides that over the 6R80. We work with customers on a case-by-case basis on when to convert to either transmission, but we typically see the reliability (ed note: with 6R80) go away somewhere in the 8s.”
The benefits, however, extend far beyond better reaction times and durability. Holliday shares, “Today’s torque converter technology is so great that running a ‘Glide or 400 allows you to use the converter to help the car run so much better in the first part of the track.” The First gear ratio in the Powerglide and TH400 are significantly lower (numerically) than the 6R80, which is why you rely on the torque converter for acceleration in high-power applications.
Additionally, the numerically lower ratios in the TH400 and ‘Glide allow the proper rear gear to be installed for the combination, unlike the 6R80.
“If your car needs a 4.10 gear, you’re not going to run that with the 6R80 because it’ll shift too quickly right off the line. The car would work better with a 3.15, but then wouldn’t be optimal down track,” explains Holliday. The final benefit is that the TH400 and Powerglide transmissions have a “true” transbrake, which delivers more consistent reaction times, and that consistency makes it easier to dial in the chassis.
One of the prime examples of success in getting a car to leave hard and be successful in heads-up drag racing is the 2014 Mustang GT that Michael Ciborowski drove to the 2018 NMRA Advanced Fuel Dynamics Limited Street championship. A 6R80 Delete Kit was installed early last year, and allowed them to tame down the launches and concentrate on consistent and quick 60-foot times. The result has been a best short time of 1.21 from a car that weighs over 3,800 pounds. Ciborowski is also the Limited Street ET record holder this year with a best of 8.735, accomplished during the Nitto Tire NMRA Spring Break Shootout at Bradenton Motorsports Park.
The 6R80 Delete Kit offers a complete package for an easy conversion as it includes a transmission, torque converter spec’d to your combination, a DSS driveshaft with billet yoke, SFI 8-bolt flywheel and bolts, SFI Bell-housing, JPR Racing Transmission mount and cross-member, B&M transmission cooler and fittings/lines, Hurst shifter, Lokar dip stick, ARP torque converter bolts, and all other adapters and parts.
There are three stages available for Powerglide kits—Stage 1 is recommended for 1,000 rwhp, Stage 2 is good to 1,200 rwhp, and Stage 3 is rated for combinations up to 1,800 rwhp. Moving to the TH400 transmissions, the first two stages are good for 900 rwhp and 1,200 rwhp, respectively. Stage 3 is recommended for any combinations that are up to and over 1,400 rwhp. Transmission Specialties provides the units for the first three stages of Powerglide and TH400. The baddest TH400 package from JPC Racing includes a TH400 from Proformance Racing Transmission and is typically found in big power street cars and heads-up 275 radial racecars that run deep into the 4s in the eighth-mile and 6-second/200mph on quarter-mile runs.
The 6R80 continues to prove its meddle as a suitable and capable transmission, especially for street cars that require an Overdrive option, but there comes a time when the power and performance require something a bit more racy. The JPC Racing 6R80 Delete Kit is easy-to-install, includes a Powerglide or TH400, are specifically designed for S197 and S550 Mustangs and can be spec’d for any application.