Muscle Mustangs & Fast Fords
One-Day DIY Torque Converter Install on a 2013 Ford Mustang GT, Part 4
We find a weakness in our Roush blown 5.0 the hard way and do an expert torque converter upgrade.
Team C&C is back for part four of our 2011 Ford Mustang GT buildup, and we have been racing our butts off to bring you some interesting info, and even some that isn't so awesome—because we're keeping it real.
Our goal with this Pony has been clear from the start—go as fast as we can using the Roush supercharger, but with the stock suspension, exhaust, and gears. It's been fun and educational thus far, and if you've missed anything, here's a recap. Please note that all of our upgrades were done in real-world, do-it-yourself situations.
We started out with a brand-new, no-frills 5.0L auto-equipped Stang and bolted on serious horsepower with a Roush supercharger kit. The OEM fit and finish made for a straightforward, two-person install with only a few nicks and cuts—and in one day we were feeding boost into our five point oh and ready to bruise Camaro and Mopar owners' egos at the local test-and-tune.
We headed down the slippery horsepower slope with the Phase One Roush supercharger (PN 421388), rated at 525 flywheel horsepower, while maintaining 50-state emissions-legal status. Wasting no time, we moved on to Phase Two (PN 421390) with a custom Jon Lund tune that yielded us a very quick 10.90 at 128 mph. There was a lot more power to be unlocked by throwing Shell URT Advanced race fuel into the mix, which led us into deep-10-second territory.
Ultimately, we gained well over 200 rwhp and nearly 120 lb-ft of torque with a one-day supercharger install, an emailed custom tune, and race fuel, all while maintaining stock driveability and reliability. But at a power level of nearly 600 hp at the tires, the factory fuel system was in starvation mode. An upgrade was a must, and again we turned to Roush for its intuitively designed offerings that never disappoint.
Within 20 minutes, we were installing a Roush plug-and-play Fuel Pump Voltage Booster (PN 421602) for 2011 and newer Mustangs. We ditched the stock injectors for ID1000 injectors to adequately fuel our boosted Coyote. From there, we turned up the wick with more boost by installing a VMP 100mm idler pulley and 72mm blower pulley. Jon Lund worked his magic and we raced all weekend at the NMRA event in Maryland in conditions that most racers can only dream about.
The Good News and the Bad News
We'll give you the good news first. In primo air, we went a staggering 10.44 at 134 mph with a 1.51 60-foot with completely stock suspension, factory exhaust, the 3.15 gear, and a factory converter. Like any race application where you push the limits, anything can be on borrowed time.
Ready for the bad news? After the glorious 10.44 pass, the oil light of doom lit up, followed by a very bad sound—it was a goner.
The oil pump gears are a known weak point in the new-school 5.0 engines. We confirmed this was the sole cause of our engine failure by sending it off to Michael Rauscher at L&M Engines for a tear down. So, if you planning serious abuse of your engine, it's highly recommended that you upgrade your oil pump gears to save some serious moolah and headache down the road.
Project C&C Coyote Lives Again
As our brand-new Steed sat engineless in the garage, we had no choice but to bite the bullet and decide on a new engine. We considered rebuilding the factory mill, but it was easier to simply buy one.
Being boost junkies, a lower compression platform was best for our needs and Ford Racing offers a 5.0 302-cid Aluminator crate engine. Loaded with goodies like Mahle forged pistons and Manley H-beam connecting rods with ARP bolts, it can more than handle severe use. At 9.5:1, it's a lower-compression option versus factory (11.0:1) specs and perfect for boosted applications like ours (a high-compression Aluminator is also available). We called our friends at Espeut Performance and Pete Espeut gave us the Team C&C hookup. Thanks to my husband, JD, the new FRPP crate engine was installed and the Roush supercharger was put back on its throne—and it purred like a kitten.
We didn't have a chance to dyno the car after installing the fuel system and smaller pulley trackside due to the tragic carnage of the stock engine, but the previous dyno numbers were 582 rwhp and 462 lb-ft of torque in 70 degree air with a custom tune, stock fuel system, and 85mm Roush-supplied pulley.
After the engine swap, we headed back to Stang-Hi Performance in Baton Rouge to get new data. It should be noted that we hadn't retuned the new engine combo and it was shifting about 500 rpm sooner than necessary because of the previous engine's tune settings. The lower compression made the numbers a little softer considering the 72mm pulley and fuel system had to equate to a significant gain in horsepower. In the 101-degree Louisiana summer heat, the dyno showed 579 rwhp and 515 lb-ft of torque.
We saw an increase of 25 rwhp between 4,000 and 6,000 rpm with the Aluminator over the stock engine and picked up 47 peak lb-ft of torque as well as averaged 35 more lb-ft between 3,500 and 5,500 rpm. In short, we lost horsepower due to the reduced compression and loss of boost due to the heat, but it gained torque and the ability to apply much more boost than before.
At the current boost level, we are seeing consistent 10.90s at high 120 mph with 1.60 60-foots. We lost some e.t. without a doubt, but the new combo hasn't been retuned to maximize power or shift points.
Installing Precision Industries Torque Converter
On our way to the Joliet, Illinois for the NMRA event, we detoured to Lead Hill, Arkansas. Buried deep in the Ozark mountains with a population of less than 300 people lies BTS Transmissions, also known as Brian's Truck Shop. Brian Thompson, owner of BTS, is one of the smartest guys on the planet when it comes to bulletproof transmissions.
Awaiting us at the state-of-the-art facility was a shiny, new Precision Industries 9.5-inch, billet, triple-disc converter (PN 509018-3) with a custom BTS 3,400-3,600 stall speed. It should be aggressive enough for the track and mild enough for street driving. The installation was straightforward, however, we do have a few tips to help your install go smoother.
To simulate the average Joe's garage conditions, we installed this baby on our backs with the car on jackstands. We began by using a 13mm stubby wrench for the two transmission top bellhousing bolts easily accessed from under the hood. Next, we removed the transmission rear sensor connection, which has a simple twist-lock design. Then we removed the trans using a trans- mission floor jack with a piece of Styrofoam to stabilize the transmission during the converter swap, as well as protect the oil pan.
The factory converter uses studs with nuts to bolt to the flexplate. The PI converter used bolts instead. After installing the converter in the transmission, we measured the depth of the converter to make sure it was fully seated. We reinstalled the bellhousing bolts, starter, driveshaft, and exhaust.
The transmission requires Mercon LV Ford transmission fluid, and we added four quarts to reach the fill line. Here's a little tip—we recommend you purchase a fluid transfer pump to help fill the transmission, because you have to do it underneath the car due to Ford not having a fill tube that reaches the engine bay.
With the transmission back in and everything buttoned up, I took her out for a spin. The driveability was incredible considering the stall this converter has. I expected something a little more aggressive, but the looseness was barely noticeable.
As a newbie bracket racer, one thing I have struggled with is the ability to stall the car at a higher rpm (above what the stock converter would allow) in order to bump myself into the proper stage depth (I generally stage to hit the Pro tree). Before the converter install, I had to worry about pushing through the beams if it was stalled beyond 1,700 rpm, which made it difficult to work on reaction times. My bump-in is much more controlled now—I have a lot more confidence at the line that I won't go red when I'm trying to cut the Tree on my opponent. Immediately, I was able to stall the new Precision/BTS converter up to 2,800 without feeling the front tires start to scoot out from under me.
On track, we saw a solid 0.1 gain in overall e.t. from the converter swap alone. We monitored the conditions closely with our trailer-mounted weather station. During a test at our local track with the factory converter, the DA (density altitude) was showing 2,000 feet (corrected DA) and we made several 10.90 passes. In Joliet's 3,500-feet corrected-DA weather conditions, we ran back-to-back 10.80s at high 120s all weekend. So, while there was a 0.10 improvement on the clocks, there would be a bigger drop in e.t. had the weather been equal to our baseline test.
To remain safe and legal, we went ahead while we were under the car, and installed a Granatelli Motorsports driveshaft loop (PN GM-DSL0507), retail price $183.75. The car still has a factory two-piece driveshaft and this will keep the driver safe in the event of a failure. The installation on the driveshaft safety loop was easy and self-explanatory.
Our future plans include a ported elbow and a larger throttle body to squeeze more boost out of the Roush supercharger, as well as an off-road X-style mid-pipe, and possibly a gear upgrade.
Our suspension friends will probably kill me for saying this, but why would we change a thing when it's easy to achieve high 1.4 60-foot times? Dead-hooking on the factory goodies is a great problem to have! We will start modding the suspension components when the rubber quits biting like a rabid animal. We're looking forward to killer air at the Bowling Green NMRA event, so check back for the latest on our Roush coyote buildup.
Just before this story went to print, we made one last trip to the track. To our pleasant surprise, after mid-and high-1.5 60-foot times, we had finally broken into the 1.4s with a 1.49—on stock suspension and 3.15 gears! That same run yielded a 10.79 e.t. at 128.57 mph. DA was above 2,300 feet, so conditions weren't optimal.