Muscle Mustangs & Fast FordsHow To Drivetrain
1992 Ford Mustang Rear End Upgrade - The Last Stand
We Wrap Up Our Little Juiced Coupe Project With A Rearend Upgrade And A Flat-Out Track Flogging.
With the bottle pressure still hanging out around 900 psi, we headed up to staging once again. The Little Juiced Coupe chirped the tires a bit at the nitrous hit, but charged to a 12.23 at 118 mph. Attempt number seven started off much the same way, with a little chirp, chirp, chirp when the nitrous oxide started flowing. We decided to try short-shifting the car at 5,200 rpm on the stock tach, and it turned out to be the wrong decision, as the quarter-mile time fell off to a 12.45 at 113 mph. Bottle pressure was down to 850 psi, but more importantly, it was time to head home. We managed to squeeze in one more pass, albeit on motor alone. At the stripe, the black notchback tripped the clocks in 13.40 seconds at 104 mph.
Keep in mind that this latest track outing was made in late June in Central Florida, and ambient temperatures were in the low 90s, with about 70 percent humidity. Though we often test at Englishtown's Raceway Park in New Jersey, where the air can be staggeringly good, this was not the case with our Southern-based project car, and thus the times were probably more representative of the national average than one might expect.
Our efforts to dramatically improve our 60-foot times at the track have fallen short of expectations, as we have only whittled it down from the 2.2 range to the 2.0 time. The higher stall speed and increased gear ratio should have us in the 1.65-1.75 range, but we've yet to get there despite all of our attempts. After reviewing the timeslips, it would seem that the car is running its best short times on motor alone, which possibly suggests that we may not have our MSD Digital 6 set optimally when the nitrous is armed.
We're giving up about 0.4-0.5 second in e.t. with the slower short times, and we're going to get the car on the chassis dyno to see if it's a tuning issue in the chip or with the Digital 6. In the meantime, we're pretty satisfied with its performance, given it has been running in the heat of the Florida sun. We look forward to the cooler, winter track days where it should easily dip into the 11s without the quicker short time. Though we're bringing this project to a close, you never know when it might pop up again for another test, but for now, we'll see you at the track. Be sure to check the MM&FF Web site and blogs for new results.
On-Track Performance Table
|FRPP underdrive pulleys, 3.55 gears, Flowmaster mufflers, off-road pipe||15.12/92 mph|
|Above plus 100 hp of nitrous oxide||13.62/104 mph|
|Cobra intake, equal-length shorty headers||14.55/97 mph|
|Above plus 100 hp of nitrous oxide||13.06/111 mph|
|MSD Digital 6||14.67/96 mph|
|Above plus 100 hp of nitrous oxide||13.21/109 mph|
|Above plus 150 hp of nitrous oxide||13.04/112 mph|
|GT-40X cylinder heads, 65mm throttle body, C&L 76mm MAF,|
SCT chip FRPP 1.7:1 roller rockers arms
|Above plus 150 hp of nitrous oxide||12.68/115 mph|
|Strange adjustable shocks, UPR lower control arms||13.78/101 mph|
|Above plus 150 hp of nitrous oxide||12.62/115 mph|
|TCI Auto AOD and 2,200-rpm stall converter||13.89/102 mph|
|Above plus 150 hp of nitrous oxide||12.75/114 mph|
|Weld Wheels, Toyo Slicks, 3.73 gears, Detroit Truetrac||13.40/104 mph|
|Above plus 150 hp of nitrous oxide||12.19/117 mph|