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V6 Mustang Exhaust & Gears Upgrade - Changing The Game
Part 2: Our underdog ’11 V-6 makes great strides with exhaust and gears
Last month, we broke into the 13s with a cold-air kit and tune on a 3.7L-equipped '11 Mustang. With its TiVCT, like on the new Coyote, the DOHC V-6 is a league ahead of any V-6 previously found in a Mustang. Heck, it's rated at only 10hp less than the '10 GT with a Three-Valve V-8.
When we started this three-part series, we warned that this might be unconventional for most readers, but it was worth looking at. In all fairness, especially with gas prices nearing $4 per gallon, most of you might be taking a second look at a V-6-powered Pony. It's hard to ignore a 30-mpg rating that rivals what four-cylinder imports were doing just a few years back. So if you can make it quick and a blast to drive with little effort, then why not?
Certainly, the new 5.0L has rewritten the books on what a stock Mustang should be, but the price tag is $30,000-for a stripper. For less money that that, you can pick up a new V-6 loaded to the gills with frills-and with money left over for bolt-ons. The money you're saving on your insurance and gas bills can go toward more go-fast goodies.
This month, we decided to trade the stock 3.15 rear gears for a set of 4.10s, as well as trade the entire exhaust system-headers back-for some aftermarket pieces. We'll update the tune to match, and hit the track yet again. Since we barely broke into the 13.70s last time, anything in the mid-13s or lower would be huge.
Back at Lamotta Performance in Longwood, Florida, Jake Lamotta started by swapping the stock 3.15 gears. All auto-equipped '11-up Mustangs are so equipped, and a simple gear swap will wake one right up. We opted for 4.10s from Ford Racing Performance Parts (FRPP) so as to not upset our stellar fuel economy too much. The gear set (PN M-4209-G410A) retails for $179.95 at www.fordracingparts.com.
Then we turned our attention to the exhaust system. Since most companies are devoting their attention to the new 5.0L, few have parts ready for the 3.7L yet. Thankfully for us, BBK Performance had its 13?4-inch, chrome long-tube headers (PN 1642; $489.99) and matching midpipes ready for us to test. The midpipe is available with or without catalytic converters, but we opted for the piece with cats (PN 1461; $469.99).
To finish off the system, we contacted Magnaflow for an after-cat system. It offers a competition version and a street version, but we chose the quieter street system (PN 15591; $886.97) for ours. The system is 100-percent stainless steel; delivers a smooth, deep tone; and includes fully polished mufflers with polished tips.
Once all components were installed, Chris Johnson of SCT Performance tuned the combination and it spun the rollers on Lamotta's in-house Dynojet to 262 rwhp and 246 lb-ft of torque. Though only a slight gain at peak, power and torque production were both up by about 6 from 5,000 to 6,000 rpm-where the gains will help us on track. The power gains combined with a lower gear ratio left us anxious to get some results on track at Gainesville Raceway.
On track, the V-6 did not disappoint. Its first run of the day ended up being the best-13.30 at 102 mph. Though it bogged a little off the line, the 2.07 60-foot time was also the best of the day. With owner Hector Navarro driving and rear tire pressure set at 26 psi, we made a few more attempts to break into the 13.20s, but to no avail. Navarro backed up the best run with a 13.31 at a faster 105, but the higher trap speed can be attributed to some tire spin off the line.
Check back next month as we install a ProCharger P-1SC kit. With that, we hope to be well into the 12s, if not the 11s. ProCharger's own V-6 made over 400 rwhp with a manual transmission, so we're excited to see what our automatic-equipped coupe will do with the same 6 pounds of boost. We might even crank up the boost a bit just for fun.