Adding 25hp to your DOHC

25 HP for the 1996 COBRA By: Chan Davis

First, for all you enthusiasts who have invested in the purchase of a new 1996 Ford Mustang Cobra; Congratulations!!! You have invested in a true state of the art, World Class performance automobile. Hats off to Ford for offering this level of technology to it's customers; not smoke, mirrors, cosmetics, and politically motivated media hype. With that statement I will put this particular soap box away; reluctantly.

By the way, who says the new Ford 4.6 four cammers are unresponsive to change and will not compete with the good old 5.0? Could it be your run of the mill low tech Hot Rod shop proprietor? Those of us that understand the true operational theory of spark ignited (SI) gasoline engines know just how absurd statements that even hint at push rod superiority really are. Do not misread this as a "put down" to Fords venerable push rod Windsor power plants. We all know their potential. All I'm asking is for all the "nay sayers" and "push rod" hot rodders, allow yourself to enter the next century with us. Overhead cam, multi-valves, and more refined computer controls is the SI power plant of the future. At least for the next few years. The reasons are numerous and are topics for other articles. Stay tuned.

Sorry about the rhetoric, but how about an additional 25 REAR WHEEL (chassis dyno tested) horsepower for around $ 700.00. Better yet all this can be yours for expending between one and two hours of your time. What '96 Cobra owner wouldn't make this level of investment for 25 rear wheel horsepower (approximately 38 crank shaft)? I thought so.

The Ingredients:

1APE/ProM high flow Mass Air Flow (MAF) meter

1Set underdrive pulleys

Dyno Performance Data:

The base vehicle configuration for the test is a show room stock 1996 Cobra with 3.73 gears.

RPM Net Gain (Rear Wheel HP)

MAF Only

3250 -

3500 -

3850 -

4250 -

4500 -

4750 -

5150 10

5500 10

5750 20

6100 20

MAF + Pulleys

3250 5

3500 15

3850 18

4250 17

4500 10

4750 10

5150 15

5500 15

5750 25

6100 25

As can be seen the MAF made up most of the twenty-five peak horsepower, making it's twenty horsepower contribution at the high end of the rpm. This, of course was not surprising considering the four cammer's high reving tendencies. Actually, this peak increase was maintained beyond the 6100 rpm shown in the above tables. This power increase is mainly attributed to the increased air flow of the APE/ProM MAF over the stock unit (1049 cfm vs approx. 650-700 cfm). Other reasons were due to calibration differences.

The second part of this equation is the pulleys. I know all of you have noticed the lack of "seat of the pants" low end torque in your new Cobra as compared to say a typically tuned 5.0. As indicated in table 2, addition of the pulleys go a long way in alleviating this anemia. As table 2 shows, the horsepower gain begins at the low end providing an impressive eighteen horsepower differential at 3850 rpm. Of course adding a set 3.73 rear gears will provide the finishing touches to this deficiency. The 4.6 four cam motor loves to rev, so don't be afraid of the 3.73 ratio. The refined driving and performance characteristics, probably the most alluring qualities of this car, are just improved. However, don't get carried away with the more is better syndrome, either. The 3.37 first gear of the Borg Warner T45 renders a lower rear gear somewhat less than desirable; detracting from the refined feel of the car. Maybe if we had an after market BW T56 with uh.... say a 2.97 first, 0.80 fifth, and .62 sixth, 4.10's would be just great. Well, we do, in fact, have a prototype installed in one of our test Cobras. NICE!!! Again material for another article. By the way, don't forget the 23 tooth speedometer gear for your 3.73's.

Well, you have just added significantly more punch (approximately 38 hp) to the already impressive factory 305 hp. Now you need some help controlling it. Not just from a straight line traction view point, but from a handling and stopping perspective. Well tune in next time, `cause we've already thought of all this.

For more information concerning these products and other performance enhancements to Ford's modular engine powered vehicles, contact:

Corral Modular - Modular Mustang Web URL: http://www.corral.net/modular Images and text (c) Copyright 1997 The Corral Modular. All Rights Reserved, Duplication Strictly Prohibited. The Corral - www.corral.net