Supercharging the 32 Valve Cobra
Monday, February 10, 1997
The 32 Valve Cobra is one of the strongest and most refined performers that has ever left a Ford dealership’s showroom. So why isn’t it more popular than the older 5.0’s? For one, the aftermarket hasn’t yet developed many parts for them and it will most likely be a couple years before there is a good selection. And secondly, very few shops have torn into the engine because of the required specialty tools, manuals, warranty issues, OBD II concerns and cost. So while it is an extremely strong engine that has far more potential than most people realize, there isn’t much that can be done to increase its performance. Well, that has just changed.
Vortech Engineering has come to the rescue of 32 Valve Cobra owners who aren’t satisfied with the power Ford gave them. Centrifugal supercharging isn’t new to the Mustang performance scene, for years, Vortech Superchargers have provided 5.0 owners with a substantial, reliable power increase. There is no need to wait for the little things that promise gains and often don’t deliver, supercharging is available now and the results are impressive, maybe even awesome.
We have just finished our first 32 Valve Cobra Vortech install and are very excited by the fit and finish of the kit and the performance gain it delivered. Like all other Vortech kits, the 32 V kit literally looks like it was designed and installed by Ford, and that’s no small feat as there isn’t very much room in the engine bay. Initially, we were disappointed that the blower shared the same belt as the other accessories, but quickly realized there isn’t any other way. Additionally, it turns out to be a benefit – because of the way the belt is orientated, a very large percentage of it wraps around the blower pulley which almost eliminates the chance of belt slippage and lost boost at high rpms. The belt arrangement should also be fine with a smaller blower pulley to make more boost. At 6800 rpm the S-trim made just over 9psi with the factory 3.5 pulley, and stepping down to a 2.9 should pose no problems and easily make over 13 psi.
Because of the DIS ignition system there’s currently no way to manually retard timing, so when you buy the kit you get a certificate for a Hypertech chip that the installer has to submit to Hypertech with some info on the car and the chip should arrive in a few days. The car can be completely finished in the mean time and driven, but should not be opened up past 5700 rpm as it WILL spark knock without the chip.
Hypertech had not yet experimented with a ’97 Cobra and the first chip we were sent helped, but the engine still knocked at 6000 rpm. After giving Hypertech our input, they mailed 4 more different chips for us to test. The fourth (most timing retard) ended up fixing the rattle. It is possible that the quality of the Sunoco 94 the car had could have necessitated the need for the increased retard. Winter fuel formulas are supposedly different than during the rest of the year. Regardless, the car now pulls extremely hard all the way to 7000 rpm, in fact, the scary thing is that it didn’t lay down at all, the car could have easily pulled much higher, but the factory fuel cut off wasn’t far away. The deep breathing 4 Valve design really shines in these high rpm conditions and a custom chip is all that’s needed to move the rev-limiter and fuel cut off up and out of the way so Cobra owners can get at the extra power waiting at 7500 rpm.
We said it pulled cleanly and extremely hard all the way to 7000 rpm, but what does that mean? Well, seat of the pants isn’t very scientific, but since it’s cold as hell up here in Michigan and all the drag strips are closed, seat of the pants is all we have. A good guess would be 11.90’s or 12.0’s. It felt incredible! No 5.0 Mustang with 10 psi and a set of gears has ever felt that good. The 4.10’s that we installed in the car are a major contributor to the performance. Although the blower does make the car feel substantially better below 3500 rpm, the gears just compliment the package that much more. Cobra owners need not be afraid of the steep gears, they’re what this deep breathing 4 valve engine was meant for. 4.30’s would also be a good choice, naturally aspirated or blown. At 80 mph in fifth with the 4.10s it turns about 2700rpm, completely tolerable.
The Vortech S-trim is perfectly suited to the deep breathing capabilities of the 32V 4.6L and this engine really showcases the potential of this blower. It shouldn’t be too long before some of the other supercharger manufacturers will offer a kit for the Cobra but, it’s important to remember that the engine is spinning to 7000 rpm and needs a blower that can supply the air flow necessary (efficiently) and survive the elevated operating rpms. The Vortech S-Trim can and does, no other street supercharger can make that claim.
We can’t stress enough how impressed we are with the results of Vortech-ing the 32 Valve 4.6, both in fit and finish and performance. Even the most discriminating Cobra owner will be satisfied with the drivability and kit quality and be awe struck by the added performance. With nothing more than Vortech’s S-Trim, 4.10 gear, Auburn differential, 31 spline axles, Megabite control arms and a set of slicks, you have a docile, refined car with a virtually indestructible driveline (stock rods and crank are steel) that is capable of running high 11’s at the drag strip and more than 170 mph if it ever had the opportunity.
The 32 Valve Cobra is one of the strongest and most refined performers that has ever left a Ford dealership’s showroom.