This spotlight car is a rather unique car to begin with. It’s a 1996 Mustang GTS. A lot of folks don’t know about these but GTS Mustangs where basically somewhat of a stripped version of the normal GT. They had no ABS, no power windows or locks and a lower cost V-6 type seats. And above all it has a not to popular factory orange color.
This particular car has had a couple of different things going on under the hood and with the rest of the power train over the years, but we’re going to center this around its most current status as far as engine and power train goes.
The owner was looking for a big jump in performance and durability but wanted to try to stay true to the fact that the car was originally 2-valve rather then convert to a 4-valve as some would do.
The new and updated motor is now an aluminum block 4.6L rather then iron which is stock on GT’s with 2-valve engines. The engine is stroked and is now a 5.0L. The heads have been upgraded to ’99 and up P.I. castings that have an Alternative Auto CNC full port job. Also the cams are mild Crower units. The compression has been bumped to 10 to 1. The trans is a T-56 6-Speed with a Cobra aluminum flywheel and clutch kit.
The highlight item and power adder on this GT is the all new intercooled Kenne Bell 2.6L twin screw blower unit. All of the front-end suspension pieces have been replaced with tubular pieces to shed some weight and promote better weight transfer for launching. The A/C has been deleted to shed a little more weight out and clean things up even more under the hood.
As the project came together we were warned that the 2.6L KB blower and throttle body would not fit under the hood. The owner wanted us to try to make an effort to not have to purchase a larger hood that would quickly suggest that things might not be so stock underneath it.
So the first thing we did was space the entire front cradle down just over 1/2” which takes the engine down with it further away from the hood, and the from there all we had to do was trim the inner frame of the stock hood in a couple of places and relocate the IAC motor. All of this made that big KB tight but not hit the hood any where.
The stock 1996 EEC-5, GT 2-valve computer runs this beast with no problems with our in house SCT custom tuning. It has 60lbs injectors and a 90mm BA-2400 MAF. The single, stock in-tank pump is upgraded and also has a “Boost-a-pump” voltage enhancer feeding the fuel pump. Also because of the compression and boost combination a Meth kit is also being used to further enhance the fuel system, cool the intake air charge further, and bump the octane up a bunch. Also as the PICs reveal we’ve also converted this ’96 GT’s ignition to “COP” (coil-on-plug) to make things more convenient and cleaner, plus bring the look and performance of the ignition up to date. The COP conversion was done strictly with re-wiring from the stock twin coil packs. No aftermarket ignitions or gimmicks of any sort used here.
Before the meth was fully done on this car, we decided to make runs with the boost at an average of 11psi which ramps up to 13ish at the end of the pull. With out the meth, on 93 octane this 2-valve knocked out almost 560 RWHP and just under 490 RWTQ Once again this is on 93 octane and no meth yet.
Once the tune got sorted with out the Meth, in order to get the most out of the meth, a decision was made to bump the boost up another roughly 3 psi. This made the average boost go up to about 14psi and creep up to near 17 at the end of the pull because of the size of the twin screw blower. This made TQ go up over 50 ft lbs at the rear wheels and the HP gain almost 65 at the tire. This should prove to be a very safe and incredibly torquey car in the real world in any gear.
This set up may not make the peaky big number of a comparable Turbo set up, but judging from the TQ numbers (especially the low and mid-range) on the graph — both with and w/out the meth in use it doesn’t take much to see what would be more fun in the real world, not just on the dyno and in a straight line.
Notice on the graphs the way the boost actually goes up near the end of the pull, this is what happens when a properly sized and large twin screw is used in the right application. The blower actually makes more boost and airflow then the motor can absorb. This was also done with a clean and simple 6-rib one belt assembly supplied from Kenne Bell with the kit, which shows no signs of slipping or not able to handle this application.