5.0 Mustang & Super Fords
1986 Mustang T-Top Finishes - Final Exam - The Project Car
This report marks the final stage of our '86 T-top coupe project. The road to completing the Fox-Rod resto of our special notchback was 11 months long. There were many peaks and valleys along the way, but the experience leaves us with a satisfying sense of accomplishment. Each time we hear our 'Stang's Keith Craft big-bore 347 and Paxton Novi 2000 supercharger scream to life, even the tasks we suffered through during the build process don't seem to be as trying as we thought.
We've covered a lot of ground in the past year, showing you many of the parts, technologies, and engineering that can and should be included in a bad-to-the-bone, street/strip 'Stang. FAST's XFI engine-management setup is among the components we've mentioned, and it's one of the really key parts on the car.
XFI is the operations center for the coupe's powerplant. It includes all the features we need for tuning the supercharged bullet, such as the ability to control every aspect of the engine's functions, with respect to air, fuel, spark, and boost. It's also capable of real-time datalogging and much more.
The management system is a breeze to install, and despite our initial apprehension, XFI is intuitive, easy to use, and isn't "too much" for the caliber of street-driven, race-ready beast we've created. Our unease was unfairly based on the opinions of 'Stangbangers who have used other laptop-controlled systems and had problems understanding them. The anxiety also came from parrots who have no hands-on experience, but authoritatively repeat incorrect information they've heard from others.
Despite its ease of use, we're novices with laptop tuning. We sought assistance from XFI experts TJ Tracey of Advanced Performance and Tom "Tom H." Habrzyk-believe it or not, that's pronounced "habb-chak"-of Advanced Product Engineering, as we made our initial venture into perfecting the 347's performance with XFI. Asking someone knowledgeable for help is something you should never be too proud to do, especially when dealing with an engine package that has the potential to make a lot of power when properly tuned.
TJ helped us dial in the motor's naturally aspirated program while we were at Keith Craft Performance Engines' facility last year and tuned our big-bore stroker to 478.9 flywheel horsepower at 6,400 rpm and 471.2 lb-ft of torque at 4,500 rpm ("Big-Bore Score," Dec. '06, p. 58). Once the blower was installed and the coupe was ready to run, TJ sent us a program to use as a baseline starting point for tuning.
Working with the Dynapack Evolution 4000 chassis dyno at Extreme Automotive and using XFI's various fuel and timing tables to make adjustments to TJ's program, your tech editor and Saul "The Surgeon" Gutierrez got the supercharged stroker up and running. Through trial and error, we established a tune that gave us good air/fuel mixtures at idle and wide-open throttle.
XFI isn't a rocket-science type of management system. We credit our quick understanding of how it works to watching the instructional DVD that's included with the unit and having a general knowledge of how an internal-combustion engine functions. XFI is a laptop-controlled method of doing the same thing carb guys do with screwdrivers, jet-change tools, and a 11/42-inch wrench to loosen the distributor hold-down bolt. We manipulate an engine's air, fuel, and spark to achieve optimum performance.
As we've stated on many occasions during this project, our goal was to produce a drag-oriented 'Stang capable of going through the same motions as a good high-horsepower street car.
It was frustrating getting the engine to start right up when we began tuning, as the motor would intermittently have a hard time cranking over. Tom H. showed us how to correct the issue by phasing the MSD distributor, and he guided us through the finer points of XFI's graphs and data-capturing ability. That helped us dial in the coupe's street-ability and dragstrip performance. Now the engine starts immediately, the motor runs and idles without having to throw it in Neutral or pedal it with simultaneous doses of throttle and brakes at stop signs, and it runs well.
We have to say, we've nailed it with this Mustang. The T-top coupe is impressive on the dyno, as it has great power and monster torque-we haven't really touched the Novi 2000's full boost-potential yet. It's a blast to drive around the streets of LA's San Fernando Valley-and, yes, for those who know the area, we have made a few full-tilt passes on "The Road." Based on results from the car's maiden voyages down the 1,320, it's clear that we've covered all the bases with our project buildup.
On The DynoOur first tuning effort was made on the chassis dyno at Extreme Auto-motive. Through trial and error, we were able to dial our blown big-bore engine combination to an impressive 473.57 hp at the rear wheels at only 5,800 rpm and 8 psi of boost. Note that the figure was derived with our Precision Industries Stallion torque converter locked up during the dyno hit.
We experimented with the lockup function a lot during our tests. With the lockup on, horsepower seems to come on/increase a bit later in the rpm range than it does with the converter unlocked. For example, with the lockup off, our engine made just more than 100 hp at 2,200 rpm. With lockup activated, we didn't see 100 hp until the engine reached 3,300 rpm. Peak horsepower-the aforementioned 473.338-really does shine with a locked converter.
Peak torque was our overall performance champion on the dyno. With the converter unlocked, our 347 put out a brutal 641.652 lb-ft of rear-wheel torque at 2,566 rpm. When we reported the results to Jeff Henry of Keith Craft Performance Engines, the man who built the big-bore bullet for our project 'Stang, his reply was, "That car is gonna blaze the tires like nobody's business-or stand straight up on the rear bumper if it hooks."
|347 WOT W/NO LOCKUP||347 WOT W/LOCKUP|
On The StreetOur '86 T-top coupe is a street car. We've outfitted the 'Stang with 17-inch '07 Shelby GT 500 wheels from AmericanMuscle.com with Nitto's NT555s (235/45ZR 17 front) and NT555R (275/40ZR 17 rear) Extreme Drag Radials for cruising the boulevards.
The seats, restored with extra padding by Oscar Barrera ("The Comfort Zone," Sept. '06, p. 144) are comfortable and Flaming River's manual rack and steering components make the 'Stang easy to handle on local streets and the freeway.
There's no questioning the coupe's power. Be it a quick snap of the throttle from a low-speed roll or a full-on pedal-mash on an open stretch of the 118 Freeway, this ride boogies and things happen quickly as boost increases.
Needless to say, our '86 turns heads the minute we slip into traffic. We're pleased that we're able to drive it and enjoy it.
Track TestOur dragstrip testing was done at Auto Club Dragway in Fontana, California, during the Pacific Street Car Association's Orme Brothers' Spring Break Shootout event.
The PSCA is a heads-up drag racing organization on the West Coast that's similar to the NMCA, as it allows all makes of doorslammers to compete in its various classes. One thing we think is cool is the fact that there are a lot of Mustangs competing in some of the heads-up categories, and many of them lay the smack down on the Bow Tie boys on a fairly regular basis.
We signed up for Open Comp, mainly to run the new car on a well-prepped track and get seat time. Our objective wasn't to win the event, and unless we got lucky in eliminations, we knew we would be First Round lunchmeat on Sunday. We were OK with that.
Our first pass was made on Saturday, using the coupe's hard-core drag-race accessories: the Performance Automatic transbrake and torque-converter lockup. Air pressure for the Mickey Thompson ET Street Radials was set at the recommended 15 psi, and a two-step launch rpm of 3,300 was programmed into the MSD Digital-7 Programmable (PN 7531) ignition box. After a not-so-good burnout, we staged and released the transbrake at a flash of amber, and the coupe took off with the tires ablaze for nearly 300 feet.
Going off and on the gas in an effort to knock down the tire spin, keep the engine off the 6,800-rpm rev limiter (the engine reaches this limit instantly), and trying to hit what we think were shift points (the light was probably flashing but we didn't see it) on time was an absolute rush. Despite how ugly the first pass was, the T-top coupe cleared the traps at 11.801/117.09 on its first-ever trip down the strip, which is impressive when you look at the XFI datalog and see there are two fairly long pedaling events out of three total, and we didn't achieve foot-to-the-floor, 100 percent throttle until beyond the eighth-mile mark.
The second pass yielded nearly an identical timeslip (11.803/116.16). We saw the same e.t. with a 3-mph increase in speed after the third lap, thanks to a cooled upper intake and supercharger discharge tube.
On Sunday, we geared up for an all-or-nothing attempt at improving on the 11.80 baseline. We made adjustments to the compression settings on the coupe's VariShock rear coilovers and raised air pressure in the drag radials to 17 psi. We also used information we learned with the datalogger to change some timing and fuel settings and add tension on the blower belt.
All the changes proved to be steps in the right direction. By launching at a lower (2,200) rpm without the transbrake, the coupe left with the wheels up and shot to its best 60-foot time of the weekend (1.539). All remaining variables fell into place, and we scored a much improved 11.318 e.t. at 119.12 mph.
While we didn't baby the coupe during the racing weekend, becoming acclimated to what it does and how to drive it correctly is reflected in the timeslips.
We're beyond confident there's a 10-second e.t. and an easy 8 or more miles per hour in our T-top coupe's near future.
It's A Wrap!We've now come full circle with our rare '86 T-top coupe 'Stang. Numerous build tasks have been completed, and our project notchback is finally up, running, and ready for its official debut to the world-in less than one year's time.
As we mentioned a while ago, our efforts to have the car ready in time for Hot Rod magazine's Drag Week last year were thwarted by time-or lack thereof. But the completed Mustang is confir-mation that taking the time to do things right is always the best option when partaking in a project of this magnitude.
You've all had a monthly, first-hand look at how a 'Stang can be resurrected from junk to rare jewel, and we hope the series has been interesting and infor-mative. We have certainly learned a lot, and we have enjoyed sharing with you everything we encountered-the good and the bad-during the process of building this special 'Stang.