origionally posted by Shawndude:
The following articles were taken from Google cache. They used to be located at this address: www.cpinternet.com/~lellis/rls10.html
They are posted here so they will not be lost forever, if the original website doesn't come back up. I have not seen these anywhere else on the web.
-Super Supra Shootout : 300+ Horse Supra Turbos You Can Build (July, 1988 Turbo & Hi-Tech Performance).
-SupraSonic : Stock & Modified Toyotas Go Head-To-Head in Our 150+MPH Test (July, 1988 AutoTech).
-Samurai Gunslinger Looking For a Showdown : CarTech Supra (July, 1988 Motor Trend).
-Kamikaze Supra : A 300-bhp Turbo Upgrade From CarTech (October, 1987 Automobile
UNLEASING SOME SERIOUS POWER FROM TOYOTA'S HEAVY HITTER
1988 brings the Toyota Supra owner one of the most extensive lists of aftermarket performance options available to any import, and with excellent reason. . . it responds!
STAFF REPORT
Since it's introduction as an '86 1/2 model the flagship of Toyota, the Supra, has received a varied reaction from enthusiasts. On the one hand, the inline 6-cylinder, 3.0-liter with 4-valves per cylinder offers as smooth and fluid a transition of power as this writer has ever driven and reflects a welcome inprovement from the earlier 2-valve, 2.8-liter unit. On the other, in naturally aspirated trim the 200-horsepower and 185-ft/lbs of torque do nothing to mask the increased weight of the new chassis.
The '87 model brought power hungry Toyota buyers a new choice in the form of the intercooled turbocharged model. With 230-hp and 245-ft/lbs torque the new Supra Turbo rewards the driver with enough power to motivate it more than 3500 lb mass to consistent 7.0 sec 0-60 runs and low 15 second passes in the mid 90's through the quarter mile. With our stock '88 test model we witnessed a best time of 6.89 in the -60 proving it close to a second quicker than our tests of the stock Nissan 300ZX Turbo.
Subjectively, acceleration aside, the biggest improvement we witnessed in playing with both versions of the car was the massive increase in mid-range torque. This torque adds flexibility to highway driving and means dropping down a gear is just not required in most maneuvers, except those beyond the limits of prudent social/moral behavior. Unfortunately those of us without the pressures of a conscience still find the performance envelope to be less than hoped for on the world's first inline six, 4-valve per cylinder, intercooled turbo engine. (NOTE: we have found with the Supra, they take several thousand miles to get broken-in and we have noted differences in zero-to-sixty times of several tenths of a second between a stock Supra with less than two thousand miles and one with 15,000 miles on it).
In terms of chassis, the stock Supra is equipped with what can only be referred to as, "THE RIGHT STUFF" with the only unequal legth A-Arm suspension from Japan. To set the record straight, there as few production vehicles that can lay claim to this state of the art race car chassis technology, those coming to mind are, Porsche's 928 S-4 and some of the new Mercedes line. Again though, the state of tune in the chassis is more refined than ready and eager. For a more detailed look at the base Turbo Supra, see the January 1987 issue of TURBO.
In both the engine and the chassis, the excellent foundation found in the base Supra Turbo makes upgrading the performance both reasonable and a relatively easy task. As far as engine performance goes, five manufacturers, Borla, Cartech, HKS, and Spearco, Turbo Accessories (Going) and TRD (Toyota Racing Development) offer a variety of components to enhance engine performance. The most reasonable first step being a low restriction exhaust system as independent testing has shown that the back pressure from the standard system is approximately equal to boost pressure at about 5800 rpm under full load.
EXHAUSTING STUDY
The stock exhaust has three basic points of restriction, first on the turbine discharge tube there is a pre-catalyst, second at a bolted flange placed in the area of the clutch bell housing there is the main converter and at the rear of the car a massive muffler. Before modifying our car we sought out and found baseline back-pressure info from tests conducted during the development stage of one of the aforementioned manufacturers.
The tests showed that at stock boost pressures of 6.8 psi, the total system restriction is 6 psi. The restriction brakes down to 3 psi in the front of both converters together and surprisingly, a like amount is found in front of the muffler. This means that for a change, a smog legal version using the muffling properties of the pre and main converters coupled to an ultra low restriction muffler can allow for impressive gains in both response and overall horsepower. Our hat is off to Toyota's cat, which several aftermarket manufacturers have noted is one of the best found on a Japanese car to date.
Looking at the eight different exhaust systems from four different manufacturers can be complicated, but with the help of Pacific Coast Performance in Santa Ana, California and their 500-horse Clayton chassis dyno we were able to get some power readings on some of the systems.
BORLA makes two different systems, both of T304 stainless steel construction featuring a lifetime warranty. Both Borla systems employ 2.5" diameter mandrel bent tubes and a single 2.5" inlet, dual 2" outlet drilled core muffler. Borla has been using the drilled core technology the longest of the various competitors. Cartech and HKS both use similar mufflers and say they do so to allow for the greatest available flow area within the limited space. Looking at Borla's two systems, the first starts after the cat and the other, as tested, includes a new headpipe without the pre-cat, as well as a main cat by-pass. Our initial testing on the unit was performed with the main cat in place and showed a 30-horse gain at the rear wheels at 5000 rpm with no other modifications. In later testing, with the Cartech intercooler, on both the dyno and at the drag strip we enjoyed a slight improvement with a cat by-pass in place.
CARTECH makes the widest variesty of exhaust systems with four. Included are bold mild stainless steel systems and both are available in legal (after the converter) and "off-highway" (turbo outlet to rear bumper systems). Like the Borla and the HKS versions, all Cartech systems bolt together in the stock locations and employ stock hangers and are built using 2.5" diameter mandrel tubes. Cartechs mild steel versions use two side by side steel packs at the rear of the car, while their T-304 units use a Borla muffler, utilizing a 2.5" inlet size with two 2.25" pathways and outlets. It should be noted that the Cartech version had slightly longer outlet pipes in back of the muffler which would prevent any discoloration if a body kit such as the Kaminari unit shown is employed. The T-304 stainless, using the Borla Muffler and 2.5 inch tubing system was tested with both converters in place (horsepower for the Cartech unit was not tested independent of other modifications).
HKS manufactures one system which is a fully aluminized 2.5" competition system starting right at the turbo going to a straight-through muffler in the position of the factory main converter and continuing back to an HKS single 2.5" inlet by dual 2" outlet aluminized muffler. The HKS system can be installed with or without (for racing use only) the cat. Our chassis testing has shown that bolting on the competition systems (no cat) from the various manufacturers averages a 35+ horsepower increase to the rear wheels at 5000 rpm with no other modifications. The HKS system proved this out with a dyno verified 36 total rear wheel horsepower increase in our tests.
The following articles were taken from Google cache. They used to be located at this address: www.cpinternet.com/~lellis/rls10.html
They are posted here so they will not be lost forever, if the original website doesn't come back up. I have not seen these anywhere else on the web.
-Super Supra Shootout : 300+ Horse Supra Turbos You Can Build (July, 1988 Turbo & Hi-Tech Performance).
-SupraSonic : Stock & Modified Toyotas Go Head-To-Head in Our 150+MPH Test (July, 1988 AutoTech).
-Samurai Gunslinger Looking For a Showdown : CarTech Supra (July, 1988 Motor Trend).
-Kamikaze Supra : A 300-bhp Turbo Upgrade From CarTech (October, 1987 Automobile
UNLEASING SOME SERIOUS POWER FROM TOYOTA'S HEAVY HITTER
1988 brings the Toyota Supra owner one of the most extensive lists of aftermarket performance options available to any import, and with excellent reason. . . it responds!
STAFF REPORT
Since it's introduction as an '86 1/2 model the flagship of Toyota, the Supra, has received a varied reaction from enthusiasts. On the one hand, the inline 6-cylinder, 3.0-liter with 4-valves per cylinder offers as smooth and fluid a transition of power as this writer has ever driven and reflects a welcome inprovement from the earlier 2-valve, 2.8-liter unit. On the other, in naturally aspirated trim the 200-horsepower and 185-ft/lbs of torque do nothing to mask the increased weight of the new chassis.
The '87 model brought power hungry Toyota buyers a new choice in the form of the intercooled turbocharged model. With 230-hp and 245-ft/lbs torque the new Supra Turbo rewards the driver with enough power to motivate it more than 3500 lb mass to consistent 7.0 sec 0-60 runs and low 15 second passes in the mid 90's through the quarter mile. With our stock '88 test model we witnessed a best time of 6.89 in the -60 proving it close to a second quicker than our tests of the stock Nissan 300ZX Turbo.
Subjectively, acceleration aside, the biggest improvement we witnessed in playing with both versions of the car was the massive increase in mid-range torque. This torque adds flexibility to highway driving and means dropping down a gear is just not required in most maneuvers, except those beyond the limits of prudent social/moral behavior. Unfortunately those of us without the pressures of a conscience still find the performance envelope to be less than hoped for on the world's first inline six, 4-valve per cylinder, intercooled turbo engine. (NOTE: we have found with the Supra, they take several thousand miles to get broken-in and we have noted differences in zero-to-sixty times of several tenths of a second between a stock Supra with less than two thousand miles and one with 15,000 miles on it).
In terms of chassis, the stock Supra is equipped with what can only be referred to as, "THE RIGHT STUFF" with the only unequal legth A-Arm suspension from Japan. To set the record straight, there as few production vehicles that can lay claim to this state of the art race car chassis technology, those coming to mind are, Porsche's 928 S-4 and some of the new Mercedes line. Again though, the state of tune in the chassis is more refined than ready and eager. For a more detailed look at the base Turbo Supra, see the January 1987 issue of TURBO.
In both the engine and the chassis, the excellent foundation found in the base Supra Turbo makes upgrading the performance both reasonable and a relatively easy task. As far as engine performance goes, five manufacturers, Borla, Cartech, HKS, and Spearco, Turbo Accessories (Going) and TRD (Toyota Racing Development) offer a variety of components to enhance engine performance. The most reasonable first step being a low restriction exhaust system as independent testing has shown that the back pressure from the standard system is approximately equal to boost pressure at about 5800 rpm under full load.
EXHAUSTING STUDY
The stock exhaust has three basic points of restriction, first on the turbine discharge tube there is a pre-catalyst, second at a bolted flange placed in the area of the clutch bell housing there is the main converter and at the rear of the car a massive muffler. Before modifying our car we sought out and found baseline back-pressure info from tests conducted during the development stage of one of the aforementioned manufacturers.
The tests showed that at stock boost pressures of 6.8 psi, the total system restriction is 6 psi. The restriction brakes down to 3 psi in the front of both converters together and surprisingly, a like amount is found in front of the muffler. This means that for a change, a smog legal version using the muffling properties of the pre and main converters coupled to an ultra low restriction muffler can allow for impressive gains in both response and overall horsepower. Our hat is off to Toyota's cat, which several aftermarket manufacturers have noted is one of the best found on a Japanese car to date.
Looking at the eight different exhaust systems from four different manufacturers can be complicated, but with the help of Pacific Coast Performance in Santa Ana, California and their 500-horse Clayton chassis dyno we were able to get some power readings on some of the systems.
BORLA makes two different systems, both of T304 stainless steel construction featuring a lifetime warranty. Both Borla systems employ 2.5" diameter mandrel bent tubes and a single 2.5" inlet, dual 2" outlet drilled core muffler. Borla has been using the drilled core technology the longest of the various competitors. Cartech and HKS both use similar mufflers and say they do so to allow for the greatest available flow area within the limited space. Looking at Borla's two systems, the first starts after the cat and the other, as tested, includes a new headpipe without the pre-cat, as well as a main cat by-pass. Our initial testing on the unit was performed with the main cat in place and showed a 30-horse gain at the rear wheels at 5000 rpm with no other modifications. In later testing, with the Cartech intercooler, on both the dyno and at the drag strip we enjoyed a slight improvement with a cat by-pass in place.
CARTECH makes the widest variesty of exhaust systems with four. Included are bold mild stainless steel systems and both are available in legal (after the converter) and "off-highway" (turbo outlet to rear bumper systems). Like the Borla and the HKS versions, all Cartech systems bolt together in the stock locations and employ stock hangers and are built using 2.5" diameter mandrel tubes. Cartechs mild steel versions use two side by side steel packs at the rear of the car, while their T-304 units use a Borla muffler, utilizing a 2.5" inlet size with two 2.25" pathways and outlets. It should be noted that the Cartech version had slightly longer outlet pipes in back of the muffler which would prevent any discoloration if a body kit such as the Kaminari unit shown is employed. The T-304 stainless, using the Borla Muffler and 2.5 inch tubing system was tested with both converters in place (horsepower for the Cartech unit was not tested independent of other modifications).
HKS manufactures one system which is a fully aluminized 2.5" competition system starting right at the turbo going to a straight-through muffler in the position of the factory main converter and continuing back to an HKS single 2.5" inlet by dual 2" outlet aluminized muffler. The HKS system can be installed with or without (for racing use only) the cat. Our chassis testing has shown that bolting on the competition systems (no cat) from the various manufacturers averages a 35+ horsepower increase to the rear wheels at 5000 rpm with no other modifications. The HKS system proved this out with a dyno verified 36 total rear wheel horsepower increase in our tests.