ma71supraturbo
09-17-2005, 08:22 PM
There are many possible modification orders, but this staged list is the system I recommend for increasing your 7m-gte's power while maintaining good reliability. Please do not begin modifying unless your car is well maintained and running with no problems (i.e. proper head gasket, no overheating issues, good vacuum, good oil pressure, no misses, etc). Additionally please continue to keep up on your car's maintainence. A vacume leak at the accoridan hose, for example, is not a particularly dangerous condition for a stock mk3. But if your car is tuned for optimum power, you have taken away the extra safety of the over-rich factory tune and you could end up doing severe damage by running lean.
The following horsepower figures are estimated at the crank (bhp) and are based on a perfectly running mk3. For reference, a stock MK3 makes 230bhp (232bhp 89+) @ 6.8psi. I chose to list crank HP estimates for a few reasons. Automatic and manual cars make the same power at the engine, but manuals put more of that power to the ground (12-15% M/T drivetrain loss verses ~18-20% A/T). Additionally, modifications like light-weight flywheels and driveshafts will increase the rear wheel horsepower without actually increasing the power at the crank. And finally, because manufacturers list crank horsepower figures so this allows more of a direct comparison with newer cars. That said, it is important to realize that your car may make more or less power depending on a number of factors, so please take these and all horsepower figures with a grain of salt.
Stage List A, MKIII Supra Turbo:
For those planning on staying with the CT26 turbo (under 400bhp)
Stage 1:
Intake, 235bhp @ 7psi
http://www.horsepowerfreaks.com/Images/Products/Blitz/Intake_Systems_SUS_POWER_Air_Filter_Kit_(Stainless _Mesh_Filter).jpg The first thing to do in increasing performance is to make sure the engine can flow plenty of air. The simplest way to help an engine breathe better is by installing an aftermarket intake. There are many different brands out there, but Apexi performed the best in this test (http://mkiv.com/techarticles/filters_test/2/). For hints on installing a full intake kit, please see this tech tip (http://www.supras.com/sogidb/index.php?jumpto=techcenter&tech_jumpto=display_techtip&id=9).
Stage 2:
Cat-back, 250bhp @ ~8psi
http://www.horsepowerfreaks.com/Images/Products/Tanabe/Exhaust_Systems_Super_Medallion_Hyper_Spec.jpg Continuing with the theme of better breathing, the next step is to install a cat-back exhaust. There are even more brands and styles of exhausts than intakes, so take your time and find one which best fits your needs for flow, looks, and sound. If you live in an area where corrosion is a problem, you probably will not want to settle for anything less than a full stainless system. You will want an exhaust that is at least 3 inches, but with turbo cars bigger is better!
Stage 3:
Downpipe/elbow/primary cat or test pipe, 280bhp @ ~9psi
http://www.horsepowerfreaks.com/Images/Products/BIC/Downpipes_Divorced.jpg If you still want more power, then its time to replace the restrictive stock downpipe, turbo elbow, and secondary catalytic converter. You will want to look for a downpipe that integrates the turbo elbow, otherwise you will end up with a 3" downpipe bolted to a 2.25-2.5" turbo elbow... BIC and Titan both make 3" turbo-back downpipes, and you can occasionally find a Defcon downpipe in the for sale section. The hot set-up now is to use the BIC "divorced" downpipe because it separates the wastegate's exhaust flow from the turbine's exhaust flow. This decreases turbulence (increasing power). Dyno tests show about a 20hp gain in using a divorced downpipe (over a standard BIC dp!). Some have noticed an exhaust leak sound at idle when running the dump tube vented to the atmosphere, so you can also opt for the re-routed version. The downside to the divorced set-up is that the divider plate is located just right for a CT26 turbo so it will not work with the bolt-on turbo upgrades -- so plan accordingly. Next in line is the secondary catalytic converter. Either use a high-flow cat (Random Tech and Titan both make bolt-on cats) or a test pipe (from Cooleeze, Titan, Horsepowerfreaks, or BIC).
Stage 3.5:
Gauges
http://www.horsepowerfreaks.com/Images/Products/Autometer/Boost_Gauges_Nexus.jpg While gauges do not increase power, they are important especially if you want to continue modifying. At this point, you're probably already boosting 9 psi, which exceeds the stock boost gauge. Installing a new one will allow you to keep tabs on your boost (and vacume). Often you will be able to spot vacume leaks just by seeing where you car idles as they generally start small... It's also a good idea to get a wideband gauge so you can accurately monitor your car's air fuel ratio. The cheap autometer gauges that read from the stock O2 sensor are worthless, so save your money for something accurate like the FJO, AEM, or PLX. Next on the list is an EGT gauge. This will monitor your exhaust gas temperature, and can be used to help you tune in conjunction with the wideband. Other good gauges to consider are water temperature, oil temperature, and and oil pressure.
Stage 4:
Boost controller, 300bhp @ just under fuel cut
http://www.horsepowerfreaks.com/Images/Products/Greddy/Boost_Controllers_Profec_B_Spec_II.jpg Now that your engine can breathe freely and you can monitor what it's doing, it is time to turn up the boost with a boost controller. There are inexpensive manual boost controllers out there, but I have found it to be a pain to get out and adjust them every time the weather changes (or if you find yourself at a stoplight next to a rumbling domestic). The solution is an electronic boost controller which can not only be adjusted from inside the car, but some can also learn to better control your wastegate allowing the turbo to spool much faster.
Stage 5:
Intercooler and hardpipes, 320bhp @ just under fuel cut
http://www.horsepowerfreaks.com/Images/Products/HorsepowerFreaks/Intercooler_Kits.jpg If you still want more power, you will want to replace your stock intercooler and the restrictive stock intercooler piping. Compressing air (in the turbo) creates heat which can lead to detonation. Since you want to turn up the boost even more, you'll need an intercooler that can not only flow better but also do a better job of keeping the air cool. At this point it also is a good idea to replace your factory bypass valve to prevent compressor surge.
Stage 6:
Fuel pump, injectors, and Lexus AFM -- 350bhp @ 16psi
http://www.horsepowerfreaks.com/Images/Products/Walbro/Fuel_Pumps_High_Flow_(Pump_and_Install_Kit_Combo). jpghttp://www.rceng.com/injectors1.gifhttp://www.horsepowerfreaks.com/Images/Products/LIPP/Air-Fuel_Meters_Lexus_AFM_replica.jpgWhen you try to boost too high, your ECU will cut fuel momentarily to prevent engine damage. Now that you want to exceed that limit, it is time to upgrade your fuel system. While it is possible to boost a little over fuel cut on the stock fuel system, it is not recommended -- especially if you have your sights set significantly higher. The first step to upgrading your fuel system is to then replace the fuel pump with one that can move more fuel. Walbro and the stock MKIV tt pump are common choices. Next is to replace the injectors. The stock 440's can flow this amount, but 550 injectors happen to match the increased flow of a Lexus AFM. The Lexus AFM is bigger than the stock Toyota AFM and tricks the engine into thinking it is getting less air than it actually is. The larger injectors offset the extra air and waalaa, you can now safely boost past fuel-cut! Details on this upgrade can be found here. (http://www.supras.com/~riemer/lexusriemer/lexusnotes.html) LIPP also makes a "replica" Lexus AFM housing that allows you to use your stock electronics and save some money and time.
Stage 7:
Fuel tuning device and dyno tuning, 400bhp @ 17psi
http://www.horsepowerfreaks.com/Images/Products/Apexi/Fuel_Computers_AFC-Select_for_Euro_Cars.jpg At this point, the car could benefit from some fine-tuning. Chances are you will be running rich, so an air/fuel controller can lean out the mixture and help further raise fuel cut. There are many options out there, so do a little research and decide on the best unit for your goals. If you must have the best, a standalone is the way to go but it is much more expensive, and is more difficult to tune (chances are you will have to have a professional tune it).
The following horsepower figures are estimated at the crank (bhp) and are based on a perfectly running mk3. For reference, a stock MK3 makes 230bhp (232bhp 89+) @ 6.8psi. I chose to list crank HP estimates for a few reasons. Automatic and manual cars make the same power at the engine, but manuals put more of that power to the ground (12-15% M/T drivetrain loss verses ~18-20% A/T). Additionally, modifications like light-weight flywheels and driveshafts will increase the rear wheel horsepower without actually increasing the power at the crank. And finally, because manufacturers list crank horsepower figures so this allows more of a direct comparison with newer cars. That said, it is important to realize that your car may make more or less power depending on a number of factors, so please take these and all horsepower figures with a grain of salt.
Stage List A, MKIII Supra Turbo:
For those planning on staying with the CT26 turbo (under 400bhp)
Stage 1:
Intake, 235bhp @ 7psi
http://www.horsepowerfreaks.com/Images/Products/Blitz/Intake_Systems_SUS_POWER_Air_Filter_Kit_(Stainless _Mesh_Filter).jpg The first thing to do in increasing performance is to make sure the engine can flow plenty of air. The simplest way to help an engine breathe better is by installing an aftermarket intake. There are many different brands out there, but Apexi performed the best in this test (http://mkiv.com/techarticles/filters_test/2/). For hints on installing a full intake kit, please see this tech tip (http://www.supras.com/sogidb/index.php?jumpto=techcenter&tech_jumpto=display_techtip&id=9).
Stage 2:
Cat-back, 250bhp @ ~8psi
http://www.horsepowerfreaks.com/Images/Products/Tanabe/Exhaust_Systems_Super_Medallion_Hyper_Spec.jpg Continuing with the theme of better breathing, the next step is to install a cat-back exhaust. There are even more brands and styles of exhausts than intakes, so take your time and find one which best fits your needs for flow, looks, and sound. If you live in an area where corrosion is a problem, you probably will not want to settle for anything less than a full stainless system. You will want an exhaust that is at least 3 inches, but with turbo cars bigger is better!
Stage 3:
Downpipe/elbow/primary cat or test pipe, 280bhp @ ~9psi
http://www.horsepowerfreaks.com/Images/Products/BIC/Downpipes_Divorced.jpg If you still want more power, then its time to replace the restrictive stock downpipe, turbo elbow, and secondary catalytic converter. You will want to look for a downpipe that integrates the turbo elbow, otherwise you will end up with a 3" downpipe bolted to a 2.25-2.5" turbo elbow... BIC and Titan both make 3" turbo-back downpipes, and you can occasionally find a Defcon downpipe in the for sale section. The hot set-up now is to use the BIC "divorced" downpipe because it separates the wastegate's exhaust flow from the turbine's exhaust flow. This decreases turbulence (increasing power). Dyno tests show about a 20hp gain in using a divorced downpipe (over a standard BIC dp!). Some have noticed an exhaust leak sound at idle when running the dump tube vented to the atmosphere, so you can also opt for the re-routed version. The downside to the divorced set-up is that the divider plate is located just right for a CT26 turbo so it will not work with the bolt-on turbo upgrades -- so plan accordingly. Next in line is the secondary catalytic converter. Either use a high-flow cat (Random Tech and Titan both make bolt-on cats) or a test pipe (from Cooleeze, Titan, Horsepowerfreaks, or BIC).
Stage 3.5:
Gauges
http://www.horsepowerfreaks.com/Images/Products/Autometer/Boost_Gauges_Nexus.jpg While gauges do not increase power, they are important especially if you want to continue modifying. At this point, you're probably already boosting 9 psi, which exceeds the stock boost gauge. Installing a new one will allow you to keep tabs on your boost (and vacume). Often you will be able to spot vacume leaks just by seeing where you car idles as they generally start small... It's also a good idea to get a wideband gauge so you can accurately monitor your car's air fuel ratio. The cheap autometer gauges that read from the stock O2 sensor are worthless, so save your money for something accurate like the FJO, AEM, or PLX. Next on the list is an EGT gauge. This will monitor your exhaust gas temperature, and can be used to help you tune in conjunction with the wideband. Other good gauges to consider are water temperature, oil temperature, and and oil pressure.
Stage 4:
Boost controller, 300bhp @ just under fuel cut
http://www.horsepowerfreaks.com/Images/Products/Greddy/Boost_Controllers_Profec_B_Spec_II.jpg Now that your engine can breathe freely and you can monitor what it's doing, it is time to turn up the boost with a boost controller. There are inexpensive manual boost controllers out there, but I have found it to be a pain to get out and adjust them every time the weather changes (or if you find yourself at a stoplight next to a rumbling domestic). The solution is an electronic boost controller which can not only be adjusted from inside the car, but some can also learn to better control your wastegate allowing the turbo to spool much faster.
Stage 5:
Intercooler and hardpipes, 320bhp @ just under fuel cut
http://www.horsepowerfreaks.com/Images/Products/HorsepowerFreaks/Intercooler_Kits.jpg If you still want more power, you will want to replace your stock intercooler and the restrictive stock intercooler piping. Compressing air (in the turbo) creates heat which can lead to detonation. Since you want to turn up the boost even more, you'll need an intercooler that can not only flow better but also do a better job of keeping the air cool. At this point it also is a good idea to replace your factory bypass valve to prevent compressor surge.
Stage 6:
Fuel pump, injectors, and Lexus AFM -- 350bhp @ 16psi
http://www.horsepowerfreaks.com/Images/Products/Walbro/Fuel_Pumps_High_Flow_(Pump_and_Install_Kit_Combo). jpghttp://www.rceng.com/injectors1.gifhttp://www.horsepowerfreaks.com/Images/Products/LIPP/Air-Fuel_Meters_Lexus_AFM_replica.jpgWhen you try to boost too high, your ECU will cut fuel momentarily to prevent engine damage. Now that you want to exceed that limit, it is time to upgrade your fuel system. While it is possible to boost a little over fuel cut on the stock fuel system, it is not recommended -- especially if you have your sights set significantly higher. The first step to upgrading your fuel system is to then replace the fuel pump with one that can move more fuel. Walbro and the stock MKIV tt pump are common choices. Next is to replace the injectors. The stock 440's can flow this amount, but 550 injectors happen to match the increased flow of a Lexus AFM. The Lexus AFM is bigger than the stock Toyota AFM and tricks the engine into thinking it is getting less air than it actually is. The larger injectors offset the extra air and waalaa, you can now safely boost past fuel-cut! Details on this upgrade can be found here. (http://www.supras.com/~riemer/lexusriemer/lexusnotes.html) LIPP also makes a "replica" Lexus AFM housing that allows you to use your stock electronics and save some money and time.
Stage 7:
Fuel tuning device and dyno tuning, 400bhp @ 17psi
http://www.horsepowerfreaks.com/Images/Products/Apexi/Fuel_Computers_AFC-Select_for_Euro_Cars.jpg At this point, the car could benefit from some fine-tuning. Chances are you will be running rich, so an air/fuel controller can lean out the mixture and help further raise fuel cut. There are many options out there, so do a little research and decide on the best unit for your goals. If you must have the best, a standalone is the way to go but it is much more expensive, and is more difficult to tune (chances are you will have to have a professional tune it).