8secSupra
25-08-06, 00:19
Myself and Dusty at MVP have been discussing an odd trend among UK buyers of PHR turbo systems. I thought this might be the perfect opportunity to offer up my thoughts on the matter.
In the US, it has become customary to purchase a fuel kit at the same time that you purchase any single turbo upgrade. People in the US learned quickly that it costs more to source all the parts yourself from 10 different vendors than to purchase a single all-inclusive fuel upgrade kit at once. We've all learned through trial and disaster that running on stock 550cc injectors and using the stock fuel rail is dangerous with upgraded turbos. True, the stock rail and injectors *can* support 500 BHP in most circumstances, but the one time you get into a race on the motorway with a bike you'll quickly discover that you run out of duty cycle at 5000 RPM even at 15 psi on a single turbo. Its just human nature to "push it" which makes this problem even worse. Here are some facts about the stock rail and the common (in the UK) method of using drop-in side feed injectors with the stock fuel rail:
1. The stock fuel rail was designed to accommodate side feed injectors for two reasons, emissions and injector pulse reduction. It was NEVER designed to support the flow of 800cc injectors. If you think about it, the orifice around each injector is roughly 4mm in diameter. So by the time you get to injector #1 you've got 5 HUGE restrictions in flow rate between the fuel inlet at the rear and the injector. That is barely enough to feed a 550cc injector, much less 800cc + sizes.
2. The stock fuel rail feeds into the built-in fuel pressure regulator between #1 and #2 cylinders. That means that there is static flow around #1 injector... ouch.
3. The fuel inlet line from the fuel filter to the rail includes a "fuel pulsation damper" to further dampen the injector pulse noise. This dampener uses an orifice and fuel line only about 7mm in diameter. Thats another HUGE restriction.
4. The factory fuel line is capable of supporting only about 520 wheel HP at the most, safely. And if the filter is clogged the slightest, that figure can drop by 50 HP or more.
5. A single in-tank fuel pump, even upgraded ones of 300 LPH, can only flow about 260 LPH through the factory fuel line and filter. By most estimates thats only enough for 450-500 BHP maximum.
6. The factory fuel pressure regulator uses a rubber inner diaphragm and tiny inner spring, it cannot be adjusted, and its barely capable of supporting a single in-tank fuel pump.
As you can tell from reading the above, the factory fuel system is very restricted from the factory just the same as the turbochargers and the 2JZ engine itself. What we are talking about here is load, as engine RPM increases, load (fuel demand) increases also. Stock 550cc injectors in the stock fuel rail dont have any reserve capacity to support a single turbo at 15 psi through 7000 RPM. Uprated 800cc injectors dropped into the factory fuel rail is an awful idea, and is NEVER used in the USA. Its considered taboo, because its the WRONG way to go about fueling upgrades. Can you imagine the #1 injector trying to starve for enough fuel through two tiny 4mm orifices at 1.2 BAR and 6000 RPM? It may work for a while, the 2JZ is known to withstand abuse for a long time. But sooner or later, it WILL catch up to you.
Having been in this industry all my life, I've seen one constant truth above all others: People WILL upgrade again sooner or later. You can spend almost as much money piecing together some parts that will "suffice" for now, but why? Fuel is the most critical component of ANY single turbo upgrade. After all, an engine is simply a component of AIR and FUEL working together. If you upgrade the turbo (AIR) but forget the FUEL, what have you gained?
I get lots of questions saying that 700cc injectors are "too big" for a PHR Stage 1 turbo kit using the 60mm turbo. Fact is, here in the USA, 95% of the fueling kits we sell are Stage 2 with 850cc injectors. The price is the same, and you WILL upgrade, plus you get extra capacity and duty cycle in case you should decide to chase a motorbike down the M1. Many of our UK customers are concerned about ECU tuning. Fact is, this has been resolved and made easy really. If you have a UK spec Supra, our MAP ECU will plug directly into your ECU and we have maps already built using any size turbo and injector combo you want. There is no need to spend thousands on an EMS system... its truly that simple. There just seems to be alot of misinformation about fueling upgrades from some UK "tuners". The Supra is a Supra, no matter what country you reside in. People are people, we all love our Supras and we all want to win any race we get into. We know these cars, and we know their limitations and their abilities using components that have been tested and on the market here in the US for over a decade.
The PHR Stage 1 and 2 fueling kits all include a huge polished 18mm ID fuel rail, injectors, injector wiring clips, O-rings, stainless braided -6AN fuel lines, fuel filter, twin in-tank fuel pumps, wiring, hoses, Aeromotive fuel pressure regulator, liquid filled fuel pressure gauge, and all mounts and hardware to install the kits. ALL of our stainless steel lines are pre-fabricated so all you have to do is install, nothing to cut and fabricate. Its top quality stuff, and I think we need to get some out there in the UK so people can see them in use. I can also offer up fully polished AN fittings and hoses, for those that require the ultimate "bling". We keep this stuff in stock, nothing to order up and wait.
Im going to do something that I rarely, if ever do. I'm going to offer up my complete fueling upgrade kit to the UK MKIV Supra Owners Club for a discount. I think a few members need to address some fuel issues along with these turbo kits I am selling. If you've recently bought a PHR fueling kit, thank you. From now until the end of September, I am going to offer up the PHR Stage 1 or Stage 2 Fueling upgrade kit for the same price to UK members. Price will be 1050 GBP plus freight (UPS about 50 GBP additional) for any PHR Fueling Kit. If you purchase a PHR turbo system in addition, I will include the freight for free on this fueling kit. You can pay via wire transfer or pay via PayPal for a 4% additional fee.
Feel free to come back with any questions, comments, or theories about the above!
In the US, it has become customary to purchase a fuel kit at the same time that you purchase any single turbo upgrade. People in the US learned quickly that it costs more to source all the parts yourself from 10 different vendors than to purchase a single all-inclusive fuel upgrade kit at once. We've all learned through trial and disaster that running on stock 550cc injectors and using the stock fuel rail is dangerous with upgraded turbos. True, the stock rail and injectors *can* support 500 BHP in most circumstances, but the one time you get into a race on the motorway with a bike you'll quickly discover that you run out of duty cycle at 5000 RPM even at 15 psi on a single turbo. Its just human nature to "push it" which makes this problem even worse. Here are some facts about the stock rail and the common (in the UK) method of using drop-in side feed injectors with the stock fuel rail:
1. The stock fuel rail was designed to accommodate side feed injectors for two reasons, emissions and injector pulse reduction. It was NEVER designed to support the flow of 800cc injectors. If you think about it, the orifice around each injector is roughly 4mm in diameter. So by the time you get to injector #1 you've got 5 HUGE restrictions in flow rate between the fuel inlet at the rear and the injector. That is barely enough to feed a 550cc injector, much less 800cc + sizes.
2. The stock fuel rail feeds into the built-in fuel pressure regulator between #1 and #2 cylinders. That means that there is static flow around #1 injector... ouch.
3. The fuel inlet line from the fuel filter to the rail includes a "fuel pulsation damper" to further dampen the injector pulse noise. This dampener uses an orifice and fuel line only about 7mm in diameter. Thats another HUGE restriction.
4. The factory fuel line is capable of supporting only about 520 wheel HP at the most, safely. And if the filter is clogged the slightest, that figure can drop by 50 HP or more.
5. A single in-tank fuel pump, even upgraded ones of 300 LPH, can only flow about 260 LPH through the factory fuel line and filter. By most estimates thats only enough for 450-500 BHP maximum.
6. The factory fuel pressure regulator uses a rubber inner diaphragm and tiny inner spring, it cannot be adjusted, and its barely capable of supporting a single in-tank fuel pump.
As you can tell from reading the above, the factory fuel system is very restricted from the factory just the same as the turbochargers and the 2JZ engine itself. What we are talking about here is load, as engine RPM increases, load (fuel demand) increases also. Stock 550cc injectors in the stock fuel rail dont have any reserve capacity to support a single turbo at 15 psi through 7000 RPM. Uprated 800cc injectors dropped into the factory fuel rail is an awful idea, and is NEVER used in the USA. Its considered taboo, because its the WRONG way to go about fueling upgrades. Can you imagine the #1 injector trying to starve for enough fuel through two tiny 4mm orifices at 1.2 BAR and 6000 RPM? It may work for a while, the 2JZ is known to withstand abuse for a long time. But sooner or later, it WILL catch up to you.
Having been in this industry all my life, I've seen one constant truth above all others: People WILL upgrade again sooner or later. You can spend almost as much money piecing together some parts that will "suffice" for now, but why? Fuel is the most critical component of ANY single turbo upgrade. After all, an engine is simply a component of AIR and FUEL working together. If you upgrade the turbo (AIR) but forget the FUEL, what have you gained?
I get lots of questions saying that 700cc injectors are "too big" for a PHR Stage 1 turbo kit using the 60mm turbo. Fact is, here in the USA, 95% of the fueling kits we sell are Stage 2 with 850cc injectors. The price is the same, and you WILL upgrade, plus you get extra capacity and duty cycle in case you should decide to chase a motorbike down the M1. Many of our UK customers are concerned about ECU tuning. Fact is, this has been resolved and made easy really. If you have a UK spec Supra, our MAP ECU will plug directly into your ECU and we have maps already built using any size turbo and injector combo you want. There is no need to spend thousands on an EMS system... its truly that simple. There just seems to be alot of misinformation about fueling upgrades from some UK "tuners". The Supra is a Supra, no matter what country you reside in. People are people, we all love our Supras and we all want to win any race we get into. We know these cars, and we know their limitations and their abilities using components that have been tested and on the market here in the US for over a decade.
The PHR Stage 1 and 2 fueling kits all include a huge polished 18mm ID fuel rail, injectors, injector wiring clips, O-rings, stainless braided -6AN fuel lines, fuel filter, twin in-tank fuel pumps, wiring, hoses, Aeromotive fuel pressure regulator, liquid filled fuel pressure gauge, and all mounts and hardware to install the kits. ALL of our stainless steel lines are pre-fabricated so all you have to do is install, nothing to cut and fabricate. Its top quality stuff, and I think we need to get some out there in the UK so people can see them in use. I can also offer up fully polished AN fittings and hoses, for those that require the ultimate "bling". We keep this stuff in stock, nothing to order up and wait.
Im going to do something that I rarely, if ever do. I'm going to offer up my complete fueling upgrade kit to the UK MKIV Supra Owners Club for a discount. I think a few members need to address some fuel issues along with these turbo kits I am selling. If you've recently bought a PHR fueling kit, thank you. From now until the end of September, I am going to offer up the PHR Stage 1 or Stage 2 Fueling upgrade kit for the same price to UK members. Price will be 1050 GBP plus freight (UPS about 50 GBP additional) for any PHR Fueling Kit. If you purchase a PHR turbo system in addition, I will include the freight for free on this fueling kit. You can pay via wire transfer or pay via PayPal for a 4% additional fee.
Feel free to come back with any questions, comments, or theories about the above!