Taking the GOLF GTI into the 9s
I have been watching for a long time the many efforts to increase the fueling capability of Direct Injection engines, and I just wanted to let you all know that if you think "Out of the Box", the solution is simple.
You only have to fit the AUDI TT RS HPFP on the TFSI engine.
To do that, you either need to have someone cast, or CNC machine a new Variable Valve timing cover, which will have the TT RS pump mounting points to put the pump in the right position. Then you need to make a Trilobe cam profile, to match the one that comes on the TT RS exhaust cam for the roller cam follower.
The LOBA 2.5 TT RS HPFP, is good to 700HP+ on a 5 cylinder engine, possibly more on a 4 cylinder. If you can convince any of the companies which make uprated HPFP components, to make a slightly larger diameter piston, you immediately get a pump which will be good for 700WHP, which will rev easily (and reliably) to 9000 rpm. There are companies that make bigger pump pistons for the TFSI pump already. Here is an example from HPFP UPGRADE
FOR EXTREME VW FANATICS: Taking the GOLF GTI into the 8's and 7's
Now that you know that 700WHP is easily possible, I would like you to know that it is also possible to double that output, simply by fitting a second TT RS pump. This of course is more complicated, but it is doable by anyone with CAD skills and access to a CNC Mill.
If you look at the TT RS HPFP, you will see that it is all contained on the Cam Carrier, and it is not difficult to design and then CNC machine a 4 cylinder Cam Carrier which will have a provision to mount the TT RS pump, in exactly the same way that the factory has done on the 5 Cylinder engine. To do this, Software Tuners will need to get involved, in order to resolve the issue of Fuel Rail Pressure Regulation with 2 pumps.
One of the problems the designers of the FSI system had, was to minimize Fuel Rail Pressure Pulsations, and one of the ways they did it, was to adjust the volume of the Fuel Rail and lines, to act as a Damping Chamber. This means that you will have to have 2 separate fuel rails, with 2 HP return valves and 2 fuel returns to the tank. It will take some development, but I think it is possible.
If you are lucky, you could get away by using the single pump signal to control both pumps, provided their cam timing is identical in relation to crank rotation. One way that you can reduce Fuel Rail pulsation, is to stagger the 2 pump lobes by 60 degrees, so that there will be a Fuel pressure event, every 60 degrees, instead of 120 degrees. This is a lot more complicated, and will probably require an extra ECU, just to control the second pump solenoid valve, with its own timing settings. The 1500 WHP GOLF will probably be the work of one or more of the Big VW Tuners, who will compete for Bragging Rights, so they should be able to deal with the Electronic side of this fueling Upgrade. Twin HPFP Racing applications will require Billet cams to drive the pumps.
Now that you have solved the Fueling problem of your cars, you can go crazy on turbo size, but always remember that big turbos have a lot of lag, and that means terrible street driveability and a slow spooling and revving engine. I have thought of a simple way to reclaim the spool characteristics of small frame turbos, and I have put it in PDF form, which you can find in the following link. It will be quite easy for you to get ATP TURBO or other VW Companies to make this quick Spool, High Torque, Twin Scroll Turbo Housing. I have uploaded it on the BOX.
Quick Spool, High Torque Twin Scroll Exhaust Housing
The reason you need to get as much torque as possible in the lower rpm range, is because if you have the necessary traction, it has a tremendous effect on the speed by which the engine goes through its rpm range. If you look at the following picture, you will understand what I mean. 4WD GOLFS are heavy, and they need a lot of torque to accelerate. They don't have a problem with traction, as BOBA Motoring has proven with the 8.6 second GOLF 2 VAMPIR.
Here's the torque comparison once again and the rate of acceleration to 7500 rpm. That's over 1.5 seconds faster, just by filling the low rpm area under the Torque curve!
Looking at the performance of Honda's, it is clear that the VW Community has a lot of catching up to do. Horsepower potential is no longer the limiting factor for you.
If a simple Mechanic from BOBA Motoring can build a 16V GOLF 2 all by himself, to embarrass the VEYRON SUPER SPORT and the AMS GTR ALPHA 12, then the American VW Tuning Industry, has a lot of work to do.
VW Golf 2 16V AWD vs Bugatti Veyron Super Sport vs AMS Nissan GTR Alpha 12+ - YouTube
So guys, have fun with this, I will sit down with Popcorn and watch who will get a VW GOLF TFSI first to the 9's, the 8's and finally the 7's...
John
I have been watching for a long time the many efforts to increase the fueling capability of Direct Injection engines, and I just wanted to let you all know that if you think "Out of the Box", the solution is simple.
You only have to fit the AUDI TT RS HPFP on the TFSI engine.
To do that, you either need to have someone cast, or CNC machine a new Variable Valve timing cover, which will have the TT RS pump mounting points to put the pump in the right position. Then you need to make a Trilobe cam profile, to match the one that comes on the TT RS exhaust cam for the roller cam follower.
The LOBA 2.5 TT RS HPFP, is good to 700HP+ on a 5 cylinder engine, possibly more on a 4 cylinder. If you can convince any of the companies which make uprated HPFP components, to make a slightly larger diameter piston, you immediately get a pump which will be good for 700WHP, which will rev easily (and reliably) to 9000 rpm. There are companies that make bigger pump pistons for the TFSI pump already. Here is an example from HPFP UPGRADE
FOR EXTREME VW FANATICS: Taking the GOLF GTI into the 8's and 7's
Now that you know that 700WHP is easily possible, I would like you to know that it is also possible to double that output, simply by fitting a second TT RS pump. This of course is more complicated, but it is doable by anyone with CAD skills and access to a CNC Mill.
If you look at the TT RS HPFP, you will see that it is all contained on the Cam Carrier, and it is not difficult to design and then CNC machine a 4 cylinder Cam Carrier which will have a provision to mount the TT RS pump, in exactly the same way that the factory has done on the 5 Cylinder engine. To do this, Software Tuners will need to get involved, in order to resolve the issue of Fuel Rail Pressure Regulation with 2 pumps.
One of the problems the designers of the FSI system had, was to minimize Fuel Rail Pressure Pulsations, and one of the ways they did it, was to adjust the volume of the Fuel Rail and lines, to act as a Damping Chamber. This means that you will have to have 2 separate fuel rails, with 2 HP return valves and 2 fuel returns to the tank. It will take some development, but I think it is possible.
If you are lucky, you could get away by using the single pump signal to control both pumps, provided their cam timing is identical in relation to crank rotation. One way that you can reduce Fuel Rail pulsation, is to stagger the 2 pump lobes by 60 degrees, so that there will be a Fuel pressure event, every 60 degrees, instead of 120 degrees. This is a lot more complicated, and will probably require an extra ECU, just to control the second pump solenoid valve, with its own timing settings. The 1500 WHP GOLF will probably be the work of one or more of the Big VW Tuners, who will compete for Bragging Rights, so they should be able to deal with the Electronic side of this fueling Upgrade. Twin HPFP Racing applications will require Billet cams to drive the pumps.
Now that you have solved the Fueling problem of your cars, you can go crazy on turbo size, but always remember that big turbos have a lot of lag, and that means terrible street driveability and a slow spooling and revving engine. I have thought of a simple way to reclaim the spool characteristics of small frame turbos, and I have put it in PDF form, which you can find in the following link. It will be quite easy for you to get ATP TURBO or other VW Companies to make this quick Spool, High Torque, Twin Scroll Turbo Housing. I have uploaded it on the BOX.
Quick Spool, High Torque Twin Scroll Exhaust Housing
The reason you need to get as much torque as possible in the lower rpm range, is because if you have the necessary traction, it has a tremendous effect on the speed by which the engine goes through its rpm range. If you look at the following picture, you will understand what I mean. 4WD GOLFS are heavy, and they need a lot of torque to accelerate. They don't have a problem with traction, as BOBA Motoring has proven with the 8.6 second GOLF 2 VAMPIR.
Here's the torque comparison once again and the rate of acceleration to 7500 rpm. That's over 1.5 seconds faster, just by filling the low rpm area under the Torque curve!
Looking at the performance of Honda's, it is clear that the VW Community has a lot of catching up to do. Horsepower potential is no longer the limiting factor for you.
If a simple Mechanic from BOBA Motoring can build a 16V GOLF 2 all by himself, to embarrass the VEYRON SUPER SPORT and the AMS GTR ALPHA 12, then the American VW Tuning Industry, has a lot of work to do.
VW Golf 2 16V AWD vs Bugatti Veyron Super Sport vs AMS Nissan GTR Alpha 12+ - YouTube
So guys, have fun with this, I will sit down with Popcorn and watch who will get a VW GOLF TFSI first to the 9's, the 8's and finally the 7's...
John
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