Quick Ship SKU #: GDP-030767-MRS GDP Mega-Rail System 03-07 Dodge Ram 5.9L Cummins 030767-MRS

This kit is the way to fuel that fire breathing 5.9L you're building with Bosch certified parts. The GDP Mega-Rail System!

The Mega-Rail System includes everything needed for installation of the entire fuel rail system from the larger 6.7L applications onto the 5.9LCummins. This simple bolt on package gives the 5.9L Cummins an edge in airflow and fueling like never before. Finally you can get the most from your modified injection pump and performance injectors!

Using the Mega-Flo Intake Manifold, Air-Boss 67 plenum and factory Bosch HPCR parts GDP has created a package that is reliable, easy to install, and out flows any other parts combination on the market. If you're pushing the envelope on 5.9L Cummins performance the Mega-Rail kit can fuel it.

The GDP Mega-Rail System is a complete package and does not require additional parts to be purchased.Installation Kit.

IMPORTANT NOTES:

• This conversion kit eliminates the factory grid heater.
• Only for single CP3 applications.
  
• If your truck is a 2003-2004 with APPS, you will also need the GDP APPS relocation bracket. If you're unsure if your truck has APPS, please contact us.

TIPS, TRICKS, AND MYTHS

Through the course of installing the Mega-rail System we have come across a few things that you may find useful.

First is the rail pressure sensor. With minor electrical connector modification, the stock 6.7L rail pressure sensor can be used on the 5.9L trucks. Due to voltage mapping differences the stock 5.9L rail pressure sensor reads roughly 13% higher than the stock 6.7L sensor at the same voltage. This kit includes a 6.7L Rail Pressure Sensor. By using the 6.7 pressure sensor on the 5.9 you can raise rail pressure approximately 13% without using a pressure box. For example, at WOT this equates to 24,860 psi actual at an ECM reported 22,000 psi. At idle reported pressure would be 5000 psi with actual being 5,650 so the difference is very small. At a reported cruise pressure of 8000 psi the actual would be 9,040 psi and this small increase is good for mileage. Since rail pressure is in essence "fooled" you will need a 6.7L rail pressure gauge connected directly to the sensor to see actual rail pressure readings.

Now, for the warnings and disclaimers...

Do not use the 6.7L rail pressure sensor if you are running a pressure box! If your tuner of choice has a rail pressure adjustment setting we recommend running the tuner at the "stock" pressure setting. Most tuners increase rail pressure to some degree. When combined with the 6.7L sensor rail pressures can get out of hand quickly. When using the 6.7L sensor always monitor actual rail pressure with a standalone 6.7L rail pressure gauge such as the unit offered by ISSPRO.

Next up is the grid heater. There has been some talk of using the stock 6.7L grid heaters (with the Mega-Rail kit) on the 5.9L head. The stock 6.7L grid heater will NOT fit the plenum opening of the 5.9L head without modification to a small casting area under the plenum cover. It can be made to work but minor grinding will be required.

We always recommend using new parts when working on the HPCR fuel systems. However, if you are looking to save some money, there are many sources for used 6.7L rails and injector lines. Wrecking yards and core supply shops have good inventory levels of used 6.7L parts now and can save you some money over buying a brand new rail and lines. Using a Mega-Rail Installation kit and a used rail setup is a great way to make big power on a budget.